OK, after a 15-year quest I finally became comfortable with the term "reed arcing."
But then... (read on).
I've used many published resources over the years (books by Tony Glover, Charlie Musslewhite, Blackie Shackner, Douglas Tate, Winlsow Yerxa...) as well as digital sources of information (web resources by Tinus, Kinya Pollard and videos by Rupert Oysler and Richard Sleigh...) and countless hours scouring Youtube (Joe Spiers, Mooncat, David Payne, etc.) and personal communications with many of the above experts as well as others. I've inhabited almost every harmonica email list or forum in that time frame, always seeking information about how to set up harmonica reeds and reed plates.
Only the more recent resources actually spell out what is meant by the terms reed arcing or reed profile. It seems that, to sum up my understanding of reed arcing after this extended quest, and to quote Joe Spiers, "Flat is where it's at." That's the same message that's spelled out in great detail in Richard Sleigh's "Hotrod Your Harmonica -- The Movie." Andrew Zajac concurs in his Youtube videos. Other than a lot of effort directed at making the reed dip abruptly into the slot at the rivet end, the message I get is to make the reed as flat as possible so that it enters the reed plate slot all at once.
But most recently, the term, "reed arcing" has come back onto my radar. I'd seen this term many times in the past but after satisfying myself that "flat is where it's at," I had basically written off "reed arcing" as customizer's shorthand for "That's for me to know and you to find out (and ~I~ ain't tellin' ya)". Fair enough. I get the idea of "proprietary knowledge." Hence my quest.
So, I'm watching the videos of the 2015 SPAH Manji seminar (at which I was in attendance) and there's Jason using the term and making a sweeping "arc" gesture with his hand.
My question: Who can (and will) take a shot at defining precisely what "reed arcing" means and detailing it's impact on the "playability" of a diatonic harmonica (or chromatic for that matter) over the flat reed that Joe and Richard proscribe? Are there learning resource that I have missed?
Many Thanks,
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Last Edited by mlefree on Jan 08, 2016 10:49 AM
1. The visual cue of the reed being perfectly flat as it passes through the slot is not the sign of perfection; It's only a landmark or a point of refence. I play each reed individually (lips on back of plate and make air flow back and forth with my mouth) and use my ears and the sensory feedback of my mouth to tell me if the reed plays well.
The visual cue helps me pinpoint how to tweak the reed shape, but the determining factor of what shape it will have is how it plays.
2. The reed needs to be curved (arced) at rest to be flat as it passes through the slot (in motion/under tension). So is the reed arced or flat? Yes, it is. :)
Thanks for the reply, Andrew. It does spur some further questions, though. 8^)
"The visual cue helps me pinpoint how to tweak the reed, but the determining factor is how it plays."
I get that. But, let's say the reed doesn't play as well as you know you can make it. Then what? How might you deviate from flatness and how might you expect the harp top respond to that adjustment? Maybe curve the tip up a bit?
"The reed needs to be curved (arced) at rest to be flat as it passes through the slot (in motion/under tension). So is the reed arced or flat? Yes, it is. :)"
Yes. The solution I understand is to make a fairly abrupt dog-leg on the longitudinal reed shape just as it enters the slot at the base. Once the reed is dipped into the slot at the base that way, it must angle up slightly to have a gap at its tip with respect to the r4ed plate surface. But from the end of the dog-leg to its tip the reed need to be flat if it is to enter the slot all at once.
So, how would the reed respond differently if it is made to be curved, presumably upwards? How much should it curve to improve, say, its "overblowability?" I ask because as best I can tell that is the only good reason to deviate from flatness. Or am I wrong about that, too?
BTW, Andrew, feel free at any time to say, "That's for me to know and you to find out (and ~I~ ain't tellin' ya)." I'm used to it. ;^)
Thanks again,
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
I've heard the flat is where it's at too. The only thing I feel qualified to comment on (or at least might have a comment that someone else could clarify) is that I've seen reed profile used as a separate thing. GermanHarpist (one of the mods from way back) had a post on profiling, but I don't have the link handy. I seem to remember he'd had it explained to him by someone at Hohner- profiling isn't the bend in the reed, but the thickness of the reed along the length. If I'm remembering correctly, as part of getting reeds of certain lengths to ring at a certain pitch, and bend in ways that reduce overall reed fatigue reeds are not strictly 3 measurement objects- length, width, height, but that height varies along the length of the reed. You can see this for sure in weighted reeds that get fat at one end, but my understanding (mind you this is vague recollections from a post several years back) that all reeds do this a little bit (and this complicated profiling is one of the reasons that for the most part why we leave the reed manufacture to the big guys.
But, take this with a grain of salt, because I haven't seen this verified anywhere and it's far enough back so my memory is a little fuzzy.
edit- one of the crazy ideas I've had over the years that I haven't had a practical way to test is that you could also manipulate the reed going through the reed plates by 'arcing' the reed plate, so that an arced reed would meet the horizon evenly, but the only ways I could think to experiment with that would be a bent reed plate, which would require a beveled comb to keep a tight air seal (or something silly like foaming the gap and cutting away the foam) or having reed plates that were flat on one side but not on the other. A CNC could theoretically cut a reed plate like that, but it would be a huge pain because you'd need a different one for each variation you wanted to test, all without any real idea of what you were trying to accomplish! :P
edit- here is the post I'm talking about, but some of the videos have been set to private.
I'm new at customizing but I can weigh in with what I think I know. And what I have found works for me so far. When you dip the rivet end as you said .... that doesn't ensure the reed goin through the slot at the same time .... try lighting the underside and closing the reed by pushing it down with a plinker of some kind..... and I start by pushing down the very tip but you should try from different spots on the reed as you may get different results. All this is covered in detail in Richard sleighs hotrod video you mentioned.
But as Andrew stated it doesn't mean it will play right. You gotta tweak it. Kinda like tuning your octaves to be beat free. Tweak a bit ... try it .... tweak again based on what u got ... n so forth. Ive tried matching reads but that doesn't really seem to work. What I mean is once you get hole. 1working ... that same profile wont work for reed 2 they re all a bit different. Gapping also changes slightly hole to hole. Althought I find 123 holes to be the problem ones idk why.
Maybe somebody can tell me if I'm even on the right page or not. But that's basically how I been setting up my harps. And its been working well so far. ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It." ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Michelle, I know you have the math and physics chops to follow what I write below, and possibly comment on the potential validity of my hypothesis.
If one starts with the goal of making the entire reed enter the slot at the same time, and assumes a uniformly varying pressure load on the reed (max pressure at the root and zero pressure on the free end until it enters the slot), the required reed curvature can be calculated based on the shape a flat beam would take under the same load. The formula can be found here and is
y= (wx^2)(10l^3-10l^2*x+5lx^2-x^3)/120lEI
where w is the air pressure applied at the root times the width of the reed, E is the modulus of elasticity of the reed material and I is the area moment of inertia of the reed ( I=(width*height^3)/12 for a rectangular cross section reed), l is the length of the reed, x is the distance along the reed from the root and y is the height of the reed at x.
If my hypothesis is correct, the optimum shape of the reed is dependent on the breath force used. Because the force on the reed is distributed (but not necessarily uniformly varying), you can not check the entry flatness by applying a point load to the reed.
Last Edited by STME58 on Jan 09, 2016 12:19 AM
Well how would you recommend checking it without pushing it in? You can't see it in motion. So..... that's the best i can think of. That's why you check it at different points along the reed to get a good idea of how is entering. That's how R. Sleigh does it.
And i could be wrong, but i think you have it backwards. I would say the pressure would be applied mostly at the tip because thats where the air is going in/out around the reed the most and moving it. But thats just my thinking idk.
And ofcourse your right about gap depending on air pressure. That's a given i think.
I just bought a few used harps for cheap. A couple blues harps n sp 20s and a hi lo country. Imma practice on them. Embossing and reed shaping. I don't plan on keeping them for playing, but i boiled em and wiped em down with alcohol because i still gotta put my mouth on em. 8^{>
---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 09, 2016 12:36 PM
"..profiling isn't the bend in the reed, but the thickness of the reed along the length. "
For the sake of clarity, let's call that "mensur". (The) mensur is usually optimal and is not easily modified anyway (you gonna grind away at the middle of a reed?); so let's just take it as it is and keep it constant. One other thing is that if you replace reeds by taking longer ones and snipping them off, you end a reed with a different pitch but a very different mensur. It likely will not play as well as it could/should. (I digress...)
I take the term "curve" or "arc" to be the thing we can easily change about the shape of the reed by bending it.
"But from the end of the dog-leg to its tip the reed need to be flat if it is to enter the slot all at once."
I disagree with that assertion - for most reeds, anyway...
"Because the force on the reed is distributed (but not necessarily uniformly varying), you can not check the entry flatness by applying a point load to the reed."
Pressing down in one spot may not be accurate but I beleive it can come close to representing the reed in moton if you press down in the right spot.
But...
Where is the right spot? I think in general it's towards the tip for longer/lower reeds and higher up around the middle of the reed for shorter/higher reeds.
"How might you deviate from flatness and how might you expect the harp top respond to that adjustment?"
For one thing, try changing the point at which you apply pressure. (See above)
"pressure would be applied mostly at the tip because thats where the air is going in/out around the reed the most and moving it"
I imagine the force applied to the reed comes from air flow. Air flows along a pressure gradient but it's not that pressure that makes the reed move, it's the contact of the flowing air with the reed. The velocity of the air is different at different points of the reed as it moves through the slot and back.
The reed is even moving faster than the air flow in some spots. I reckon this would be terribly complicated to model. But I'm not that smart... I stick to playing the reed, making a change and re-checking to see if things are better or worse. Repeat as needed.
Good post andrew. Thanks. ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 09, 2016 2:55 PM
Both Andrew and @Killa_Hertz have mentioned that the pressure distribution on the reed is probably not uniformly varying. I would agree but I though this would be the best approximation. The reason I chose the tip to be the point with zero pressure is because when the reed is away from the slot there is nothing to stop the air flowing from one side of the tip to the other so the pressure on either side of the tip should be the same. This will change fast as the tip enters the slot. The reed and air flow is a very dynamic situation and things like the Bernoulli principle will come into effect.
I agree with Andrew's assertion that there may be a point on the reed that is could be pressed into the slot to check flatness that gives a reasonable approximation of what happens when played. I do not think this point is at the tip of the reed. I disagree that you can't see the reed in motion and I present this high speed video I took to support my assertion. More work is needed to get a camera angle that really gives the view you want.
Last Edited by STME58 on Jan 10, 2016 1:23 AM
Yea but dude who has a high speed camera sittin around? I mean really. We're tryin to make the best of what we got right? If you can improve the way people are doin harp work in a practical manner than cool, but let's not get too carried away. If u push the reed down at the tip, then afew spots throughout the rest of the reed you should get a good idea of what's Goin on.
It's not going into space or anything. You don't have to over do it. Just get it to play better. It's time consuming enough as it is without busting out the gas cromatagraph spectrometer. ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 10, 2016 11:57 AM
Killa Hertz, the thing is, if you could get a rough idea of what a 'perfect' reed looked like you could theoretically model other reeds on it without having to run the camera on all of them.
And of course, there is always the overlap of interests. To some of us the theory is interesting just in itself, even if it's practical applications might be limited.
I saw recently, on the Yonberg site, that they have changed the shape of the chamber between the reeds. They say it improves the airflow and stability. I have no idea what they are talking about, or if what they are saying is verifiable, but it's interesting and makes me want to go look stuff up.
http://en.yonberg-harmonica.com/ ---------- Nate Facebook Thread Organizer (A list of all sorts of useful threads)
Yea i know i was just bustin his chops. To each his own man.
But i don't think you could shape one based on info from another. It seems that they all take something different to play right. I could be wrong tho, its been know to happen
Has anyone actually played a yonberg? ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 10, 2016 1:31 PM
@Killa_Hertz, Ok, I will one admit to a bit of pretentiousness because I have access to some pretty cool equipment. My intent, as Nate suggested, was not that this is a tool for adjusting an individual harp but as a tool for understanding the underlying principles. Part of the reason for posting the video (which I have posted before on this forum) is to give others, who may have a better understanding of harps, a change to see what is going on. One thing you can see in the video is that the speed is not high enough to capture the exact moment the reed enters the slot. The camera I occasionally get access to can go much faster but much more light is required to get a good image. As it was the harp was lit so bright it was hard to look at. If you can get a clear picture of the reed shape in play, and you know the static read shape, you could calculate the force distribution on the reed. This in turn could yield a rule of thumb for where to press on the reed to best approximate the playing shape.
People like Andrew have a good empirical understanding of what makes a harp play well. It would be interesting to see high speed images of good and poor performing harps to see if the good playing harps do, in fact have reeds that enter the slot all at once.
I know buddy. I know exactly where u were goin with it. It is a good idea. I was purely just havin fun. No offence intended. The video is appreciated as well. I would like to understand any and every aspect of the inner workings of a harmonica as possible. So thanks for that.
And Don't take anything i say too seriously. Lol.
furthermore i was just rebuilding a harp. And as i was arching the reeds i notice that even tho i do arch them they are still fairly straight. So im not sure what to think any more as far as straight or arched. Lol. And from the underneath when you look at the light it looks pretty straight. I think if you get the rivet end gap right you don't need as much bend either.
I also found a better way to bring the "heel" (i guess you would call it) back up out of the slot after offsetting the reed at the rivet end and it goes down too far. Instead of pushing it up from the bottom or underneath (which always caused me to put a very light ripple which i had to then get out) instead i take my straight pick Like out of those pick sets you can buy at the hardware store. So basically a metal toothpick. Well i take that and put it under the reed perpendicular to the slot, at the tip of the pick so its thin. And i run that back about 3/4 of the way back and it pulls the reed up and out evenly. Takes soooooo much time or of the gapping process the way i was doing it. So maybe that can help somebody idk. I'm still workin out the bugs in everything I'm doin. ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 10, 2016 9:15 PM
Gent's I just spent an hour editing a response to y'all's replies but in trying to use the postage stamp-sized editing window it took me so long that I accidentally hit the wrong key and lost it ALL.
I'll try again tomorrow, using a better editing tool.
Meanwhile I'll do a Rain Dance to the Great Forum Spirit asking her to please deliver us a real forum environment here on Dirty South. You know, the kind that has a usable captchya code system and WISIWYG editors like the all other forums I inhabit have.
I do appreciate your thoughts!
Thanks,
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Last Edited by mlefree on Jan 10, 2016 10:02 PM
One thing I am learning as I continue to work on harmonicas (I just did one for STME58, replaced the plates on a low C Manji) is that the sound is the ultimate determinant. Sometimes when I am tuning for compromise, the numbers don't tell me as much as the sound--and then I can interpret the number to guide me to the right sound. What I mean to say is, if it sounds (or feels) good, it IS good. So a reed can appear to be profiled by the book, with arcing to support a flat entry into the slot, but if it doesn't play right, something needs to be adjusted. Sometimes I think about what Joe Spiers must do to get those harps sounding so good. There are so many things he does, I am still learning, but "it's all about the reeds." Captcha is gjrhpy PS Michelle sorry about your loss
Last Edited by Gnarly on Jan 10, 2016 10:08 PM
@Killa_Hertz, I was just thinking, if you have access to a gas chromatograph, perhaps you could do a study to find out exactly the optimum mix of garlic, onion alcohol etc should be on the breath for optimum tone. ;-)
@ Gnarly, The low C works well. Fun harp for rhythm playing.
That fact that one can get different results from the same set of numbers tells that the numbers don't do a very good job of quantifying the important parameters. A tuner gives you one number for the pitch and says nothing of all the overtones present. Maybe some day we will have better measurement tools.
Hey Steve-- The tuner I have been using lately (APTuner) has a strobe mode that shows the different octaves, so that can be off-putting when tuning the harmonica (although it is cool when I tune tone chimes at work, they have minimal overtones). It also has a mode with a needle that might be more appropriate, maybe I should try that. One really cool feature it has is Performance Analysis Mode, where it shows the notes (and levels of the notes) over time. Here's the link: http://www.aptuner.com/aptuner_index.html
The Windows version seems to be shareware--I have it on my iOS devices.
Last Edited by Gnarly on Jan 10, 2016 11:24 PM
Great question Michelle. I have been wondering about this myself, as I am starting to tinker in this area. I have always assumed that flat is what you want. But if a slight upwards curve is the goal, where should the arc be, and how should the final reed appear (at rest)?
1. Some people have proprietary knowledge they choose not to share.
2. Some people don't have as much proprietary knowledge as they let on - at least not as formal as one would love to believe.
3. No one has all the proprietary knowledge - double true since not everyone has the same playing style.
4. What knowledge is being shared is often confusing because of semantics.
IME, the world of harmonica (and I am sure other avenues) gets hung up on status and image, sometimes, more than actual substance.
After years of my own crude research, teaming up with several custom harmonica builders, learning from what people do share, and playing a ton of harps, I've found that the method Richard Sleigh shares in his video for reed shaping works pretty well for me.
I try to get the reed to close in the slot evenly and then make tiny adjustments from there. I find the longer heavier slots turn out a bit different than the higher ones. (EDIT: I have an unusual style in that I overbend, but attack more like a blues player and play A LOT on the high end...so I need an OB set up that isn't too tight or I can't play with the dynamics I like to)
That works for how I like harps and how to set them up. I would love to be more involved with this and offer customs publically (again), but my life situation doesn't allow it. ---------- Mike My Website My Harmonica Effects Blog
Last Edited by HarpNinja on Jan 11, 2016 2:45 PM
OK This time I'm trying to write in Open Office. We'll see how that works.
Lots of good input here folks. Much appreciated! I'll try to respond more or less in order.
I'm glad we can all agree about nomenclature and in particular that reed profile means the thickness of the reed from root to tip. I've seen reed profile and reed curvature (arc) used interchangeably. I had thought it was customizer's deliberate effort to obfuscate their descriptions.
Andrew, in review I'm not sure I'm following the meaning of your statement, “The reed needs to be curved (arced) at rest to be flat as it passes through the slot (in motion/under tension).” Are you saying that the reed tip bends down first so that it needs to be curved upward in order for the entire reed to be straight on entering the slot? If so, Steve's high-speed video seems to confirm that. Further, if that ~is~ what you are saying, it seems one would “tweak” the curvature such that the reed arced slightly upwards towards the tip. And if that is true you have lead me to a new level of understanding about how, where, and why to make those 2nd order adjustments (after the visual cue of the reed being perfectly flat as it passes through the slot is satisfied), ala, yours and Richard's videos. And that would be very cool if that is the case!
Nate, a curved reed plate strikes me as a manufacturing nightmare. You'd obviously have to have curved combs and curved cover plates.
Killa, I understand the concept of tweaking but I'm not comfortable doing it randomly. I'm seeking input on how and where to do the tweaking. That's the essence of my post.
Killa, Nate and Steve – The issue of where to push down on the reed to simulate deflection due to air pressure doesn't seem to me to be a complicated one. Seems that as long as your pressure doesn't ~deform~ the reed by pressing too close to the reed tip or too close to the base where the pressure would be transferred to the rivet you're OK. I reviewd Richard's videos and he just uses his finger and makes no mention of pressing with a tool or in different spots.
Steve, aside from losing my previous attempt in replying, it took me a while because I was most intrigued by your ideas. It's been a while since I had my Applied Mathematician's hat on but I do have a few issues with your ideas.
Those beam deflection equations give the y deflection as a function of x distance along the cantilevered beams unde the various loading conditions. I'll need you to explain to me how: 1) your “goal of making the entire reed enter the slot at the same time” is reflected in those equations; 2) since those equations give y deflection, further calculations would be required to calculate, say, the radius of curvature along the beam – maybe you don't mean mathematical “curvature”; 3) I believe that at the air flow and the relatively tiny dimensions of reeds and the air passages around them that we are dealing with a turbulent flow situation rather than laminar flow. I therefor think that the air pressure would be more or less constant throughout the reed chamber, ergo, a uniformly distributed load rather than a linearly varying one, greatly simplifying the equations. Though it sounds reasonable I really can't comment on your hypothesis of optimum shape being a function of breath force (pressure). But, since we've agreed that reed profile thickness varies with x, those rectangular beam equations are probably invalid anyway. Bottom line, I don't think there is a closed form solution for determining ideal reed shape. Maybe FEA?
Andrew, I am curious about your use of the term, “mensur.” Also, “...it's not pressure that makes the reed move. It's the contact of the air flowing with the reed.” How does that differ from air pressure?
In terms of changing the shape of the reed chamber, Douglas Tate use to install “Tate ramps” in the higher toned chambers to tune the volume of the chamber to the particular reed's vibrational frequency. I believe that Brendan's new 3D-printed combs have the same desirable feature. I don't think it has anything to do with airflow or its direction, though. The wavelength of harmonica tones is measured in meters so there is little if any reflection or “bouncing around” inside the reed chamber. As I said, turbulent flow.
Gnarly, it's precisely that grey area (Twilight Zone?) when the reed is apparently arced correctly but it doesn't sound right that I am trying to better understand.
Mike – I get proprietary knowledge. I am a patent holder myself. I also get not sharing it. Hence my offer to Andrew and others to feel free in saying, "That's for me to know and you to find out (and ~I~ ain't tellin' ya)." Everyone seems to agree that Richard's a a fine approach to get that first order condition of the entire reed anteing the slot at once. What remains ethereal to me are those “tiny adjustments from there.”
This is turning into a dynamite thread. Thanks for all the stimulating input!
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Last Edited by mlefree on Jan 11, 2016 8:19 PM
Michelle ... i must have seen a different video. In the hotrod videos watch the part where he uses the tweezers to adjust the "root" of the reed. He explains and demonstrates pushing down on multiple places to see if you get different results. Its toward the end of video 2 i believe.
Point is he uses a tool to push down and in multiple places. ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 11, 2016 8:19 PM
Killa, I was looking at around 29:00 in his 1st video, not the tweezer bonus section at the end of the 2nd.
You're right, though all he says is that he pushes the reed down in different positions to see if he gets a "different reading." He doesn't say anything about what might happen if he did get a different reading as the reed he works on exhibits the same issue in all positions.
I'm not sure what to make of that. Does anyone else?
Thanks for the pointer, Killa.
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
I think what he means is that ... if you push Down on the tip sometimes it may look like it closes flat or the base is high. But push in the middle and the tip is high or whatever . Obviously we all get that. So what i think is that the part your pushing on doesnt count. Push on the tip to get your base reading. push near the base to get your tip reading. Then adjust accordingly. Or something like that. one thing i think is true is that there are no absolute rules here. Just general guidlines. Tweak it till it sounds good. But that is how I interpreted it.
And obviously you have to use your own judgement to see what you have to do to make it enter straight. ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 11, 2016 10:05 PM
Michelle I feel yr pain---Few years back I got excited about the overblow thing overdraw as well -read everthing , bought everything --while trying to learn how to do ob and set up harp to ob or od-----I learned about--- tuning--[arcing or opposite,de-arcing (straightening)]---etc etc-tip scooping-flattening the reed longitudinally--waxing rivet end or nail polish—[ruperts ‘ slight flip up at end of reed’] ----after ruining a few reeds and then practicing on crappy reeds [ie Johnson] The positive I got out of it was 'getting lucky on a couple' so that they easily ob on 6--fairly easy on 5ob---- sometimes on four ob and didn’t jam up up during regular playng--some of my manjies or crossovers od 7 out of box----but through it I learned the way I like 'MY' harps tuned--I like clean octave splits—more or less equal temperament—I learned the easiest way for me to tune was [dremel tool for ‘10 cents or more off’ followed with sanding stick-that’s just what work for me—also misc chisel scrapers and sleighs 45 degree chisel deal for reeds that were sharp]-----that’s 2 positives---- also learned how fairly quickly and easily, to replace a bent or broken reed or just 20 year old metal fatigue reeds[ [I use mini bolt and star nuts left over from harponline to attach reeds]—that’s 3 positives---I agree with Rupert that sometimes the height at the rivot end is to high [height of reed from reed plate, not the width ]---and that GENTLY closing it a little makes it more air tight—4 POSITIVES---I basically learned how ; I like my harps to play “action’ just like on my guitars. which I work on— 5th positive was that I learned from Todd Parrot for crossharp, to ‘ flatten the 7 draw a ½ step to get b3 for blues, still have major 3 on the new 7 blow bend--- this helped me tremendously to tie the hi end of harp into the low end of the harp, in a more bluesy sounding harp—it’s the same note as 6 ob but different feel—now all my harps are that way, except for harps, I use with a rack for Neil Young Petty Dylan etc 6th---In the middle of it all, I realized I wasn’t even that good at playing regular harp—so why was I worried about overblows and od------------------------that started unbelievable quest to learn the ‘ENTIRE HARP,NOT JUST HOLES 1-6---[ but the entire harp up from 1-10 down from 10-1, fluidly not just occasionally playing the hi end and then jumping back to 1-6 —because I remember J ricci saying “ learn a lick at the low end then, learn or try to learn the sam lick at the hi end--- I learned if u mess with reeds to much ‘they become fatigued’ ---I learned it was difficult “ for me” to ‘ emboss’ the “correct” amount—so I only do it on harps that are ‘REALLY AIRY’ and that Andrew Zajac-- Joe Speirs etc would probably be, the way to go for me for ob or od set up--- --------------------------------------------I NOTICED THE REEDS THAT SEEM TO OB [OD, only 0n hole 7 for me] THE BEST WERE IN FACT [ALMOST STRAIGHT parallel w/ reed plate and very close to reed plate] [ WERE SLIGHTLY CLOSED UP A LITTLE MORE AT RIVOT END , HEIGHT WISE] [THEY DID INFACT, ENTER THE REED PLATE EVENLY ( LOOKING WITH PROPER LIGHT FROM BOTTOM)---- ‘ I PERSONALLY DIDN’T SEE TIP SCOOP DIFFERENCE---[NAIL POLISH or wax, nail polish in my case---—put on rivot end and ‘extended down about 1/8” on reed plate as well, helped the squeal and ob] In other words nail polish put on rivot end and onto reed and reed plate for 1/8” down from rivot then ‘’ LEAVE NAIL POLISH ON REED PLATE, BUT CAREFULY WIPE OFF TOP OF REED] Think the nail polish extended down 1/8, tightens up th side gaps at that end==learned and used turbo tape--- I also think Andrew Zajac, speirs etc-have been doing long enough now to where simply way more practiced, experienced and polished—they can do it almost by feel—But there are ” a lot of positives about learning harp mechanis etc GOOD LUCK AND I TOTALLY RELATE
"Are you saying that the reed tip bends down first so that it needs to be curved upward in order for the entire reed to be straight on entering the slot?"
I would say that it can. The whole length of the reed is compliant, not just the base.
" I therefor think that the air pressure would be more or less constant throughout the reed chamber, ergo, a uniformly distributed load rather than a linearly varying one, greatly simplifying the equations."
and
'“...it's not pressure that makes the reed move. It's the contact of the air flowing with the reed.” How does that differ from air pressure?'
First off, to me "breath force" can mean both pressure and flow. When we play, the distinction is mostly irrelevant. But for the sake of modeling what's happening as we play, I find it useful to make the distinction.
Air (or any fluid) flows along a pressure gradient. The pressure begins in our vocal tact and exerts a force which can change the shape of the resonant chamber. The size of the resonant chamber needs to be precisely controlled to create the sound we desire. Example: If we play louder, our autonomic system takes care of squeezing and relaxing muscles in the mouth to keep the resonant chamber the correct size, using feedback from our ears.
So, it's important to think of pressure in of itself.
But the pressure in our vocal tract causes air to flow through the system. In the case of a blow note (and an airtight harp) the low pressure end is on the outer side of the slots in the channel. Everything in between feels a pressure gradient.
It's air flow that causes the reed to move, not pressure. Yes, the size of the pressure gradient affects the amount of airflow but in thinking of what makes the reeds create sound, I find it more helpful to think of air flow rather than just the pressure gradient. For example, the flow of air is interrupted by the moving reed - resistance is not constant. Is air flow turbulent? I beleive it's a mix of both laminar and turbulent flow, again depending on (but not limited to) the motion of the reed.
A reed with an aerodynamic shape will feel "stiff". It's not the metal that's stiff, it's the fact that the air is flowing *around* the reed instead of the reed catching it like a sail. That's why I make the distinction here.
'Andrew, I am curious about your use of the term, “mensur.”'
To start, I should explain the German word Mensur as explained by Steve Baker: “Hohner uses this term to refer to the physical dimensions of the reed—length and width. With any given Mensur you can make the reed sound at different pitches through the type of profile milled into the upper edge of the reed, i.e. the variation in thickness throughout the length.” ---------- Custom overblow harps. Harmonica Combs and Tools.
Last Edited by arzajac on Jan 12, 2016 8:32 AM
Snowman. What are you talking about when you mentioned sleighs 45 degree chisel? I'm unfamiliar with Any techniques that use chisels. Please enlighten me. Thanks
Andrew the way i think of it is.... well let me say that when i have been setting up my reeds, after getting them to go thru the slot even, i close the gap. (Obviously) so the majority of the reed is more or less flat with the reed plate and Barely above (practically closed). And the tip is slightly higher so that the air can catch it. They used to have more of an arch, but The way ive been doing it recently you can barely even see the arch because it so light, but it's there.
Does it sound like I'm on the right track I mean it works well. I'm just not sure if it could be working better.
The way i thought it was functioning was that the air flow was lifting the tip. But it seems like your saying the flow initially effects the whole reed. So would it work better to have more of a gap along the whole reed so the air can get under it?
Sorry i never went to college. So me n physics don't exactly get along. Lol. Maybe you could dumb it down for me.
Also was interesting about the aerodynamic reed feeling stiff. So conversely A non aerodynamic reed would feel light and airy? Makes sense.
---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 12, 2016 9:59 AM
Andrew, first let me express my deep appreciation for your participation in this thread. It would be far less stimulating without it!
You've said some things that I'd like to explore further. I'm not trying to be argumentative here.I have a lot of respect for your opinions and views and am trying hard to understand them. 8^)
“...The whole length of the reed is compliant, not just the base. “ I would think that the tip would be far more complaint than the base.
“In the case of a blow note (and an airtight harp) the low pressure end is on the outer side of the slots in the channel. Everything in between feels a pressure gradient. “ Maybe I don't understand. The pressure gradient is across the reed, high inside the chamber and low outside the reed slot (it's a blow note). Otherwise the reed would not close, air would not flow over it and it would not vibrate. What am I missing here?
“It's air flow that causes the reed to move, not pressure. Yes, the size of the pressure gradient affects the amount of airflow but in thinking of what makes the reeds create sound, I find it more helpful to think of air flow rather than just the pressure gradient. For example, the flow of air is interrupted by the moving reed - resistance is not constant.” I'm really not understanding how air flow can be separated from pressure gradient here. Pressure and flow are ~totally~ coupled! In terms of what makes the reed create sound, I think we can agree that sound waves are produced by the reed “chopping” the air flowing over it, producing waves of alternately compressed and rarified air. At the moment the reed enters the slot the air flow is briefly interrupted or more properly, greatly diminished, with air still flowing around the the reed and through the gap between the reed and the slot. If air flow were completely stopped the reed would stop dead too and no sound would be produced.
Is air flow turbulent? I beleive it's a mix of both laminar and turbulent flow, again depending on (but not limited to) the motion of the reed.” Here is a “wind tunnel” video air flowing over a “closing reed” and into a reed chamber. This is visual proof of how turbulent the airflow is after it passes though a reed/reed slot. I suppose one could imagine that the incoming air exhibits laminar flow, though I doubt even that is true. But it would be hard to argue that the air inside the chamber is anything but turbulent as the eddies are easily visualized.
I can provide further scientific evidence of turbulent flow on the opposite side of the reed plate if you like but this is getting long...
“A reed with an aerodynamic shape will feel "stiff". It's not the metal that's stiff, it's the fact that the air is flowing *around* the reed instead of the reed catching it like a sail. That's why I make the distinction here. “ I'm trying to imagine what you mean by a reed with an aerodynamic shape. I feel that the reed must act like a sail at least until the vibration is initiated. I think it is the physical force of the air molecules against the reed surface that initiates the vibration, whether it be an opening or a closing reed. How else could you explain the physical dynamics of the forces acting on a reed to get it to vibrate? The air flowing ~around~ the reed can't be exerting much of a force normal to the reed surface.
I guess I'll have to ask Steve about “mensur.” None of the definitions in the various languages resemble anything like that. Fencing comes up a lot.
Again, I'm indebted for your participation, Andrew!
Michelle ---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Snowman - I like the way you focus on all the positives!
"Does it sound like I'm on the right track I mean it works well. I'm just not sure if it could be working better."
One way to know if it could work better is to play a reed, make a change based on a visual pattern of the reed shape and play the reed again to see if there is a change in response/tone/volume, etc... If the change is positive, try making a bigger change until the response is not so good. If the response is negative, try the opposite or something different. Myself, I play the single reed on the plate off the comb by putting the back of the slot to my lips. The mouth is a very sensitive piece of equipment when it comes to feeling the sensory feedback of a mal-playing versus well-playing reed.
"Pressure and flow are ~totally~ coupled!"
Flow and the velocity of air are also coupled. But velocity implies direction. Not all of the air flow will impart viscous force upon the reed. I believe that if you only consider pressure, you must assume that all of the air flow is acting upon the reed and that's an incorrect assumption on which to base a model.
"Here is a “wind tunnel” video air flowing over a “closing reed” and into a reed chamber. This is visual proof of how turbulent the airflow is after it passes though a reed/reed slot. I suppose one could imagine that the incoming air exhibits laminar flow, though I doubt even that is true. But it would be hard to argue that the air inside the chamber is anything but turbulent as the eddies are easily visualized."
I dunno. I don't know how relevant the turbulence of the air after it exits the slot is on reed shape. But with the reed in motion, I'm certain there are moments of laminar flow - when the air velocity matches the movement of the reed. I also imagine that a properly shaped reed will influence on those periods of laminar flow. But this is beyond me, I have no evidence either way.
My point is, I don't think it's safe to assume all flow is turbulent when creating this model.
"I'm trying to imagine what you mean by a reed with an aerodynamic shape."
Here's an example: As you bend the very tip of a reed down towards the slot (while keeping a working gap so that the reed can be played), you will find the reed plays less and less well. To me, that's because more and more air is flowing around the reed rather than exerting downward force upon it to get it moving. Conversely, as the reed is shaped to more efficiently catch the flow of air, the reed plays with less and less effort.
Trial and error. Got u. Thanks. Lol. That probably is the best advice. Idk why i was waiting for a secret formula. Experience is the best way to learn anything.
What did you mean about putting the plate to your lips? Using the french tuner? Or .... ??
Btw French Tuner is a great tool Thanks.
Let me ask you a question about the french tuner since i brought it up. Does it matter if you tune both blow and draw plates with it while blowing. What i mean is....if i tune the draw reed as if it were a blow reed, would it have any negative effects? Because it seems easier to just keep using it. Especially to get the octaves beat free.
Obviously you could turn it around, but then the reed hits your lip.
That aerodynamics explanation also made alot of sense to me.
Thanks for all the help. I understand you guys get paid to do this. Giving away too much would not be advantageous. But i really appreciate any and ALL advice you are willing to give.
But until i can make combs as good as yours. (Which will be Never) You ll always get my buisness.
Thanks Again
---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Last Edited by Killa_Hertz on Jan 12, 2016 6:23 PM
I didn't mean to imply that we should only consider pressure all the time, only in terms of what actuates the reed's vibration from standstill. I was trying to understand your analysis where you think more about flow than pressure. I agree that airflow is what causes the reed to move after the pressure gradient across an opening or a closing reed. We are also in agreement that resistance isn't constant. Resistance is cyclic, reaching a maximum when the reed closes.
Interesting you mention velocity. In case yoi haven't seen it, here is a PDF of the slide show at a scientific presentation by TurboDog Antaki, I wish I could see a transcript to have the full descriptions of each of the slides. Maybe the good Dr. still has it. The slides are very informative in and of themselves, though.
Most of this is just because it's interesting at this point, but I'll call your attention to the Velocity Vector plots, the Static Pressure image, and particularly the CFD Analysis of Harmonica Reed computer simulation. The velocity vector diagram shows the highest magnitudes flowing backwards along the under surface the reed. I can see how a curve at the tip would be more aerodynamic! The Static Pressure image show that, except right around the tip of the reed the pressures above and below the reed are fairly constant. No particular point, it's just interesting.
The most germane image in terms of laminar vs. turbulent flow is the computer simulation again showing the “Unsteady vortices downstream” mentioned in the computer simulations on Antaki's web site.
We'll just have to disagree about the important of the presence of turbulent flow on the opposite side of the reed plate. From my experience in the fluid dynamics of blood flowing across a constriction in an artery, I believe that the downstream turbulence provides a sort of “back pressure” that is quite significant to pressure gradients across the constriction and what is happening on the upstream side. This back pressure limits the flow that might otherwise occur under laminar flow conditions. There is after all, conservation of flow in a closed system. I think blood flowing across the resistance of a constriction and air flowing across the aerodynamic resistance of a reed are quite comparable. In fact, there are electrical analogs to this whole situation but I am not an electronics engineer. Is there a EE in the house? Check this out:
I am interested in your idea of moments of laminar flow. Its also possible that there is a transitional period when there is a combination of laminar and turbulent flow. Do you have any corroboration for that or is it a gut feeling? I do know that laminar or turbulent depends on the Reynold's Number of the system. That depends on a number of factors, principle of which are the viscosity of air and the velocities in the system. I'm actually having a little fun doing some research trying to put some numbers on this in light of the information within the plots and images in Antaki's slide presentation. I'll report back when I have something. There is actually a lot of technical information out there that bears light on this subject but it's scattered around some. I'm looking at Pat Missin's Scientific Studies page for guidance.
Lastly for this round, I need to consider what it means to have air flowing only over a curved surface. I understand the Bernoulli effect in terms of air flowing over a wing, but that is a totally different situation. What's weird about a harmonica reed is that the air flow actually flows backward under the reed as pictured in the Velocity diagrams in Antaki's slide show.
This is one of the best threads I've participated in on Dirty South. I'd like to see Steve back and I've been hoping to garner Winslow's interest. But we've got a good head of steam and I feel like I am really learning something.
Cheer's, Andrew!
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Last Edited by mlefree on Jan 12, 2016 7:38 PM
With regard to "mensur," a consultation with Winslow revealed further details.
He recalled Steve Baker has having referred to mensur and reed profile independently. Steve spoke of reed profile as its varying thickness along its length.
Winslow was also helpful in finding a German-English dictionary that came with mensur as meaning something other than fencing:
I haven't had much chance to really dive in and digest all that is being presented here, but I did want to respond to Michelle's post from yesterday.
I did use the term curvature in a sloppy manner. What I was referring to is preferably best called profile, as in “profile of a surface” that is used in geometric dimension and tolerancing to define a shape exactly.
The beam equations I pointed to show the profile of a beam under various loads. I selected uniformly varying and Michelle makes a good case for constant pressure. In an analysis of reed life I posted here a couple of years ago, I assumed constant pressure and got a breath force vs reed life result that seemed to be within reason based on experience. I am sure the actual pressure distribution is much more complex and varies with the position of the reed throughout its oscillation.
The beam formulas describe the shape a straight beam will take when loaded. My hypothesis is that if you start with a beam that is bent to the "loaded" shape and apply the load to the other side, it will end up straight. The beam equations shown are for beams with constant cross section. If you go to the basic formula for beam deflection you can calculate the shape of a beam of varying cross section under load using calculus and integrating from the root to the tip. My hypothesis about the beam curved so it’s shape unloaded is that of a flat beam loaded, going flat when loaded, could be proven or disproven just using mechanics of materials formulas and calculus. I would not be surprised if this has been done. Perhaps it has even been given by some materials science professor as a test question!
There has been some discussion as to whether pressure or flow is what moves the beam. I would say that it is pressure only, although as Andrew pointed out, pressure and flow are closely related. One of these relationships is the Bernoulli principle which I am sure comes into play here. I know this is very esoteric, and there are good techs turning out great harps without getting to the bottom of all this. Just like a good bike mechanic can assemble a durable wheel without understanding the physics involved or a driver can win races without knowing equations for inertia or coefficients of friction. What people come up with empirically is amazing and it every bit as valid as the analytical method. I believe the two methods can complement each other very well.
In a dream world, I would love to see a team of a physicist, a musician, a harp tech, and a mechanical engineer with a well-equipped lab determine what effect each parameter of a harp reed and slot has on the way it plays. With this information you could specify parts for the harp such that if they meet print, the harp assembles and plays in tune and overblows as desired with no adjustments. I think that if you knew the exact shape the reed needed to be you could develop coining dies to produce them in volume to very tight specifications. Once you had the dies specified, they would probably cost $5k to $10K per reed. A fine blanking tool to make reed plates would cost about the same. So after a year or so’s work by several people and a $110k to $220k tooling investment per harp key, you could turn out custom quality reed plates for a recurring cost of around one dollar each. Of course, even if you sold them for $100 each, you would probably never sell enough to recover your investment.
Last Edited by STME58 on Jan 12, 2016 11:55 PM
The 45 degree thing actually is actually 'Reed scraper' ----R sleigh calls it ='Super sharp draw scraper mounted in pin vise handle" "sorry Im not the shiniest apple that fell from the tree" -- I think andrew was saying that my harps that play well could play even better--I'd have to agree---once again --being worked on by a much more experienced person than myself---and andrew when u said "I would say that it can. The whole length of the reed is compliant---, not just the base''--- I guess a better example of what I meant was, sometimes when u look at a reed slot and reed from underside with light on top --I can see a larger height gap ' at he base' of one reed, higher than the the rest of the reeds, maybe .001 to .002 higher-- sometimes for me I lower that gently ---but try to keep the reed and base fairly even with reed plate ---NOT A DIP AT BASE, THEN back UP AGAIN --- wHEN i look at a manji and or crossover --especially manji cause 'they don't have a rivot deforming the base' the reed seems to be extremely-uniformly-- straight and uniformly , close to reed plate--pass through reed plate and close it evenly with a little less light at base, than less expensive harps------ anyway --I SURE WISH SUZUKI SOLD IND REEDS OR 3 PACS LIKE HOHNER--- CROSSOVER IS MY CHOICE THESE DAYS JUST FOR THAT REASON-- I LEARN A LOT FROM THIS SIGHT --AND LEARNING AND KEEPING AN OPEN MIND EVEN AS AN OLD FART ---' KEEPS MY BRAIN YOUNG AND STILL EXCITED ABOUT THINGS-- THANKS
Folks, I have been drawn away from my computer for a short spell, but am still keen on this fascinating thread. I am indebted for all the time and thought embedded in your considered participation.
Meanwhile I'm pondering the most recent input, especially Steve's. Lots to think about there.
MUCH appreciated!
Thanks,
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Yeah, it is certainly valuable to have the insight of all concerned. I wish Suzuki US sold individual reeds too, but it's not going to happen any time soon--I wonder if there is an international source for those phosphor bronze reeds . . .
you may be in luck there.... brush up on your mandarin, the girl from eastop will be in town in a few days. ---------- if you appreciate what you have... it becomes more.
I was wondering how eastop and maji reeds stack up myself.
As Snowman was saying .... my first couple attempts at bringing the Root (rivet end) down flat, I did just what he was saying (not to do) and offset the reed down to the plate. Now i did this because it's the way i was shown. But after looking at it i knew it had to be affecting function somehow. Even though it did close the gap. It just doesnt seem right. And esecially after taking a hard look at the manji (as he already pointed out). When I looked at how a stock manji was setup and how most of the reeds where damn close to going thru evenly. With little to no gap at the Root.
BING! *light bulb* joe spiers voice echoes " Flat Is Where Its At!"
I have been curving my reeds simply because its the only way i knew how to make it work. To bring the reed down as low as i can then scoop the tip up with just enough gap to catch the airflow and not choke.
With the root offset meathod my reeds got straighter, but it just doesnt seem right to put a bend in the reed like that.
But apparently (by evidence of the manji reed setup) if you do it "Correctly" you can keep the reed flat the whole way with no offset and it plays much better. Now is there a better way to get the Root lower on a Hohner Or A harp with riveted reeds where the base is alot higher?
The manji reeds also seems to be much more susceptible to minute changes. Does anyone else find this? Or is it all in my head?
These are things im noticing, but they could all be wrong IDK. I'm still kinda figuring it all out.
Editted For Clarity. ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Just a lil' HaHa HooHoo on the 3/4 - 4/5!
Last Edited by Killa_Hertz on Jan 14, 2016 5:23 PM
@1847, I was gonna say something along those lines . . . But the reeds are not exactly the same, I have worked on Easttop harps (I tuned a chromatic to Orchestra). I reckon they are close enough though, and I bet Danny G will have replacement reeds sooner than I will . . .
@KillaHertz I believe the Suzuki harps are more airtight than the Hohners--but they can be virtually the same if you work on them, you can improve the Hohners with the usual procedures. I like Hohner MB reeds, SP20 et al. And having the reed enter the slot perfectly helps to give you an airtight harmonica, but there still needs to be a gap when the reed is at rest or you can't excite the reed.
Last Edited by Gnarly on Jan 14, 2016 3:03 PM
ok its bugging me..... i am trying to remember her name... is it sunny? ---------- if you appreciate what you have... it becomes more.
Last Edited by 1847 on Jan 14, 2016 3:05 PM
Sorry i re read my post and it was unclear. I was trying to do multiple things at once.
Read it again i fixed it.
In short how do you make a reed straight without the rivet end offset meathod? ---------- "Trust Those Who Seek The Truth... Doubt Those Who Say They Have Found It."
Just a lil' HaHa HooHoo on the 3/4 - 4/5!
Last Edited by Killa_Hertz on Jan 14, 2016 5:20 PM
“The beam formulas describe the shape a straight beam will take when loaded. My hypothesis is that if you start with a beam that is bent to the "loaded" shape and apply the load to the other side, it will end up straight.”
I like it!
“The beam equations shown are for beams with constant cross section. If you go to the basic formula for beam deflection you can calculate the shape of a beam of varying cross section under load using calculus and integrating from the root to the tip.”
True, and the equations for beam with constant cross section might well serve as a first approximation.
My hypothesis about the beam curved so it’s shape unloaded is that of a flat beam loaded, going flat when loaded, could be proven or disproven just using mechanics of materials formulas and calculus. I would not be surprised if this has been done. Perhaps it has even been given by some materials science professor as a test question!”
Seems that you could prove/disprove your idea empirically with your high-speed camera. I'm big on experimental versus theoretical approaches to solving engineering or scientific problems. [I once was asked to look into another engineer's project because he had long been stymied with his theoretical work. I just made a physical model and tried it, tweaking it until it worked. Took me two weeks. He resigned and I got his job. I felt terrible about my “triumph.” I've had many similar advances applying empirical science.] Anyway, you could shape a reed as you describe using the given equations for a constant cross section as a starting point and “film”it in use. If the reed doesn't achieve perfect flatness, “tweak” your resting shape until it does. I already ~know~ it will work!
I don't know of other applications of a tapering beam. I'm sure they're out there somewhere.
“There has been some discussion as to whether pressure or flow is what moves the beam. I would say that it is pressure only, although as Andrew pointed out, pressure and flow are closely related. One of these relationships is the Bernoulli principle which I am sure comes into play here.”
It's difficult to impossible to intuit just how the Bernouilli principle comes into play. I suspect that is why the air flow reverses its direction just as it passes the reed's tip (see the slides from Antaki's talk). Another thing about the Bernoulli principle that is at work here that is unlike the more familiar airplane wing is that air is flowing only from one side of the reed (for all practical purposes). Counter-intuitively, when that happens a force is exerted ~toward~ the side of the airflow. What I don't know is the relative magnitude of that force and the pressure coming from the windy side of the reed. It's easy to get lost with that sort of thought experiment or doing lots of math (ergo, my empirical experiment).
“...What people come up with empirically is amazing and it every bit as valid as the analytical method. I believe the two methods can complement each other very well.”
Hear, hear!
In a dream world, I would love to see a team of a physicist, a musician, a harp tech, and a mechanical engineer with a well-equipped lab determine what effect each parameter of a harp reed and slot has on the way it plays....”
Well, Steve, I've always said, “Just because you don't own a Cadillac is no reason to not get a driver's license.” With the combined understanding and experience of the members of this list, even the members participating in this thread, we have the capacity to marry engineering and harmonica technology, to the benefit of harmonica technicians and thence players. I know I have learned much so far and I don't feel we're done yet.
Those are some terrific ideas and technology you have there, Steve. I'd ~really~ like to see you try the experiment I outlined above or a variant. Thinking about it gets me excited!
Thanks for getting back to us here!
Michelle
---------- SilverWing Leather - Custom leather creations for musicians and other eccentrics.
Killa, my understanding is that of Gnarly's. The only reason to dip the reed into the slot at the root is to minimize the gap that would otherwise exist on either side of the reed 2-3mm from the rivet. I've noticed a significant improvement in air-tightness after doing so.
So, Snowman and Killa, I'd really appreciate you further explaining why you feel this isn't a good idea.
Honestly, I've not worked much on Suzukis. I've owned a full set of Promasters that I've half-valved for a decade now and they've been rock steady. Hohners and Lee Oksars dominate my customer base. I don;t know if the paucity of my Suzuki experience is due to their durability or their relative rarity in my 'hood. I do know that the only Suzuki reed I've replace is from a Chinese model. My Promasters have been problem-free. I don;t wanna fix 'em because they only required gapping and they work just fine as they are.
I must also testify that my own workhorse harps are SP20s. I love 'em. They're more comfortable in my hands than MBs (I have full sets of both). I have a treasure trove of SP20 and MB donor harps so I am basically set for life and happy as a pig in mud about it. The vast preponderance of my harmonica technical work has been on Hohners with a smattering of Lee Oskars.
Thanks,
Michelle
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Last Edited by mlefree on Jan 16, 2016 10:42 AM
Michelle, I will prepare a response when I have more time. You and I seem to think similarly.
On the topic of "Mensur" and fencing, I noticed when my boys were taking fencing lessons that many of the fencers took great care to bend their foil into a shape they considered optimum. This was done by stepping on the blade and pulling the hilt up. Kind of reminds me of arcing a harp reed.
