In another thread the topic of sp20 gaps was raised and I mentioned how I'd purchased a couple just so I could understand what was going on. I told how I had a Bb which on investigation was gapped about double wide compared to what I thought would be about right. I'd also observed that the reed action/aka reed shape seemed very good and I expected a simple reset of gaps would be all that was required to make this harp very good. It was speculation at that point but today I reset the gaps, in much the way I'd anticipated...that is, I lowered them by about half. The result was a very sweet responsive harp which I'd be happy to play on a gig. All the bends became easily available including the 10 half step...ok not easily in that case, but it is there and only my skill in hitting it at fault. The 6 overblow was also no problem. This harp was a progressive sp20 with the original sp20 plates and screws; that is, not drilled to accept rocket covers and fitted with 2mm screws. A really pleasing result, among the best sp20s I've ever played. Now to see if the Db will respond equally well to a little toothpick attention. I'm pretty sure it will. My obs of the reed shape led me to be quite confident these harps would only need gapping.
I think this topic is appropriate for beginners page. I know there are different opinions, but IMHO, knowing how to adjust a harp is an important skill that can make a great difference to a player's progress. Utk2pb
I agree that it's important, and I usually end up tweaking the gaps on the draw reeds. It always helps
But, I know the blow reeds also play a part in draw response. It's sort of trial and error on those (or so it seems) unless you take the plates off. Any general thoughts on gapping blow reeds? If looking down at the blow plate, where should the reed sit in the slot?
I've mostly got SP 20s. So far, the Progressive reed plates seem to be pretty good in terms of shape.
Jut as an aside, the old Special 20 Marine Band lids fit the Progressive (most of my harps are now Progressive/Rocket plates with old-style lids . . . which I think looked much cooler)
I agree SuperBee, it's important IMO that beginners know how to do this and not be afraid of it. Otherwise they're always gonna be at the mercy of the manufacturer and the way it was set at the factory. Most of the time, from what i've seen and heard from others, the factory set up is rarely, if ever, optimum.
My new SP20 'A' had really wide gapping. I had to adjust most of the reeds down by a good bit.
of course, with a sp20 there is an internal sprue might get in your way. you can cut those out.
it may be pertinent when thinking of the video i posted above, to be aware Joe has set the reeds for the 10 overdraw. thats not a technique i have developed...but i suspect he set the gaps a bit tighter than i need
i checked my Bb with feeler gauges. my 8,9,10 blow and draw reeds are all set with gaps in range between .002" and .004". these all work for me. you can go tighter, some may like to go wider...i find if i go much tighter than this i start to get problems with reeds jamming from moisture when i practice a lot. and wider encourages harder blowing which i think is the enemy of learning finesse i try to not spend too much time messing with the high reeds unless they are really misbehaving, when i was starting out i spent a lot of time trying to rectify ham-fisted attempts to squeeze every last bit of response from high reeds...these days i think...i am not trying to overdraw so if the reed will give up the bends and sound clear and loud and consistent in pitch..thats all i ask
here is Joe's second adjustment video. some really good info in this as he moves from 9 down and discusses some particular quirks of each hole
Last Edited by SuperBee on Oct 17, 2015 3:50 PM
Joe's videos are great references - Thanks for re-posting those! I play a lot of SP20s --come wide-gapped from factory/ootb. I always adjust new harp reeds. mostly a trial and error method. I used toothpick and thin paper method, but the Lee Oskar tool kit has a nice brass tool that works nicely especially on blow reeds on Sp20 where that bar is in the way. Like Joe did in the videos, I close them too much and then have to open again. Oddly It seems "gapping tight and then back" method works on reeds that don't seem leaky, but are not bending very smoothly. This includes Seydel steel reeds. I guess Im just "breaking them in?"
Last Edited by Billfish89 on Oct 18, 2015 1:02 PM
Thanks for this. I agree that this is a suitable topic for beginners. Otherwise you might buy what is in fact quality instrument, but think it isn't any good.
These basic operations require a light touch, but not the finesse of a watchmaker.
It's important that beginners know that. Of course then you can choose to DIY or pay someone else to do it.
Re blow reeds: Ron I'm glad you asked. I was in a hurry before and slightly misread your post, I'm sorry. I agree it's important. For starters I'd suggest having both reeds fairly evenly gapped. If the chamber seems leaky I'd close them up, but close both of them, at least at first. You may eventually find its better for you to have one set a little wider than the other, but remember they do interact and if one is set too wide it will affect the response of the other. I've seen a few memorable extremes, where the player had closed the draw reed right up with the effect it was quite compromised; still not very responsive and very limited dynamic range. In all cases the blow reed was set very high...the solution was to open up the draw and close down the blow...one of these harps I acquired from the original owner...he was so disgusted with it he sold it...I found the 4 and 5 reeds unplayable..once i reset the gaps as above I found a very nice harp... Gaps aren't always the whole story, but as Joe mentions in his video above, it's one of the most important adjustments and one of the easiest. I have another harp here, gaps seem pretty good but it's a dud. It's the reed shape at fault I think...for me that's the next step...actually, I usually look at that at the same time as setting gaps, but for starters gaps are where the best value comes from. Reed shaping is a bit easier to mess up
Re the blow reeds again - you can adjust them with the reed plates on can't you? I know there's the 'sprue' on the SP20. Actually it was a while before I took my plates off, and even then I didn't clock the sprue. I first read about it on MBH - and that was also the first time I'd heard the word 'sprue'!
Last Edited by MindTheGap on Oct 19, 2015 3:38 AM
Yes you can adjust with plates on, just as Joe demonstrates in the videos. Sprue: You probably can work around it. I adjusted my sp20 with plates off and was happy with result but I'm fairly used to eyeballing them.
I adjusted a SP20 A last night...thought it was pretty good but this morning played it properly and found the 2 blow needs opening. I guess that's 'stuffy'. I've got a G with 1 blow that way too. Yeah I don't know why G would be a particular problem. The lower pitches do need a bit of a longer run up I suppose. But...the differences are greater as the note gets lower...the difference between the 10 of a G and the 10 of a C is not as great as the difference for the reeds in chamber 1 of those harps.
I've just read through this thread again and I think this is relevant. I picked up a Sp20 in G yesterday, I don't like the stock combs but gave it a go out of the box it. It was leaky on the 4 and 5 holes the rest were ok. On taking it apart I could see the reed gaps were set quite wide so I eased them down by about half. The reed shapes looked pretty good. The draw plate only took a minute to flat sand and installed a 'tin sandwich' style comb and I've now got a very nice responsive 'G' harmonica. I certainly don't do blow bends or anything like that but all the usual 1 to 6 draw bends are all there nice and easy. One thing I will mention, the packaging was for a 'Progressive' Sp 20 but the cover plates were the old style Special 20 Marine Band, yellow key sticker on the case and 2mm screws for the reed plates.---------- Happiness is taking things as they are.
