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I've put up three short audio files on my website of me tapping the top of my braced adirondack SJ cutaway I've been working on. There's some explanatory info with the first one. I've done some initial shaving to the braces, and my hunch is that I can go a bit further, but if you guys would have a listen and give me you opinions, I'd sure appreciate it. My website only allows me to put up 128 kbit/s files, so there's probably some loss of sustain -- the adirondack is quite stiff and ringy.

I did this about a year ago with the OMs I was working on, and it generated some very ineresting discussion, so I thought I'd do it again. Here's the link: http://sculptorjones.com/section/58357.html Any comments are welcome.

Ken

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Mountain Song Guitars www.mountainsongguitars.com

I pick 1. Only because it sounds better to me.

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Waddy

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Sound Clips of most of my guitars

To my ear thumbnail #1 and #3 seem to be the same pitch just tapped at different cadence and at varying location on the top. #2 sounds as if you changed the suspension point (where you held it) and you have a loss of resonance due to the hand damping the wave. I dislike tapping faster than the decay as done on #3 because the info giving seems to my ear to be confusing.

Okay, sorry for the confusion. I've updated the 3rd file so that the two two tones are panned left and right, and are evenly spaced. They are the same top, at the same stage, just held differently as Michael stated. I guess I'm hoping to get some opinions on the quality of the tone -- if the top still seems too tight, or not. Purely subjective, of course.

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Mountain Song Guitars www.mountainsongguitars.com

I do not have pitch perfect ears by no means but it sound to be near G to me which is where I would tune to. I hear nice complexity and the sustain is fine to my ears. I would rather risk being a tad tight than loose as you can adjust when strung up if need be but it is tuff to add to the bracing once material is removed if you know what I mean Vern.

Ken buddy two things:

First when I tried like heck to record tap tones using an external mic and later the integral mic on my Mac laptop the recordings never sounded like what I heard with my ear. With my ear I distinctly heard a prominent note and it would sustain for 3-5 seconds. On the recordings that I made it sounded like a recording of someone banging on the wall and had no musical note that could be discerned.

So number one, since I do hear a musical note on your recordings what is your set-up i.e. mic, recording software etc. please?

Secondly what I hear, and again this may be because recording tap tones is very difficult to capture with a mic, is a musical note but with little sustain and a fairly high pitch. In my experience as I remove mass from the braces and if the top was thicknessed to my target deflection the note that I hear gets lower in pitch. The note that I hear from your top(s) is a higher pitch than what I hear from my tops. This says to me that your tops are braced stiffer and/or have more mass to move. This is not a bad thing mind you - just different.

The duration of the sustain is a very important part of how I tune my tops and again I am not sure if any recording is going to reproduce this for a listener who is not taping the top in person.

good info here....I'll be watching this thread closely.This tap tunning remains a mystery to me.
big John

Well, out of curiosity, I just played along with the 1st recording, and as best I can tell, both the fundamental and overtone come in around A#3 and A#2, respectively. Spectrum analysis in Audacity seems to bear this out. That said, then Hesh, you're right that the top is still a bit tight if I want to get it down to a G, as per Michael's suggestion.

Hesh, my chain is: sounboard (top facing mic) -- small felt-covered wooden mallet -- AKG C2000B large diaphragm condenser mic -- Toft ATC2 preamp/comp/eq (light compression, no eq) -- Tascam FW1884 firewire interface -- Cubase SX3.

The AKG is a pretty good mic, not great, but it was set up from another recording session, so I went with it. The little wooden mallet doesn't have much oompf behind it, which is partly to blame for lack of sustain. I can get it to ring better with my finger, but don't get as consistent hits. Given the stiffness of the top, I do think I can feather the edges down considerably once it's attached to the sides, and hopefully this will bring the fundamental down another couple of semitones.

Is there any agreement on a good fundamental frequency to shoot for? Seems like I remember someone else mention the 200 hz range (G3).

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Mountain Song Guitars www.mountainsongguitars.com

I'd like to hear the recordings with more time to hear the sustain- ie, slower tapping. I also
agree with Hesh, it sounds tighter and higher than I shoot for in my tops. As you continue to
reduce the bracing stiffness, the tone will (to my ears), get lower and sustain longer. Micheal
is also right however, that you can adjust the tone once the box is complete- both by shaving
the braces and thinning the top, or wait until the guitar is completely finished and you've played
it for a while by shaving the braces only. I did this on my third guitar, and it opened up the sound
a huge amount. I'm going to go back and do the same thing on my first- a Hauser-based classical.
On my fourth, a small 0 12-fret, I think I went a little too far at the braced top stage. I'm seeing
soundboard distortion in front of the bridge. Not much I can do about that now, however...

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Gene

Politicians and diapers must be changed often, and for the same reason- Mark Twain

New file up: http://sculptorjones.com/artwork/414535.html

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Mountain Song Guitars www.mountainsongguitars.com

Hi Ken,

I was wondering if you are tapping directly over the bracing positions on the top of the soundboard.

I'm not hearing a lot of "musical" ring in your tap tones, yet, but this could have something to do with top thickness, etc. I guess I'm meaning the sustaining note after the initial tap. BTW what was the thickness of this particular soundboard before you braced it?

Thanks, and great subject for a discussion.

Cal

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I would say it sounds a bit tight from what I got, but I think I went a bit too far on mine. What is your thickness? Sounds like .110+ to me !

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Thanks for the input, y'all. On the latest file, #4, I'm tapping in a circle starting at the tredle side of the waist, then clockwise around the edge of the lower bout, then spiralling in as I come up, finishing over the bridge plate. The plate definitely has more sustained ring than the audio is revealing, thanks to the low res mp3 encoding.

This top is .112" adirondack. I left a couple thou for finish sanding.

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Then you will scrape the lower bout down a bit, and near the edge of the soundboard quite a bit more.

Should be a killer!

If you have really small plane, you could tweek it from there even.

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Here is what a Parlor Guitar is for!
http://www.youtube.com/watch?v=oEa8PkjO6_I