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A while ago I was thinking about experimenting on a build. I was sitting on a plane, thinking about my favorite old TLR camera. I had been wanting to figure out a way to do an adjustable sound hole on a guitar- hoping to allow the player to focus the sound in one direction or another. I decided to try to adapt the leaf style aperture from my TLR to this project and make an aperture for the guitar.

The "sound hole aperture" took over a year to fully design and make functional. I made it out of spruce and other light materials to keep the weight down.

The device had to be installed before the box was closed, which made the finish process "interesting" around the sound hole.

Overall, the sound hole aperture does effect the tone slightly, but it is more noticeable to the player than to the audience in front of the instrument. The additional weight on the top dampens the sound enough (even with a lightly braced top and a light weight bridge) that the guitar sounds a bit thin. So this one falls more in the form than the function category.

Not all experiments turn out the way we want or expected, but that doesn't mean I didn't learn anything! It was fun and gets me excited for my next experimental guitar.



For a full write up and more pics check out my website:
http://www.ensorguitars.com/zebra_sitka_gallery.html

Also on my website is a video:
http://www.ensorguitars.com/zebra_sitka_video.html

Thanks for looking.

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ELEVATE || Next Level Lutherie
http://elevatelutherie.com
&
http://ensorguitars.com

Now that's thinking outside, err uh, inside the box. Cool idea!

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Good judgement comes from experience. Experience comes from poor judgement.

Just a thought, maybe you could mount the aperture mechanism to the back?

Mike

Well it is quite a beautiful sculpture regardless of tone. You could always remove the experimental work if you don't like it. Ramirez built a guitar he called De Cámara which had an 'apature' built along the rims about in their mid point. Almost like an interior top with a huge sound cut out. A baffle of sorts. Anyway kudos to any luthier who experiments. When I did experiments years ago I never took the time to make them look good.

Oh great....now I also have to worry about f-stops when I play
Must be a very cool mechanism in there. I'd love to see more of it

it looks wonderful! congrats!

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member of the guild of professional dilettantes

Or a mini one for a sound port! It would have no dampening to the top and would be cool!

Way cool!

Impressive!

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Brian

You never know what you are capable of until you actually try.

https://www.howardguitarsdelaware.com/

ZekeM,
Actually it does have a sliding door on the soundport, which makes a very clear difference in the bass response for the player.

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ELEVATE || Next Level Lutherie
http://elevatelutherie.com
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http://ensorguitars.com

Looks like it'll eat guitar picks! Kidding aside, I really like what you've done, Chris. This is a beautiful guitar!

Alex

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"Indecision is the key to flexibility" .... Bumper sticker

Very cool Chris!
Since the aperture is not traditional, another way to make it dampen the top less would be to move the sound hole to the upper bass bout. Have you thought of that? Then there is the option of suspending it from the rim so you keep the traditional sound hole location. The possibilities are...not quite endless, but there is certainly more than one other option now! It looks cool as h-e-double-hockey-sticks though! I like the guitar too. Very nice looking in all respects!

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http://www.CostaGuitars.com
PMoMC

The aperture is extremely cool, but. There are so many incredible features on this instrument. I particularly love the painless bridge with straight saddle and offset string holes. The cutaway and bevels are beautiful too. Amazing,

cool! You jus thought of everything then!

Very cool!
Awesome craftmanship.
I'd like to see China try to copy this!

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wah
Wah-wah-wah-wah
Wah

Love that

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EddieLee

What does this guitar not have? Sculpture was the right word. I think James Bond would be proud to own this guitar.

I should have added that your craftsmanship is amazing. Beautiful guitar. And one with an F stop none the less!!

Chris, that's a beautiful rendition of an interesting idea. An alternate approach might be to switch to Waterhouse stops.

If you used thin carbon fiber disks and cam-locked them in place using lightweight studs in the top, you could greatly reduce the weight issue.

Of course, that's not nearly as cool as a continuously variable soundhole!

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D..

Sounds pretty darn good to me. Is there any chance of a follow up video demonstrating the differences in sound when you open and close the aperture?

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David Morris

Chris, that's an impressive idea and some brilliant execution.

I don't know how much weight you needed to mount on to the sound board to make the aperture work, but I'm guessing that the size of the arm bevel, the size of your bridge, and the size of the sound port all contribute to keep the box from sounding to its potential. You've basically shrunk the size of the sound board, stiffened it up, and maybe given the box too much air. I think that each of these factors would lean a guitar's sound away from round and warm.

Because I see genius at work in your aperture idea I'd be curious to know how another guitar would sound with it if that other guitar had no arm bevel and a traditional size bridge.

Sorry for sounding to critique-y. There really is some genius in your idea.

Phil

Thanks for all the replies.

Phil,
I very much appreciate your analysis of my guitar. The intention of the aperture was to allow the player to shape the tonal signature of the guitar (more mids, trebels, or basses) for whatever particular song or sound they want at the moment. Knowing that the aperture would add significant weight (I think it was 120g), I went for a more active, lightly braced top. I left the lower bout braces (all of them) uncoupled. I also went with a light weight bridge- 27g. (On a side note, the wenge bridge was so porous that when I was gluing it on, some glued came up through the top of the bridge on the wings!) The armrest does significantly reduce the active area of the top on the bass side, but from my experience, this doesn't normally "dampen" the sound of the top as much as reduce the "boomyness" of the guitar. Since the top of this guitar is now closer to the width at the LB of my parlor, I could understand if it sounded similar to my parlor, but that is not the case. Also, having a cantilevered neck normally adds a bit more volume and sustain to the body. That is the case in this guitar. I know it sounds odd, but the guitar sounds a bit choked and loud at the same time.

Back to the main point, the aperture: the device helps to focus the sound in the mids slightly, but it is really only noticeable to the player. The dampening effect that it has on the top is the largest problem (also the fact that it would be extremely expensive due to how many hours it takes to pull off). I think Tony had the best idea- moving it to the UB. But unless I have someone specifically inquire about it on a guitar, I won't be adding it to my list of options anytime soon.

All these observations are based on the guitar being strung up for less than a week. I will be interested to see how it matures with more time under tension.

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ELEVATE || Next Level Lutherie
http://elevatelutherie.com
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Really nice work, and ingenius idea!




What exactly do you mean by F stop?

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Francis Richer, Montréal
Les Guitares F&M Guitars

Cameras use something called F stop, aperture setting. http://en.m.wikipedia.org/wiki/F-number#section_2

Though its not entirely an accurate use if the term, since focal length means nothing in guitars.

I was looking around on the guitar : ''What the heck is a F stop...?!"

Makes sens now.

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Francis Richer, Montréal
Les Guitares F&M Guitars