Hmm....A hollowbody experiment?

The_Sentry

New member
I was thinking about the nature of the hollowbody guitar after doing one, and I know full well about the issues with feedback. What typically causes the feedback (read about this in a Les Paul biography) is the microphonic pickups vibrating right along with the top of the guitar. The whole fix for controlling feedback was to introduce the solid body where the top did not vibrate the pickups.

So...if that's the case.....I may try an experiment with a hollowbody guitar if I can find one at a reasonable cost (and it won't destroy the value...so it'll have to be a knock off, no name, no value...)

There's this spray foam that is often used in conduits for outside plant (telephone, cable TV, power, fiber optics) that is used to keep water out and vermin. It's lightweight, and if kept out of the elements, it lasts a long time. It's a spray and expand type of material.

So...the thought...

If there's a way to spray this stuff inside of the hollowbody guitar (under the pickups only...not the entire guitar)...and the pickups were resting on this foam, the movement of the pickups should be reduced dramatically...and this should also allow for the archtop to be cranked with gain at much higher levels. The closest equivalent I can think of are people who stuff the cavities of their F block archtops or cover up the F holes ala BB King...

but it's all a case of trying to keep the pickups from moving/vibrating. The trick would be a way to keep from foaming the whole inside of the guitar....maybe carboard could be placed inside to keep it from happening.

So...thoughts on this? Think it's worthy to try it? Granted, I wouldn't do this to an expensive model, but I'd love to see the results on a cheaper model (tone loss from woods vs. the big gain of being able to crank that hollowbody to the moon...)
 
Re: Hmm....A hollowbody experiment?

How can I put this? Dumb idea. If you plug up a hollowbody, you lose the rich acoustic overtones, which is it's claim to fame. Why have a hollow body then? You lose the main benefit. And to actually buy a hollowbody just to plug it up with crap, is pretty weird. If you're paranoid about feedback, get a 335 or a solid body in the first place.

To reduce potential feedback, some hollowbody makers put dowels or other wood supports under the bridge, to limit the vibration of the top.

I've seen plenty of guys use full depth hollowbodies at typical bar gigs, at reasonable volumes, and there's no issues. Just hold your strings or turn down the volume when you're not playing. Maybe you have to avoid facing your amp...big deal. Nugent used a Byrdland for years at concert volumes, and when he wanted, he could get some incredible low octave feedback from it (like a roaring lion). The feedback was controlled and only when he wanted it. What are you so worried about?

If we could only channel all this brain activity...
 
Re: Hmm....A hollowbody experiment?

I was thinking about the nature of the hollowbody guitar after doing one, and I know full well about the issues with feedback. What typically causes the feedback (read about this in a Les Paul biography) is the microphonic pickups vibrating right along with the top of the guitar. The whole fix for controlling feedback was to introduce the solid body where the top did not vibrate the pickups.

So...if that's the case.....I may try an experiment with a hollowbody guitar if I can find one at a reasonable cost (and it won't destroy the value...so it'll have to be a knock off, no name, no value...)

There's this spray foam ...

I'm just gonna cut you off right there. I've read enough.

No.

Please don't do this.

Thanks in advance.
 
Re: Hmm....A hollowbody experiment?

How can I put this? Dumb idea. If you plug up a hollowbody, you lose the rich acoustic overtones, which is it's claim to fame. Why have a hollow body then? You lose the main benefit. And to actually buy a hollowbody just to plug it up with crap, is pretty weird. If you're paranoid about feedback, get a 335 or a solid body in the first place.

To reduce potential feedback, some hollowbody makers put dowels or other wood supports under the bridge, to limit the vibration of the top.

I've seen plenty of guys use full depth hollowbodies at typical bar gigs, at reasonable volumes, and there's no issues. Just hold your strings or turn down the volume when you're not playing. Maybe you have to avoid facing your amp...big deal. Nugent used a Byrdland for years at concert volumes, and when he wanted, he could get some incredible low octave feedback from it (like a roaring lion). The feedback was controlled and only when he wanted it. What are you so worried about?

If we could only channel all this brain activity...

Dowels might not be bad..;.

Geez Guys, I ask a stupid question about a 50-100 dollar hollow body and y'all act like I just crucified the J man himself.

Gimme a break already....

... oh my god!

He's just invented... the SEMI HOLLOWBODY!!!

Eh, whatever.....

Oh, PS:

If you haven't tried this, then how do you know?
 
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Re: Hmm....A hollowbody experiment?

To reduce potential feedback, some hollowbody makers put dowels or other wood supports under the bridge, to limit the vibration of the top.

I read about this on the Gretsch forum years ago - a sound-post like in a violin. Someone spoke about feedback in hollowbodies being often the result of the top and back resonating at different frequencies, and installing the sound-post underneath the bridge eliminates this by making them resonate in unison.
 
Re: Hmm....A hollowbody experiment?

... and you got some answers! :naughty:

Good and well.

The problem is this: There can be guesses as to how this might turn out, but unless you've done it, or you've seen it done, IT'S NOT KNOWN.

But, I suppose this is the internet where people can stay at a Holiday Inn Express and be crowned experts in their respective topical discussions.

Where do I sign up for this?
 
Re: Hmm....A hollowbody experiment?

But I have tried it...it was a mess and it didn't work as well as you might think. A dowel, a block under the bridge (like a ES 225) or just picking an archtop with a stiffer top (like an old Epi) works better...just saying.
 
Re: Hmm....A hollowbody experiment?

I have had plenty of feed back situations with solid bodies before. Actually I like feed back on demand. A semi hollow or full hollow may be the guitar of the new century since so many places want you to play at levels that their patrons can talk over, and with the drums behind plexi glass baffles, these days.
 
Re: Hmm....A hollowbody experiment?

We're talking about spraying foam inside of a hollowbody guitar to fill up some of the hollowness and get more gain with less feedback?

Yeah they figured out a better way to do that in the 60's...the ES-335...

If you want a hollowbody tone, the feedback and vibration is part of that. If you want a semihollowbody tone, get a cheap semihollowbody guitar and save yourself the trouble.

If you want a guitar that doesn't care how much gain you throw at it, get a solidbody.

I'm totally in favor of experimentation and trying new things to improve the world, but i mean...you're not gonna make that wheel any rounder bro.
 
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Re: Hmm....A hollowbody experiment?

We're talking about spraying foam inside of a hollowbody guitar to fill up some of the hollowness and get more gain with less feedback?

Yeah they figured out a better way to do that in the 60's...the ES-335...

If you want a hollowbody tone, the feedback and vibration is part of that. If you want a semihollowbody tone, get a cheap semihollowbody guitar and save yourself the trouble.

If you want a guitar that doesn't care how much gain you throw at it, get a solidbody.

I'm totally in favor of experimentation and trying new things to improve the world, but i mean...you're not gonna make that wheel any rounder bro.

I hear ya, Empty...but there's something that's gotta be stated here.

I can't just walk into any store, find a guitar, and "hey, there it is".

As a lefty....I take what I can get.

If I was to do this, the biggest trick would be to get the foam under the pickup area only...not throughout the whole guitar. It's more of a case of isolating the vibrations....completely isolating them.

Eh...I'll probably do it anyway. Usually when people are this apathetic or negative it just gives me more reason to do it. :banghead:

But I have tried it...it was a mess and it didn't work as well as you might think. A dowel, a block under the bridge (like a ES 225) or just picking an archtop with a stiffer top (like an old Epi) works better...just saying.

That's a pretty big thing to admit in light of the responses here.

:nana:
 
Re: Hmm....A hollowbody experiment?

the biggest trick would be to get the foam under the pickup area only...not throughout the whole guitar. It's more of a case of isolating the vibrations....completely isolating them.

Eh...I'll probably do it anyway. Usually when people are this apathetic or negative it just gives me more reason to do it.

I've gotta question for ya:

Why in earth you posted here to ask for opinions if you don't wanna listen to them anyway?

You just can't take to hear that's just a BAD IDEA, uh?

Have a Merry Christmas, pal.
 
Re: Hmm....A hollowbody experiment?

I've gotta question for ya:

Why in earth you posted here to ask for opinions if you don't wanna listen to them anyway?

You just can't take to hear that's just a BAD IDEA, uh?

Have a Merry Christmas, pal.

If the response was non-plussed or neutral either way...I probably would have written it off.

Overtly positive or negative....well....that's a different story. :naughty:

PS: Does anyone have any pictures of the dowels?
 
Re: Hmm....A hollowbody experiment?

I was thinking about the nature of the hollowbody guitar after doing one, and I know full well about the issues with feedback. What typically causes the feedback (read about this in a Les Paul biography) is the microphonic pickups vibrating right along with the top of the guitar.
didn't Gibson already address this issue with electric hollowbodies by developing the "floating" pick up used on their jazz boxes?
 
Re: Hmm....A hollowbody experiment?

In 99% of the time, in the guitar world, when ever you have a great idea, you can be assured some one else has already had the thought, and tried it.
 
Re: Hmm....A hollowbody experiment?

I don't have a pic, but you can use a 1" hardwood dowel from any hardware store; measure the inside dimension from top to back near the neck and bridge pickup with the strings loosened. Cut to that length so it's a slip fit, put a dab of Titebond on it, and wedge it in place. The string pressure will help keep it in place...this is a lot more rigid than the foam and will probably work better. It's also reversable...try it; it's easy and cheap. Have a nice holiday...
 
Re: Hmm....A hollowbody experiment?

I have had plenty of feed back situations with solid bodies before. Actually I like feed back on demand. A semi hollow or full hollow may be the guitar of the new century since so many places want you to play at levels that their patrons can talk over, and with the drums behind plexi glass baffles, these days.

+1. Absolutely. I think bands in small venues that blast the patrons with loud music are inconsiderate & immature. People come to these places to hang out, socialize, have a couple drinks, talk, laugh, and hear some music...in that order. Having to scream in someone's ear because the band is so loud is ridiculous. And let me assure you, most local bands aren't good enough to be playing at those volumes anyways. Loud bands chase off customers. When your ears start to crackle, it's time to go. People usually don't to bars to sit & stare at a band for 4 hours straight, and not say a word. Who do those bands think they are, God's gift to music? In the average bar, turn it down boys. Save the volume for big venues & outside concerts.
 
Re: Hmm....A hollowbody experiment?

In 99% of the time, in the guitar world, whenever you have a great idea, you can be assured some one else has already had the thought, and tried it.

I'd say that 99% is conservative. It's probably higher than that. Electric guitar development peaked in the 1950's. There's been millions of players all over the world tinkering with their guitars for decades.
 
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