The ~dead~ Chambers

[frank falbo]

Some quick non-hypothetical, non wannabe principals:

If the chambers come up under the bridge, they'll affect the way the bridge vibrates. How thin the wood is under the bridge affects the sustain. If a guitar has a bridge area that "floats" a lot more acoustic sound will be produced, vs. one that has the bridge area glued to the back wood. Both of those things will be audible electrically.

The size and shape of side chambers can impact the acoustic resonance, but are less likely to affect the plugged in tone. Most of the plugged in tone variance is from the fact that the sides are hollowed out at all.

When chambers are connected from treble to bass side, a lot more air can be moved around. Sometimes that will sympathetically affect the vibrations of the bridge area and neck joint area, and that does affect the plugged in sound. Especially when an amp is blasting back at it, developing new vibrations above and beyond what the strings are producing. But moreover, connecting the chambers in the middle, between the bridge and neck can weaken the body's rigidity (in a good way) and that's how it's affecting the strings vibration and the plugged in tone.

Try to think about the kind of sound your internal frame will make, without thinking about how the outer shell will reflect the sound internally and externally.

The only way an F-hole can affect feedback is if the guitar was feedback prone to begin with. Primarily that's going to be in "floating top" guitars. Regardless of whether there's a center block for stability, if the center block isn't attatched to the back all along that main section, it's still floating IMO.

Is that spouting garbage? Feel free to let me know if it is, but I think they're some basic principles that can get a newbie started, without the voodoo. Of course there's always this simple equation:

chamber=good

[Drak]

No, that's all very good and very useful advice. what you said is perfect and thanks for posting it.

It's just that now, someone will want to argue a point you made, then someone else will jump in and have to give their page-long diatribe, hehehe.

We should lock it now.

Or, I can just sit back and enjoy another hypothetical chambering thread.

[komodo]

Some quick non-hypothetical, non wannabe principals:

chamber=good

←

Thanks much Frank.

This forum has been wonderful for it's cross section of knowledge. Even if there are no right and wrong answers, one can learn much from hearing from several peoples opinions.

I must also add that I have learned much from reading Siminofs book The Luthiers Handbook. While it may not be a definitive text, it does cover much of the science and backstory of guitar acoustics (esp. acoustic guitars). Because the tone chambers make the solid body sort of a neo hybrid, it's interesting to look at straight acoustics, solid body and everything in between and then form your own opinion.

KOMODO

[Myka Guitars]

Have any of you experienced any tonal differences in these 3 types of guitar?

1. Solid body with chambers

2. Semi-hollow

3. Hollowbody

If so you understand garbage. If not then you probably haven't build many guitars based on garbage. All of my guitars use garbage theory in their construction and the result is a more controlled tonal outcome. If you understand that varying levels of garbage will produce subtle variations in the above guitar types then you can work with garbage. If not then it's all garbage, so just throw it away.

Edited July 15, 2005 by Myka Guitars

[bigdguitars]

Drak no fun today huh? thats what makes us who we are. =)

One thing for sure is that chambering has two effects:

one it reduces the weight of a guitar body that is known. you can weigh it.

two it has some effect on tone. What it is cannot be measured unless you the time and can find enough data to prove your point.

[Drak]

All good information.

[bigdguitars]

I always wanted to play one of those Carvin Fatboy guitars, the construction was pretty neat, not so sure what it would sound like though.

http://www.carvin.com/products/guitar.php?ItemNumber=HF2

I would repsond drak but its not worth it.

[Digideus]

OK, Im gonna ask a "serious" question in two or three ways so everyone gets what Im really asking.

1. What tonal qualities does Chambering actually make to the guitar? Can you give a bona fide example of it?

2. What musical styles benefit from a chambered guitar?

3. Does Chambering limit the choice of Pickup (in terms of the amount of distortion a pickup creates, for example, heavy distortion HBs compared to PAFs, and what about Actives like the EMG81)?

I know its a bit of lame question in terms of the type of music I play (Chainsaw/hammerblow distortion), but im interested in the practical application of chambers and what they actually do. I expect that Blues/Jazz players would find chambers more appealing because of the lower distortion they play with whereas Metal and shread players would steer clear. Is that a fair comment?

someone should retitle this thread "CHAMBERS 101"

[Drak]

Nice.

[GregP]

My amateur take on chambering and F-holes:

Chambering like the one in my pic or the honeycomb chambers like some of the Warmoth products, will primarily affect weight. In turn, this may have a minor effect on tone due to the overall reduction of mass, that is noticeable to someone with golden ears but which would be undetectable to me.

With very thin walls, the wood will be less restricted and will be prone to vibrate more, I would guess; however, by the time you go that thin, you're better off going with semi-hollowbody construction IMUE (a new one-- In My Uneducated Opinion). With a semi-hollowbody guitar, my experience is that there is a huge tonal difference, plugged or otherwise.

To understand an F-hole's role on feedback, first you need to understand feedback itself. Feedback can be microphonic or sympathetic. Without going into details, microphonic feedback happens when the electronics (ie. a microphone! or for guitars, pickups that have vibration-sensitive coils which act like a microphone) re-amplify the sound signal coming back at them from the speaker. Sympathetic feedback happens when the instrument's strings (or whatever-- a drum's skin can receive sympathetic feedback) are hit by the soundwave coming from the speaker. If the string is at a the same pitch as the sound source, or shares similar fundamental harmonics, it will be more prone to vibrate. So, it's almost as if the speakers are 'playing' the guitar, which puts it into a feedback loop.

Now, where does the F-hole come in? Well, without the F-hole, the soundwaves are hitting only the string itself and the solid hunk of wood that is your guitar. The lack of an F-hole 'shields' the chambers from the soundwaves. Think of an empty room with a closed door. If you yell at the door, I bet SOME of your voice will make it into that empty room, but not a whole lot. Now open the door and yell again. The empty room will reverberate and echo. Adding the F-hole is like opening the door.

So, if the chamber is tuned and you are using a resonant wood, an F-hole will assist your guitar in vibrating sympathetically to the soundwaves. These vibrations transfer to the bridge and headstock, where they join up with the strings (which are already beginning to vibrate sympathetically on their own) and therefore add energy to their motion, creating feedback more easily.

On a guitar like the one in MY pic, I don't think an F-hole would make a lot of difference, but it WILL make "some". On other guitars with different construction and different materials, the effect will be greater or lesser, and the effect on the tone will therefore be greater or lesser.

Greg

[thegarehanman]

I just looked at the fat boy. Looks like Carvin's a step ahead of me with the neck through semi hollow. I'll bet theirs doesn't look as good though.

[Drak]

[frank falbo]

I see what you mean Drak, although so far, nothing said has been contradictory or combative. We're miles ahead of the curve. But, um..now I'm responding so...

Sorry Digideus I really want to minimize the"bootjack". It's all so theoretical that the only thing I can think of is to just reinforce the constants. Just keep the focus in your mind on what it's doing to the bridge, and the types of vibrations the bridge will send back to the strings. When you take wood away, you alter the way the body and bridge react to the string energy. These questions are really best answered by playing a bunch of guitars, and if you have the luxury, building a bunch of them too.

High energy music favors a tight attack and bass. Usually that's best suited with solid woods. "Loosening up" the wood surrounding the guitar's core and bridge will also loosen the attack and swell the early decay of a note. It also makes the guitar vibrate more in the hands of the player. That can be psychosomatic. A good hollowbody changes the way the player plays just as much as it produces it's unique sound.

Sidenote on feedback; I was referring to sympathetic feedback, but that includes feedback between the pickup and pickup mounts. That's sometimes misinterpreted as microphonic because if you hold the pickup steady it goes away. If the pickup is microphonic it will feedback in anything regardless.

Let's all try to search INWARD for our own answers to these types of questions, shall we? Seriously, hollowbodies are so much more responsive to the player's technique, that the same guitar can mean different things to different players. There's really no right answer, because a good hollowbody will augment each player's technique. So one guy says "I like XYZ hollowbody because the attack snaps back at you. It's got good bark." The next guy, on the same guitar will say "I like it because it's so mellow and smooth." and it's all because of the way the guy's playing it. A maple neck through "floydeyemgee", for example minimizes those variants.

Also it's common knowledge that a pointy headstock will negate the effects of the chambers.

[Mattia]

Re: chambering, I do feel it's got an effect on sound, but it's one of many, many variables in construction, like anything else. All your choices will affect things, but it makes no sense to try to control every single one before you start building. Build, change things on the next one, and figure out what works for you.

My chambered guitars (which is most of them) also usually have carved tops, both inside and out, and they do feel very 'lively', have a prominent mid-range, but do not suffer from any lack of 'bite'; my brightest guitar is my first scratch-build, a semi-hollow with a carved top, inside and out, and a block under the bridge. No F-holes, but it does give me very easily controllable feedback, even at moderate volumes.

Chambered bodies vibrate differently from solid ones, obviously. What this means to the tone exactly depends on playing style, hardware choices, neck construction, wood choices, electronics choices, other construction decisions, and probably a few other things to boot. I think the only thing I've found across the board is that chambering makes a guitar a) lighter and slightly more responsive. I won't pretend to be able to predict how it'll affect the tone on any guitars but my own, and even then it's a bit of a crap-shoot.

[Digideus]

good stuff guys. pretty much what I thought. I especially like the "Avoid pointy headstocks with chambers" comment

When youy say Sympathetic feedback, you mean like a Dulcimer? Or am i thinking sympathetic strings that are played at the same time there?

I dont think chambers are for me with my music, but its all good and worthy of learning.

[frank falbo]

When you say Sympathetic feedback, you mean like a Dulcimer?  Or am i thinking sympathetic strings that are played at the same time there?

←

No, it's like where the body wood (usually the top) or parts of the guitar get caught in a woofy howl. A guitar with a floating top can do that, and in that case, the F-hole augments it like GregP said, by opening the door. It's not the strings.

[GregP]

I don't mean to contradict you when you're agreeing with me, Frank; however, sympathetic feedback IS primarily a function of the strings, not the body. My point was that body design can affect how rapidly the strings' vibration matches that of the sound source (the speaker). With a more resonant body, more energy will be transferred to the strings along with the energy hitting the strings directly from the sound source.

However, it doesn't mean that there are additional strings whose purpose is to resonate with sympathetic feedback the way some folk instruments have. I don't recall dulcimers having sympathetic strings, but I'm definitely not an expert.

Greg

[Digideus]

I don't recall dulcimers having sympathetic strings, but I'm definitely not an expert.

Hehe, this is gonna sound geeky, but I learned that from Composer Howard Shore on the Lord Of The Rings DVDs, where he talks about the dulcimer in his soundtrack having sympathetic strings.

Cheers for the info Greg.

[GregP]

Curious bloke that I am, I had a quick (ie. not exhaustive) peek around, and here's what I discovered:

I was thinking of a "mountain dulcimer" when I said that I didn't think they had sympathetic strings. A mountain dulcimer is almost like a wee guitar played on your lap by plucking with your fingers or a plectrum.

You may have been thinking of a hammered dulcimer, which seems to be referred to as a "Biblical dulcimer" by some people, though clearly that can't be its real name, but is rather the context through which some people know the instrument. The hammered dulcimer often features 2 bridges/2 sets of strings, but these are for playing different notes altogether, not for sympathetic vibration. Also, the strings are 'doubled up' like on a mandolin; however, they are both physically hit with the hammer at the same time, meaning that they're not exactly reproducing sympathetic vibration, either-- the energy is generated by the hammer, not by one string's vibration causing the other string to vibrate in sympathy.

Now, that's just an aside to the issue, and I thought I'd share it just because I'd poked around, not because I'm disagreeing with any one particular point.

LOTR was a great set of movies-- I don't remember the dulcimer, so I'll have something new to look for next time I watch it.

Greg

[javacody]

When you have two strings that run together, as on a mandolin, dulcimer, or 12 string, the strings that run together are referred to as "courses". I don't know why, but there it is.

I've seen a really cool looking scandinavian made violin with sympathetic strings that ran under the violin's fingerboard. I'll have to see if I can find a picture on the net. Also, Sitar's have a similar setup (well, with movable frets of course!)

Edit: Found the Fiddle!!! (actually called a Hardingfele or Hardanger Fiddle) http://www.fiddlingaround.co.uk/scandinavi...ia%20frame.html

I think I need a dragon or lion's headstock on my first guitar neck!

Check out the inlays on this company's fiddles:

http://www.hardingfele.com/

To hear what these instruments sound like (they have kind of a bagpipe's dissonant drone to them at times), go to

http://homepages.wmich.edu/%7Ecode/hardingkvartett/

They've got some MP3's on this site.

Anyway, sorry for hijacking this thread, I just thought it would be cool to show you all this really cool little instrument.

[GregP]

Awesome discovery, Cody! I never would have found out about this instrument otherwise.

[jay5]

So now that Drak has decided to stay I can ask him this, what grit is that sanding disk you use?

[Drak]

On the label it says 40 grit, extra coarse.