Solid Body/Chambered Acoustic guitars

[btjjdb]

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I'm interested in solid body/chambered acoustic guitars as a simplified build for someone who has not built a guitar before. Carvin does them, Washburn has done them, Gibson/Epiphone with the Chet Atkins/SST models , Fender does the Acoustisonic Strat and even the well reviewed Tom Anderson Crowdster. I really like th Crowdster, but not for $4000.

Some of them have a completely solid body and some have chambering in certain places. Any reason not to completely hollow it out?

Please correct me if I'm wrong, but it would seem with a traditional bent side type of acoustic, that the many types of timbers used can and have been quite dense.

Therefore, could an acoustic guitar body be constructed like an electric and then route the inner chamber out and then build a traditional guitar top and bracing.

I noticed in the gallery section, Nick O built a Telecoustic in a way that I'm talking about.

I'm thinking it my be easier for a first build, without having to go overboard with the tools.
With a good pickup/preamp, how close can this type of design get to sounding like a normal acoustic?

Brenden

[Nick]

The early chambered designs (such as the Gibson 335) were an attempt to stop the, until then, fully hollow bodied guitars from feeding back in the burgeoning amplified age. They had a solid strip of wood running down the centre of the guitar and fixed to the top & back plate to tie them together, which effectively divided the guitar into 2 seperate chambers and reduced the possibility of feedback due to the fact that neither plate could freely resonate when acted on by an amplifier's speaker. The Fender thinlines had chambers routed into the solid body wood under the F holes, I think more in an attempt to lighten the body rather than for any acoustical advantage & of course retained the electric pickups so in essence was still an electric.
I'm not familiar with the more modern versions you've mentioned but my intention when I built the Telecoustic was to have a hybrid that gave not only an electric sound but an acoustic sound via the UST and onboard preamp. Did it work? Not fully on that build, the electric sound was just that but the acoustic sound didn't give me that 'full' acoustic sound, it was sort of inbetween somewhere. But I'm attributing that more to the fact that I was an acoustic virgin on that build & the top was overbraced for it's size so it was never going to behave like a true acoustic top. I think if I did another it would turn out better after having learnt abit more since then. Remember, the acoustic sound I'm talking of is only the amplified UST sound, unplugged it hasn't got the soundbox volume (size) to reproduce an unamplified acoustic guitar sound, it has slightly more volume than a full solidbody when played unplugged.

[btjjdb]

Thanks Nick,

I am am really looking for as close to regular acoustic amplified sound as possible, not unplugged. A carved out solid body with say 20mm or more sides, would give enough space to do things like arm bevels and body contours without the complications & engineering challenges of trying to do those on a regular bent sides acoustic guitar construction.

With a fully hollow guitar with an acoustic guitar top and no sound holes, does feedback still become an issue?

I have also considered building something like the Yamaha SLG100S Silent guitar which seems nothing more than a stick with a pickup and some electronics.

I really want to build a guitar or several to try to experiment and impliment as many ergonomc features as I can to help with the carpal tunnel. I just don't want to waste anymore money on commercial designs that I can't live with long term. I'd rather have 1 good body and build 20 different bolt on necks for it, to find what neck & fretboard shapes work best for me.

I've got a cheap Monterey Dinky strat, that I'm thinking of bolting on an Acoustic pinless bridge onto and chucking a pickup into.

Brenden

[graham mcdonald]

In one way routing out a hollow in a big block of wood and putting a soundboard on top could be a way to make an acoustic guitar. There are a couple of practical considerations. The commercially available ones you mention from Gibson and Fender have a thin, shallow body, around 50mm in depth. This means they are never going to work very well as an acoustic guitar. They are all essentially electric guitars with some 'acousticness' claimed in the sound or at least in the marketing. A pure acoustic guitar has to be around 100mm in body depth. It needs that for the volume of air that has a helmholtz resonance somewhere around G-G# on the bottom string. You then have to find a big enough piece or pieces of really dry wood 100mm thick to make your guitar body from. Two pieces of 8" x 4" or maybe four pieces of 4" x 4" all very accurately surfaced and glued to gether. After that you have to get a really grunty router and remove most of it and work out what to do with the large area of fragile endgrain at each end. At the neck end, the endgrain also has to deal with the not inconsiderable torquing force of the neck and strings.

The other thing to think about is that you could make several guitars from thin plates using the wood the router has turned to sawdust.

I know there was some discussion recently about the 'best' pickup for an electric guitar. I really don't think there is a 'best' one. They all sound like pickups, not guitars.

cheers

[P Bill]

Are you talking about making an acoustic instrument with the back and sides carved from a solid slab ? There is a South American instrument made this way. I forget what it is called. It's bigger than a mandolin, has ten strings, and the body from memory is about 50mm deep. The carving of the body is traditional. I don't know the thickness, but 6mm on the sides would be getting thin, especially on the end grain. I would think you could arch the bottom as a normal arch top bottom.

I chamber EUBs to lighten the instrument, but mainly to change the tap tone. The difference is remarkable, night and day really. On my basses this acoustic difference is best served by piezo tabs. The sound is woody and warm going towards acoustic. The usual complaints about piezos don't seem to be such an issue with the bass frequencies.

[Rick Turner]

My crew and I have built over 2,000 semi hollow "amplicoustic" guitars and basses. They have bent sides, bookmatched tops and backs, and a solid Western red cedar center block. Think 335 meets Telecaster and a Ramirez. They work just fine. Take a look at:

http://www.renaissanceguitars.com

Yes, we also build full hollow body guitars and solid body instruments.

[Rick Turner]

BTW, I consider the semi-hollow build to be easier and more efficient with timber resources in many ways than a hollowed out "nut bowl" guitar, not that they don't have their place as well.

[btjjdb]

Hi Rick,

The Renaissance RS-6 is exactly the sort of thing I'm looking to build. It's the side bending part that I don't have the equipment or skill to be able to do. I just wish I could see what these look like internally in terms of the chambers, bracing etc.

So are these esentially a solid block of wood in the center with bent sides and thin top and backs? In terms of the amplified tone through pickups how different are these to the frame type of guitars like the Yamaha SLG100S, TheBONE, Soloette etc, which are basically a stick? Do the chambers actually add anything to the amplified tone?

As a kiln operator in a timber mill, I can get a hold of easily, timbers such as Jarrah, Karri and Yellow Stringy Bark. Karri and Jarrah have been used as back and side material for acoustic guitars. The only reason to consider a hollowed out guitar is really simplified construction.

[Mike Thomas]

Just a quick aside, to say how much I enjoyed your new (?) website Rick. There is a wealth of really interesting stuff there for builders as well as for prospective purchasers of your instruments. And what a lovely performance by Ingrid Michaelson!

[Rick Turner]

Hiya, guys, especially to you, Mike!

I'm at a point where I honestly can't tell the difference between bending sides for a semi-hollow guitar or routing out a solid block as far as ease of build goes. It's almost literally six of one or half a dozen of the other. I can understand that for someone who is not used to bending sides for "acoustic guitars" that may seem to be an exotic endeavour. But once you get into it, it's all kind of variations on a theme...making solid timber be and do what you want it to do/. At this point in my career, it's as much about what I think I can SELL as what I can MAKE. I can pretty much make anything I can think of; most of woodwork, whether it be hand work or CNC work is at my fingertips. I know that sounds pretty egotistical and cavalier, but it's simply the truth now that I'm in about 45 years at doing this stuff. I've pretty much been there, done that with regards to how guitars are put together, and now ALL the methods are just colors on the palette.

So what do you WANT to build? How does it sound? So figure out how to do it...

[Taffy Evans]

Hi all, this thread brought back memories of a festival I attended quite a few years ago, to display my guitars. There was a guy there who had full acoustic guitars he said he had carved from a solid piece of timber.

Thats all I can remember. So it has been done.

[jeffhigh]

If you dont want to set up for bending, pay someone else to bend the sides to shape for you.
Waste of a big chunk of wood to rout it out, and then you have to leave the sides thick to avoid it cracking on the exposed end grain sections

[Peter T]

So what do you WANT to build? How does it sound? So figure out how to do it...

This is very good advise. As a carpenter I'm always being asked for advise from people who want to do their own projects around the house (pergolas, decks, extensions etc.) Often design concepts are compromised jumbles of what people think they are capable of achieving. With this mindset the endeavor often turns out harder than it should have been and the result less than satisfactory.
My advise has always been to picture (or hear) the end result which you really want to achieve, and then work backwards from there. Challenge yourself, and only then will you achieve full satisfaction from the result.

Pete.

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