Hybrid Plans

[dpm99]

I'm hoping to start construction on this soon, but I want to have my plans vetted first. Below you'll find a picture of the top, the binding plan (just a sketch), a side view, and a back view. Please forgive the lack of sophistication here. It was done with Paint, and much of it is just a rough sketch. The plan is to make a true hybrid that can hold it's own as an acoustic guitar. Here's the plan so far:

Top: Flat top Sitka Spruce

Body: Fully hollowed out, 2" thick (Wood TBA)

Neck: Bolt-on laminate with carbon fiber rods and StewMac double-action truss rod (Wood TBA)

Electric pickups: Seymour Duncan P-Rails

Acoustic pickups: K&K Pure Western Mini (It's what David Myka recommended to me, and I think it's the way I want to go. Not positive yet though.)

Output: I haven't got a definite wiring scheme yet, but it will involve sending the acoustic sound to the mixing board and the electric sound separately to an amp.

Strings: Hybrid (e.g. DR Zebra)

Scale: 24.75"

You'll notice a big piece of wood around the pickups in the bracing plan. I got that idea from Rick Turner. It should help with feedback. I think everything else is fairly obvious from the picture. A couple notes. First, the body shape is derived from the Gibson Barney Kessel, with the primary differences being that I've modified it into a single cut and, obviously, it's a flat top. Also, I was planning originally on a 4" thick body with bent sides, but after doing some research, I've come to a tentative conclusion that none of that would effect the acoustic sound when plugged in (which is all I care about). If anyone thinks differently, I'd love to hear your thoughts.

Opinions? Criticisms? Suggestions?

Picture Scale: 1 square = 1 inch

Thanks,

-Dave

P.S. Before anyone mentions it, yes, I've seen the Anderson Crowdster Plus. It's a great guitar.

Edited November 20, 2008 by dpm99

[dpm99]

Woah, you're right! I'd never seen a Byrdland with a Florentine cutaway until you said that, and now I'm finding lots. It's pretty similar, but my lines are a little different. Thank you for your kind words. I've put a lot of thought into the design.

I'm still debating whether I want a bigger body. I waver back and forth. I also came up with another idea tonight for a sound hole. I'm going to incorporate a "part-time" sound hole into the control cavity cover. That way I can experiment with it even after construction is finished by making new covers. I can also bring a couple to each gig, so I can change them out depending on what kind of sound I'm getting, or if I'm having trouble with feedback.

Since hybrids are weird and unpredictable, let me throw out some questions and see if anyone will bite.

1. How would you expect this guitar to perform as an electric guitar?

2. How would you expect this guitar to perform as an acoustic guitar (for those that understand acoustics, which are also weird)?

[Geo]

I'm not sure how much acoustic volume you'll get without a soundhole.

But I LOVE that design, even at this early stage. I'll be very interested to watch your project and hear what you think of the result.

I'm sure you've thought of this, but anyway... balance... with such a small acoustic body, you might want to keep the head-end weight down (small headstock, mini tuners, etc.) Just something else that popped into my head.

Edited November 21, 2008 by Geo

[dpm99]

I really appreciate that, Geo. As for the sound hole, it's sort of a misnomer. You may know that already. But really the sound comes from the sound board. The hole is more or less a vent. At least that's what I'm told. David Myka has been helping me a little, and he said the same thing. And I'd be hard pressed to think of anyone with more knowledge about hybrids that would actually talk to me and help me with my design. I'm really grateful to him.

I think the balance is gonna be ok. I've actually changed the design since I put that last one up, on some advice from David. I mentioned this in my response to MexicanBreed, but I've actually integrated a couple of sound holes into the design now. You can see them on the back of the guitar. They are integrated into the control plates, which will be held on with strong magnets. jmrentis is gonna show me how to do that. (Right J?) That way, even after construction is done, I can dial in tone by playing around with different sizes and shapes of the holes.

I've thought about balance a little too. I think I'm gonna make the sides and back 1/2" thick, which is about twice as thick as you'd find on an acoustic. I'm also going to make the body 3" thick instead of 2". I think it will help the acoustic tone enough to be worth the sacrifice of a little comfort. Anyway, it should be significantly heavier than your average acoustic, but lighter than most electrics.

Here's the latest sketch. FYI, I'm really thinking walnut for the body with a bearclaw spruce top, and a walnut neck with a maple center stripe. What do you think?

Edited November 22, 2008 by dpm99

[Geo]

As for the sound hole, it's sort of a misnomer. You may know that already. But really the sound comes from the sound board. The hole is more or less a vent.

Right... but I think the hole is essential for the soundboard to "breathe" so it can make sound freely. But that's just my "hunch", I'm not terribly knowledgable about acoustics.

I also think maybe the soundhole serves the same purpose as a port in a closed speaker enclosure... again, letting it breathe.

I've thought about balance a little too. I think I'm gonna make the sides and back 1/2" thick, which is about twice as thick as you'd find on an acoustic. I'm also going to make the body 3" thick instead of 2". I think it will help the acoustic tone enough to be worth the sacrifice of a little comfort. Anyway, it should be significantly heavier than your average acoustic, but lighter than most electrics.

Sounds like you've got the balance figured out. The thicker body is a good idea, you'll probably get more acoustic volume. Regarding the back and sides... I've read somewhere about the back influencing tone just like the top does. I mean, there's a reason acoustic backs and sides are ~1/8" thick instead of being thicker. Try playing an acoustic pressed up against your body, and then move it away so the back doesn't touch your body. It sounds different.

What I'm trying to say: you might want to go with a thinner back at least if you want more acoustic sound.

[dpm99]

Right... but I think the hole is essential for the soundboard to "breathe" so it can make sound freely. But that's just my "hunch", I'm not terribly knowledgable about acoustics.

I also think maybe the soundhole serves the same purpose as a port in a closed speaker enclosure... again, letting it breathe.

Right. Helmholtz Resonance. Should be ok to have it on the back though, right? When Taylor was designing the T5, they started with the sound hole on the back, and only changed it because Bob Taylor didn't like the way that looked. Supposedly, the effect was the same.

Sounds like you've got the balance figured out. The thicker body is a good idea, you'll probably get more acoustic volume. Regarding the back and sides... I've read somewhere about the back influencing tone just like the top does. I mean, there's a reason acoustic backs and sides are ~1/8" thick instead of being thicker. Try playing an acoustic pressed up against your body, and then move it away so the back doesn't touch your body. It sounds different.

What I'm trying to say: you might want to go with a thinner back at least if you want more acoustic sound.

That's a thought worth considering. You're right that it will influence the tone. Doesn't everything with acoustics? It will have an effect on the vibration of the top, which will change the acoustic sound. It would certainly be possible to do it too. I could even brace the back, like on a normal acoustic. I dunno. So many ways to go. How do you think that would effect the electric guitar sound? Or do you think it even would effect that?

Thanks for your help, Geo!

Edited November 22, 2008 by dpm99

[Geo]

Should be ok to have it on the back though, right? When Taylor was designing the T5, they started with the sound hole on the back, and only changed it because Bob Taylor didn't like the way that looked. Supposedly, the effect was the same.

Sounds like it would accomplish the same purpose. I wonder, though, if that would be allowing the back to "breathe" rather than the top. The sound coming off the top of a guitar is very different from the sound coming off the back... of course that could be due to the different wood, thickness and bracing pattern. Really I'm just thinking out loud...

That's a thought worth considering. You're right that it will influence the tone. Doesn't everything with acoustics? It will have an effect on the vibration of the top, which will change the acoustic sound. It would certainly be possible to do it too. I could even brace the back, like on a normal acoustic. I dunno. So many ways to go. How do you think that would effect the electric guitar sound? Or do you think it even would effect that?

If you go with a thin back like on an acoustic, I think it needs to be braced. Of course, this Taylor 110 that I'm trying to fix for my brother has no bracing on the back, and the back is a sort of domed laminate. So it may depend on the strength of your material and how much of a radius you give it (more radius = stronger)

Are you still thinking a hollowed out body? If you go with a thinner back, it would almost make more sense to bend the sides, attach with kerfing, etc. like on a normal acoustic. But then it would be less of a hybrid and more like an acoustic with pickups on it. BTW I think the switchable soundholes on the back is a good idea. You could do all sorts of stuff with that. Be sure you give the top a radius like on an acoustic (arch the braces, etc.)

The electric sound... I imagine it will drop out some of the "glassy midrange" that distinguishes a solidbody from an acoustic. Humbuckers are probably a good choice for this; I think Strat-like single coils would be very thin and honky.

A few times, I've played my acoustic into an SM57 run into a Princeton Reverb, which is a very distinctly "electric" electric guitar amp. The sound was incredible, though very bright and "changy", like an early Beatles sound. I wouldn't expect that from your concept, but still, something more to consider.

Edited November 22, 2008 by Geo

[dpm99]

Sounds like it would accomplish the same purpose. I wonder, though, if that would be allowing the back to "breathe" rather than the top. The sound coming off the top of a guitar is very different from the sound coming off the back... of course that could be due to the different wood, thickness and bracing pattern. Really I'm just thinking out loud...

Well, if nothing else I'll have some research to share, and we can all learn from it.

If you go with a thin back like on an acoustic, I think it needs to be braced. Of course, this Taylor 110 that I'm trying to fix for my brother has no bracing on the back, and the back is a sort of domed laminate. So it may depend on the strength of your material and how much of a radius you give it (more radius = stronger)

Are you still thinking a hollowed out body? If you go with a thinner back, it would almost make more sense to bend the sides, attach with kerfing, etc. like on a normal acoustic. But then it would be less of a hybrid and more like an acoustic with pickups on it. BTW I think the switchable soundholes on the back is a good idea. You could do all sorts of stuff with that. Be sure you give the top a radius like on an acoustic (arch the braces, etc.)

The electric sound... I imagine it will drop out some of the "glassy midrange" that distinguishes a solidbody from an acoustic. Humbuckers are probably a good choice for this; I think Strat-like single coils would be very thin and honky.

A few times, I've played my acoustic into an SM57 run into a Princeton Reverb, which is a very distinctly "electric" electric guitar amp. The sound was incredible, though very bright and "changy", like an early Beatles sound. I wouldn't expect that from your concept, but still, something more to consider.

There are so many ways to go with this project as far as the thickness of the sides and back. But I made a choice today and bought enough walnut to make 21" X 18" X 3" body blank. It will involve gluing together seven pieces of 8/4 walnut, so making the body blank will a a big task in itself. But I think I've got a plan, and I think the walnut will be a good choice for the project.

The pickups are Duncan P-Rails, which I think will do a lot to combat the thin tone. I don't know if you've seen the demo video for these, but the humbucker sound is almost too big. I'm interested to see how it'll sound on something like this. I should at least have a lot of tonal options.

[foil1more]

If you want more acoustic volume, you could add a small crescent shaped f-hole on one or both sides of the guitar.

[dpm99]

If you want more acoustic volume, you could add a small crescent shaped f-hole on one or both sides of the guitar.

I actually don't want more acoustic volume. The less the better. I just want good acoustic tone.

[jmrentis]

LOL, yeah as you saw with my cavity plate it takes someone who works out to get that thing off, lol. I think in an instrument with bigger volume like an acoustic or hybrid like this that'll have wood cavity plates you'll want the strength in magnets to hold the plates on well so you don't end up with some vibration or rattling from it. I hadn't realized how strong the magnet setup I used would be and it really wasn't needed on my project, but I think for this one, you'd be better off using that setup. I can't tell you how neat I think the removeable sound hole idea is, it leaves room for permanent experimentation on your guitar, that's very neat. There are few ways to really accurately compare instruments because even with the same plan you end up with different cuts of wood, strength in joints, etc. With those holes you'll be able to record some bars with the holes in place and some without and see how it differs which will of course greatly affect future plans, though honestly, I'd try to keep that as your signature feature.

Well, plan is looking great, can't wait to see how it comes out. Best of luck with everything! J

[fryovanni]

I usually get confused when I see all sorts of design elements that serve a purpose on a given style guitar mixed into a guitar. I know there are those who say a solid body with proper electronics produces the most convincing amplified acoustic sound(short of micing). I know some seem to really like the sounds they produce when acoustic instrument design is integrated into an electric.

I think a lot of what you are doing is likely a crap shoot as to what it will do to the performance, but it may sound really cool. If your really only wanting a pure emulation of an acoustic flat top, I would try to go down a more uniform path. Either have faith in the electronics system(Rick Turner has really dug into this, and may have a system that could have a good chance of solid results) in a solid body format. If you want to go the "capture the performance" way, the K&K mini western seems to be a nice way to go. I would make a box that performs well though if I went that route, since that is what you are trying to capture(the soundboard performance is effected by the box). If your aiming for a semi-hollow sound (which is a pretty broad range of sounds, and often embraces a more, bit of this bit of that sound). Then go with whatever seems like a good idea to you and see what happens, but don't over think it too much you will drive yourself crazy. Really you are way out of the range of true predictability(by that I mean in the "refined" or closely controlled) in design, because your meshing so many bits together.

Remember, these builders that have refined their production models have done so after many baby steps and subtle changes to a concept they followed. You would find they persued many concepts only to scrap the idea for this reason or that. It takes a lot of trial and error, and you can't take huge steps because you can't tell what is making this or that happen(at least if you want control over the design). So don't rack your brain too much, or try to micro manage every little thing. Just go with your gut and have fun with it.

[Geo]

If you want more acoustic volume, you could add a small crescent shaped f-hole on one or both sides of the guitar.

I actually don't want more acoustic volume. The less the better. I just want good acoustic tone.

Oh... I thought you wanted an electric guitar with electric tone influenced by how acoustically responsive the body was. So really, you want electric tone, and amplified acoustic tone?

[dpm99]

Rich - Thanks. You hit the nail on the head. Who knows what this is gonna do. I'm trying to make some educated guesses and arrive at something useful. In the end, it will hopefully at least be pretty, and it may be really great. But like you said, it's a crap shoot.

Geo - I think you've got it. I play in church, and have to switch back and forth between electric and acoustic A LOT. If I have to switch guitars, the piano player starts going into crazy interludes to stall, and sometimes I need electric and acoustic within the same song. I do a good bit of solo finger picking, and you really good tone for that. From there, I might have to jump right into a heavily overdriven rhythm part, or solo my way through some crazy gospel song in Eb with nutty jazz chords. It's really too much to ask of a single guitar, but I find that a lot can be accomplished with electronics.

Anyway, it will be interesting to see how it all turns out. Hopefully it will at least sound comparable to my T5. We'll see.

[Geo]

Geo - I think you've got it. I play in church, and have to switch back and forth between electric and acoustic A LOT. If I have to switch guitars, the piano player starts going into crazy interludes to stall, and sometimes I need electric and acoustic within the same song. I do a good bit of solo finger picking, and you really good tone for that. From there, I might have to jump right into a heavily overdriven rhythm part, or solo my way through some crazy gospel song in Eb with nutty jazz chords. It's really too much to ask of a single guitar, but I find that a lot can be accomplished with electronics.

Ah! Been there... that's a pretty demanding type of situation.

Still, I think it would be an interesting exercise to try and build this with at least decent acoustic tone/volume. Feedback may be a problem though... perhaps run it through a graphic EQ and notch out the offending frequencies? Because if you make it acoustically lively you WILL have feedback problems... so perhaps it would be better to build it less acoustically active and rely on the electronics to deliver a decent sound to the PA.

which has already been said. read posts next time...

Edited November 24, 2008 by Geo