New Bass Design For 3rd Guitar At Roberto Venn

[DFW]

There have been modifications to this design as I further realize my calling and ability. I am adding 12 sympathetic strings going up the neck, under the fingerboard, as well as 6 harp strings on the bass side with a fingerboard underneath (to ease harmonic tapping). I'm going to be using custom Pickup the World pickups with the three string groups split up and blendable via 3 slider controls mounted on the Ash portion of the treble wing. It's now got a 6 octave fingerboard as well. The woods to be used are as follows:

Central Body: Mahogany

Body Wings: Ash

Neck: 2 piece Maple

Fingerboard: Pau Ferro

The treble bout will be angled at 15 degrees to facilitate bowing on the highest string. The tuning will be based on D, fifths on the man strings, various D chords on the harp strings and variations on D and it's fundamentals for the sympathetic strings (D, A, G and their octaves, split into groups of 2, 3 or 4)

I am designing a forearm mounted bow for bowing, along with the use of a regular bass bow and my plucking technique.

Missing from this picture are the sympathetic strings, the tuning machine detail for the harp strings, the Jiwari for the sympathetic strings, the 12th fret up (still designing the headstock) and volume controls.

[thegarehanman]

So you'll have 16 strings running up the neck, is that correct? 12 of which will be under the fingerboard? What are your plans regarding the neck, piano tuners for the 12 sympathetic strings to reduce clutter? Also, what are your plans for beefing up the neck to compensate for the large amount of string tension while still keeping it reasonably thin and not neck heavy? I've actually been giving a neck with strings under the fingerboard some consideration over the last few months, mostly inspired by a violin I saw years ago. I've already designed what should be a strong, hollow, average thickness neck, but I'd be interested to hear your ideas as well.

[DFW]

So you'll have 16 strings running up the neck, is that correct? 12 of which will be under the fingerboard? What are your plans regarding the neck, piano tuners for the 12 sympathetic strings to reduce clutter? Also, what are your plans for beefing up the neck to compensate for the large amount of string tension while still keeping it reasonably thin and not neck heavy? I've actually been giving a neck with strings under the fingerboard some consideration over the last few months, mostly inspired by a violin I saw years ago. I've already designed what should be a strong, hollow, average thickness neck, but I'd be interested to hear your ideas as well.

Yea, 16 neck strings. I'm going to line the sympathetic string channel with graphite for strength and won't have a truss rod. Without frets the neck relief isn't too important. Also it'll be pretty thick with the cello-y fingerboard on there, probably around 1.250 at the nut. There'll be a two layer split headstock with 6 mini sperzels per side mounted ala classical on the bottom level and the bass tuners mounted normally on the top. as for the weight issue I figure a singlecut mahogany bass body will counteract most of the headstock mass and have an optimal strap departure position.

[davee5]

If you can manage to get the strings under the fingerboard to be equal and opposite in angle/tension to the strings above it, then you really won't have any need for a truss rod because they will implicitly counter the over-the-fingerboard stings tension exactly right.

The carbon might still be wise for keeping stiffness in the face of tension or angle errors, but my real concern would be about compression on the neck wood, rather than off-axis tension pulling it out of line and bending it.

Sure seems like a lot of work to me, but you seem determined enough that I'm willing to say "I want to see how this thing turns out" without being sarcastic.

-Dave

[fryovanni]

Why would you want sympathetic string? I am assuming you have a specific reason.

Peace,Rich

[thegarehanman]

I was always under the impression that a straight neck was even more important on a well-tuned fretless than on a fretted one as you'd want the strings quite close to the fingerboard. So dfw, the 12 sympathetic strings are going to be guitar strings, right?

[thegarehanman]

Rich, check this out. That's where I got the idea from, but I want to try it on a bass. I have a feeling that the energy generated by the main course of strings on a solid body bass will not be great enough to send the sympathetic strings into motion enough for them to create an audible noise. However, I've got a pretty cool electronics configuration I've been working on that would fix that.

I just wish I had time to build guitars right now...more importantly I've been dying to get to that acoustic.

peace,

russ

[DFW]

I'm looking into ordering custom .010 gauge strings in 4' lengths, which might be a bit of work to find but I'll put that in. If anyone has any resources I'd be much appreciative.

As for straightness I'll be overbuilding the neck and stuffing it with graphite, ans it'll be relatively short as the body joint is slightly beyond the first octave. Compression will be unavoidable but as this is my first I've got to see where all of the problems arise before I can solve them.

After some thought I've also switched the design to a hollowbody, thanks in part to thegarehanman's last post. I'll post the refined design tomorrow. The mahogany center portion will be the cavity with a cedar top. She keeps the ash outer wings, but there will be some switching up there which wil be shown in the revised design. The fingerboard for the harp string will be suspended. There will be a soundpost routed out of the cavity for both the main bridge and the jiwari.

To be continued

[thegarehanman]

dfw, with your current top design, i doubt you'll ever be able to get the top to react like a real hollow body type, even if it's constructed like one. It's simply too small an area, and the shape isn't exactly conducive to decent compression on the top. I have a feeling the only way to acoustically duplicate the hardingfelle's results in bass form would be to build a full out contrabass. If I ever get around to building an electric bass with sympathetic strings, I plan on agitating the sympathetic course electromagnetically. I'm also planning on using a full carbon/kevlar hollow neck no thicker or wider than a standard electric bass neck.

peace,

russ

Edited April 17, 2007 by thegarehanman

[fryovanni]

I am still trying to grasp what would be expected from a bass(in terms of what is it supposed to do to the sound). The quick change to a "hollow body" is making me think a real plan is not really in place. Is the goal to build electric or acoustic(or a wishy washy mix)? It seems like a very complicated mix of functions. Do you feel you are optimising for these instruments or are you placing so many demands on the stick of wood you will be accomodating via compromize?

I may just not be seeing the genius in the design( well if it takes one to know one I may never see genius period ). As a grouping of electric instruments with very closed systems it looked neat . The farther you get into a more open system or fine tuning and controlling your closed systems the less I see the function in your design.

Peace,Rich

[thegarehanman]

Your definitions of closed and open systems are a bit confusing, rich. , but I think I know what you're getting at, you mean mechanically closed or open without consideration of electronic signals. I agree with you though, it seems that the sudden change after I posted the hardingfelle link is an indicator that little research has been done on the subject. Sure, you won't know exactly how this thing will work until you build it, but you can get pretty darned close to understanding how everything will interact with some simple analysis' of each mechanical system. I hope you realize that the uses for this sort of bass will likely be quite limited and probably no modern bassist is going to want to work solely with this type of instrument. It will certainly be a fun instrument if you can get the sympathetic strings working properly, but for most it will remain a secondary instrument.

[DFW]

You guys have a good point, I'm doing little more than dicking around. It's wishy washy, poorly planned, based very little on what's been done before, with every choice made on gut feeling. But I'm building her and if she works, awesome, if not, no skin off my back, I'm still graduating and still very deep in the beginning stages of luthiery. I have a feeling she is gonna do what I want her to do, and that's all the motivation I need.

Rich, I want her to sound like a forest.

[the telecaster kid]

I say go for it, but don't listen to me, I'm in the middle of screwing up my first build.

Also, what program did you use to design that?

[thegarehanman]

DFW, look at it this way. It's not impossible to agitate those strings on the sympathetic course mechanically...but it will be quite hard. You'll need to get as much of the energy from the main course to the top as possible, to set the top into motion. Also, you may want to isolate the harp so that you don't waste energy sympathetically vibrating those strings that could instead be used to vibrate the real sympathetic course. If an acoustic bass is a bone stock speaker, then this bass would probably be a bose speaker...but bose speakers are only what they are because of the design and thought that goes into them. Inevitably your next version of this will improve upon the current one, but why not put the hours you're not at RV to read up as much as possible on acoustic design(if you're going with a flat top) and archtop design(if you're going with a carved top). Also, try to figure out which instrument in the stringed instrument family has the highest downward string pressure(on the top) to top area ratio. Focus on this instrument as it will be the closest in terms of tops specs and bracing to what you want. I'm not trying to shoot you down in those previous posts, I'd really love to see this work well. I'm just trying to get you thinking about how to make it work well.

peace,

russ

[fryovanni]

You guys have a good point, I'm doing little more than dicking around. It's wishy washy, poorly planned, based very little on what's been done before, with every choice made on gut feeling. But I'm building her and if she works, awesome, if not, no skin off my back, I'm still graduating and still very deep in the beginning stages of luthiery. I have a feeling she is gonna do what I want her to do, and that's all the motivation I need.

Rich, I want her to sound like a forest.

DFW- Like I said I just don't see where your going, and that may just be my lack of vision. I hope it works just the way you want it to.

Russ- Sorry if I am not very clear(my communication skills are lacking). What I mean by open or closed relates to the strings. I think of a more open system as one that uses its string energy to drive a soundboard and produce sound acoustically. The soundboard needs to be flexable enough readily accept the energy and utalize it. When I say closed system I mean a system that is not designed to transfer energy to the body/neck as readily because the body is not meant to be the primary source of sound. Both types of systems work well in their own way, but both are very different in how they use string energy to produce sound(but both have strengths).

Peace,Rich

[DFW]

Also, what program did you use to design that?

I drew it by hand.

I'm just trying to get you thinking about how to make it work well.

peace,

russ

Well, I have taken your advice about been doing some research, and I'm thinking of just going the solid body route and nixing the sympathetic strings until I better understand acoustic construction. The hollowbody thing was an impulse and I don't have the time to build such a complex instrument. Also I don't see any reasonable way of driving the symps in a solid environment. Fortunately I'll be in Santa Cruz this summer and Fred Carlson says he'll tell me a bit about what's going on in the acoustic realm.

[thegarehanman]

Well, since I don't plan on being a professional luthier or selling this idea to the masses for that matter, let me get you thinking about a design.

Your second course of strings is slightly shorter than the bass strings and have a bridge located somewhere between the main bridge and the end of the neck. The symp. strings anchor at the headstock, but are tuned at the body end using something like steinberg gearless tuners, with the strings going over a tom before hitting the tuners, of course. the signal from the main course is picked up by a mag. pickup and to sent some form of a sustainer meant to recieve a bass signal but drive guitar size strings(the symp. course). Since your symp. strings' pickup would also fall under the main course, a mag pickup is out of the question here. Instead, perhaps piezos in the tom bridge. Have the ability to tweak your symp tone and main tone, and probably the relative volumes of the two before sending them to your amp and you're in business. The whole concept makes me think of reverb that plays complimentary notes rather than the same notes the guitar plays.

What's the neck made from, you ask? Well, it's a completely hollow kevlar/carbon fiber neck of course!

just remember where you heard it first.

peace,

russ

Edited April 20, 2007 by thegarehanman

[DFW]

Well, since I don't plan on being a professional luthier or selling this idea to the masses for that matter, let me get you thinking about a design.

Your second course of strings is slightly shorter than the bass strings and have a bridge located somewhere between the main bridge and the end of the neck. The symp. strings anchor at the headstock, but are tuned at the body end using something like steinberg gearless tuners, with the strings going over a tom before hitting the tuners, of course. the signal from the main course is picked up by a mag. pickup and to sent some form of a sustainer meant to recieve a bass signal but drive guitar size strings(the symp. course). Since your symp. strings' pickup would also fall under the main course, a mag pickup is out of the question here. Instead, perhaps piezos in the tom bridge. Have the ability to tweak your symp tone and main tone, and probably the relative volumes of the two before sending them to your amp and you're in business. The whole concept makes me think of reverb that plays complimentary notes rather than the same notes the guitar plays.

What's the neck made from, you ask? Well, it's a completely hollow kevlar/carbon fiber neck of course!

just remember where you hear it first.

peace,

russ

That's a pretty darn good idea, and it seems everything is figured out, But I'm currently in no position tobuild something like that, especially that neck. All I have to work with is wood basically. And it's kinda all I want to work with, but that's just personal philosophy. I'll probably just end up building this completely acoustically in the enar future instead of here.

[Myka Guitars]

Fortunately I'll be in Santa Cruz this summer and Fred Carlson says he'll tell me a bit about what's going on in the acoustic realm.

DFW, this sounds like a great time to me. Fred is an amazing luthier and an endless source of inspiration for me. I am sure you will have a good time and Santa Cruz is a beautiful place to be.

Personally I like the ideas you and Russ have been evolving on this thread. I am also working on something with sympathetic strings although it is only conceptual at this point. I think that one of the better ways to get the symps to move is to have them anchored to the bridge somehow to take advantage of its rotational movement. I have also thought about an extension off the bottom of the bridge that only needs to be maybe 1/2' to 3/4" long, just enough to amplify this movement. This way it is directly coupled with the top string movement and the additional leverage just might provide enough mechanical energy to make it work.

Sometime in July I will start prototyping my ideas. I'll keep everyone informed on what I find out.

~David

[DFW]

I think that one of the better ways to get the symps to move is to have them anchored to the bridge somehow to take advantage of its rotational movement. I have also thought about an extension off the bottom of the bridge that only needs to be maybe 1/2' to 3/4" long, just enough to amplify this movement.

~David

Well in my original idea the symps ran over the same bridge as the main bass strings, as it's a custom near-cello sized bridge and has the height necessary to have two planes opf strings.

[weaponepsilon]

After reviewing the evolution of the design, I think I like the second version better. However, in my opinion, I think it would look better without those wings. I gives it a bit of a neo classical look and reminds me of a harp. Anyone?

[DFW]

After reviewing the evolution of the design, I think I like the second version better. However, in my opinion, I think it would look better without those wings. I gives it a bit of a neo classical look and reminds me of a harp. Anyone?

Well, I can't get rid of them because they're my trademark, and I love them. Also they make playing it a lot more comfortable.

[DFW]

O' ficially in progress:

[Campylobacter]

Finally! I'm looking forward to see this finished!

[DFW]

Finally! I'm looking forward to see this finished!

Alright, My brain took over and things are changing, it has it's own agenda and my concious aint' privy to the aims. Here's the picture of what I've got so far:

It's morphed into a harp bass with the long strings rather than short. We'll see where this goes.

By the way, this is no longer my official 3rd instrument, as it is unsanctioned and unauthorized. I am going to have a set plan, proposal and all the specifics set before construction. My third instrument is going to be this, a Fanned Fret Harp Mandolele. I've been working on the design for the past 3 weeks in conjunction with William Eaton, and now I'm toying with bracing paterns. I've also decided to bend sides rather than do what's pictured, rout them from a body blank. t's going to have 8 nylon main strings tuned organically in a combination of mando and uke tunings with six harp strings tuned organically to something as yet undetermined, though they will be in the register of a guitar's upper mids. The top is to be Cedar and the back, sides and fingerboard will be Pau Ferro. The neck will be mahogany. Same as our acoustics, the back will be radiused to 15' and the top to 30' and glued on at 50'. William and I were discussing the plan today and the innards are going to be changing quite a bit, but the profile you see is the profile it will be. The scales are 15 1/2" and 13 7/8".

Edited April 28, 2007 by DFW