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I have a friend/ customer who loves his basses. This one acoustic bass of his came in for a looksee. No projection.

I pointed him to the article by Cumpiano where he rants at the idea of an acoustic bass guitar. Great article. He said basically, forget it, and call it what it is an electric hollow-body bass. Problem, no projection.

http://www.cumpiano.com/Home/Articles/Special%20interest/Acb ass/acbass.htm

In the shop just now we too this Michael Kelly 5 String Bass to task. The sound hole measured .250 inches, but we find it has a double spruce layer, much like a Lowden guitar. Okay, no real way to see the layering, but peering down the bridge pin holes, aha, there is the thickness of spruce.

I took an 1/8th slice of a business card and marked it off for about 3/8", then took scissors and kept trimming off marks from the end, until I could see the thickness now on my little guage. Measuring those marks with a caliper, well, the thing is .195 thick. Also visible is the thickness of the bridge, and bridge plate, both darker in color, and within an acoustic guitar's appropriate thickness.

I sanded the mold mark off the top of the bridge, fit the pins a bit better, then stashed it away ready to inform the owner to put a for sale sign on it. Oh, and one last embarrasing thing for the company that made it.....

The bridge and bridgeplate fall between the two tone bars. No kidding. While the bracing didn't see too heavy, it was awful crowded at the lower bout with two tonebars, too thick a top and I'm guessing, the bridge is only 5 inches from the tail block. The above is a formula for FRUSTRATION.

This was one of those online purchases. I'm convinced if he'd played this in a music store, he'd have just walked away. Anyone else with acoustic bass blues like this owner?

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http://www.dickeyguitars.com

You'll most likely have to take the space out of the URL to Cumpiano to get it to work?

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http://www.dickeyguitars.com

Edit: I sanded the mold marks off the top of the saddle, yep, it was plastic instead of bone. [not bridge]

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http://www.dickeyguitars.com

I have to disagree with Bill C. on this one, Bruce

I built a ABG a few years ago just because of that widely-held belief that it couldn't be done, effectively.

I think he's right if he's talking about an over-built guitar body with big strings.

What I built was 34" scale. The top was Doug. fir arched to a 15' radius, braced very light with a BIG heavy Hondo RW bridge.   The back was African Mahogany with a light x-brace (no other braces on the back) The neck, Maple/Mahogany 3 piece, with CF reinforcement, and a small headstock. (Which I think all cut down on The "heavy neck problem")

I built it as an R & D guitar, but one of the first pro. bass players that played it insisted I sell it to him. I told him I'd make him one just like it, but he wanted that one. He plays it on jazz gigs.

Anyway it sounds really big, loud, and it's very comfortable to play.

I've often thought about building more of them, but I'm really keen on where I'm going with the 6-strings I'm building.

I sure wouldn't tell anybody NOT to build a ABG. they are a lot of fun and have a place at any acoustic jam I've ever been to.

long

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"No man ever steps in the same river twice, for it's not the same river and he's not the same man.” -Heraclitus of Ephesus

Bob, that is great news. The MK Chinese is overbuilt and just threw convention for an acoustic guitar out the window. It's pitiful.

I wasn't paying attention too much to a recent thread. But I thought someone had given it a try, but could not remember details.

Got any pics of yours Bob?

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http://www.dickeyguitars.com

I have a Taylor AB-1, and it is probably the loudest ABG that I've heard. The body is much larger than any other ABG as well. Unfortunately it still is tough trying to play over a banjo and mandolin. After digging in hard for an hour or two, my fingers feel like they are worn down to the blood vessels. I've been considering a Guitarrone style body with a fretted 4 string 34" scale neck....actually I've been considering it for about a year and a half. I guess when I get back home I'll have to just do it.

Al

I love my Breedlove acoustic bass.  Was replacing a piece of junk that was a impulse buy years ago, but when I started playing bass in an acoustic band, wanted to to upgrade.

Had to shop a bit before I found one that, to my ear, didn't sound like garbage, so I'll give you that.  But in my opinion Breedlove did a good job.  - Bill

I have asked for plans for an ABG a couple of times, but nobody seems to have built one from the plans I found and I dont want to waste my time building something that will sound bad. If anybody comes up with a pretty good set of plans with a proven record, I'm interested in purchasing the plans.

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Reguards,

Ken H

This five String had a real problem with the fifth string. It was so low, it was hard to even tune it. I'm glad to hear about the Taylor and Breedlove being more viable.

I noticed too that the Martin B1 seemed to have the bridge in the right place at least.

The Michael Kelly was such a basket case. Playing with moving things around, it wanted to join the body at the 17th fret instead of the 15th to get the bridge in the sweet spot.

I took some good looks at the Tim Olsen GAL plan and it looks good. From what I have seen though, I'd stay away from adding a fifth string for an acoustic.

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Bruce, I didn't take any pictures... The bass was sold so quickly I kind of forgot. I should get some photos of it sometime soon though. It should probably be on my website.

long

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"No man ever steps in the same river twice, for it's not the same river and he's not the same man.” -Heraclitus of Ephesus

I took Cumpiano's rant as a challenge, rather than a statement of the facts of what is acoustically possible given the physics of the body size (which is his major assertion.) I agree that "size matters", and you're not going to get deep loud bass notes from a parlor body with a 34" scale neck bolted on, but I *believe* that an acoustic bass can be optimized for a given body size.

My hypothesis:
Given the magnitude of the strings' shear force, an acoustic bass with strings that stop at the bridge will need to be braced pretty substantially, or the top left pretty thick - otherwise, the instrument will fold up pretty quickly. From my understanding, heavier bracing favors trebles, and conversely, a more flexible top with lighter bracing favors bass. So, how can you build with a lightly braced, more flexible top? Don't make the top handle the shear force. I'm going to try a refinement of the concept explored in the 1890's "Tilton Improvement", with a bar running from neckblock to tail block (forget the resonator) and a tailpiece (which together handles the shear force), and using what is essentially a pinless bridge to maintain the break angle over the saddle. (As an aside, I thought I invented the concept. Ha! I just didn't know my guitar history!)

My one and only guitar (so far) uses these engineering concepts (and unique bracing), and it was apparent from the moment it was first strung up that loud, articulate, and sustaining bass was present.

I have an acoustic bass "on the drawing board", to follow 3 other experimental guitars. I'd love to see some other luthiers exploring the concept too, and share your outcome - good or bad.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

If you look at the numbers, you'll find that string tension is not really a big deal. I use Thomasik Acousticores on the Taylor they are worth the extra cost.

Al

I built mine to be amplified, having read Cumpiano's article, and expecting it to be very quiet.

Very much an experiment so I used my WORST cedar top.....

I was delighted to be nearly blown out of my chair by the volume!!
the body is a dread size, full fender scale.......







Oh yes, bracing.......

very simple, as light as I could get away with.......

obviously carved after this.....


here's a soundclip un amped

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My soundclick xx luthier blog xx luthier soundclick

[QUOTE=DennisLeahy]
My hypothesis:
Given the magnitude of the strings' shear force, an acoustic bass with strings that stop at the bridge will need to be braced pretty substantially, or the top left pretty thick - otherwise, the instrument will fold up pretty quickly.

Dennis
[/QUOTE]

Dennis, you bring up a good point regarding string tension. I don't really know the numbers, and I may be wrong... but It seems that 4 bass strings would have less pull at the bridge than a 6 string guitar.

Al, Do you have some numbers we could look at to compare?

long

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"No man ever steps in the same river twice, for it's not the same river and he's not the same man.” -Heraclitus of Ephesus

[QUOTE=Bob Long]... Do you have some numbers we could look at to compare?

long[/QUOTE]

According to the numbers posted here: D'Addario Acoustic Bass strings, the tension adds up to about 191 lbs for a 4 string bass in "standard" bass tuning. So, I guess I spoke out of turn in saying the shear force is high - that's the same ballpark as a 6-string acoustic guitar in standard tuning.

I may have gotten it stuck in my head that the shear would be high when I got the numbers for a 5-string or 6-string bass, or even a guitar with added sub-bass strings (all of which I have thought about over the past couple of years.) Anyway, sorry for the disinformation.

Dennis

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Dennis Leahy
Duluth, MN, USA
7th Sense Multimedia

Diameter Tension
Item# Note inches mm lbs kg

XLB035 G 0.035 0.89 25.7 11.66

XLB055 D 0.055 1.40 34.7 15.74

XLB075 A 0.075 1.91 38.0 17.23

XLB095 E 0.095 2.41 34.4 15.60

EXL180 - Extra Super Light

This may be part of the answer for an acoustic bass? Lighter Strings for a long scale, total tension is 133.1 lbs.. Not that is less than a set of steel string strings, isn't it?



Just for comparison on the bass strings, a six string 80/20 medium set for steel string guitar is 173.5 lbs. tension.

This thread is beginning to make some sense.

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http://www.dickeyguitars.com

http://www.daddario.com/Resources/JDCDAD/Images/Products/EXL 190.gif

This set of D'Addario round wound nickel is only 155.1 for this long scale bass set. Size: 40, 60, 80, 100.

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http://www.dickeyguitars.com

Martin, thanks for showing us your bass and for the sound clip.



A friend sent this along. I notice the quite large lower bout, and the ultra-small bridge. That bridge surprised me for sure.

Link to the Tony Revell Acoustic 4 String Bass, he worked in the UK for Overwater.



Interesting thumb rest.

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http://www.dickeyguitars.com

Bill, does yours look like this one?

Comes with a Fishmann, don't most cutaways?

Perusing the current lineup of Taylor Guitar, no acoustic bass. There were T5's, Grand Symphony's, The New Hard Body Electrics, no abg? Well, we know what's coming next, the NEW Taylor Electric Bass Guitar.   

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Bruce, the Taylor bass was a colaboration between Steve Klein, Taylor. They are very cool with alot of advanced design.   You can find out more Here

long

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"No man ever steps in the same river twice, for it's not the same river and he's not the same man.” -Heraclitus of Ephesus

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http://www.dickeyguitars.com

Peterson and his Klein/Taylor Bass.

These are quite stylish.

http://www.kleinguitars.com/KleinGuitarLinks/bass.htm

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[QUOTE=Bruce Dickey]
Bill, does yours look like this one?

Comes with a Fishmann, don't most cutaways?
[/QUOTE]

Yes but fretted.  Fishman, yes.  Take a look, top middle: http://i139.photobucket.com/albums/q319/wmansfield/IMG_1907. jpg?t=1192061212

It's a Breedlove Atlas, so not high-end, but it gets the job done.  - Bill

 

Bill, I smell a commission coming on. How about a body trace off that Breedlove Atlas. It's really nice looking. Sometimes I tape four pieces of printer paper together for body traces. How big is that baby?

It appears to join at the sixteenth fret. Also, can you tell me the scale length, I have an ebony board that is cut to 34" and needs a home. If this body is close to a grand auditorium, I have it molded already. I suspect it is longer and wider and deeper.

Another thing that would help is to tell me what strings it's using.

And, what other acoustic bass is that Ovation or Applause? The one in the lower right corner.

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http://www.dickeyguitars.com

Yeah, I guess I could do that.  Asking to send it snail mail?  Let me have your address -

Breedlove has the specs on their web site - http://www.breedloveguitars.com/instruments/guitars/atlas/ab j250_sm4/index.php

Here's what we have:

Body Style: Jumbo Deep Body, Soft Cutaway
Body Depth: 5” at Tail Block, 4” at Heel
Width at lower bout: 17 ”
Scale Length: 34 "
Nut Width: 1 11/16”
Neck width at body: 2 5/16”
String spacing at saddle E-E, 2 5/16”
String gauge: 0.100-0.045"
Finish: Satin
Top Wood: Solid Sitka Spruce
Back: Mahogany Laminate
Binding (body & neck): Black binding
Rosette: Abalone with black border
Nut and Saddle: Tusq
Frets: Jumbo
# Of Frets: 23
Fingerboard and Bridge: Rosewood
Inlay Pattern: Offset Breedlove Pattern Pearl Position Markers
Headstock Overlay: Rosewood
Tuners: Chrome Grover Tuners
End Pin: Ebony
Electronics: Fishman Classic IV Pickup

So string gauge is above; I've got D'Addario acoustic bass strings on it, I think that's what they sell it with (May be EXP); haven't found anything better than D'Addario for acoustic bass strings.

And yes, joins at 16th fret.

Yeah, the other bass is an Applause.  I have fond memories of upgrading from it.