Official Luthiers Forum!

Hey guys...
I havent been around in a while. Not because I havent wanted to..believe me....
but being super busy, with the usual life crisis popping up here and there, and having a crappy frustrating computer... have all piled up, to what amounts to basically >neglect.. on my part, towards my OLF friends!
Sorry about that and people I have supposed to have been in touch with,, sorry... but life has truly been insane this summer...
I have been busy building guitars, hand planes, nicknacks for friend and finally >a proper workbench with my new unisaw!!!
SOOOOO Pleased with that purchase~!
ANyhow I been missing the OLF so I decided to brave the pitfalls of this crapbox comp and pop my head up... Hello!

I need to consider some new guitar building projects, and I am leaning towards building a guitar with a body style of my own design, one with recurved shoulders this time, as I admire the work of Howard K so much...
But one request I have recieved from my sweetie, is for an acoustic bass..
(the thought of jamming on the back proch with my darlin tickles me pink)
However..
This is something Im completely in the dark about and I was wondering if someone could enlighten me about some basics about acoustic bass construction
What do I need to consider here with respect to building this thing?
Are acoustic basses essentially amped up acoustics with slightly beefier bracing?
does it require a thicker top back and sides? or the same as an acoustic?
Does the bracing differ? and if so how?
Im imagining that the bracing would need to accomodate the different bridge position that a bass requires ..but also figuring into the sonic considerations of the instrument as well.
Its really hard to track down info on the subject, Ive noticed...
Mabye someone who has some experience or knowledge on the subject could chime in here? Id be really appreciative if you could...
Im really going to try to be on here more as I miss the OLF and my buds here... I will have pics of things Ive built soon for you too..
Thanks all you guys... I cant believe I missed the swapapalooza! I also missed the Vancouver Island Guitar Builders Show also I think...
Oh well there will always be more...
Cheers
Charlie

Hi Charlie,I have a client who has been wanting me to build him an acoustic base.I`m pretty much in the same boat your in.If you find out anything be sure to let me know.Sorry I`m no help.
James

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James W Bolan
Nashville Tennessee

Hey Charlie, welcome back (mind you I've been gone most of the summer too).

Sounds excitting as usual my friend. Look forward to seeing some pics of what you've been up to.

Cheers

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"There's really no wrong way, as long as the results are what's desired." Charles Fox

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the bass - you will need to sit down and draw it out Charlie ....

start with a big body shape, jumbo, and deep - 5 inches .. you need a lot of soundbox volume to have any hope of reproducing low freq with any intensity - string basses are huge for a reason, they have to be to work right. Dont bother with anything lower than an E (typical 4 string) - even that will be tough to get volume from.

Pick a scale length .. 32-34 inches or so ... I would put the bridge near the middle of the lower bout, and figure where the neck joint is ... moving the soundhole forward lowers the helmhotz freq - I would do that too. Then see how many frets you will have on the neck, and then lay out the bracing to catch the bridge wings. check the daddario site for the tension at your scale length .. brace accordingly.

here are some larrivee patterns .. the one with the bridge patch way low is the bass .. I have my doubts that it works acoustically all that well, its driving the top too close to the tail block IMO.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

Yup.

Basically you got it ...amped up acoustics with slightly beefier bracing.

Larger boxes with longer necks and beefier bracing is about it.

Back don't need to be thicker...ribs don't matter much. thinner backs on acoustics bring out the basses anyways,

Well thats how me see it, but then what do me know?


blessings
the
Padma

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Audiences and dispensations on Thursdays ~ by appointment only.


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I've got an ABG plan here that I've been meaning to get to. Purchased off ebay from a retired luthier by the name of Mark Stanley from Ranier, Washington. I don't have an e-mail address but pm me for his mailng address. It's a nice plan and well worth the $25.

This plan has a Jumbo shaped body that is 18" wide and 23" long, 34 1/2" scale with a 14th fret neck/body joint.
Steve

just looking at the Daddario site, in the string tension page .. for acoustic bass PB strings, 4 string, at std pitch on a 34 inch scale, the total tension is about the same as a guitar with med strings .. I wouldnt beef up anything bracing wise except the neck with some CF bars along side the truss rod.

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Tony Karol
www.karol-guitars.com
"let my passion .. fulfill yours"

interesting thread.
I helped a friend making his acoustic bass but the big question I've got is : how much compensation must we put ? The scale lenght is something like 32" (if my memory is good).
could somebody help me ? (with, if possible an answer in millimeters... because for me, inches don't mean so much)
thanks

Flo,
Try this page, you can set it for metric.
http://www.stewmac.com/FretCalculator

Thanks Hupaand,

I tried this tool once but it gave me 2,3 cm compensation !!!
so, if anybody who'd have made one could tell me how much they put it would be lovely.

Cheers

I got a sensible answer when I used 'acoustic guitar' as the instrument. When I called it a 'bass' I got a very high number. I haven't built one, but I want to soon and I also want a good number for the compensation. For a guitar with 860 mm scale the compensation was 862.998mm on the treble E and 867.237 on the bass E. Sounds more reasonable than 2.5 cm.

Did anyone find a good plan yet? Steve pm`d me about one but I couldn`t find it.It`s suppossed to be on Ebay .
If anyone finds it,please let me know . James

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James W Bolan
Nashville Tennessee

James,

On ebay, look up seller "elvan777"

Steve

Thanks again,Steve.I found it,sorry for being such a dunce.I ordered the plan ,it looks really thorough.I feel with my limited abilities, a plan will bring it all together.Just too many questions.
JAMES

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James W Bolan
Nashville Tennessee

The guy sends a booklet with the drawing that explains how he developed the plan also. I thought this was helpful. It answers some of those questions you'll have as you build.

Steve