French Bass Brace advice

[Adrian Levi]

I've removed the fat brace from the back and what a nice piece of old spruce it is . It will come in super handy for the top repairs that are needed.

The back is in decent shape and Ill be inserting a centre strip throughout which means Ill need to remove a bit of back wood.
Im sticking to Kens ''do it right first time '' advice.

Now for yet another question or two ( if Im asking too much please tell me to shut up )!
How many back braces should this bass have ?And also is there an optimal positions for them ?
I've seen basses with 3 , 4 and 5 braces before ?

[Adrian Levi]

Originally Posted by Adrian Levi

I've removed the fat brace from the back and what a nice piece of old spruce it is . It will come in super handy for the top repairs that are needed.

The back is in decent shape and Ill be inserting a centre strip throughout which means Ill need to remove a bit of back wood.
Im sticking to Kens ''do it right first time '' advice.

Now for yet another question or two ( if Im asking too much please tell me to shut up )!
How many back braces should this bass have ?And also is there an optimal positions for them ?
I've seen basses with 3 , 4 and 5 braces before ?

oooook , no bites on this one

So now Ill try and be more direct .

'' Is the Venerable Arnold E. Schnitzer in the house ? "

What really interests me is the middle back brace seeing that it is directly coupled with the sound post .
Are there any thoughts on maybe using lighter wood to facilitate vibration to the back plate , or would heavier wood be better better for some reason , or is it just a simple matter of there being no definitives here ?

[Matthew Tucker]

Aah ... easy questions I see

Why do you want the back to vibrate at all? just asking.

[Thomas Erickson]

Originally Posted by Matthew Tucker

Aah ... easy questions I see

Why do you want the back to vibrate at all? just asking.

Dynamat?

[Adrian Levi]

Originally Posted by Matthew Tucker

Aah ... easy questions I see

Why do you want the back to vibrate at all? just asking.

Well Matt this is what interests me , should the back vibrate as much as possible or not ? Or does it really matter? Will my bass perform better if I fit a
middle brace of maple (heavy) or one of spruce...or once again does it really matter?

[Matthew Tucker]

Well that is the balancing act ... and where the art comes in i suppose. Whatever vibration is happening at the back of the instrument, that is energy that is NOT moving the front. So it robs the front of energy at certain frequencies and thus colours the sound and decay characteristics of the bass. I like to imagine the extremities; if the back was made of concrete the top would receive and emit all of the string energy, with a lot of sustain,but the sound might not be pleasing (it might - who knows?). On the other hand I imagine if the back were made of rubber and could freely vibrate it would dampen the movement of the front resulting in short sustain and dunno what tone. And that's not taking into account the structural necessities. Somewhere in the middle is right. As a broad generalisation, I think for arco, sustain is not so critical but darkness is, for pizz/jazz use sustain is more useful and the decay characteristics of the bass are more important. but it depends on the player too.

But with all that above, its still hard to know for sure what the effect of one or other change will be!

I would replace the brace with spruce as it was originally, probably a 4-5" centre brace, one across each bout to give a slight and even radius to the back if possible, and one at the bend if it needs it. Depending on the position of the bend, you may choose to put one brace near or on the bend for the upper bout.

Or you could get really funky and do a cross brace!

[Adrian Levi]

Originally Posted by Matthew Tucker

Well that is the balancing act ... and where the art comes in i suppose. Whatever vibration is happening at the back of the instrument, that is energy that is NOT moving the front. So it robs the front of energy at certain frequencies and thus colours the sound and decay characteristics of the bass. I like to imagine the extremities; if the back was made of concrete the top would receive and emit all of the string energy, with a lot of sustain,but the sound might not be pleasing (it might - who knows?). On the other hand I imagine if the back were made of rubber and could freely vibrate it would dampen the movement of the front resulting in short sustain and dunno what tone. And that's not taking into account the structural necessities. Somewhere in the middle is right. As a broad generalisation, I think for arco, sustain is not so critical but darkness is, for pizz/jazz use sustain is more useful and the decay characteristics of the bass are more important. but it depends on the player too.

But with all that above, its still hard to know for sure what the effect of one or other change will be!

I would replace the brace with spruce as it was originally, probably a 4-5" centre brace, one across each bout to give a slight and even radius to the back if possible, and one at the bend if it needs it. Depending on the position of the bend, you may choose to put one brace near or on the bend for the upper bout.

Or you could get really funky and do a cross brace!

Interesting thoughts there.
What is the deal with cross bracing ? I've always wondered about those basses with a single longitudinal brace .....

[Matthew Tucker]

Ask Ken McKay he's done it. I haven't.