Bracing material?

[critofur]

Originally Posted by TestTones

Show pics of any of your ...Meanwhile any guitar or bass cab made out of real wood or even cheap pine ply will sound better than any MDF cab with the same speakers.

Ah ha! A guitar or bass cabinet has a very different set of goals than a home/studio speaker/monitor.

With the guitar speaker it's purpose is not to accurately reproduce a recording whereas that is the purpose of the other speakers.

I suppose with a bass speaker, you may have the issue that you wish to achieve better lf output by having a stiff cabinet.

[Baseballbat]

Originally Posted by JRKO

Planet10 can put it better than me so its best to quote ''Hign mass is a myth (lots of myths started by marketing departments to help them shrink costs). If you have 2 materials with the same stiffness, the light one is better.

High mass is not a myth. If you want to reduce transmission of sound through a wall, you'll need mass. The more, the better. The problem in speaker design is how to achieve the higher mass. Simply increasing the thickness of the material will make the panel much more stiffer (thickness^3) than heavier, therefor raising both resonance frequency* and Q.

MDF is both less stiff and denser [than BB]. A good receipe for energy storage

If it is less stiff it will store less energy.

[mondogenerator]

+ 1 million

[planet10]

Originally Posted by Baseballbat

therefor raising both resonance frequency* and Q.

A good thing AFAIC

dave

[JRKO]

As I've been reading up on box materials I realise that our posts, mine included, have drifted to the 'MDF vs ply vs blah blah blah for cabinet construction discussion' rather than the original topic of 'bracing material?'

(BTW blah blah blah is vastly superior material to both ply & mdf as is infinitely stiff & infinitely dense. Finding a stockist on the other hand is improbable )

Now back to studio for our scheduled program!!

[Kooshball]

So how about a horizontal window pane in combination with a vertical window pane that crosses through it creating a cross if viewed from a certain point. This seems like it would be extremely rigid and capture the strength of the ply...

[JRKO]

do you mean it would look like a cross from the left or right hand sides?

Ideally they should be unevenly spaced otherwise your creating a set of smaller vibrating panels.

As all the movement & energy in a box comes from the driver, bracing the driver against the back panel and ideally the top and bottom with a holey brace is a very good place to start. You could then run dowel braces across the cabinet thru the holes!

[Kooshball]

Originally Posted by JRKO

do you mean it would look like a cross from the left or right hand sides?

Ideally they should be unevenly spaced otherwise your creating a set of smaller vibrating panels.

!

Yes, but it could be offset if necessary. It seems that it would tie in the top and bottom of the cabinet as well and keep the horizontal braces from being floppy.

[Charles Darwin]

Generally it is a good idea to make the bracing from a different material than the cab itself and use a lossy adhesive ie one that does not set solid.

Unevenly spaced is also a good move as JRKO said and to make sure that it is not parallel to the cabinet walls.

[JRKO]

the cabinet is vibrating because of the driver. No driver, no vibrations, no need to brace.

Sink the vibrations direct from the driver into several panels and the energy is shared/divided amongst them. You reduce the amount of energy that gets channeled into the faceplate (which is the most susceptible as it holds the driver) which in turn vibrates and distorts the drivers output further.

Dump that energy in the most efficient way you can and the panels require less bracing