Can metal internal bracing of a subwoofer enclosure reduce its efficiency?

reinforcing the cabinet from the outside?

An example (exe-spine down the back.

Maiko-early-braces.gif


dave
 
Steel is not used in speakers apart from the screws.
Ehm!!! The heaviest part of a speaker is the magnetic circuit (plates and polepiece) and it´s made out of .... steel!

And yes,many speakers also have stamped steel frames.

Forgot to mention the bass entention is achieved thanks to the pasive radiators tuned to about 32hz
Not a small detail by any means ... and you waited for post #19 to mention it?

As a side note,I guess your "small" box" statement is misleading too.
Care to share size and details , such as passive radiators in it ?

And any other important detail you forgot to disclose?
 
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No, I meant enclosures entirely made out of metal or plastic.

Their material can be 2-3 mm thin.

However composites with wood exist.

Or: Mr Reckhorn (Germany) sold subwoofers in cylindrical shape made out of stiff paper 5mm thin. It's stability comes from the shape.
 
Smaller subs means smaller spans of board that are not as prone to resonances comparatively. But bracing is almost always important.

I have a small non braced sealed box with 1 inch baffle. I experienced with bracing outer sides of the two largest panels with strong maple 1x2". I couldn't make out a discernable difference.

If metal interfered what would they make speakers with.

I experimented with using threaded steel bar braces with poly tread locking bolts. It eats up far less cab space and has far more strength.

A 3/4 round bar holds panels rock solid. If in doubt go up to a full one inch. Or change out steel for stainless steel thread bar and go a size or two smaller if space becomes very critical.

Only trouble with using those is the anchor bolts on the outer panels can be unsightly.

I came up with a way to anchor them on the inside. Yet be possible to spin a nut on one end to put a bit of pre load on the two panels its supporting and lock the panels up tight.
 
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Don't know if it was mentioned here yet, but I have noticed often times some manufacturers of "cheap" subs and speakers will often use some of the cabinet panel resonance modes to reinforce the output of the system, which can make it sound like it has more output. I've seen this in poorly braced FLH and BLH designs as well.
 
Re reinforcing from outside.

Yes I did it where it made more sense for a recent aluminum subwoofer. For two reasons. Boundaries were already tight. And second the braces pull double duty. They made perfect footer mounts. Pictures are easier.. I will get an image up in a day or two to best explain.
 
Can this metal pieces interfiere with the magnetic field of the driver to the point where the flux is "weakened" thus making it less efficient or reducing sensitivity? I can imagine the magnetic field pattern can change. And the flux would go to the metal bracing (partially) if it's a bit close to the magnet, instead of concentrating the field in the gap/motor structure.
As the bracing goes around the cabinet, there is already a large air gap (several inches) that would reduce the flux through the bracing to a value that is too small to affect sensitivity.