[Scott Dorsey]

Barry wrote:

however.. I wish I knew what the heck ya'll was talking about..
it sounds like your removing mudd from a room.. to sweeten the room
a resonating cabinet... you say solidify the cabinet.. you make it
sound like that is the solution exclusively.

It is. The solution to cabinet resonances is to fix them so the cabinet
doesn't resonate.

If a panel the cabinet is able to flex in and out, when you put a swept
sine wave through it, you will see one big peak in the response that is
the result of the first vibrational mode of the panel, and more peaks
for the other modes.

You CANNOT fix this with equalization, because it's nonlinear. The
size of the peak depends on how strong the signal exciting it is. This
is because the wood is not forming a perfect drum head, but it's taking
a considerable force to start it bending.

The ONLY solution to this problem is to reinforce the cabinet, stop it
from bending, and make the cabinet resonance go away.

If you look at the response of the bass bin on an Altec A-7 for instance,
you'll see it looks like a porcupine with all the narrowband resonances.
You can spend all day trying to fix it with sharp notch filters, and at
the end the response you get is worse than when you started out, except
for continuous tones at calibrated levels.

Nail some 2X4s to the outside of the box, toss a couple bags of sand
around it and a couple more on top, and you'll see the response flatten
way out. Stopping the cabinet movement stops the resonances.

Everyone says, don't use eq, but nobody says exactly how to cancel the
peak resonance freq....

Depends on what CAUSES the resonance, and where it is.

If you have a narrowband woofer like a bandpass cabinet, it is designed
to have one narrow peak in the response, and no equalization in the world
will fix that. You need to toss the cabinet out and put the driver in a
cabinet that is tuned for broadband response. When you do this, it won't
be as efficient, and you won't be able to play it as loud (because it will
take much more excursion of the driver to get the same level out). But it
will sound a lot better.

People use bandpass cabinets because they are small and cheap and give
a lot of thump with very little power. But they are not and cannot be
broadband.

Lemme ask.. what about phase inversion.. I have a button on my console
that does just THAT
what if I added the PRF to a track then inverted it... would that
remove the PRF

PRF?

or am I just a babbling clueless wanna be

We are all clueless sometimes on some things.
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."