Driver params for max. efficiency in a sealed box


2008-06-09 6:34 pm

A theoretical question which I'd like to get an exact answer for. This is for a project, but I ask that practical questions would come later, after the theoretical side is solved.

We assume I have a sealed box of fixed size, say one cubic feet. I also have 10 Watts of amplifier power. I want to have as much output at 20Hz or 30Hz as possible. Question is, what parameters should I look for in a driver?

Quick, tentative answer. Having toyed with one of Linkwitz's spreadsheets, I have come to think that within reasonable limits, nothing else matters except force factor (BL). In simulations, the Shiva X2 does better than most, given its high BL (15.3) with coils in series.

I know that practically, everything I need, is to see that my chosen driver will reach its excursion limits at low frequencies, given the amplifier power I have. Theoretically one can buy very much very cheap wattage using readily available PA power amplifiers. But if I want to get along with an amplifier I already have, and avoid problems with power compression, this viewpoint might have some use.
As much as possible,says nothing.The "as much" could be anything from 0.00001 acoustic watts.
There are so many factors to be computed into the equation,that a box-driver compo should have,in order to function as you want,with your 10W amplifier,that is non wise to try to single out one,in your case BL.
Your question is a little tricky.

B.L (not the force factor)