Re: Measurements

Posted by Duke [ 208.98.184.1 ] on June 05, 2008 at 23:33:23:

In Reply to: Re: Measurements posted by Akouo on June 05, 2008 at 15:56:22:

A solid state amplifier will perform as predicted by a loudspeaker modelling program into that 130 ohm peak. So, it's not really a problem.

However, a low-damping-factor tube amp (SET or OTL) will put out increased power into those impedance peaks. The high output impedance of such an amplifier in effect raises the speaker's electrical Q, so the result is too much bass energy unless you re-tune the box to a lower frequency to take advantage of that extra bass energy. In effect, you can extend the bass maybe 1/4 to 1/3 octave deeper than it would have gone otherwise. So in effect this extra bass extension is a "free lunch" available from certain amplifiers.

I use Precision Ports modular port system, and attach the pieces together with a wrap of electrical tape, so it's relatively easy to change the port length to account for amplifier type and/or room acoustics. I wish I'd have brought longer ports to Lone Star; I was expecting to be in a much bigger room but that didn't work out, and in that smaller room the bass was a bit more full than I like.