Subwoofer Upgrade
The Dayton Audio SPA250DSP plate amplifier. This is essentially all of the guts of a subwoofer except for the actual driver.Of course, you can use this amplifier in a new subwoofer, but for just under $200 it makes for a great solution to an old subwoofer!
The biggest hindrance to most mid-fi subs is not really the motors so much as the lack of good EQ capabilities, and good crossovers.
This little unit can take your old sub and do crazy good things with it. I highly recommend it!
Speaker Conversion
A possible mod is to convert full-range speakers to a speaker + subwoofer.There are a number of manufacturers like Vandersteen, Thiel, etc. take the approach of using a built-in subwoofer amp in their full range speakers. The big advantage is a beefy bass amp and being able to carefully tailor the bass response of each speaker.
Typically you run your amps "full range" so there is no crossover in the critical mid-bass/mid/treble region. If you are spending big dough in your preamp and DAC that's probably how you want to go.
On the other hand, if you are more about high value, high performance, th SPA250DSP includes a line-level crossover, making it ideal for using low power amps for the mid/treble.
