Very cool. I've been thinking about doing this myself. Guess this is all the work for me. Tapping's easy.
Thanks for the info.
And just to clarify for everyone, (just semantics perhaps) when you say hi/lo converter, you're talking about a speaker level to line level converter, right?
Also, are you aware whether the subs are receiving discrete channel information or is it just a matrixed L/R into a single low freq channel? This may make installation easier and just send a mono signal to the amp, not that you couldn't do that anyway.