Recently I purchased some bi-amp modules from the SNA classifieds:
This is one module and includes 2 channels:
50w class AB
350w class D
Switch mode power supply.
Since I have two of these modules, they are enough for active 2 way speakers.
With a few inputs and outputs I have 4 channels of power amps.
Coming soon: active surrounds
Soon here is a stretchy term, meaning hopefully some time this year. I bought these to power some active surrounds. The 50w channels will be more than enough for the tweeters and they are class AB. This is a good thing as I don't believe Class D is suitable for treble. I do have some hesitations even for midrange use, although they will probably be good enough.
The design I have in mind will involve compression drivers in waveguides for the treble, and efficient 10" mids in a low profile wall hugging design.
Why active? It might seem like overkill, but when these modules came up at a very attractive price, they were hard to pass up. Active are easier to design and it was a good excuse to get a MiniDSP board which I intend to use - the cost is similar to that of a passive crossover and it could easily work out cheaper considering I can try different options without buying more parts.
So the plan is to obtain a box from a non-working amp and include the MiniDSP crossover along with the amp modules all in one.
The surrounds are shown here: