Recently I have been experimenting with pc based crossovers. The basic concept for this is the following chain:
PC->HDMI->Home Theatre Receiver->7.1 pre outs->Amplifiers
For this I am using a laptop with an HDMI output. This also functions as a full 8 channel sound card. All processing is handled in Reaper, http://www.cockos.com/reaper/, an excellent, flexible audio host.
Initially I am using FOOBAR, http://www.foobar2000.org/, as the music player, and using reapers reaout as the output. Reaper can then capture this stream and apply any VST plugin, in this case crossovers. The output is then spread over 6 HDMI output channels to the Receiver.
For more details see the tutorial.
In this case I am using a basic Yamaha receiver equipped with HDMI and pre outs. It is an older receiver which lacks the latest Blu-Ray codecs, but will still handle 96/24 LPCM over HDMI. I then use the pre outs into my stack of amplifiers, but you can also use the internal amplifiers.
Simply set the receiver to HDMI multichannel in, and enable pure direct mode to bypass as much processing as possible.
This of course renders nearly all the functions of the amplifier obsolete, it is simply being used as an 8 channel dac and pre amplifier with a convenient interface. The advantage is such a receiver can be had for under £100.
The downside to this is unknown compatibility, one of my 3 laptops refuses to connect with the receiver, and I have yet to find out why, so YMMV.
In this case I will be using what I have on hand, a pair of vintage Crown/Amcron PSA-2 amplifiers, and a Harmon Kardon Citation 24.
Part 3 will cover the construction of the speakers.