This was fairly straightforward: I would need a Windows PC, a multi-channel sound card and three stereo amps. The PC was a several-years-old Dell that I knew was going to be pretty much silent, running Windows XP. I struck lucky with the sound card, finding that a Creative X-Fi is very well behaved with respect to powering on and off silently, and that its drivers would allow one sound card to perform simultaneously as:
- destination for audio apps
- source of audio for the crossover software
- multiple analogue outputs as destinations for the crossover software.
In other words, with a single sound card I could transparently process any and all audio from the PC and route it to my speakers with no question of sample clock problems, as all functions would be locked to the same sample clock
I knew I could buy a multi-channel AV amp, but I fancied the flexibility and cheapness of buying a few second-hand stereo amps, and settled on three Denons at about £40 each – higher power for the woofers, and lower for the mids and tweeters. I needed a few jack-to-phono cables and these came in at about £10 in total. A long reel of chunky zip wire cost about £20 and I fitted several 4mm banana plugs to these cables.
I placed a 100uF reversible electrolytic in series with each tweeter for protection against low frequency signals (the software could go wrong) and possible surges from powering-on the amps or PC.