Prodded by some recent comments, I was looking at the 2x4 MiniDSP module's specs. It's pretty good, actually! I'd never looked at it very closely because I was focused on the Darbari and I knew I needed 3-way actives, so 2x4 wouldn't do. But here's what I like about the 2x4:
- 24-bit ADC and DAC, which means volume control in the digital domain will work just fine. They've not scrimped on the sample size -- they've just cut the sampling rate to half compared to the 4x10. I can live with that.
- support for a pot based volume control. This means that I can buy a motorised pot remote volume control kit and build a preamp around the 2x4. Have an input selector to select from a few inputs, feed the selected input to the 2x4, control its output volume using the pot, and I have an inexpensive and perfectly usable preamp with 4 channels of signal out for actives
- It has all the flexibility for biquad programming which the 4x10 has, allowing me to do crazy filters to really tame metal-cone drivers (one of my original reasons to look at the 4x10 for the Darbari).
Fantastic. Once the Darbari starts singing, I can almost feel a 2-way coming up, with Dayton RS 150 metal-cone mid-bass drivers from diyaudiocart. Take the output of this xo-preamp, feed four channels into my currently unused Yamaha RX-V800 receiver, and am all set up for a nice small-room system. You can argue about my choice of power amplification of course, but you can't deny that the 2x4 forms the basis for an excellent xo-preamp for two-way actives. Why, one can even make a single-chassis integrated amp with the preamp, xo, and four channels of LM3886 from diyaudiocart at an amazing price point. Just putting heatsinks on the sides of the chassis will be enough to run four of these modules, and everything will easily fit into a 2U or 3U box. Even heatsinks with horizontal fins will work well at these power ratings, thus making it easy to buy heatsinks in India.
The madness continues.