I just joined after lurking for too long...
Jason,
Thanks for asking!
What I most dislike about my system is that it doesn't sound like live music. To the extent possible I would like to fix that. I think you guys are on the right track.
I've come to some conclusions after 50 years of thinking and listening. Phase distortion is the elephant in the living room. I have never been fooled into thinking reproduced sound was live sound except in a couple of circumstances. The odd thing about that is these circumstances always involved really cheap single transducers running without a filter, straight out of whatever crappy source was laying around at the time. There is a reason headphones can sound so good: Linear phase response (or at least closer than some 3, 4, or 5 driver nightmare with several pounds of power-soaking filter components torturing the input into output streams that approximate linear frequency response at the expense of really wild phase response...). Even good headphones can get into very audible and objectionable intermodulation distortion with large scale, low frequency inputs, so it is clear that the best sounding 20-20k response system is going to have to have multiple drivers. Reading the forums, I think there is a significant movement afoot to incorporate active filters in both the time and frequency domains for such transducer systems. This implies a lot of DSP power, and closed form filter algorithms for the best performance. It also implies that everything should stay in the digital domain up until the last possible stage. There are already products in the market incorporating these ideas, and I suppose the KEF X300a series is a good example of that.
I know you guys don't want to do transducers and given my understanding of all y'all as a company, I quite agree. You do, on the other hand, have high power DSP, a closed form filter algorithm that lines everything up at the output end of the DAC, and some pretty convincing amplifier technology with limited feedback loops.
- An aside: The concept of feedback in an individual amplification stage, and even more overall feedback, always bothered me. The explanations I read treated the subject as if a signal at the input of the chain could be fed back instantly from the output to the input. Instantly, as in no time delay. Faster than the speed of light! (the musings of a ten year old at this point) Then I learned about the components used in an amplifier and feedback bothered me even more. Frequency and power dependent plate-cathode-grid resistances and capacitances, and the BJT and FET equivalences thereof. Then the other components in the chain, such as coupling capacitors, voltage dividers, etc., ad infinitum. Poles everywhere, time delays, phase variance as functions of frequency and power out the wazoo, and instant additional phase distortion as a result of feeding that mess back in the gain loop so it can go around and around again and again. Umm, don't you make an amplifier into an oscillator by introducing feedback? Just sayin... I've come to the conclusion that phase distortion is the enemy and gain stage feedback is a primary culprit. I think human beings are extraordinarily sensitive to phase relationships as evidenced by the ability of people with binaural hearing to discern the source of a sound with incredible accuracy. Not to mention, less feedback sounds better…
So, what product would I like to see? A plug and play, OEM product that is configurable for multiple channels, and software (argh, groan) tools for filter design that corrects frequency and phase not just at the output of the DAC, but all the way through the chain, to include the natural phase distortion/time misalignment of whatever transducer system someone is trying to implement. Maybe even room correction if the OEM wants to go off the deep end. Filter design is the OEM's problem, just give them the tools. DIY? No support, ever, no returns, buyer beware. Or not, you have a better sense of that than I do. Modular. Input stage(s), distribution stage in several flavors, DSP engines with DACS, DC coupled to a couple of different options for output power, maybe a control stage with remote (hey everyone is screaming for that; Me, I don't care... If it sounds good). All internally balanced as a high end option, SE as a price reduced option, maybe. And don't forget that elusive ADC you may or may not be thinking about/actively pursuing, it has a place in this product line for (gasp, heresy) an analog input. This all seems to fit pretty well with your upgradeable-component concept that we first saw in Bifrost.
Give the first set to Linkwitz and see what he does with it.
Scott