Rich has been a trooper driving 2 hours each way 3 times in a few weeks to set up the dspMusic in my room. After I heard his prototype at RMAF last year, I put myself in for testing his dspMusik. We set up first where I replaced the Marchand analog crossover with his dspMusic. The digital direct was a revelation in what digital processing can do in it's domain. Taking the analog preamp and analog signal processing out of the loop, everything was processed in the digital domain before the excellent DACs outputted analog signal to the amps. I could have lived with it just fine if I didn't have a stable of turntables and 5k plus records. Some of my beloved opera and classical music do not exist in the digital domain. When the analog front end is introduced via the phonostage and preamp into dspMusik through it's ADC loop I lost some clarity and the tonal liquidity that makes vinyl so magical. It wasn't much of a drop off, but the veiling was there and my Koetsu wasn't delivering it's mid-range magic (bloom). I put the analog x-over back in and the seduction came back to female vocals but clearly there was a drop off in the bass precision.
The compromise Rich and I arrived at is to retain the mid/high to analog processing and use the dspMusik to processing just the bass (from 280Hz down). I have 4 10" woofers on the VMPS RM40s, 2 12" and 2 15" ona pair of VMPS Larger Subwoofers, and 2 18" woofers on a pair of sealed box subwoofers custom made by Kevin Haskins from erstwhile DIY Cable. I wonder what happened to him. All dedicated to producing music 280 Hz down driven by 5 amps -- a pair of Acoustic Reality 1001s, a Crown K2 and 2 Dayton SA1000s. My room has been extensively treated for bass damping. We are matching the low-pass on the RM40 woofers with the Marchand high-pass of the ribbons at 280Hz using Linkwitz-Riley 4th order filter. Once a first order high-pass chip arrives from Marchand, we can match the low pass on dspMusik to try that set up. The 10" woofers are high-passed at 80Hz and the subs take over from there with low-pass set up at 80Hz. We put in a volume control on the eAR 1001s as I don't have any volume control on those amps. K2 and SA1000s have volume control. SA 1000s also have phase control. The "rear" subs are actually beside the listening position and there is no room to place them further back. Rich measured the distance from the front subwoofers to the listening position and put in a delay so that the "rear" subs could act as if they were further back in the room. The phase was reversed using the control on at the amp.
With everything put together, we fired up the amps and listened. We had to adjust the eAR amps up. You could tell the lower mid-range lacked punch. Once we adjusted it by ear, we were good to go. Since we are not using digital direct through dspMusic, we had had to get my digital front end (PC audio with EMM DAC2x) integrated. We couldn't get a EMM driver to install on MS-3. So we went back to my music PC which uses the SOtM USB card that is powered by it's own battery PS. I use J-River and I have always had some drop out issue with big files with play from memory setting. So I wanted to try foobar and see if it did better. I used to run foobar with my Empirical Audio stuff but I had a tough time setting up the whole thing to run DSD or even PCM. Learning curve was too high for me and I did have J-River that was working, albeit with a little hiccups. Rich took over and breezed through the set up to play PCM. He had to look up and download a few things and toggle some switches and he had the DSD direct running all within 30 minutes total. Then we heard a dropout. I had told him that I wanted seamless play between tracks as a lot of the classical music is continuous and track dividing is really arbitrary. That seems to be the issue as buffer setting need to be low to play seamless and the DFF files are big. So we set the buffer way up and no dropout occurred. It was just one track but I am optimistic that I have finally "licked" the problem. BTW, the track (a DFF file of Organ playing Bach's Toccata and Fugue in D minor, BWV 565) never sounded better. I could discern the primary notes in the second octave and even the B0 at 30Hz was clear. I can't wait to completely dial in the FR and listen to some deep bass.
After Rich left, I played Norah Jones' Blue Note issue Come Away with Me on vinyl and then on DFF playing DSD direct. The vinyl has got its grooves back. I am happy.