Originally Posted by sdrucker
The other thing to watch for IMO is that having another device in the signal chain (i.e. Dspeaker Dual Core or a MiniDSP) can have an impact on the gain structure. At least with the MiniDSP, there's something like a -6 db decrease in signal by inserting it between the pre-out and subs, with the usual unbalanced RCA connection. I had to do some finesse with the MiniDSP volume levels and a control I have on my Denon that I used as the amp for individual channel level adjustment to avoid having strange db levels show up in Trinnov Optimizer - e.g. a sub at -6db and the mains at -11 to -15 db. The odd thing is exactly the same volume levels when I ran Audyssey XT32 resulted in a tighter trim range - subs at -0.5, and my mains between -1 and -4 db.
Don't know about you, but I also found it harder to get the subs recognized by having that extra device in the mix. It appears to be more "all or nothing", meaning that literally just adding the external sub management device and keeping the volume level at 0 led to the subs not being recognized by the R-972 version of Trinnov, or creating sub trims that were too high in Trinnov Optimizer (e.g. that discrepancy I cited above, which is usually a sign that the subs are too hot).
Hmmm...did you do any measuring to see if the Dual Core was improving the sub channel? Curious, since with REW, I've found that at least this version of Trinnov does very little to correct the bass other than broad volume gain/boost adjustments, at least vs. XT32.
The first problem that I am having with the DC (Dual Core) is one that I am not sure can be overcome: Transparency. I am not using it in conjunction with my R-972 at all. My goal was to head towards a MAP (Multi Analog Preamp where I would only EQ my 2ch audio below the Schroeder Frequency. The R-972 would be used with a BD player for SACD, movies, Blu ray concert videos, etc., whose pre RCA outs would also be routed to the MAP. I had read on several sites where DC owners had complained transparency. So, after getting one I went after testing this first as this from the get-go could be a deal breaker for me. Secondly, I tested the DC's ability to EQ. Here is a brief sequence of my test procedure. Only XLR cables were used except for: A) USB Pangea-AG from PC to DAC B) Morrow RCA M1's from R-972 > Power amps
Test 1: Computer > DAC (FAT, Firestone Audio Tobby) > Power Amps
Test 2: Computer > DAC (FAT, Firestone Audio Tobby) > DC (By Pass Mode) > Power Amps
Test 3 Computer > DC > Power Amps
Test 4: Computer > DAC (FAT, Firestone Audio Tobby) > R-972 > Power Amps vs Test 1, and Test 2
In Test 1 I established the baseline for transparency. BTW, after owning a number of DAC's. I found the FAT's USB implementation to be superior. My W4S DAC 2 could only compare equally when inserting an Audiophilleo.
In Test 2 I inserted the DC in By Pass Mode into the chain. The was a slight flattening of sound in the upper midrange, and treble areas. A slight loss of "black" between the notes. Had I been using the W4S DAC 2 in USB mode I might not have heard it. This was a big disappointed to me as it means that the DC does not have true By Pass capability.
In Test 3 I took the FAT completely out of the chain to see if somehow it together with the DC was causing the transparency issue. I tested this way, and then back to Test 1. Again transparency was an issue. Doing this A/B between TEST 1 and 3 clearly revealed it as a problem.
In Test 4 I wanted to compare the transparency of the R-972 in the chain with Trinnov OFF (in both the EQ Mode, and the Spatial Modes) vs the DC in the chain in By Pass Mode. Here R-972 was completely transparent.. Zero loss in transparency, whereas again, there was a minor, but noticeable loss of transparency with DC even in By Pass Mode.Bass EQ Test
2 CH Stereo with Dual Subs: I have been experimenting with DC almost everyday, but cannot achieve an equal quality of bass equalization as I can with Trinnov. Trinnov also seems to meld the subs with the mains better than DC. There is a more awareness of crossover points with DC, whereas it is more seamless with Trinnov. More to come on this later as I am still testing here.An Experiment with 2ch Bi-amped mains:
As as experiment to avoid the transparency issue but still have good bass eq in 2ch stereo I put the DC in the part of the chain that only feed the lows of a 2.5 Polk Audio LSI9 speaker set up. Here was the chain:
Computer>DAC - XLR out directly to power amps channel one. Speaker cables from channel one of power amps to mids/highs on speakers
- RCA out to RCA in of DC. RCA out of DC to RCA in on channel two of power amps. Speaker cables from channel 2 of power amps to lows on speakers.
In this way I am attempting to avoid the transparency issue in the mids/highs which I do not want to EQ anyway, and EQ only the lows <200hz of the speakers (which is the crossover point in the speakers own crossover) system in hopes that this non-transparency issue will not be noticed.
I have run out of time for now, but will report back on this. But what I am realizing more and more is what a truly high quality processor the R-972 really is. I really had no idea of the R-972's transparency until testing the DC. It's was just something I had not thought about or considered. But now that I am aware of this I am appreciating the R-972 all over again in a new way.