It would be nice if the REW filter parameters could be imported to the 976, but it is at least nice that it has the ability to apply room correction. In practice I see this as a minor inconvenience as I expect they are not often changed. But, it's also the reason I looked at things like Dirac Live. Not only does it apply IIR filtering, it also provides FIR filtering. The former allows for your classic rolloff and parametric equalization (center frequency, bandwidth, and gain/attenuation) which helps with room correction (and a bit with less than ideal speakers, though there are limits). But, FIR allows for impulse response correction, so the signal from the woofer arrives at your ears at the same time as the tweeter. While IIR filters are implemented in few stages (4 for the typical biquad filter), FIR filters can have hundreds or thousands, each adding to computational complexity. Furthermore, you can't simultaneously optimize for a smooth frequency response AND impulse response, so trade-offs have to be made. Dirac Live offers one such kind of trade-off. Trinnov offers a different one, and various manufactures have their own.

I've always thought room correction belongs OUT of a preamp/processor. Alas, this is hard to do in the digital domain: if noting else copy protection schemes get in the way. I've come to the conclusion that the easiest way for me is to use a nanoAVR HD and HDA (the latter with a Dirac Live update) to do bass management, and Dirac Live, between the AVR output of an Oppo transport, and the analog pass through inputs of the 976, using the latter for a volume control. For less critical listening (game consoles, etc.), they can be switched THROUGH the 976 HDMI imputs and use it's REW-compatable parametric equalization.

But, my research lead me on an interesting journey of how audio (and to a lesser extent, video) is processed in the professional production and recording industry. Stop reading here if you're strictly interested in 976 stuff, for here be dragons.

See, you can't get 8 digital audio signals out of an HDMI link, not without designing your own hardware. You CAN get them out of a 3G SDI video signal, and (unprotected) HDMI to 3G (and 12G for 4K) converters exist, and at reasonable prices (Blackmagic makes some nice cheap ones). But, then they are in AES/EBU format. Fortunately, the miniDSP DDRC-88D can handle this just fine! But, then what? Multi-channel DACs with AES/EBU inputs are not cheap. And in the professional world, they tend to include as many A/D channels, which increases the expense ($2500 and up for 8 channels, but often with better specs than consumer audiophile 2ch DACs). Now, there are active speakers with AES/EBU input options (HEDD Type 07, for example), that aren't too expensive (under $1k per speaker, and $400 for an AES/EBU or Dante input), so it IS an option, doing volume control in the DDRC-88D. Notice, no 976 required in this scenario: switch consumer HDMI before the Oppo, take the Oppo AVR output, strip HDCP (there are ways), convert to 3G SDI, deembedd the 8 channel audio, and Bob's your uncle.

If stripping HDCP isn't your thing, then one can always get a Vanity HD board for the Oppo, with 8 channels of digital audio on 4 SPDIF links. They can be converted to AES/EBU levels easily enough, but it is not clear if the DDRC-88D will like the consumer as opposed to professional subcode. miniDSP hasn't answered my query in this regard. However, the Mutec MC-4 (around $700) will happily convert SPDIF to AES/EBU or ADAT (more than 2ch SPDIF in the professional world, but limited to 8ch@48k, 4ch@96k with SMUX/2 (two cables for 8ch), or 2ch@192k (four cables for 8ch)).

Then, things get MORE interesting! With a Focusrite RedNet 3 ($1000), you have 32 combined channels of ADAT or AES/EBU (8 of these) input and output, with a Dante gigabit Ethernet interface. Basically, this places 24 ADAT input/outputs AND 8 AES/EBU input/outputs on an Ethernet network to do with as you please.

So, you go SPDIF into the Mutec MC-4, converting them the ADAT and ithen nto the Focusrite RedNet 3, To this, you attach your DDRC-88D, connect a PC running the Dante Controller, and set up your routing: ADAT to AES/EBU, AES/EBU to network. You then put your active speakers on the network. Just think: an Ethernet cable per speaker to a switch.

What speakers? Well, the HEDD Type 07s accept Dante input modules as well as AES/EBU input modules. For other speakers, one can buy single and dual channel Amphe-Dante adapters ($169 and $199 respectively), that are literally Ethernet in, analog audio out on XLR connectors, that all professional active speaker (and many amps) accept. (I think they are limited to 48Khz sampling rate.) They do require PoE (power over ethernet).

Now, Dante requires an Ethernet capable of supporting MANY packets (each one is about 1ms of audio, so at 48Khz, that's 48 24 bit samples, or 144 bytes, and for 8 channels that 8k packets per second). The system supports up to 512 channels on gigabit networks, though you need good switches.

So, $800 for the Vanity HD, $700 for the MC-3, $1000 for the DDRC-88D, and $1000 for the RedNet 3. $3500. Starts to approach the cost of a top of the line A/V preamp (Emotiva revealed their RMC-1 for $5k). And you still need speakers: about $1200 a pop for Hedd Type 07s with Dante inputs, or if you want to go cheap, Emotiva Stealth 8s with Amphe-Dante's for $1100. Add about $100 to $200 for a good gigabit Ethernet switch.

But here's the thing: you're now in production/recording studio quality territory. For about the same cost as upper mid-fi equipment. More inputs? Well, HDMI switches aren't all that expensive, even 4k ones. The biggest part of the expense is getting the audio into the format you want: there's no good reason Oppo transports, processors, and preamps can't have Dante Ethernet ports. Want more audio source selection? Get a bigger Ethernet switch. Imagine the cost savings on all those HDMI and analog ports. Removing format conversion costs leaves one with $1000 for the Dirac Live processor, and $100 per channel for Dante back to analog to feed an amp or active speaker. With the Emotiva XMC-1 running at $2500 and the RMC-1 at $5000, can you imagine if the 976 had Dante I/O instead of all the silly ports (yes, now you're processing audio exclusively), or an HDMI switch and audio deembedding to Dante, perhaps with some kind of processing inbetween?

Sigh.

One thing I wonder is if a Homeplug powerline network would be adequate to support a SMALL number of Dante channels. Then you could manufacture powered Dante speakers THAT YOU JUST PLUG IN. No more 5.1, 7.1, 7.2.4, etc. cabling nightmares. This is particularly true since Dante supports multicast.

The big wrinkle in all this is DRM. HDCP applies not only to video but digital audio embedded with it. But, let's say we allow ONE ADC conversion extra. Then, all one needs are as many analog to Dante adapters as one has audio channels. Going the "professional" route like I illustrated is like a root canal: HDMI audio extraction to SPDIF, SPDIF to ADAT, ADAT to AES/EBU, AES/EBU to Dante. $2500 for 8 channels, or $312.50 a channel (I left out the Dirac Live processing). Not TOO bad, but surely we could get that down to $100: If one can get an Amphe-Dante DAC for $100 a channel, one should be able to make a similar ADC for the same price. I also think the powers that be are more concerned about video rather than audio "piracy".

Ah well. I will probably go the nanoAVR route to analog XLR active speakers via a 976, but will certainly watch Dante (and the related standard AES67), for future audio handling, not in the production and recording environment, but in the home).