Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems The Quasi-Official Meridian CEDIA Q+A Topic.

Seems to me that it's caught between a rock and a hard place. It has to handle potentially different encryption, protocols and physical connectors at both ends. Logically, they'd make the system modular: "HDMI input module + core processing module + MHR output module", but that would require a lot of collaboration with different partners. Also, how many receivers are even putting out the eight processed channels over HDMI?

Wouldn't it be more accurate to say the M is trying to "comply" with this requirement, rather than trying to "get around" it?

MHR is encrypted, isn't it?

Dan

Yes and yes.

Scan of TCS3 on AVS, half way down page

As we can see from this scan the addition of the XLR digital outs is no afterthought, being well integrated into the back panel. Tact must be aware of the HDMI rules so one would think they have a plan in mind but it is hard to imagine what it could be.

Theta had always touted for the ultimate HT to use their digital outs into their top end Gen VIII outboard dacs. The Casablanca III can send the LCR over AES/EBU. Naturally they will want to continue this and not abandon current customers with this setup. What could they have in mind?

None that I know of. The only ones that I know of that even do DD are M, Theta, Tact, and Goldmund. There might be some in the pro world.

Actually I believe there were 8 people using digital speakers last year, now up to 12 this year. In the pro world digital speakers are more common. Also the HDMI encryption would prevent the use of outboard digital equalizers and digital crossovers (DEQX) or any type of digital outboard box. Finally, and most importantly, it would require me to reconfigure my system.

I only said "get around it" because the HDMI rules say you must use their encryption. M will need special dispensation to have MHR accepted.

Ah, I see, thank you for the clarification.

Dan

Perhaps to use the Tact processor you are going to have to use Tact amplifiers with the de-encryption occuring in the amplifiers. Thus, you would have encrypted digital out of the processor and analog output from the amplifiers.

Here is a quote from the current description of their digital theater:

"TCS mkII and S-2150 digital power amplifiers can be used in a 7.3 all digital home theater configuration. AC3/DTs digital bit stream is connected to one of TCS mkII digital inputs. TCS mkII performs all surround sound decoding, base management, room correction, level balancing, time alignment on all ten channels. TCS mkII digital outputs are connected to corresponding S-2150 digital inputs. S-2150 is a true digital power amplifier (not a hybrid) that operates in digital domain and converts digital signal to analog directly at the loudspeaker posts."

It would seem a simple step to put the de-encryption in the amplifiers. This is not unlike Meridian's model, except that Meridian takes the further step of integrating the actual speakers themselves in the package.

Can somebody remind me of the restrictions on outputting unencrypted PCM from decoded DD and DTS soundtracks on DVD? IIRC, there is a copy protection bit which, if set, means that the (lossy) soundtrack can't be output digitally.

If my memory isn't failing me , is this bit normally set? The implication being that MHR was also needed for transfer of non-high-resolution decoded DD/DTS soundtracks.

I bring this up because, presumably, Hollywood would have probably had to give the DVD Forum the nod before MHR was mandated as an acceptable encryption protocol.

That certainly does sound doable and make good sense.

The only quibble I would have is that Tact announced the TCS3 would be ready in May 2008 without making any annoucements about a de-encypting HDMI amp. But of course it hasn't been released either........

One of the posters on the AVS thread when asked how the TCS3 could output digital with an HDMI source stated: "it's down sample to 48 khs uncompressed pcm. No problem with HDMI if it was 96 khz it WOULD BE A Problem."

I assume that is totally incorrect?

The codecs are supposed to be deterministic and the outputs should be identical.

Once again, we're back to Meridian's ability to "do the right thing" with respect to clocking and jitter reduction coming out of the decode.



I don't think so. They've said that MHR actually improves sound quality by randomizing the signal. Since M isn't really into the whole "voodoo" style high-end I'll give them the benefit of the doubt that the additional reclocking necessary at each end keeps lowering jitter spectrum.


It might be viable, but you'd need to set the 568 for non-MHR digital output.

Because, the decoding in the source + upsampling *may* be inferior to decoding in the G68 and no upsampling. [/quote]

Who said anything about decoding in the source? I was talking about the external audio processor that everyone keeps saying M will release.

My understanding from the reports is that the HDMI Box will not be doing any decoding; instead the decoding will be done in the source, the source will output encrypted multichannel LCPM over HDMI; the HDMI Box will decrypt the multichannel LPCM, re-encrypt it using MHR, and pass it to the 598.2MM/G68/861 for decryption and processing, and output it as MHR encrypted digital to DSP speakers or as unencrypted analog to other amplifiers/speakers. Just speculation though.

That was my understanding too.

Ok.

Why? The G68 accepts an MHR input?

Oh ok. I was working on the assumption that the external box will handle LPCM only.

Given it's importance to the Meridian sound it looks like we need a Wiki entry on MHR and it's stated benefits...?

Mark