Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems MHR in M processors

I am not very familiar with the M system and would someone provide me an explanation about the MHR, MMHR, upsampling and high speed yellow light of the DSP speakers. The following are my questions:

Q1. If I playback a Redbook CD and feed this 16/44.1 signal to one of these M processors (568,568.2,568.2mm,G61,G61R,G68) via its 1 x coaxial digital input, is each of these M processors able to output an upsampled digital signal to the 24/96 DSP speakers? Is this upsampled signal known as MHR or a 24/96 signal?

Q2. Under what circumstance a 24/96 DSP speaker will has its yellow light turn on? If a transporter feeds a 24/96 SPDIF digital signal directly to the 24/96 DSP speaker without a M processor, will the yellow light turn on?

Q3. Is a 596 able to output a high resolution signal (MHR) on playback of redbook CD? Is this MHR only applicable to DVD playback? The 596 specification documented " 1 x digital coax SPDIF/IEC1937/MHR for transferring PCM up to 96kHz 24-bit Dolby Digital (AC-3) or DTS bitstream". Is it true that only the G08, 800 and 808 can output an upsampled 2CH digital signal on its coaxial digital output?

Q4. Am I right that only those DVD players having 3xSPDIF coaxial outputs, or the 598 having the smartlink, are able to output a MMHR signal to a M processor?

Q5. Given that a 24/96 DSP speaker can upsample a 16/44.1 incoming signal via its D1 or D2 input (Am I right?), shall I expect an easily distinguishable improvement when this DSP speaker is fed with a high resolution input (with the yellow light on) in comparison to a 16/44.1 input without upsampling.


Many thanks in advance
KC Lee

1) 24/96 and 24/88 are upsampled (2x sampled) signals. MHR (Meridian High Resolution) is a Meridian proprietry encryption protocol used to encrypt high-resolution data where copy protection is required. MHR also has lower jitter transfer properties than SPDIF.

2) The light will be on when a DSP 'speaker receives a 24/96 or 24/88 signal.

3) I don't know about MHR on the 596. Apart from the G08(.2), 800 and 808(.2), the G91 and G92 also upsample (in stereo mode only) and output the upsampled PCM on coax.

4) MMHR is something new. The only Meridian product with such a connection is the HD621 which has an MMHR output. MHR/SmartLink is a six-channel protocol and only Meridian DVD players implement it. An unencrypted six-channel digital connection (at 44.1, 48, 88.2 or 96kHz) is possible with non-Meridian kit which has been modified. I have a modified HDMI-to-analogue converter, for instance, which has been modified to be an HDMI-to-SPDIF converter.

5) Depends on the upsampling. At the moment, only the 808.2, the HD621 and some of the loudspeakers have apodizing upsampling (which is supposed to make a big difference to the sound quality). The CES '09 answers were clear: Upsample where your first apodizing upsampling component is.

Some additions to VK's excellent reply...

2) I don't think it's limited to 24-bit signals. I'm fairly sure that 16-bit 88.2 and 96kHz signals also trigger the yellow LED.

4) MHR stands for Meridian High Resolution and is a stereo digital audio signal over an encrypted SPDIF stream. I believe the extra M in MMHR stands for Multichannel. Going by the 8P8C connector on the back of the HD621, my guess is that it will handle up to 4 stereo pairs of MHR (corresponding to the 4 RCA phono sockets next to the MMHR connector).

2) You are absolutely right. 24-bits are not needed.

4) I imagine that MMHR is capable of more than eight channels.

How so?
My assumptions were 1) that each of the 4 twisted-pairs in MMHR carries a differential SPDIF (MHR) signal, like the audio part of Speakerlink (of which only one twisted-pair of the Cat5 cable is used for audio), and 2) that the control bits normally used in SPDIF can be used by either DD/DTS for compression or by MHR for encryption, but not both.

3) 596 does not internally upsample redbook CD, but will output native 24/96 from a DVD.

Dear all,

Many thanks for your clear explanation, which explain almost every question.

The only question left is that "If I playback a Redbook CD and feed this 16/44.1 signal to one of these M processors (568,568.2,568.2mm,G61,G61R,G68) via its 1 x coaxial digital input, is each of these M processors able to output an upsampled digital signal?"

Best Wishes
KC Lee

Yes, but the vanilla 568 does not have enough power to apply it to rear and surround speakers - ie in Trifield mode. So these would remain quiet on a 568.

MMHR is different to SpeakerLink which uses one twisted pair for comms. I imagine that MMHR will multiplex the channels down one or two twisted pairs.

[/quote]
Yes, but the vanilla 568 does not have enough power to apply it to rear and surround speakers - ie in Trifield mode. So these would remain quiet on a 568. [/quote]

Ian,
Many thanks