Meridian Unplugged - Powered by MrTechGuy.co.uk Forums Discussion Meridian - Systems Oppo as DVD Audio-Player 5.1 Analog Direct or through HDMI on an HD621

I moved from a G91 analog unbalanced out to a Oppo BDP-93 via HDMI to HD621 to G68SL balanced out.

For 2 channel DVD-A I found the G91 to be superior.

I also find it hard to understand for 5.1 whether the Oppo, the HD621 or the G68SL is really doing the downmixing to 2.0 (I have only 2 speakers). To ensure I had dialog on movies I've set up the HD621 to be typed for stereo, so I think that's doing it. I really wanted the G68 to downmix but was not able to get movie dialog (ie center channel content) when the HD621 was outputting 5.1.

I'm not thrilled with my setup for DVD-A right now, though there's no doubt that for Blu-Ray and Netflix the Oppo is streets ahead of the G-91 :-)

Some other things also changed esp use of a PS Audio Duet for power filtering with the new setup - so there may some other factors at work here.

The HD621 cannot downmix channels - if you have set the HD621 to stereo mode, then it will be signalling this fact back to the Oppo via HDMI and the Oppo just sending 2-ch PCM to the HD621. The HD621 can downsample to a lower sampling rate, not downmix channels themselves.

Hope this helps.

John

As John noted above, set the HD621 for 5.1 so that the Oppo transmits all six channels. The HD621 will then pass that along to the G68 for downmix to stereo. Your G68 will do a better job than the Oppo for downmixing.

Cheers

George

I am a bit confused about. I do not want to downsample the signals. My qestion is when i play a DVD with a PCM 5.1 soundtrack (Some DVD's with music has uncompressed PCM soundtrack) do you then prefair the Oppo/HD621/G68 or the G98/G68 combo?

Cheers Jack

Jack,

You have MCH sources and a 2CH output. Your question was whether the source devices or the processor do the mix down to 2CH.

With HDMI the target device tells the source what it is capable of accepting on its inputs. If you set the HD621 to tell the Oppo that it can acccept 5.1 then 6 channels of PCM will be delivered to the HD621. The HD621 will then output this over the 3 x SPDIF connection to the G68 which will then do the 2CH mixdown.

If you set the HD621 to tell the Oppo that it can acccept only 2.0 then 2 channels of PCM will be delivered to the HD621. The Oppo will have done the downmix. The HD621 will then output this over the first of the 3 x SPDIF connections to the G68 which will then output this as L/R.

Anyway, I do not have any 5.1PCM DVDs so I can't comment on the sound quality.

In my setup, I have found the Meridian spinners to perform poorly as DVD players (though they are superb as CD players) and prefer the Oppo 83 hands down (I've since moved to the Oppo 93, which is better in most respects). If you use an external video processor, as I do, the inability to output 'source direct' from the Meridian players is a significant shortcoming, and for reasons long unclear, the picture from both the G98 and 800 is shifted about 5% to the left. At the end of the day, though, the important preference is yours - what do you think, in your system, with your equipment?

I feel pretty strongly that in all cases, with Meridian kit, you are better off keeping things in the digital domian as long as possible. In your original post you talked about using the HD621 versus an analog connection, but with a G98, you'd also have the option of connecting digitally via 3xSPDIF. In that case, the comaprison between Oppo83/HD621 and G98 is somewhat different (i.e. the G98 will likely be superior for DVD-Audio).

Hope this is helpful!

Hi Jack

Perhaps I've been unclear, but downmixing is not the same as downsampling. In your case, downmixing is reducing 6 channels of sound into two, whilst retaining the original bit rate and sampling frequency (ie 16/48 for decoded BD discs).

Downsampling would be taking , say, 96kHz material and changing it to 48kHz.

So in your system, you want the G68 to do the job of changing 6 channels into two. The HD621 will actually upsample the 6 channels' worth of 16/48 content from BD discs (or DVD-A discs) to 24/96 and it will apply apodising as part of that process.

Hope that's clearer.

Cheers

George

In my setup I have G98DH and G68ADV. I am soon also an owner on the Meridian HD621 box.

Meridian G98 is superb as CD player, and some prefer it as DVD-Audio player and some not.

The Oppo is superior to DVD and Blu-ray.

Thank's for the help.

Regards Jack

Mr Meridian,

I didn't see your message before I send the last one.
I now understand downmixing and downsampling.

Is it right that the HD621 upsamples 6 channels (DTS and 5.1) to 96kHz from DVDs, using the HD621?

If I understand it right, it also upsamples Blu-Ray material to 6 channels 96kHz, using the HD621?

I have a bit hard understanding, my English is not that solid.

Regards Jack

The HD621 only handles PCM. Legacy bitstream is simply passed through as DD/DTS converted from the HDMI based carrier to SPDIF/MMHR. Hi-res lossless bitstream formats such as TrueHD are not supported.

Thus the source has to decode DD/DTS, including TrueHD etc. to PCM so that the HD621 can 2x upsample/apodise 44/48 PCM to 88/96 PCM as and when required.

Now I think I understand. I'll give it a go when I get the Meridian HD621. If I get stuck I will return as it would be a shame not to configure it with the best possible configuration.

When listening to Trifield from my G98, I can set the delay on the surround speakers. Is there a way to set it, other than listening to what sound right to the ears?

Cheers Jack