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[Prognathous]

MC is certainly very impressive, but it does have one significant problem - if the zones are overlapping (as in my case), it's possible to hear a delay between them. This is especially noticeable if one zone uses an analog signal and the other uses a digital signal which needs further decoding by the receiver. Is there any way to resolve this problem? I tried messing with the timing field, but couldn't really understand how to set it up (it's not documented).

BTW, for future versions, you (jriver) might want to add a feature that helps synchronizing zones by sending them the same signal an using a microphone to measure and adjust the lag. How about that?

Thanks,

Prog.

[modelmaker]

I know synching zones is at present not possible. I can't give you the technical explanation, but someone will not doubt explain it later tonite.

[Mastiff]

It's not possible because it doesn't work. How's that for a technical explanation? It all goes to the very small differences between sound card chips and it can be fixed with a witches brew that you make burying a black cat on a churchyard on a thursday night, and... No, that was curing acne! Sorry about that.

But seriously, I have a separate zone for sync (sends out the TV audio, Internet radio, music to several rooms on parties and so on). Then the output from that is split between the inputs to the other zone's sound cards, and those are switched with Girder and NetRemote.

[Prognathous]

It's not possible because it doesn't work.

Is my microphone suggestion technically feasible? and how about tweaking that timing field?

But seriously, I have a separate zone for sync (sends out the TV audio, Internet radio, music to several rooms on parties and so on). Then the output from that is split between the inputs to the other zone's sound cards, and those are switched with Girder and NetRemote.

But the delay is introduced by the decoder in the receiver. I don't see how a single zone can solve that, after all, the delay comes later in the chain.

Prog.

[Alex B]

Just on yesterday I experimented with the "Timing (ms)" adjustment.

I tried to sync the Zone 2 with the active Zone 1. At first the zones were clearly out of sync. When the timing difference reduced the effect started to sound more like an echo. After a lot of tries I ended up using -80 ms with the Zone 2 (you can use minus signed values too). It is not yet perfect, but the difference is very small. The physical distance between the rooms makes its own delay that can be more.

It was a time consuming process because the Zone 2 playback had to be resynchronized after each change. It is easier to adjust if you use music that has a distinct beat and rapidly changing parts.

[Prognathous]

Interesting. How is it set up in your case, Alex? Which zone was the laggy one? Which one did you adjust?

Prog.

[Alex B]

Zone 1:  Terratec DMX 6fire 24/96
Zone 2:  Build in C-Media CMI9739A

I played Zone 1 and adjusted & synchronized Zone 2. In this case I used analog outputs. I am going experiment with an external decoder later.

BTW,

Once again I stumbled on this when I tried to syncronize an MPC file on two zones:



The decoder should really be fixed. Foobar2000 can decode two MPC files at the same time. Safely.

MC could also sync the zones after decoding in case the same source is used. That would lessen the processor usage and perhaps the lag variation too.

[Mastiff]

That sounds very werid. I have a digital signal from three of the sound cards to three of the zones (living room, bedroom, home theater), and there's not a millisecond difference between them. Have you tried to feed the same signal in analogue and digital to your zones (with jack splitters) to see if it's really the decoding?

[Prognathous]

I haven't tried an analog connection. I don't have a 10m long cable (only a long optical cable).

Could it be that all you digital receivers take roughly the same time to decode?

Prog.

[glynor]

I only have a very basic level of experience with digital receivers... However, knowing what I know about the power of computer chips, and the power it would take to decode a digital music signal, and the cost of that silicon power...  I would be fairly shocked to learn that different decoders would induce delays differing by more than a millisecond (or a few at the absolute extreme end).  My guess would be that most of them, even pretty cheap ones, would have pretty similarly speedy decoding times.

As I said though, I have no direct knowledge one way or the other.  I'd be curious to know though...  Think there's a way to look up the decode performance on different chipsets?

[Mastiff]

I was a bit unclear. There isn't a millisecond of difference between those three digital receivers and the analog stuff I also use (like a couple of boom blasters). And you're right, glynor, there is no delay in that. Not audible delay, at least, and probably hardly any measureable delay. My receivers range from a very cheap Panasonic in the bedroom to the Onkyo 939, former $ 5000 flagship of Onkyo, in the HT, and there is no difference at all.

[mauka]

i have been knocking myself out trying to get the zone sync to work..... So it doesn't really work? The sound on Zone 2 stops after every song.