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sto
2012-03-09, 03:27
Hi All

I've got three Receivers that are plugged into different types of amp and when played in sync are slightly out of time due the variation of IO circuitry in the amps. It's a fairly usual problem I'd imagine.

I've tried adjusting the delay setting for the various players but never seem to get it right. I've tried it using standard music tracks and also a metronomic beat track.

Has anyone got a better way of setting up the delays accurately ?

Thanks

pippin
2012-03-09, 04:18
Anything that doesn't have too much rhythm should do.
The important point is to sit close to the speakers or the way from the speaker to your ear will add delays.

Actually listening can work quite well for determining sync.
I was recently testing sync for the new iPeng and that found me sitting between a pair of speakers connected to an SB3, a Radio and a single earplug from the iPod touch and in that setup (< 1m distance to all speakers) I could actually even hear when the server was doing it's 11ms corrections to bring the players back in sync when they drift beyond 10ms.
It's not an echo or something you can hear but you can hear the direction of the sound change. You can even hear the drift, the sound seems to move or shift direction.

It will all go away when you are more than a meter or so away because then phases are not aligned anymore.

Tex
2012-03-09, 11:51
I am curious as to whether you have all the receivers connected via their analog connections. I tried to synch 2 units that were connected 1 digital output & 1 analog and was never able to synch them. Now I have all units connected via their analog outputs and can't detect any difference or lag.

garym
2012-03-09, 12:05
I am curious as to whether you have all the receivers connected via their analog connections. I tried to synch 2 units that were connected 1 digital output & 1 analog and was never able to synch them. Now I have all units connected via their analog outputs and can't detect any difference or lag.

I have a mix of digital out and analog out devices being synched and haven't had any issues syncing them. This is all via local LMS. There have long been problems getting perfect synch when connected to mysqueezebox.com instead (although I read that maybe there is newer firmware that fixes this).

pippin
2012-03-10, 01:01
I don't believe you can get perfect sync over the Internet.
Digital connections may or may not cause issues depending on how the downstream equipment delays the sound.

Mnyb
2012-03-10, 01:18
I don't believe you can get perfect sync over the Internet.
Digital connections may or may not cause issues depending on how the downstream equipment delays the sound.

Yes I have a souround processor and digital xover so my main stereo has delay but you are never really equdistant to all your speakers so tuning in a good compromise is a bit tricky .

So any good music suggestion for perfecting this ?

sto
2012-03-11, 04:29
I could actually even hear when the server was doing it's 11ms corrections to bring the players back in sync when they drift beyond 10ms.[/QUOTE]

That's interesting, it never occurred to me that you'd be able to hear that, something to factor into my efforts.




I don't believe you can get perfect sync over the Internet.

I thought LMS didn't even try to sync internet streams ?

sto
2012-03-11, 04:39
I am curious as to whether you have all the receivers connected via their analog connections.

I use thier analogue connections. Until I introduced a surround sound amp into one of my set-ups I didn't need to any tweaking but the new amp has a very noticeable delay. I assume it's because everything gets fed through the processing circuitry before the final power amp, the delay is still present when selecting the 'Direct' option.

Pippin's point about getting close to the speakers is a good one as is using irregular music. I'm actually wondering if using some spoken word tracks would be a good idea, I'll try it and report back.

Thanks for the thoughts everyone.

toby10
2012-03-11, 05:35
...... I thought LMS didn't even try to sync internet streams ?

It does, and usually quite well.

garym
2012-03-11, 05:38
It does, and usually quite well.

yep, I can synch internet radio streams with different players and it is rock solid.... (playing through my local LMS).

SuperQ
2012-03-11, 10:07
I don't believe you can get perfect sync over the Internet.
Digital connections may or may not cause issues depending on how the downstream equipment delays the sound.

You can never get "perfect" sync over anything. However there are very good methods for getting time within microseconds over networks, including high latency and asymetrical latency. I wish I could find the info on this off the top of my head.