Music through 2 Apple TVs not in sync

Are they hooked up to completely different sound systems (i.e. make, model, age etc)? Could be that one sound system processes the digital signal faster than the other, in which case you'll struggle to get them in sync. Possibly (and other people may argue differently) you could buy two digital-analogue converter (DAC) units and feed an analogue signal into your amps - that would be the closest you'd get, IMO.

atrevers said:

Are they hooked up to completely different sound systems (i.e. make, model, age etc)? Could be that one sound system processes the digital signal faster than the other, in which case you'll struggle to get them in sync. Possibly (and other people may argue differently) you could buy two digital-analogue converter (DAC) units and feed an analogue signal into your amps - that would be the closest you'd get, IMO.

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Well, he could swap the positions of the old and new ATV, to see if that is the issue.


In the event that it isn't, either get a new ATV (so both match), or maybe a new Airport Express (which also has AirPlay).

Fair point - I hadn't digested the fact that it was an old and a new Apple TV when I made my original reply.

I have used both gen 1 and 2 to airplay with no sync issues. I presently use 2 ATV2's, and 2 Airport Expresses, and 1 ATV1 to play music in my house and yard at the same time. some wireless, some wired.

I certainly would swap the 2 and see if it changes.

I run 2 zones through one receiver, with an ATV connected by HDMI for zone 1 and separate analog audio cables for zone 2. They are always out of step, even if I cancel the audio retardation on the digital connection (which is necessary to hold back the audio to allow the video processing to catch up).

This is just timing conflicts. The OP is trying to do something this software is not designed to do. It would be the same if he hooked up 2 CD players and had someone try to push play at the same time... only this is worse because there is no way to ask the system to even try to synchronize the music playback.

In this case, there are 2 separate devices with 2 separate CPU's. Yes, they may be linking into the same iTunes library on the same wired or wireless network. But pull those TVs out of the equation and try to do the same with a couple of iDevices (also with independent CPUs). Without some software running to synch up the devices, they have no way of knowing when to start playback in unison with the other device.

It sounds like what the OP needs is for Apple to make multiple-Airplay functionality have some added code for synching. I doubt that's there now.

Instead of trying to do this with 2 largely independent systems, I suggest buying something made for this... something to take the output from a single TV and push it to the 2 independent sets of speakers. Something like this: http://www.iogear.com/product/GHPAKIT/

If the OP has a receiver, I'd run the audio out of the TV into the receiver and then use the receiver to push the signals to more than one room. Someone mentioned a zone 2 receiver earlier. THAT (too) will work.

HobeSoundDarryl said:

This is just timing conflicts. The OP is trying to do something this software is not designed to do.

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That's a rather strong statement. I've had two Airport Expresses *and* my local Mac all playing from one iTunes instance in perfect synchronization for hours at a time. It's obvious to anyone who has done it that Apple is delaying the local iTunes output enough to sync it with the Airport Express.

A.

Alrescha, you're right. I don't work at Apple so I can't know for sure if they've anticipated such a scenario and wrote it into the Airplay code. I guessed that this would not be widely anticipated and thus NOT be in the code. You and EvilC5 have now both suggested that it will work. The OP might now take your evidence to know that it can be done, and that he should simply experiment and/or describe what (else) he's tried and the result (seeking more help). My apologies for jumping to a conclusion that was apparently wrong.

HobeSoundDarryl said:

The OP is trying to do something this software is not designed to do. It would be the same if he hooked up 2 CD players and had someone try to push play at the same time...

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Sorry, but I thought this was the whole point of the airport express, and now airplay. Multiple rooms all in sync.

From the apple air play web page "Hear everywhere at once. Say you have one set of speakers in your bedroom, one in the office, and one in the living room. For the ultimate sonic panorama, you can stream your tunes to more than one room simultaneously, so you’ll never lose the beat, no matter where you are in the house."

Hardly a sonic panorama if they are all out of sync!

As has been suggested I'd rule out digital processing delays in the amp by swapping about.

HobeSoundDarryl said:

The OP is trying to do something this software is not designed to do.

It sounds like what the OP needs is for Apple to make multiple-Airplay functionality have some added code for synching. I doubt that's there now.

I don't work at Apple so I can't know for sure if they've anticipated such a scenario and wrote it into the Airplay code. I guessed that this would not be widely anticipated and thus NOT be in the code.

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or maybe you're commenting on something you have no clue about?

I've been using multiple airports in sync for at least 5 years (although previously was called airtunes)
i don't have an first get appleTV though. but i do use 3 airport expresses, and appleTV2 and a denon airplay capable receiver. and all playback in sync.

from an iOS device, you can only stream to one thing at a time. from iTunes you can stream to multiple.
or with airfoil you can pick any program to stream from, and send to AirPort Expresses, Apple TVs, third-party AirPlay devices and in addition Mac, Linux, Windows, and iOS devices.


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to the OP
it should work.
try rebooting all of your network gear (anything the signal passes through)

if that doesn't work as has been mentioned try swapping stuff around to see if the delay is happening after the apple gear.

Well I can't comment technically, but I have a similar set up to the OP and have no issues with synchronisation.

I have an itunes library on my iMac Apple TV 1 (with Denon amplifier) in the living room, Apple TV2 (with Cambridge Audio DAC and Cambridge Audio amplifier) in the music room and speakers connected from the iMac in my office.
When I play music to al 3 sets of 'speakers' selecting this at iTunes, I get music from all 3 systems and it's perfectly in sync.

The only difference is that my system is hardwired, perhaps this has something to do with it?

GilesM said:

Well I can't comment technically, but I have a similar set up to the OP and have no issues with synchronisation.

I have an itunes library on my iMac Apple TV 1 (with Denon amplifier) in the living room, Apple TV2 (with Cambridge Audio DAC and Cambridge Audio amplifier) in the music room and speakers connected from the iMac in my office.
When I play music to al 3 sets of 'speakers' selecting this at iTunes, I get music from all 3 systems and it's perfectly in sync.

The only difference is that my system is hardwired, perhaps this has something to do with it?

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The most aggravating thing for me is that my three sets of speakers are *almost* in sync but not quite, so I've got this sort of *chorus* effect which is making my girlfriend nuts.

rneglia said:

The most aggravating thing for me is that my three sets of speakers are *almost* in sync but not quite, so I've got this sort of *chorus* effect which is making my girlfriend nuts.

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Often due to processing delay inside the audio equipment once the signal leaves the AppleTV.