Supernait + Airport Express = 1/2 second dropout at 5 seconds into audio stream

Posted by: MattP on 14 November 2008

Hello,
I've got a problem with streaming audio via an airport express (via itunes) to a supernait via an optical cable.
Consistently, at the 5-6 second mark into a stream (song) the audio drops for about a half second then recovers. The rest of the stream plays without interruption until a new stream is created for the next song then it repeats at the same point.
My suspicion at this point is that it is something that the supernait is doing, due to:

1. Occurs when either of my two Airport Express devices when plugged into the supernait via an optical cable (removing AE issue).

2. Occurs when AE is cabled directly to the mac with wireless turned off (removing wireless issues).

3. Occurs on multiple source Macs, both desktop and laptop (removing some issue with the individual source computer.)

4. Streaming via AE to a Yamaha AV amp via same optical config does not have any dropouts. (again, attempting to remove AE issue)

5. When playing to both internal computer, and SN via AE, the internal speaker continues to play the stream whilst the SN/AE drops out and recovers at the same 5-6 second mark.

6. There are no dropouts when directly connecting the mac to the SN via an optical cable – in fact this is how I’ve had it configured for the past year. Its just now I’ve moved the SN further from the computer than the optical cable can reach.

Any ideas? Has anyone else experienced this issue?

Matt
Posted on: 14 November 2008 by David Dever
Perhaps the SUPERNAIT is switching between wide-lock and VCXO re-clocking mode. Consult with your retailer for a fix, which can be implemented via the front panel in program mode
Posted on: 14 November 2008 by winkyincanada
I get the same symptom; but it occurs only once, and only after resuming playback from pause in iTunes.

Other issues causing dropout are my microwave and I occasionally get very intermittent performance for a minute or two - that may be someone else's microwave? It fixes itself OK, but sometimes a re-start works too. I live in an apartment which has lots of WiFi clutter.
Posted on: 14 November 2008 by thesherrif
sounds like a buffering issue to me
Posted on: 14 November 2008 by David Dever
Yes, good point.
Posted on: 14 November 2008 by Mickyblueyes
I sadly get exactly the same dropout 7-8 secs in to staring play back or un-pausing with my AE (N).

Mine only started after update to iTunes ver8, never did it with 7. I tried to revert to iTunes 7, but seems impossible on a Mac? unless someone can point me in the right direction, I have searched many a forum to find info.

Interestingly though if I direct connect my MacBook Pro with the same optical link and play direct it is fine, so it isn't the iIunes issue more an airTunes one in ver8.

I have also updated my old wireless router to a Netgear N speed to no avail and tried various network/airport tweaks to no avail. I would be very grateful for any insight also cos it does me heed in Frown
Posted on: 14 November 2008 by winkyincanada
My theory on my own problem (not Matt's - but it is similar)....

It seems like a buffering issue to me too. When you re-start iTunes from pause it more-or-less immediately instructs the AE to play what's stored in the AE buffer, but iTunes then takes too long get fully started up and transmit data to re-fill the buffer. Once it gets going and catches up it is fine.

I base this theory on the fact that I don't get the issue when I start playing from from scratch, but only when I restart from pause. Starting from scratch takes a lot longer than re-starting from pause. This is because iTunes needs to be fully operating anything before any data gets sent to the AE. The buffer begins empty, so the AE must wait.

Oh, I should add for clarity that my audio files are called up wirelessley from my TimeCapsule (which also serves as my router).

This doen't help Matt a bit, of course. And his issue is also somewhat different.
Posted on: 15 November 2008 by garyi
avole, what lappy you using? yours sounds more like a laptop that cannot have to many processes running without running into trouble, that would be Vista then. haha.
Posted on: 16 November 2008 by MattP
For a test, I did a trial restore of itunes 7.7.1 on one of the macs, and so far I have not had any dropouts playing to the SN - thanks for the heads up on this.

I will look at downgrading the main mac/library now - hopefully without losing the itunes specific metadata (play counts etc, playlists etc) and iphone apps, but it does seem that the itunes library format is different between 7 and 8, so unsure how successful this will be.

Matt
Posted on: 16 November 2008 by spacey
interesting.... i was going to start a thread asking exactly the same questions. i have the following:

11N rated airport express into a supernait via optical.
A 2TB raided 10/100 NAS connected via RJ45 to a netgeat 11N router.
A vista OS toshiba tecra M9 which is also 11N rated.

i control itunes wirelessly from this laptop and also find exactly the same dropout as you all do. even when the laptop is wired to the router via RJ45. im sure i didnt get this before itunes 8 but then ive only had this issue since using the AE. apple have changed the AE once and it helped but not cured the fault. i have tried changing channels on the router this also helped but not cured it. if i have the music on a local drive in the computer then i dont get the issue...... anyone got a cure.... i realy pees me off coz i bet its a simple simple thing but its just not obvious.
Posted on: 16 November 2008 by garyi
I believe in simplicity where networks are concerned Rtee, if you think about it your is not simple.

You presumably have your itunes library on the nas which is databased on the laptop. So basically if you want to play music on your laptop you will firstly ensure your nas is available then launch itunes.

You will then select a track. Your network then has to click into action, it will fire a request from your lappy to the router, then from there to the nas. The nas will respond with the file and send it back to the router, then down to your laptop.

Now if you want to hear it from your hifi you are sending a request from your laptop, this is going to the router then to the nas. Then from the nas to thr router to your laptop, then from your laptop back to the router, then from thr router to the express.

I can assure you, you will always have issues doing this. Far better than the nas would be a computer elsewhere you can VNC into. That way the traffic would only be computer>router>express, not laptop>router>nas>router>laptop>router>express.
Posted on: 16 November 2008 by spacey
gary your right i do have all the tunes on the NAS and itunes on the laptop. so the path of laptop>router>nas>router>laptop>router>express seams to be correct but why should this be so demanding of a 300mbps wireless network and if the laptop is connected to the router via RJ45 its still doing the same - even if i turn the wireless off on the laptop.?

i have actually been looking into building a computer with raid facility, optical in/out, wireless and cd/dvd/blu-ray. a media PC basically. all into the same casing as a nap 200. the only issue so far is getting the case Smile

what are you running and how?

regards.
Posted on: 16 November 2008 by garyi
Because regardless of the speed of your network, which if its N is probably more like 140, you will be restricted by the slowest component.

So is your lappy Wireless N? And you have already mentioned your nas is slow..

I already went down the route you are having problems with, and I'll tell you now, its the NAS device and iTunes, they will never work properly together. I got a mini and Frobo and stuck it in a garage, YMMV.
Posted on: 16 November 2008 by spacey
laptops N, yes. i think its the NAS also. thats why im looking into building a networked media computer. so your drobo and mini and not wired into a router?
Posted on: 17 November 2008 by spacey
avole please read my first post 6 up. all the thing you mention are said there....

so this is a common problem then? i dont really want to mess about. if i could solve it by just clicking a button id be very happy.
Posted on: 17 November 2008 by spacey
avole thankyou it would be great to spend as little as possible, nothing at all would be even better Smile

i dont think its itunes 8 either. i did mention in my first post that if i have the music on a local drive in the laptop then i dont get the dropouts, it only happens when i call my music up from the NAS? so i thought it was that, is this the case? it runs in this path: laptop>router>nas>router>laptop>router>express
Posted on: 17 November 2008 by Mickyblueyes
Just out of interest which router are you using?
Posted on: 17 November 2008 by nap-ster
There is an option for the buffer size in iTunes. Admittedly you only get to choose between small, medium and large.

It is in the Preferences > Advanced Tab.
Posted on: 17 November 2008 by Wazza69
Looking on the apple.com forums this appears tp be a widespread problem with ITunes 8.Hopefully a future update will resolve this issue.

For some people, updating the AE firmware seems to have helped.

Thanks
Posted on: 17 November 2008 by garyi
r-tee if you connect the nas directly to the lappy you will probably find it works fine. However this defeats the purpose of a laptop in my opinion.

My drobo is connected to the mini with USB so its not networked, and the mini is connected to the airport extreme with ethernet so enjoys gigabit speeds.
Posted on: 17 November 2008 by spacey
i am using the latest "next" 802.11N neatgear router. all my kit is N rated. the NAS has to be connected to a router for access. its doesnt have USB except as a print server.
Posted on: 17 November 2008 by garyi
Avole, it may not indicate that at all, it could easily be the network choking, or how itunes is dealing with it.

I had nothing but issues with a NAS I have to say. I find them a struggle in the home environment compared to small headless computer.
Posted on: 17 November 2008 by spacey
i dont think traffic on the wirelss network is an issue when playing music form the NAS as discribed i can download 100s of MB worth of files form the net directly to my laptop with no problem but if i try to access the NAS while playing tunes it has a little blip and either pauses itunes or stops for a few seconds then starts again.... thats why im thinking of making a silent headless dedicated raid computer with optical out and optical drive.
Posted on: 19 November 2008 by LeeTom
I am having the same issue: dropout 8 seconds into playing. airport express optical -> supernait. it only happens with the supernait.

i ended up using an AppleTV's Airtunes instead, and that fixed the problem. Plus, I think it sounds better to boot.
Posted on: 19 November 2008 by garyi
I don't really see why the supernait would be an issue in this case.

If wirelessly then the only link I can think of is the new wireless N expresses. Best bet would be if someone has an NVI to see how its locking on.

As I understand it the audio midi app in the utilities folder only effects hardwire output, but it might be worth returning it to a default state just in case.

Other options might be to try earlier itunes for PC:

http://www.oldapps.com/itunes.htm

For mac:

http://www.oldapps.com/download_iTunes_mac.php
Posted on: 19 November 2008 by Mickyblueyes
garyi,

I have tried installing the old v7 iTunes which will fine but there seems to be no way to regress the library/music database to allow v7 to read it. Are there any instructions/advice on how to anywhere?

I'm still convinced it's just an AirTunes glitch in iTunes v8 & still in v8.0.1, not network traffic or caching