blessingx Posted March 21, 2011 Report Posted March 21, 2011 Recently changed over my rig a little (including moving to a 16-bit DAC and thus back to an Airport Express) and when listening to several quietish opera tracks over the weekend I noticed many pops not there before. Originally thought something may have happened to the file, but narrowed it down to the APX. Have play files through Squeezebox Touch (fine), two Airport Expresses (not fine), on multiple outlets (not fine), under various power conditioning (not fine), with two DACs (not fine), wireless or wired (not fine), AirPlay from main computer or iPad (not fine) and a ton of tracks since (not fine). Firmware on both shows 7.5.2, which is current. Anyone else have problems lately? It's most noticeable on quiet passages, but clearly so then. Pretty irritating. Also I thought the APX topped out at 16/48, but it appears 16/44.1 now (at least through iTunes - haven't tested elsewhere).
digger945 Posted March 21, 2011 Report Posted March 21, 2011 I had this problem here while back with a pc using foobar. I think it was the properties of the device, checking or unchecking the box for "allow other applications to take exclusive control of this device" or something like that. Really weird and very annoying. I'll probably remember something else just as soon as I hit the post button. Is this problem with a recently acquired dac?
blessingx Posted March 22, 2011 Author Report Posted March 22, 2011 Yeah if you can remember anything let me know. Aren't a ton of options in the Airport Utility. And tried a couple dacs. In fact have since tried straight from APXs analog (same issue). And here's another weird property. It happens at the same, or nearly same, point in the songs (but not same tracks if using another device). Something about the decode or stream.
The Monkey Posted March 22, 2011 Report Posted March 22, 2011 Ric, did you get any new appliances or otherwise change the load on the circuit?
Dusty Chalk Posted March 22, 2011 Report Posted March 22, 2011 16-bit DAC, but are you playing 16-bit soundfiles? Would the airport express pass the files bit perfect if asked? Ditto 44.1/48kHz.
blessingx Posted March 22, 2011 Author Report Posted March 22, 2011 (edited) I think it's a multi-network issue. Have three networks scattered through out the house. House here being a one bedroom apartment shared with a girlfriend, too many devices doing a variety of things and too many lead painted walls to make everything easy. The newest APX crossed networks ('cause it's way 40 feet over there). Will have to do single network testing over the next day or two. And I just moved from DA10 to D/AC 2000. Old, but 1990 moar better. Hell, maybe I should just go with this instead. Seems simple enough, can move between rooms and helps the social social. Edited March 22, 2011 by blessingx
NekoAudio Posted March 23, 2011 Report Posted March 23, 2011 What's your wireless speed? I noticed some issues with my AirPort Express playback while on 802.11b but nothing really after moving to 802.11n. Interference from competing networks or other sources might be increasing packet loss.
blessingx Posted March 23, 2011 Author Report Posted March 23, 2011 (edited) You guys may be on to something, but well, I'm confused as ever. Knocked down to a single wireless network. Took everything offline except laptop, Airport Express and iPad. Tried with Airport Express wireless or wired (Airport Extreme). Streamed from iPad or MacBook. Created 5Ghz network (with different name) and put everything on that. Same issue. I've settled on a single track for testing - Natalie Dessay's Suis-Je Gentille Ainsi? from Airs D'opéras Français. For when she hits high Cs that track sounds like it's skipping/clipping. Happens lots of places elsewhere, but most obvious there. Many changes since I last used an Airport Express for audio, from DACs to laptop placement (far away from router), to controlled by iPad, to new Airport Express firmware, but have switched around variables to eliminate most of them. Also plenty of bandwidth. I don't know enough about the data stream, but it's almost like it's being caused by the complicated passages/high sample-rates. Steve Earle's bare cover of Pancho And Lefty gets mostly by scott free. The Dessay track goes crazy (even in quiet passages where most noticeable). I'm kinda at a loss at this point. If anyone has any further suggestions please suggest away. And just to reiterate: multiple Airport Expresses have been tried, multiple DACs, multiple amps, multiple phones, multiple tracks, multiple networks, multiple rooms, wireless v. wired, Squeezebox v. Airport Expresses, iPads iPod v. MacBooks iTunes, iTunes v. Play/Airfoil, whisky v. beer. Edited March 23, 2011 by blessingx
blessingx Posted March 23, 2011 Author Report Posted March 23, 2011 (edited) Should have added - when I listened straight to a then wireless Airport Express' analog output (RS1 on low volume) I eliminated the toslink cable and DAC with same results. I'd believe this was a weird decoding/firmware issue if it wasn't for that fact that it's multiple Airport Expresses and no one else is complaining. So I have a AT&T modem-router with wireless turned off 'cause I plug in the Airport Extreme to create a network and extend with Airport Expresses. I've shut off wireless completely and cabled everything to the Airport Extreme (same result) and then moved it over to the AT&T (same result). Confused as hell. Will try unplugging the Airport Extreme completely and testing the AT&T tonight, though that won't long term work for other reasons. Thanks everyone for trying. Edited March 23, 2011 by blessingx
The Monkey Posted March 23, 2011 Report Posted March 23, 2011 Ric, have you gone straight ethernet with wireless turned off on every device?
blessingx Posted March 23, 2011 Author Report Posted March 23, 2011 (edited) Ric, have you gone straight ethernet with wireless turned off on every device? Every device in chain - MacBook and Airport Express (and turned off iPad - music controlled from MacBook), but haven't shut off entire apartments wireless (in respect for GFs evening work). Will eliminate entire wireless tonight and unplug Airport Extreme. Turn off lights. Sit very still. Running out of tests. Do live across from a park with a shit load of spiders??? Edited March 23, 2011 by blessingx
blessingx Posted March 23, 2011 Author Report Posted March 23, 2011 (edited) But what happens to the sound scorpions when the radiation hits California? EDIT: That's kinda how the clicks sound. Edited March 23, 2011 by blessingx
NekoAudio Posted March 23, 2011 Report Posted March 23, 2011 Are you sure you just don't have a bad rip? Do the problems appear in the same place on a track, every time? You said you didn't hear it with the Squeezebox, but maybe that was transcoding (depending on your setup) and so things got masked/removed.
blessingx Posted March 24, 2011 Author Report Posted March 24, 2011 Freaky, isn't it? It's a lot of tracks, and I haven't taken a look in Audacity, but the Dussey tune plays fine from MacBooks audio out, iPads audio out or Squeezebox. I even just turned on home sharing on the iPad and streamed the track from the laptop to it and played fine. It's only when the Express (well, one of them) gets involved do the popcrackleclicks sound. And yes they appear at/nearly the same location in the song every time. And if I play a HDCD track through the Express it registers as such on the DAC, likely indicating bit-perfection... but that doesn't mean the spiders won't appear after.
blessingx Posted March 24, 2011 Author Report Posted March 24, 2011 With my trusty kerosene lamp by my side, I turned off the iPad, turned off iPhone, shut down work laptop, turned off MacBook wifi and plugged in to AT&T modem-router, turned off Airport Express wifi and plugged in same (and made appropriate settings in Airport Utility). Verified other Airport Expresses had no power. Unplugged Airport Extreme from wall so no wireless at all. Unplugged a couple wired devices (Blu-ray and Squeezebox) from AT&T modem-router. Just a MacBook and Airport Express, some power to each and the DAC & amp, and an increasingly frightened cat wondering what's going on. I almost felt like I was Patrick82. Hit the track in iTunes and ran over to LCD2s. Out of silence rose... fuckin' POPs! If anyone is really bored and want to test the same track on their Airport Express setup (thought again the issue isn't remotely limited to this track) here it is. Can probably skip to last 1 min. as most pronounced there. http://www.megaupload.com/?d=JU4BH81R Can CIA wiretaps screw with music streaming?
blessingx Posted March 24, 2011 Author Report Posted March 24, 2011 (edited) Jacob, thanks much for testing. Do you have a way to test by chance without the Express (the iMacs audio out, etc.)? Trying to figure out if you've confirmed a problem with the file or the Express. Downloading Audacity. Edited March 24, 2011 by blessingx
blessingx Posted March 24, 2011 Author Report Posted March 24, 2011 (edited) Does last 15 seconds go crazy (including thumps)? I fear if it's the file as it's a lot of files then. And much thanks for the tests. Edited March 24, 2011 by blessingx
NekoAudio Posted March 24, 2011 Report Posted March 24, 2011 I tried it on my iMac digital out and didn't notice any severe problems, but perhaps two or three locations where there was some minor noise. Extremely faint. I tried it from my iMac (wired) to my AirPort Express (wireless) digital out, and noticed some extended crackling (about 5s straight) at one point around the 2m05s mark. But rewound about 25s to replay the same location and the crackling was gone. Perhaps there was some interference at that particular moment. Otherwise, no problems playing this track via AirPort Express.
blessingx Posted March 24, 2011 Author Report Posted March 24, 2011 (edited) Thanks for checking you two. Jacob, I think we are hearing different pops (think giant scorpions). Wes, maybe the same, but mine don't go away with rewinds. I'm flummoxed. Hearing it the same on Ran Blake at the moment comparing Express v. Squeezebox. Edited March 24, 2011 by blessingx
Dusty Chalk Posted March 24, 2011 Report Posted March 24, 2011 Can you use a visual editor to look at the exact spot and see if there's anything there in the file? (And yes, we would need more than the second, otherwise I'd do it myself.) I'm listening on linux, and I hear nothing unusual, except a weird divide-down artifact/synthetic warbling sound @ 2:44, not a snap, crackle, nor pop.
digger945 Posted March 24, 2011 Report Posted March 24, 2011 I couldn't get my AE to work, but will check some more tomorrow. Sounds very clean using my regular setup. Lenovo T500/iTunes, Bridge, Gamma2/EAD 7k.
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