AIR1 v AIR2 v Spark

[Womaz]

I don't think there is too much wrong with Devialet's networking approach 

That seems like quite a strong statement given the number of people that have reported dropouts and stuttering on here. In fact one person (Womaz?) was able to reduce the incidence of white noise by simply changing the location of their computer strongly suggesting a network-related issue.

My feeling is that the problem is highly complex and multifactorial, otherwise it would have been solved by now. For instance I have heard reports of the frequency of white noise being reduced through the use of mains conditioners which didn't really make much sense at all.

On a number of occasions Devialet have claimed to have fixed the problem only to have the proverbial Jack-in-the-box pop out with mallet in hand.

Guillaume

Yes it was me. When I move the lap top into the room where the router is I have never had white noise or drop outs. As soon as I move it back to my kitchen/office I get about 20 minutes and the white noise kicks in.

I have done this about 10 to 12 times now to test the theory, and every time the white noise appears. When the laptop is in the same room I have listened withoy issues for as long as 6 hours. The white noise or drop outs have never occured when lap top is in same room......yet

It is a strange one as the kitchen adjoins main room and there is only a matter of say 4 meters with lap top placement. There is however a wall too.

Steve

[Antoine]

For Antoine, you do not always need to know exactly what is happening "inside" to try to solve a problem. As I say sometimes, you do not need to be God to cure people.

I applaud your willingness to help but I'm staying out of this discussion, it's bad for my blood pressure. I've already seen too much nonsense and utter BS written on the AIR issues (which never plagued me BTW) and am seeing it again already.

Good luck to you all.

PS: I do agree with PhilP, the white noise issue is very unlikely a network issue but rather a timing/buffer corruption issue. Playback is the real time process, not the network part as that's only used to fill the buffer.

[ThierryNK]

I had  the following experience:

Ethernet over Power Line with Ayon S5 Streamer and Todaldac d1-server




All is OK most of the time.

Then, I downloaded big files from the Internet, or copy big files from one computer to another one, with data that do NOT go through the Power Lines.

Guess what? Big noises and streamers crashed.

Kind regards

[AlexS]

For Antoine, you do not always need to know exactly what is happening "inside" to try to solve a problem. As I say sometimes, you do not need to be God to cure people.

I applaud your willingness to help but I'm staying out of this discussion, it's bad for my blood pressure. I've already seen too much nonsense and utter BS written on the AIR issues (which never plagued me BTW) and am seeing it again already.

Good luck to you all.

PS: I do agree with PhilP, the white noise issue is very unlikely a network issue but rather a timing/buffer corruption issue. Playback is the real time process, not the network part as that's only used to fill the buffer.

I would also like to register my agreement with Antoine and PhilP on this matter.
We should always differentiate white noise proper (continuous loud hissing sound, which does not self-correct itself, unless AIR is restarted) and occasional drop-outs/stutters. WN is not likely to be related to networking. I think we have the following evidence, which supports this hypothesis (at least, for Windows; I can't speak for the Mac):
1) The latest beta version of AIR improved things for, at least, some users, and that version changed the implementation of the timer (or rather how time is obtained from the Windows OS?)
2) Disabling the screen saver helped other users. But this has nothing to do with network traffic, but rather CPU load.
3) Others observed that migrating to Windows 10 fixed the problem.
To sum up, it's as if under certain conditions, perhaps involving extra CPU load (or maybe some background process like Windows Update kicking in, when it thinks the CPU is idle, and causing the processor to abruptly shift from the power saving state to the regular one), AIR starts sending gibberish to Devialet.

[Manfred]

Since I migrated to Win 10 4 weeks ago, added Fidelizer Pro 2 weeks ago:

• No white noise
  
• No stuttering/cracking - if no syntheticly created
  
• Creating stuttering: If I make a backup from my NAS (creates ~800 Mbit/sec workload on the network + 20-25% CPU load on my i7 there is sometimes some stuttering)
  
• I have a dedicated intel NIC in my HTPC for my D-200 (typically for 44kHz/24bit network load it is a straight line, for 192kHz/24bit is it near a straight line.)
  

My personal conclusion: With Win 10 and the latest ß-driver for Air no white noise, but:
Air requires a certain amount of ressources, regarding network, CPU, # of threads and interrupts. If that does not fit you will have stuttering.  I have (also used for gaming):

• Seasonic Platinum Series Fanless 400 PSU
  
• MSI Z87M Gaming Mainboard; Qualcomm Killer LAN (data network)
  
• Intel Ethernet card (pure audio streaming)
  
• Intel Core i7-4770T Processor up to 3.7 GHz, 45 W TDP 8MB Cache, 4C/8T
  
• 8GB (2 x 4GB) Corsair Vengeance DDR3 DRAM 1600MHz C9 Memory Kit (CML8GX3M2A1600C9)
  
• Noctua NH-UB9 SE2 (CPU Cooler) + 1 x Noctua NF-A9 PWM (replaces packaged fans)
  
• 2 x Noctua NF-S12A (Case FAN's) replacement of the Fractal build-in fans
  
• MSI N750Ti TF 2GD5/OC graphics card
  
• 500 GB Samsung 840 EVO SSD Three-layer Cell Solid State Drive
  
• Samsung SN-506BB/BEBF Blu-Ray drive
  
• SOtM tX-USBexp Audiophile PCIe to USB Audio Card (audiostream for video with madvr)
  

[Confused]

My recent experience with AIR is as follows:

Windows 10 / Latest Beta AIR / hard wired Ethernet. Sometimes it works 100% perfectly. With the latest beta version of AIR, I got white noise when the screen went into "powersave" mode (blank screen). Disabling the screensaver / powersave mode has cured "white noise" 100%, I have not experienced this for about 5 month now. I do still get crackles, stuttering and other similar artefacts. Some days 100% perfect, some days not. It appears to be very random, but does fit with the theory of a PC multitasking / performing background tasks and then causing some kind of upset to the clocking.

In the absence of a robust cure offered by Devialet, my view is that the solution, or at least a work around, is to suss out which processes in the PC (or Mac) are upsetting AIR and make sure they are disabled / removed from the machine or whatever whilst streaming. I have noticed a few cases of people claiming AIR works perfectly, people running stripped down / audio optimised PC's or Windows Server 2012 Nas drives etc. I'm sure this is not coincidental.

[Rufus McDufus]

OK, I've tried a few things. PC connected directly to Devialet 200 via one single cat 5e cable.
Firmware 8.1.3 on Devialet, AIR 2.1.4-beta4. Playing music using iTunes. I just used 16/44.1 CD rips.
Windows 7 64-bit Ultimate on PC. I couldn't be bothered to type the specs in so image capture of 'hwinfo' below. System was a pretty decent gaming PC 3 years ago and probably moderately overclocked. Most services including AV disabled. I tend to run the system pretty lean anyhow.

Firstly I tested various nmap portscans of the Devialet while playing music - intense, w/ UDP, all TCP, slow comprehensive etc. etc. Nothing produced any issues.

Next I went back to testing the display power off/on (via Windows 'power options'). In High Performance (which I always use) with the display set to switch off after one minute I managed to get AIR to crash completely when moving the mouse to power the display back on.
I then had trouble reproducing any issues so set the power plan to 'Balanced' with screen switch-off set to 1 minute. OK, when display powers off I'm starting to get stutters in the music. Big stutter sometimes when moving the mouse to re-enable the display.
Switched power plan to 'Power Saving' w/ display switch-off set to 1 minute. Now I'm getting constant stuttering - though again only when the display has switched off after 1 minute. Stuttering is constant like the volume is phasing up and down several times a second. I have to restart AIR to fix it. Went back to High Performance plan and couldn't reproduce problem again and got bored.
Task Manager showed barely any system load or memory usage all throughout.
There does seem to be a link with power options and particularly with display power off/on. I'm wondering if the graphics card is a factor here?

Interestingly I have a 2008-vintage Asus Eee PC and it never has any problems with AIR.

Here's the specs. Graphics card is AMD Radeon HD 7950 with latest drivers.

[Confused]

Interesting comment re the Eee PC Rufus, and it reminds me that my old and very clapped out Windows Vista PC (now long dead following hard disc failure) also used to run AIR perfectly, 100% perfectly, no stuttering white noise or anything else.

[thumb5]

Again, there is no specific "audio timing" in an ethernet transmission.

If there is a buffer on the receiver side, there is no "real time" involved, the same way you download a file from the internet.

If the buffer is not large enough compared to network latency and performance, than there are dropouts, but no "noise" in the audio output, except if an empty buffer crashes the audio process, and this is very unlikely.

Just unplug your ethernet cable, and listen how long the music still plays, it will give you an idea of the buffer size on Devialet.

Kind regards

I've done that test a while back, and found that the buffer is sufficient for a substantial break in network connectivity - over one second - without missing a beat.

I've never suffered white noise, but an interesting test occurs to me which would be to capture the audio stream packets while playing a pure tone through AIR, and compare with what's transmitted during a white noise episode.  I found that while the stream sent to the Devialet is not simply linear PCM samples, it's pretty close to it (maybe with some normalisation/scaling thrown in).  If you see the same stream during a white noise episode it would point to a problem with the network interface/stack on the Devialet itself, but if the stream changes during white noise- and it should be a dramatic, easily visible change - that points to the problem being in the AIR software on the computer.  (For what it's worth my money is on the second case.)  Maybe someone's already done that test?

[ThierryNK]

Ian's white noise issue has been solved

Kind regards