XPS 15z Crackling Audio with Network Traffic

Hi

I bought an XPS 15z about a month ago. i7 2640M CPU, 8GB RAM, 750GB drive etc. All pretty standard since there is limited options on these things. For the most part I'm happy although missing page up/down/home/end keys is a bit silly. Also IE9 keeps losing focus and I can't figure out why but that's a software issue.

Anyway when there is significant network traffic any audio playback becomes crackling and distorted. To reproduce:

1) Connect to a Wifi network - 802.11g 2.4GHz doesn't seem to have the issue nearly as much. but with 802.11n 2.4GHz and 5GHz it always works so could be related to data throughput. I get speeds up to about 15MByte/sec over my network and typically about 10-12MByte/sec. In my case I am connecting to an Asus RT-N56U access point.
2) Connect to a file share on a remote device over the Wifi and copy a large file to or from the remote device
or
2) Generate significant network traffic over Wifi (e.g. using iperf)
3) Play any sound in Windows Media Player or any other program (e.g. playing system sounds). Use a local file to rule out network issues.

Sound is distorted and crackling whilst significant network traffic is occurring.

Dell have been good enough to replace the machine with a brand new one after I reverted to a complete factory image and the problem was still there. I updated the drivers as they suggested and the problem was still there.

Anyway, the new machine (I have two in front of me) I received today has the exact same problem so it's either a hardware design issue or a driver issue.

Has anyone else seen this or could try something similar on their XPS 15z and let me know if theirs does the same?

Thanks

 

All sandy bridge model has a Crackling Audio problems. you can try copy 8G data from C: to external driver or what, then until try play music also has a same problems.
I already complain many time, buy all tell me is 'normal'.

 

Do you have any more detail on this? Who says it's normal? This machine is using Realtek High Definition Audio although I do see "Intel(R) Display Audio" show up in Device Manager.

Copying to/from a USB stick (about 20MB/sec) and to/from a USB external drive (about 80MB/sec) does not show the problem at all.

 

Using DPC Latency Checker shows massive latency spikes when Wifi network traffic is occurring which then leads to likely audio problems.

 

Try to turn off equalizer in Dell audio. It might be helpful.

 

Yeah tried all of that with their technical support person (along with a bunch of irrelevant things like changing the "Ad-hoc channel"). Makes no noticeable difference.

 

Ugh. Now Dell want to replace the Intel card with a Dell one. Not so keen on that to be honest. I'll bet they rock up with some crap old model with less performance or without Bluetooth or something like that.

Would be nice if they just fixed the fundamental problem. I'd guess debugged drivers could fix this. I'm really surprised no one has found this before.

 

No, anyway they should replace with exactly the same wifi card Intel 6230. After replacement, you can check model pf wifi card via AIDA64.

 

Yes, I have two machines with the same hardware produced at least a month apart that have identical problems. It's a hardware design problem or a driver problem (or a problem with a large batch of production).

I'll be able to see the Wifi card model in Device Manager if it's changed significantly. They are proposing replacing it with a "Dell" card but won't tell me what exactly that is yet. I don't really know how that's going to be possible since there is only one option for this laptop whereas I know some of the others you can select Dell/Intel/Broadcom etc.

 

Please stop posting wrong information.

 

Do you know what he might be referring to here then? Dell seem to not have any idea and surprisingly no one else is confirming my problem even though I can reproduce it on a brand new out of the box machine (x2) with no driver changes, installed software or anything....

 

Wish I could help but I cannot recreate your issue on my laptop.

 

Thanks but it is a different laptop although similarly specced.

 

For what it's worth I haven't been able to reproduce the issue either.

 

What sort of throughput are you getting with file transfers? Definitely the higher the transfer rate, the worse the problem gets. What sort of access point do you have?

This is confusing for me then since I have two brand new machines the same both doing it independently.

Also I do have the i7-26 40M

 

I've done a lot of transferring over my local network especially since I have one of my Externals connected to my router, I'm using a netgear wndr3400. It might the difference in processor as I now notice ours is different, but idk what the connection might be. Maybe it has something to do with power draw? But then I guess if it did you'd probably hear it when you game or do anything intensive. If you do figure it out I'm curious to know what's causing it.

 

I wouldn't expect that small CPU difference to be the difference that prevents you reproducing it

You can hear the problem on any playing sound when *significant* network traffic occurs like copying a large file. Glitches/scratches in the sound as if the raw data being sent to the audio card is being corrupted. So it only occurs on sound actually playing but also it would make sense since every audio producing program suffers from it. The glitches don't occur if nothing is being played though.

Gaming or other CPU intensive tasks aren't needed to make it happen. Just network intensive.

 

So Dell replaced the card today with a Dell 1701 card (aka Broadcom chipset). Using DPC latency checker it's fixed BUT:

1) It doesn't support 5GHz 802.11n or 802.11a that the old card did

2) It only supports x1 802.11n (i.e. 150Mbps). The old card did x2 300Mbps

So I've more than halved my wireless network throughput. I'm not going to accept this from Dell. I want them to fix the hardware I bought rather than replace it with inferior hardware with less functionality.

Don't really see what the point was of doing this. It's fairly obvious, it was the network card/driver. They even sent a new motherboard as well. No point in that since I still have two complete machines that both have the problem i.e. it's not a physical hardware fault.

 

I also have the same problem that you experienced. I noticed that the crackling audio happens when there's network traffic over a wireless-n connection (I have the Centrino 6230). To hear the audio crackling I would:

1. Load a 1080p video from YouTube
2. Allow HD buffering from Netflix while streaming
3. Play a local music file while generating network traffic

When I play the local file and do the above 3 things with an ethernet connection, I don't hear the crackling.

I have restored to a factory image and this still happens. Do you know if this is a hardware problem with the wireless card? Could it be interference from the wireless card?

 

Mine was originally Centrino 6230.

Either it's the card itself or the driver that is somehow corrupting data sent to the audio card as I see it. I don't know if these things share a bus or what these days. I would guess it could be fixed with a driver change in the network or audio drivers. The problem is that so far Dell don't seem real interested in investigating.

All Dell wants to do is swap out parts until it works. I already have two complete machines sitting here with the exact same problem. So unless they have both have the exact same faulty component, another new one isn't going to fix it. They even sent out a new motherboard the other day with the tech! If the second whole new machine didn't fix the problem, it's unlikely a third motherboard would either.

It could be a design issue but I think PC hardware is better than that. It's a Intel CPU, chipset and wireless solution so one would hope they played well together.

I can only suggest you report it to Dell under warranty and maybe you'll have more success than I at getting them to look at the issue rather than hope it's hardware.

It is also possible it's the audio hardware/driver but the problem did go away (I think 100%) when the card was changed.

Using DPC latency checker will show you. You'll get lots of red peaks.
DPC Latency Checker

With the new card I do occasionaly get red peaks but not nearly as much as before.

 

Yep, just as I suspected, it's the wireless card.

I opened the same 1080p video from YouTube (as I did before) and immediately got very bad latency as shown by the Latency Checker. The latency persisted until the video finished loading, at which point it went back down. But until that point, the only thing I got was red bars.

To confirm this, I played the same video using an ethernet connection on my 15z and got very few red bars. I even played the video on an IBM ThinkPad and only got one red bar as well.

I went ahead and reinstalled the wifi software but it was to no avail. Also, since I reverted back to factory install and installed the Centrino driver, I am now wondering what I should do from this point out.

 

Is it an XPS 15z? If so it will still be under warranty.

All you can really do is either live with it or put in a support request. They will probably try and just replace bits hoping that will work which we know it won't.

There aren't any updated drivers on Dell's website. Maybe there are updated drivers direct from Intel?

Also I lose the Intel Wifi with the Dell branded card. Not sure if I would have used it but I might have. It's the speed loss that annoys me the most.

 

There seems to be updated drivers if you check the other XPS 15z thread.

Here you go. Drivers and Downloads | Dell [United States]

 

Thanks for the heads up. Doesn't show up under my service tag (Australian delivered XPS 15z) through the regular support page.

Also the link directs me to
http://downloads.dell.com/FOLDER00171337M/2/YPYJF_A04_ZPE.exe

Which is giving a 404 not found error at the moment.

Edit:
It doesn't work if I use the Dell single file download but it is downloading using their multiple file downloader

 

I appreciate your help Shonky, and you too, Alias. I have tried installing the driver from the link you posted but it didn't make a difference. Problem is, I still have latency issues which is a major problem for me because I stream content over the internet all time.

Do you guys think that this is a hardware issue at this point? Unless I'm missing something, I think I've ruled out the possibility that it's a software issue considering I have restored to a factory image and installed several different drivers for the wireless card.

 

I think it's a "design" issue either in hardware or drivers.

New hardware has been proven to not fix it so it's not a faulty part unless there is a very large batch of bad components (long shot).

Restoring to defaults just proves that you haven't installed other software or changed a setting that introduced the problem.

Is your machine an XPS 15z?

Is it under warranty (a 15z would be)? If so report it to Dell. More people can only help push them for a solution.

PS: I haven't tried the new driver myself yet. The machine I'm using has the different Wifi card in it now. I need to unpack the new machine to try it on the original card.

 

Yeah, I do have a 15z.

I'm hesitant to contact support because this is a replacement for my XPS 15 which I bought in late May. I had all sorts of problems with the fan and now I'm downright getting annoyed that I'm continuing to have problems with one of their machines. But it looks like I don't really have a choice at this point. Since my 15z has the originally warranty of the 15, I'm still covered.

Although, I have found a use for the Intel WiFi so I really don't want to have to get a new card. If I'm not mistaken, did you say that getting another Centrino 6230 WON'T solve the problem?

 

Well you can put the tech support call in and just point blank refuse if they don't fix it how you want.

I want the x2 300Mbps 802.11n and 5GHz back so the replacement card is not an acceptable replacement and the Dell guy knows that. Took him three days but today came back with:

"Kindly be informed that I have escalated this case to my management team for the best next course of action."

I didn't get the 6230 card replaced with another 6230 card. I got a whole brand new machine with identical specs. My original was bought in a local electronics store and the new one was a conventional order from the factory like all Dells used to be. The problem remained, so a new card is very very unlikely to fix the problem.

 

Looks like the driver linked by Alias has been updated. I think before it was 21st November. Now it's showing as 1st December. Filename is still the same and it's still showing as "A04". I can't tell if the 14.2.1.1 is updated.

However I cannot download it either using the single file or multiple file method. I get a 404 not found using single file and a "Session corrupt" using the multiple file download option.

 

I had wireless speed issues when i got the 15z yesterday. Solved them by uninstalling the bluetooth wireless component. Try that as it solved my ping/speed problems.

 

@Alias
Thanks for the tip but it didn't help.

@Shonky
Are you still unable to download the driver for your machine?

Also what's puzzling is that I was playing a game against my cousin over my home network and there was a ton of network traffic. But at that time, I never heard the crackling sound - it's only now that I hear it.

 

Tried it just now and the multiple download method is working now. Will compare with the previous download to see if it's any different. I haven't tried the new one yet though. My "normal" machine has the Dell old card in it. I need to unpack and try it on the replacement machine.

As for gaming, I would say gaming doesn't produce massive amounts of traffic. Best I've found is either iperf or doing a simple file copy from machine to machine (assuming you have two machines including the 15z). And definitely more traffic equals more glitching.

 

Alright, let me know if the new driver fixes the problem on your replacement machine. Unfortunately, it didn't do anything for me.

And I also talked to a Dell Support rep and he agreed to replace the Centrino card with an identical one.

 

I'm going to be busy with work for a couple of days but maybe by Wednesday I'll get it out and give it a go.

The 1st December version *is* different based on just a binary compare. It reports itself as A04 in both though.

I think if they are just replacing the network card like for like you are probably wasting your time.

 

Yeah, that's what I told them but I guess I'll have to convince them not to...

 

I currently use channel 1 in the 2.4GHz space. Now they are telling me to try channel 11 on the replacement machine (still with the Intel 6230). I was mainly using 5GHz though since I get better speed there and can set it for 802.11n only

I have already done this for them long before the replacement machine arrived and also the problem was occuring at 5GHz too. So this will not help and we're going around in circles now.

 

Yeah I know we're wasting time with this.

I'm not sure if this will help, but I've been talking to a Dell liaison who has been in contact with their engineering department. He claims that engineering is "aware" of the problem, though I'm not sure what they plan to do about it. I plan on following up on this and I'll keep you posted. If anything, he can help get the wifi card replaced. This is his page on Dell Forum:

Sign In to Your Dell My Account

 

I just tested a different 15z to see if it also had latency problems. To generate network traffic, I streamed same YouTube video I've been using to test and the computer, in fact, had pretty bad latency problems. On average, the computer had about 4000µs of latency while the video loaded. However, the person said that she never hears that crackling sound.

At this point, I'm convinced that you're correct - this is a design flaw of the 15z...

 

Did you hear the crackling/glitching during your test?

I definitely think a lot of people wouldn't notice it. I certainly wasn't looking for it. It took me a while to figure out what was happening. It was just I was copying a lot of files to the new machine whilst playing some MP3s...

 

I have the same problem here. I think it's probably a driver problem. Had the same issue on my Lenovo ThinkPad W510 when it first came out. Updated the drivers back then and it was resolved.

 

So reading the Dell Community Thread: XPS 15Z Audio issue said to disable the on-board NIC "Atheros AR8151 PCI-E Gigabit Ethernet Controller" in Device Manager makes the stuttering audio go away for me. Not really a solution when I'm connected via network cable but it works.

 

Yeah I'm pretty convinced a driver fix could solve the problem, but convincing Dell is another thing.

Disabling the Ethernet NIC doesn't do anything for me. I'm not using that interface anyway.

Unsurprising Dell's suggestion of changing to channel 11 made no difference (at 2.4GHz). The problem occurs with both 2.4GHz and 5GHz anyway.

I see there is yet another new version dated 5th December here:
Drivers and Downloads | Dell [United States]

Will give that a go now.

 

Upgrading to the 5th December driver *might* have improved it a bit (and perhaps also improved the speed - I was getting 16MByte/sec between floors). Still getting the red peaks in DPC Latency Check and still getting the audio glitches.

 

Did you download the driver that Shonky posted a link to? And also, I've read through the entire forum and NONE of the suggestions worked for me.

Didn't work, unfortunately... I get upwards of 32000 nanoseconds of latency.

 

Yeah I don't think its really made any difference actually now. I think just sometimes it's a bit better than others.

 

It was easy for me to notice though, because I'm constantly streaming lectures for class. And when I did the test on that 15z, I didn't notice any crackling. Then again, the latency was MUCH lower on that computer than on mine.

EDIT - This is what the Dell rep told me after I told him the whole situation:

"I know that a 15z and a xps 15 have been tested. No sound glitches either way. Engineering stand on this is that it is likely a Windows 7 issue. Windows 7 doesn't protect real time audio playing. So anytime that you have a number of processes going while listening to audio any one of them could interupt the audio track playing. It is typical for processes to interupt one another, but for the most part users will never know the differernce. Audio playback you can notice a huge difference.

In your case since the problem doesn't happen with the wifi card disabled, it may be something different. Since a very few are actually reporting this problem it may be that your card may be defective in specific, although it doesn't have to be that. Replacing the card is about the only way to find out."

 

The reason not many are reporting it is that it's easy to miss most of the time. I reckon I could reproduce it on any machine.

As I have a complete brand new machine I am pretty sure it's not a hardware failure.

Also the same machine with a different Broadcom based card has the problem fixed.

Blaming it on Windows 7 is a cop out if you ask me. Engineering have obviously not actually tested it I feel. It also does it with an Apple Airport Express so that should be common enough to source to replicate.

At least my Dell Tech isn't blaming it on stuff like that yet. He's was making me jump through hoops like changing Wifi channels, running it off AC vs battery etc initially. He has gone a bit quiet lately so I think he's going back to his management for a solution and maybe to push it back to engineering properly rather than "engineering are standing by the machine".

I did find these but they are actually older than Dell's A04 5th December drivers (14.2.0.10 vs 14.2.1.1):
http://downloadcenter.intel.com/Det... 64-bit*&DownloadType= Software Applications

 

Thanks for the link to that driver, but didn't work either. I really don't want to keep trying drives since it's gotten me nowhere.

Quite frankly, I already jumped through enough hoops with Dell Support when I had problems with my XPS 15. That's why I contacted that Dell tech directly, though, his solution is to replace the Centrino card with an identical one. He insists that the only way to pinpoint and solve the problem is through replacement, even though I expressed my concern that a replacement probably won't solve my problem.

Since you have a machine without the problem, what would you recommend I do? I would like to have this solved before the holidays.

 

Well I don't really have a machine without the problem. I have a hobbled machine that doesn't exhibit the problem. I have lost significant functionality and I don't consider this at all fixed. If you're prepared to accept that, you could propose a replacement with a different part.

You could let them put a new card in to prove it's not a hardware issue. A hassle to deal with plus Dell techs (here at least) are pretty rough when they pull machines apart - I've seen it enough times before.

Direct them to this thread in particular to show it's not a one off problem.

I'm just going to keep pressing for proper investigation and a driver fix.

 

BTW, did your tech make you go into device manager and change some of the settings to the Centrino card?

And I'm not sure if I mentioned this before, but my XPS 15 had the same Centriono card and I never heard any crackling. Is it possible that the antenna itself is causing this? Sorry, I'm not THAT tech-savvy, as you can probably already tell.