e6500 crackling audio

I did get a sense that they are aware of the problem but judging from the conversation I had with the tech they are babes lost in the forest on this one. The way he went about the troubleshooting lead me to believe that they are clueless about the source of the matter. He said things like well we have had some luck with this or this if it works would be a temporary fix etc.

As mgrier said you should call in. The more pressure they feel from the users/customers the more motivated they will be to close this matter once and for all. I am sure they are tracking this issues and the more frequently it appears on TSR reports the more likely it is going to get the eye of a bean counter.

If this becomes a big looser for them in terms of cost of support someone will eventually get tasked with firing up the folks responsible for fixing it.

 

I returned the e6500 because the sound issued returned. I replaced it with a MacBook Pro.

The best help I got was found right here in this thread. Thanks to all that committed so much time to resolving this.

 

I thought i'de chime in about an identical problem i had with my thinkpad t400.

the solution was installing the 8.2.0.1001 intel matrix drivers (crackling is completely gone)

it appears that the intel matrix drivers for AHCI are problematic, you can test this by either a) disabling AHCI in your bios; b) uninstalling the Intel Matrix drivers (goto device manager-> IDE ATA/ATAPI..->Intel(R) ICH9M-E/M SATA AHCI Controller-> uninstall; or c) rolling back the driver

Windows apparently has its own AHCI drivers so you *should* be fine...

 

Hi there, I'd like to join the self-help group on crackling audio with several laptops, in particular with the E6500.

5 Days ago I got a brandnew E6500 with latest drivers installed (by the way - there was no factory-image of the system on the recovery partition, same to you?). After configuring the system to my needs I sat back and wanted to listen to some music... I don't have to tell you what I experienced. It took me some days to find this thread, thank god. I'd like to give a detailed summary from the lessons learned in this thread and what helped me finally.
I hope that other users who find this thread for the first time may profit from this summary (former diversed information now in one place) in understanding what there goes wrong and how to work around it. The information in this summary is gathered from this thread (thank you all, guys!) and is extended with information I found at other places and my personal understanding on the issue.

My System:
Latitude E6500, Vista Ultimate 32-bit SP1, Intel Matrix Storage Driver/Manager 8.7, Dell 1510 Wifi (driver: 4.170.77.3)

My Problem:
Crackling audio (drop-outs), sometimes stuttering. Sometimes all of the time, sometimes just a few times in a minute. Video also hangs sometimes but more seldom.

The situation (what I have learned here):
The crackling/stuttering audio and also the stuttering video is related to bandwidth restrictions of streamed data packets between hardware components. The available bandwidth for these streamed data packets is influenced by device drivers and the operating system (software). Example: If you listen to a mp3-file on your harddisk, data packets are sent from your hardisk's controller to the mainboard of your system. They are first processed by the mainboards hardware which is managed by device drivers (e.g. chipset drivers, harddisk drivers...) and finally by the software that decodes the mp3 (audioplayer). The audioplayer then sends data packets to the audiodevice driver which then sends data packets to the audio hardware. You can call this sending and processing of data packets as "streaming". Streaming of data packets that contain audio or video data is time critical. In order to hear a clear sound or to see a smooth video these data packets have to be streamed fast enough between hardware components, device drivers and within the OS. But there are many hardware components in your computer system that need an amount of bandwidth to stream data, for example your graphics adapter, touchpad or your WLAN-Card. If there is one hardware component that occupies a large amount of bandwidth for these data packets, other components might suffer (work slower). If there are many hardware components that need a specific amount of bandwidth, the sum of the necessary bandwidth might exceed the limits and one or more components might work slower. As the bandwidth for a particular component is managed by its device driver and the OS, a bad programmed device driver or OS-component may cause problems in time critical streaming of data packets for the whole system. This is what happens here and causes problems with audio and video playback/recording.
There is a tool that checks the "bandwidth" for data packets of your Windows-System: DPC Latency Checker. You will there also find a more detailed and technical correct definition of the simplified term "bandwidth" used in this summary.
I used this tool and found out that my system has very high latencies (and therefore bad "bandwidth" for time critical streaming) as described in this thread. As other users reported using the SATA/Raid device driver from Intel (Intel Matrix Storage Driver/Manager 8.7), there are *only* red bars/high latencies and not only spikes for my system.
Further research took me here (thanks Barny for this link posted in this thread). The finding of this article is that before Vista SP1 the problem with network and audio was in an opposite way: playing audio/video caused the network transfer to slow down. You see that some Vista services are also responsible for handling time critical audio/video data packets within the OS and between hardware components. So crackling audio is the result of bad latencies which are the result of interaction between device drivers and Vista services.

Solution/Work-Around:
In general the solution is: lower the "bandwidth" of all hardware components. OR: lower the bandwidth of a particular hardware component that steals an unnecessary amount of bandwidth.
The greatest problem of these latencies seems to be the software (device drivers, OS) and not the hardware itself. If you read through all of the 274 previous posts in this thread, you will find that it is common sense that the actual Intel Matrix Storage Device Driver 8.7 steals an unreasonable amount of "bandwidth" from the system and therefore is the main reason for crackling audio/video for systems with actual drivers. There are 3 possibilites for you to improve audio/video playback/recording related to that Intel driver:
1. Roll back to driver version 8.2 (see software support page of your system or go here, select your OS, on next page scroll down and klick "previously released area"). But be aware, there have been issues with burning CD/DVD media with this driver version! These issues have been fixed in version 8.5 (carefully read this page). I do not know if version 8.5 produces such high latencies as well as version 8.7.
-OR-
2. Leave 8.7 on your system and disable the multimedia-bay (or cd/dvd-rom) in your system's BIOS! (disabling the device driver in the OS hardware manager won't work). After rebooting your OS latencies are quite good! This was the first thing I tried and after that I HAVE A CLEAR SOUND AND NO VIDEO STUTTERING! Why does this work? After you have disabled CD/DVD in BIOS (!) Windows won't occupy any resources for that and so the Intel Matrix Driver will not care for CD/DVD and in consequence LOWER a large amount of "bandwidth" for its duties! Probably the fixing of the CD/DVD-burn issue in 8.5 correlates with that. So if you use this method you have to decide every starting of your work session if you want to listen to music or want to work with your CD/DVD-drive and enable/disable it while booting.
-OR-
3. Install Intel Matrix Storage Driver/Manager 8.8 that has been released a couple of days ago!!! I tested it on my system and I had almost good latencies with this new driver version! I could reenable my multimedia-bay in BIOS and latencies were quite fine!

Other additional work-arounds:
It was reported in this thread that audio crackling/drop-out has something to do with WLan. This is what I found out when I explored changes in WLAN settings of my Dell WLAN 1510 a/b/g/n (driver 4.170.77.3):
I can confirm that using the WIFI hardware switch (enabling/disabling) will cause high latencies for two seconds. It definitely correlates with audio drop-outs on my system. When WIFI is set to OFF latencies are *a very little* better than WIFI turned ON *in average*. With WIFI ON I now explored changes in WLAN-frequencies (e.g. activating/deactivating the "a"-band). When the "a"-band is deactivated, there are bad latency peaks - first every couple of seconds, and when the system is running for some time there is a peak about every minute. There is also crackling audio while hearing music - this is when the latency is over 18000ms on my system. If I turn on the "a"-band again, there are TWO bad latency peaks which follow very close each other! And my audio crackles more often for a short period! My conclusion is that the WLAN-adapter needs one hardware interrupt for each frequency range ("a": 5GHz, "b/g": 2.4GHz). If you have enabled the a/b/g-ranges there have to be 2 system-interrupts for the hardware. With every WLAN-hardware interrupt a high amount of data is processed through the OS to the WLAN-card (likely looking for available networks). If you have both frequency ranges active the amount of needed "bandwidth" nearly doubles. I experienced that only one small latency spike (<18000ms) for one second will cause no audio problem on my system (it is somehow compensated - hardware buffer?) but if there follow two spikes each other (latency for two seconds) I get audio crackling. As you can see disabling one WLAN frequency range *can* improve audio playback as there is one hardware interrupt needed less from the system. Disabling the whole WLAN-card improves audio further as there is another free interrupt-time for the system.
Update: Thanks to a post from tubby I found and installed these WLAN-drivers: they are for use with Inspiron/Studio DESKTOP computers and an ASUS WLAN-adapter, but this ASUS WLAN-adapter seems to have a similar chipset like the DELL 1397/1510 WLAN card. The driver is from broadcom and seems to support all native broadcom WLAN-adapters like mine in my Latitude After testing this driver (5.10.79.7, released from Dell 3/12/2009) I experienced another positive impact on my DPC latencies! When listening to an internet radio stream with WLAN there were NO more latency spikes!!! And therefore no crackling audio anymore! This is also with a-band activated!
But: when I was surfing the internet while listening to that internet radio station, there occured another audio crackles! They came up when I was *scrolling* through web pages! It was worse when I used Opera as a browser installed on an USB-stick (http://www.opera-usb.com). So even with better SATA- and WLAN-drivers there are other unidentified bottlenecks for time critical streaming under Vista SP1...

Conclusion:
If you gather all information in this thread you might conclude that every mentioned work-around (to disable this or to turn off that) may help. It's just freeing system resources/system interrupt time and therefore is more time for data packet streaming with audio/video content.
The greatest problem is the Intel Matrix Storage Device Driver 8.7 as it accounts a large amount of system interrupts ("bandwidth"). You may roll back to version 8.2 but get corrupted CD-R/DVD-R when burning media. Or you can disable your CD/DVD in the system's BIOS. Or you want to use the new Intel Matrix Storage Device Driver 8.8! AS MANY PEOPLE REPORTED IN THIS FORUM THIS MIGHT HAVE A GREAT POSITIVE IMPACT ON YOUR AUDIO/VIDEO PROBLEMS! However, there are some users where it seemed not to work very well.
You can also disable several other devices. As mentioned here disabling the "a"-band of the WLAN or disabling W-LAN in whole can improve quality *but has a little impact overall*.
For this moment upgrading your DELL WLAN-DRIVER seems to solve crackling audio with your DELL WLAN turned on!
Software driver updates for your hardware components might either improve or worse the situation of the latencies and corresponding for the audio/video playback/recording. I suggest measuring DPC latencies with the above linked tool before and after installing any driver update to help you to decide whether you keep the new driver or not.
If you have the possibility to downgrade your OS to Windows XP that might solve your problems as well as some users reported here.

This summary is a contribution to everyone who helped getting light into the dark with crackling audio on E6500 and other laptops. Thank you.

p.s.: thank you very much for your positive feedback and the reputation point

 

The 8.8 Matrix driver do reduce latencies... though they do also inactivate the Turbo Memory (if you have it).

 

Wow, Deichjunge, allow me to applaud you for your hard work and research into this matter. I haven't tried implementing any of the work arounds yet, but I am glad to see that the problem is finally understood. I always knew it boiled down to driver problems, but your post is great for explaining everything.

 

yeah Deichjunge, nice work... everything in your thread proved true for me (was surpised about the DVD issue).

Thanks alot, appreciate the time you invested and for sharing your findings - helped ALOT!

kudos

 

IMSM 8.8 doesn't fix the issue in my case, so going back to 8.2.

EDIT: After going back to 8.2, I noticed same kind of latency spikes. So this all is not as simple as just updating IMSM drivers...at least in my case Now going again to 8.8 to see how lucky I am.

 

For me it does!

 

After updating to IMSM 8.8 from 8.2 my crackling audio is MUCH worse with the WiFi on (dell 1510)! I kind of feeling helpless since I hate dealing with Dell Support...they usually install all the bloatware like DCP to see if it fixes it and kills my time!