I've been having a problem lately with popping and crackling on my speakers. The popping and crackling occurs when there's a huge explosion (ex. Battlefield 1942) or a really really low tone sound/voice (I can't really explain this one but the Crypt Fiend's voice from Warcraft 3 is one example and another would be a low note/bass portion of a song. Changing the subwoofer volume in the software or lowering the subwoofer volume has no effect on the popping sound.)
I thought the left speaker was blown because that was the speaker that would pop or crackle but when I put right speaker plug into the left speaker port on the subwoofer, it would crackle and pop to at the same time the left speaker would in a song.

Here's my comp specs:

Asus P4C800 Deluxe Motherboard
P4 2.4GHz
Geforce 3 Ti 500
Audigy 2 (The regular one)
Western Digital 120 Gb Harddrive
512mb DDR RAM
Altec Lansing 251 5.1 Speakers

Any suggestions on how to fix this problem?

Someone told me that the subwoofer doesn't provide enough watts to each channel (only 90) and that's why it might crackle the way it does. However I can't seem to get only 2 speakers to work. Even when I set it to 2 speakers in the Creative Advanced Hud Console sound comes out of all 5 speaker and set the switch in the back of the subwoofer to 2.1/4.1 channels sound still comes out of all 5 speakers. Restarting the computer doesn't help either. Changing the plugs around doesn't work either, the green plug apparently seems to be the only one needed. I could pull out the black and yellow plugs and leave the green one in and sound still comes from all 5 speakers and the subwoofer. The manual doesn't help because the diagram of the soundcard ports don't match the ones on my audigy 2.

There is nothing wrong with your speakers. I have had the same problem with mine before. I very seriously doubt that there is anything wrong with the speakers. The issue usually lies in the sound card or drivers.

Make sure you have the most up to date sound drivers available for your sound card. The Audigy 2 is known for having some compatibility issues which *may* be the problem but I am not sure.

You could downloading updated drivers, removing the current ones, then installing the updated drivers.

Battlefield 1942 also has some sound problems in my opinion, because I've not only had problems once or twice with popping and cracking in all programs but once I had an issue with just Battlefield 1942. I tried lowering sound detail but that didn't work.

Although the thing that fixed my problem was getting rid of the sound card I had and using onboard sound instead. The sound card I had was really cheap, which cost me about $30 and just had problems constantly with it. The only problem with onboard sound Ive had was the volume not being loud enough, but once C-Medias drivers were updated that fixed the problem plus added a lot of new features that I could change.

If you haven't already, give that a try. BTW, go in Control Panel and System, Device Manager and right click on everything under sound and if your able, click Uninstall. Then install the update.

So I have the same problem after the system has been running awhile. I also notice during the popping and electrical noise that sometimes the power LED on the R front speaker goes dim/out. Sometimes sound stops altogether and the light is out. I took the sub apart and noticed the control box was very hot, but no loose connections that I could see. I have placed a small fan to help ventilate the area, but doubt seriously this will help. I also sent an email to AL about he issue. Any speakers made for gamers with cooling fans?