I replaced my G wifi card for an N card and now I have static through my Creative 4400 speakers.
Any idea how I can solve this without changing the speakers? Strange that the shielding works with G and not N?
Try changing wifi channel, maybe by using different frequency it will not interfere so much.
Sounds like you need a low pass filter at the input to your amp. As I mentioned in another answer to a similar question, the filter should have a corner frequency of 1 MHz or so. These are sold as noise suppressors, or if you have a soldering iron, this would be a very simple, cheap project / kit (google RC low-pass filter, use a filter calculator). The audio frequencies that you want (10 Hz to 20 KHz) are so far away from the Wifi spectrums (2.4 GHz to 5.8 GHz, iirc), that the filter's job will be very easy; no need for complicated designs or expensive parts.
I know this is an old question, but it gets a lot of views. This must be a common problem.
I have a similar creative unit. Pressboard box with subwoofer, and amp. It hears the cell phone tower connection easily. It doesnt have a lot of ventilation slots on the cabinet. Because of that it is possible to shield it with a ferrous mesh or thin sheet of rolled steel (idea) without blocking vents.
With digital, it still can get interferance, but they have optical connection, balanced connection, and sharp on/off signals that either work or dont. The problem here though, is probably the signals going right to the amp and its (antenna like) curcuitry , and the lack of sheilding.
To reduce the effect of the interferance , often you can increase the signal (turn up the volume on the computer to max) And decrease the ammount of amplyfying (turning down the speakers) That would increase the "signal to noise ratio".
Old school amps and tuners, would have been in vented steel enclosures, been grounded, or provided for grounding. High end electronics can have PCBs with layers that provide sheild. You might get away with very simple single metal sheild just leaning there.
I have a simple sheet of thin rolled steel from the hardware store, that I have used before. If something was a problem of interferance, I could just place it under, or over, or on the side of. I could tack it to places on the wood desk. I could just use it to Test quick what the problems are , to move things around.
You could crack open the box, and redesign it a bit, by putting sheilding on the inside. You can "craft" a thin sheet of steel or iron, by gluing black vinyl to it, or painting it black, use it on the outside to block signals. You could just move the speakers and the wi-fi further away from each other.
If that problem becomes solved, this interferance blocker sheet, could be used to test or temporarily fix other interferance issue later. It could be used to redirect (parabola) or block signals also. The sheet can be connected to a devices ground or earth ground, but it is not usually much better that way.
A positive outlook of the problem , you have a pretty strong wi-fi going :-) so that's good.