I’ve noticed my computer’s stereo speakers(Creative) behaving very oddly in the past couple of days. The left speaker wasn’t working properly, resulting in a muffled sort of sound. I tried testing the stereo by shifting the balance through Windows to only the left speaker, and sound could be heard, though only very faintly. I tried playing a stereo sound test on Youtube, and could tell that the sound was getting progressively(though not linearly) better, until after playing the test three or four times, the sound through the left speaker started playing normally, and remained normal until I switched the computer off. The next day, the same thing happened. What’s going on?
Start by making sure everything is secure. The most obvious would be to make sure the jack is pushed in all the way in on the back of the computer. If it’s popped out a bit that will cause strange things to happen. After that, make sure the connection to the speaker (and any other connections along the way) are solid.
The next thing to do is to swap the two speakers, disconnect them and plug them in on the opposite sides (or just swap the wires if that’s more convenient). If the problem follows the speaker, you have a bad speaker, if the problem stays on the same side, it’s something further up steam. Anything from a bad wire, to a bad connection to even a bad sound card. If the sound card is integrated you can just get a cheap sound card to drop onto the motherboard to fix the problem.
Anyways, first, check the connections, that’s usually the culprit.
I checked the connections immediately the first time the problem surfaced. Nothing was loose, and the problem recurred in the manner described the next day.
Unfortunately I do not have the option of switching speakers to try and isolate the problem - the right channel has a different type of cable. The Creative system I have(http://us.store.creative.com/Creative-A220-2.1-Speaker-System/M/B003FWHTTA.htm) is a 2.1 system, the sound cable goes from PC to right channel, which in turn is connected to the bass unit, and the left channel(the problematic one) is connected to the bass unit.
If the speakers aren’t brand new, the problem could be internal dirt/corrosion on one of the controls (volume, bass, balance). If you haven’t done so already, see if there’s any change in the left channel when you adjust the controls.
Are you plugged into a sound card or the motherboard? If it’s plugged into a sound card you could try moving it over the motherboard, or another computer, if either is available and see what the results are.