PC Speakers Changing Volume

[conglo]

I have a Cambridge Soundworks FPS2000 PC speaker system. It's a standard 4.0 + subwoofer setup.

Sometimes the volume changes. I can't reproduce it when I want; it randomly happens. It seems to be a drop in volume and them it will randomly go back up in volume at any later time.

The volume levels don't seem to change. The lower volume always sounds the same and when it goes back up, it sounds the same. So, the volume levels aren't random, but the amount of level drop seems to be consistent.

What would cause this? Bad Caps?
Do you think this is something that is fixable?

Thanks.

[PlainBill]

Re: PC Speakers Changing Volume

I have a Cambridge Soundworks FPS2000 PC speaker system. It's a standard 4.0 + subwoofer setup.

Sometimes the volume changes. I can't reproduce it when I want; it randomly happens. It seems to be a drop in volume and them it will randomly go back up in volume at any later time.

The volume levels don't seem to change. The lower volume always sounds the same and when it goes back up, it sounds the same. So, the volume levels aren't random, but the amount of level drop seems to be consistent.

What would cause this? Bad Caps?
Do you think this is something that is fixable?

Thanks.

It's almost certainly NOT related to caps. Two things seem most likely; the volume control (if it uses a mechanical (potentiometer)) volume control, or a poor connection to the sound card.

PlainBill

[conglo]

Re: PC Speakers Changing Volume

The cables feel pretty solid, but I may buy new ones.

As for the volume control...
There is a mechanical pot in it. I never use it though. Could it just "go bad" if it is untouched? Of course, I did touch it when I first noticed this problem.

One other thing that I think it could be...
I've unplugged the audio cable without first turning off the speakers and it made hums and pops. Would that break anything?

Thanks.

[Krankshaft]

Re: PC Speakers Changing Volume

That depends if the volume control is simply a voltage divider and DC applied to a terminal of an IC controls the volume. It may be due to a temporary swing in supply voltage.

Be sure to check your audio source first though.

[conglo]

Re: PC Speakers Changing Volume

The audio source is good. I've tried with three different sound cards and they all do the same thing. Then, thinking it was my computer, I tried it with a portable MP3 player and I got the same results.

I figured it must be the speakers.

[kikkoman]

Re: PC Speakers Changing Volume

my creative surround speakers did that too after a while (and i barely used the volume control.)
the poti in the cable remote control was a really shitty one. a pencil and some grease fixed it for a while, i didn't bother to find replacement pot

since creative builts parts of these cambridge sets you might have the same issue.

[lucky13]

Re: PC Speakers Changing Volume

The cables feel pretty solid, but I may buy new ones.

As for the volume control...
There is a mechanical pot in it. I never use it though. Could it just "go bad" if it is untouched? Of course, I did touch it when I first noticed this problem.


Thanks.

Well, if you turn the pot and the sound is scratchy when you are turning it, then it is the pot.

[conglo]

Re: PC Speakers Changing Volume

Well, if you turn the pot and the sound is scratchy when you are turning it, then it is the pot.

The sound isn't scratchy when I turn the pot.

Does this positively eliminate the pot?

[Krankshaft]

Re: PC Speakers Changing Volume

Not if the POT isn't controlling the audio output directly if it's supplying a DC voltage to an IC then you probably wouldn't hear anything.

Try shooting some Deoxit into the POT move it back and fourth about 10 times and see if that helps. A good place is usually where the leads go into the casing that's a clear shot to the wafer and wiper.

I haven't found a scratchy POT yet Deoxit couldn't fix.

[Logistics]

Re: PC Speakers Changing Volume

Is there an air-conditioner or large refridgerator which turns on periodically in the house. Maybe it's causing a voltage drop due to a large draw, resulting in you seeing less volume.

Just an idea.

[Junk Parts]

Re: PC Speakers Changing Volume

I use a pair of older Cambridge Soundworks PC speakers. I had a problem with low volume on the left channel. It went down but never came back up. On mine the RCA cable from the right speaker to the left was dying. I just stuck another RCA cable in it and its been fine ever since. Now I have another problem with them. The headphone output is stuck open. I guess it will cost about a big one dollar to fix it. I'm lazy. They may get fixed by 2011 or so.