speakers

i just moved my computer around and reran all the wiring. somehow my speakers now are giving off a low sound even when volume is off. it sounds like interferenc, but the speakers are in the same place i had them before and i tried moving them but that didnt help.

 

Hi

check the connection where the cable from the speakers plugs into your sound card - confirm that it's fully inserted & try rotating the plug round in it's socket (gently!); also try moving it in and out a tiny amount (fraction of a millimetre)

also, ensure no strain on this cable is pulling on the plug

low-pitched hum from speakers often caused by poor connection at this point - and you wouldn't get rid of it with Windows volume controls or mute functions.

best wishes, HJ.

 

ok, i've tried all that but no success. the sound is just like you descibed, a low hum. could there be a problem with the wiring? think it would be worth buying new speakers? guess i can try new ones and if still there i could return them. any other suggestions?

 

Hi again

from the way you describe it, it's a wiring issue - so lets pursue it like that for the moment

(unless you want to upgrade the speakers anyway!)

it would help to know:

- do the speakers have any controls on them? (on-off switch, volume control)
- how and where does the mains lead (power cable) for the speakers connect? (own mains connector, surge protector, or adaptor which sits at the the back of PC intercepting the power going to the monitor)
- taking into account all your computer equipment which requires mains (line) power. Is this power sourced from only one wall socket (outlet) in your room, or are you using more than one?
- what country are you in pls.?

best wishes, HJ.

 

Ok. I'm in the U.S. The speakers have no controls on them. The speakers connect directly to the computer. one cable to the USB and one cable to the sound card. And yes all my computer equipment is through one outlet connected by a surge protector/battery backup.

 

controls -

I have a feeling this is going to be a USB thing rather than an audio thing - unfortunately I have no experience with USB, none of the computers here has USB.

If you have more than one USB socket on the computer, try plugging the speakers power into another socket. It seems there are two sorts of USB socket - in terms of the amount of power available for a peripheral...

one sort of USB socket is good for 0.5Amp, that would give you 2.5W...

...but the other kind of socket only provides 0.1Amp which is nowhere near enough for your speakers.

(source: Dallas Semiconductor data for TEA2025B = amplifier IC for driving speakers from sound card output, USB powered)

if it's not that, I'm at a bit of a loss - the other possibilities I had in mind were all for "normally" powered speakers ie deriving their power from mains (line) in some manner.

best wishes, HJ.

 

Wow! Well, that did it. Never would have thought USBs were different amps. I had tried it in one other socket previously, but had the same problem. Today, thanks to your suggestion, I tried it in another of the slots, and that took care of it. I guess thats gonna be something to remember. That could possibly cause all sorts of problems when hooking up ther components. I will have to try and find a place to read up on that. Thank you very much for the help Hugh.

 

thank goodness! - I'm like a fish out of water with USB...

here's the pdf where I found it - bit technical but good info. Looks like you have to suss whether the USB is self-powered (up to 0.5A available) or bus-powered (only 0.1A max)

is there any way of distinguishing the sockets by just looking at them, I wonder... or do you really have to look at the manual for the computer to see which ones you have?

...bit tedious if they look the same from the outside!

best wishes, HJ