Speaker problem

[tagal4]

I have a set of Harman Kardon speakers that worked great on my desktop computer that is running Debian Stretch, then I started having trouble with sound only coming from one speaker (the one with the controls) and not the other; finally the sound quit altogether. The speakers won't power on and they have a separate power supply (and I checked all the connections), so my first instinct tells me the power supply could be bad, although the fact that one quit before the other gives me pause. I installed a set of JBL computer speakers I borrowed that don't have a separate power supply and no volume control and I can only get a very low volume from them - so low I have to hold one of them to my ear to hear it.

I reinstalled pulse audio and alsa mixer and set them to their highest levels and made sure pavucontrol was installed. That's about all I could figure out to do from reading info on the web. Can I rule out a software problem then and conclude that I need a new power supply for my original speakers, or a new set of speakers? How come some speakers need a separate power supply and some don't? Is there any advantage of one over the other in terms of performance or sound quality? At what point do I need to look into getting a separate sound card? I just want to make sure I cover all the bases before I buy something - like a new set of speakers - that doesn't solve the problem.

Thank you in advance for any help with this matter.

[arochester]

Could you try the Harman Kardon speakers in another computer?

I have Harman Kardon speakers and they work for me in both Stretch and Buster.

Just bought Logitec x140 speakers for £10 from eBay, used but new quality. I had tried them on holiday and liked them.

[tagal4]

I don't think these speakers will work on another computer because they won't power on so I haven't bothered trying. My old computer is in the attic so it would be a major ordeal to get it down and set it up just to try out speakers that I doubt would work anyway.

I've looked into the Logitech speakers. It looks like they don't require a separate power supply like the Harman Kardon ones do. Is the sound quality as good on them?

[FreewheelinFrank]

Some speakers run off USB power. The specification for USB maximum current output is 500mA for USB2 and 900mA for USB3. Technically, the connected device is supposed to "negotiate" withdrawing maximum power. Whether or not computers actually limit the current to USB speaker is not something I know about. I assume speakers are dumb devices and simply try to draw the current they need. But computer hardware that is actually implementing the specification might limit power to 100mA.

500mA at 5V gives a power output of 2.5W. Given that speakers are not 100% efficient, that means a power output per speaker of probably less than 1W from a USB2 socket- which is fairly pathetic, and that's assuming the computer lets the device have the full current. If it doesn't, sound output would be truly feeble.

I have a pair of USB powered speakers which I was surprised to see were rated at 1.3A. They actually worked OK plugged into a USB3 port, but I didn't want to risk damaging the computer and bought a 2A phone charger for a couple of quid (£) and used that.

Looking at the USB specifications, I see that there is a Battery Charging (BC) USB port which will supply 1.5A. My speakers I imagine were made for one of those, but none of my computers have one.

1.3A at 5V gives a power output of 6.5W. Again, because speakers are not 100% efficient, the power output is 2.4W per speaker. (I know this from the specifications.)

They are fine for general use but not very loud. A decent pair of speakers would put out 10W or more per channel- and for that you are obviously going to need an external power supply.

So, check the current rating for your JBL speakers, and make sure it is within the limit of the USB port you are plugging it into.

And maybe try them plugged into a high powered USB adaptor (phone, tablet) to make sure the computer isn't limiting the current available to them, assuming they have a separate 3.5mm jack for input.

As to the non-functioning Harman Kardon speakers, I doubt a failing power supply could cause one channel to fail. Have you tried a multimeter? Is the power supply still putting out the specified voltage? If it is, I'd suspect the internal circuitry.

[tagal4]

Yes, I tried to test the power supply with a multi meter but couldn't get a reading, so I'm thinking it's dead.

I really liked the pair a of Harman Kardon speakers when they were working, so I may look for another pair of them. Just looking on eBay it looks like the power supplies for the HK speakers are half as much as the speakers so I may just replace the whole shebang and be done with it rather than try to revive what I have and spend as much money in the process.

Are add on sound cards worth getting if you just have modest computer listening needs?

[4D696B65]

Are add on sound cards worth getting if you just have modest computer listening needs?

Absolutely not, onboard audio is more than adequate for most people

[tagal4]

Thank you for all the good replies. They have been very helpful.