I have an older Logitech 5.1 speaker system for my computer that uses 3x3.5mm plugs for input. All of my newer computers only have a single 3.5mm output that handles 5.1 + voice (apparently I was mistaken, this is not possible). What kind of converter can I use to funnel all three of those speaker inputs into a single output?

Edits based on comments:

  • Speaker model is X-540
  • I'd like to get full 5.1 support with decent quality audio, but if the best we can do within budget is simply get all the speakers working I'll take that solution too.
  • Budget is around $100 but less is always better
  • The speakers will be shared via KVM among 3-4 computers, all with 5.1 support via USB but none with optical/coax
  • What is the model of the Logitech speaker system?
    – 0-60FPS
    Dec 27, 2016 at 18:18
  • 2
    Can you give us the models of the computers? There is a 3.5mm to optical but they are rare. It seems that maybe your computers do not have true 5.1 sound. Also are you looking for true 5.1 sound or are you just looking to get all speakers working?
    – Jeff
    Dec 27, 2016 at 18:23
  • 1
    You might need a USB sound card to run the 5.1 system properly, it doesn't seem like your computers support 5.1 audio.
    – 0-60FPS
    Dec 27, 2016 at 18:24
  • I've browsed through Amazon and found nothing exciting in the USB sound card department. There are basically two models (rebranded by a dozen manufacturers) and neither outputs anything over 16-bit from what I read in the reviews. Any suggestions in that department?
    – thanby
    Dec 27, 2016 at 20:53
  • Do you have a budget?
    – 0-60FPS
    Dec 27, 2016 at 22:55

2 Answers 2


The other answer's suggestion is a bit expensive for my taste (with several hundred dollar).

So I can recommend the soundcard I'm using myself to power my 5.1 speaker system. However you don't really need all the features so instead I'm gonna recommend the functionally largely equivalent, but cheaper version:

The ASUS Xonar U5

On Amazon.com and on the official website.

For the relevant I/O it features 3x 3.5mm jack output for your speakers as well as S/PDIF. The audio processor seems to be just slightly worse than that of my card but should still do a good job. Not that I don't know whether Dolby Live (a driver technology to dolby digital encode the system audio on the fly so you can squeeze the data into the bandwith limit) is a thing for the U5 so you may not be able to use more than two speakers over SPDIF.

OS compatibility is a given and it will work with all Windows and OS X / macOS versions (at least down to Win7).

If you're feeling fancy you could also go with the Xonar U7 however then you'd have to look out for the fact that left and right have RCA instead of 3.5mm jack output (but the bundled software seems to be better with the U7).


Top of the line for external sound would be the Creative X7

Official page

Also: 3.5mm to RCA adapter

And in case you need the reverse of that adapter: RCA female to 3.5mm adapter

  • @thanby Don't forget to match the impedance of your speaker system (4Ω)
    – 0-60FPS
    Dec 27, 2016 at 22:54

Your Answer

By clicking “Post Your Answer”, you agree to our terms of service, privacy policy and cookie policy

Not the answer you're looking for? Browse other questions tagged or ask your own question.