Left right balance issues

Hi. New to Roon.
I am using a late 2014 Mac Mini as my core. I have it plugged directly into KEF X300A Wireless speakers with a USB to mini USB.

The signal path is great, my issue is everytime I use it there is a few decibels difference between them the channels, left or right and different if I shift the ports around, sometimes it works.

I am trying a new cable but thought I would check with the community for any other reasons this may be happening?


Have you tried adjusting the balance control on the slave speaker?

Edit: How do you have them hooked up to each other? Are they connected with a USB cable or running wireless?

As long as the signal stays in the digital domain, a change in balance needs processing. That does not just happen. Surely not when both, L + R are traveling trough the same cable. Looks like the KEF is a digital active speaker, so I assume that all signal processing (inc. D/A) is handled inside them. Maybe your speakers are faulty?

Did you measure? How much is it?

Note: The perceived balance does not have to come from loudness differences alone, it can also come from a delay.

What ports? What’s the meaning of this statement?

Hi. The speakers are connected with a USB cable. I can fix by adjusting the balance on the slave speaker, but Roon is the only source I have the issue with

I also have a rega turntable connected and zero balance issues. I can also airplay with no issue. Only via Roon do I have the issue. Sorry I mean when I try a different USB port on the back of the mac mini. Probably a 5 decible difference but it varies sometimes more.

If there are no processing instructions setup by you in Roon’s DSP settings for that zone with the issue, then look out for it on your MacMini.

If you use another player software on your MacMini to send audio to the KEF’s you don’t have the issue?

I do enhance the signal path. I guess I can try turning the DSP off and see what happens. I suspect it may be corrosion on the USB ports, the mac is quite old and I live in Singapore so very humid.

I don’t see how that corrosion should do the math required to change the balance between L + R channels in a digital audio stream. And Roon is all about digital audio - no D/A processing included; no analog output.

Great idea. I will test that and let you know

Yes same issue if playing via itunes so not a roon issue.

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I have managed to fix it. I added Speaker Setup to the DSP and increased the gain on the left speaker by 5 decibles. Thanks for your help.

While you surely can do that, you might still want to inspect the settings on your MacMini - possibly you changed the balance settings there some time ago (unintended).

All seems OK but in sound preferences it is saying the selected output device has no output controls.

If anyone else is having this issue I discovered the following app that automatically adjusts balance issues with connected USB devices to a mac. Apprently a known bug. It has worked perfectly for me.


@Nathan_Taylor, I moved this thread to the KEF discussion group so other KEF users may be able to provide ideas.