I replaced my old monitors with a pair of HS5 speakers and I got a lot of interference picked up. I have recently replaced my Behringer UMC interface with a UR44C which I am most impressed with but the issue remained. Windows 11 PC of recent vintage but no special sound cards or video cards, just Intel chips.
I isolated the issue.
Independent of volume - noise happens with volume on the interfaces at zero.
If I disconnect the USB it is silent (but…!)
The noise seems to be affected by the mouse moving, but not sure if the RF is related to screen changes or mouse.
Both interfaces produce the noise.
The old speakers didn’t seem to produce the noise, but as I cooked them, I can’t isolate. However, the connection was to one speaker with a lead from the powered speaker to the extension.
Switching 1/4" cables did not affect it.
I thought my 1/4” cables were good quality but I cracked the problem, but don’t understand why. I put stereo 1/4” cables to connect each individual HS5 and the connection is now silent.
Agreed with Nico5.
Balanced cables are less sensitive to EMI interference.
If it were me, I would still be trying to find (and eliminate) what is creating the electric noise to start with, not only for my insatiable curiosity, but also to avoid hearing it again later on your recordings.
Even more so that speaker inputs (10k ohms impedance) are normally not so sensitive to EMI, so the culprit emitter could be abnormally strong.
I once found out that the wall plug of an HP printer was leaking EMI like crazy that my microphone cables picked up in some contexts.
It is a puzzle. And agreed, it would be nice to pin down as it hints at something going bad somewhere.
The best I can localise it to is within the PC in that the USB cable being attached is the factor. I’ve switched USB ports, tried the UR44C powered through a 3.1 USB-C, switched various other USB ports when powered through the power supply. I have eliminated it being the interface as I mentioned.
I’ve tried removing the wireless keyboard & mouse USB dongles, and it does stop if the PC is powered down. As the PC is a silent PC, no fan just a massive heatsink, and is essentially just an ASUS motherboard with Intel chipset, I am left with disabling things like Bluetooth which I don’t normally use. I’m sure there’s a long list of things I’ve not tried!
The inputs to the interface are reasonably quiet, the only other RF I suffer from is the Strat single coil pickups are prone to picking up the central heating pump when that kicks in, which is what puzzles me, I would have thought I’d struggle with recording noise. The fact it is independent of output volume so it is the speaker cables themselves picking up the RF - the headphones output is silent. Longer cables seemed more prone as you’d expect. I am suspicious that something about the HS5’s happens to have tuned into the noise.
Yeah - all the evidence suggests RF - otherwise the balanced cables shouldn’t really have made a difference.
Some USB cables come with a little magnet wrapped around them - typically nearer to one end. If you have some, and you’re curious enough - that’s one thing I’d do some testing with (USB cable with magnet vs without magnet).
Occasionally, a monitor could also be a source of RF interference.
Did some more playing, switching back in a known noisy cable.
Flight mode, disabling displays, powering down displays, unplugging and switching off wireless devices, disabling WiFi make no difference.
Disabled the C1E power thing. No difference.
The one thing that stopped the noise was putting the system to sleep. However, after a few seconds, the sleeping PC decided to do its own thing and the disks activated. I am pretty certain the RF is coming from one or both of the SSD drives. It has the same sort of pattern as the flashing of the drive LED.
ALWAYS(!) use balanced cables from interface to powered-Speakers,(XLR or TRS jacks) , there should be no hum or noise. If it does hum, there is something else going on. (f.e. the interface too close to another device’s Powersupply).
My naïve thinking was that if something had to be balanced, then they’d fit a balanced connector.
Anyway, after having a “How are people supposed to know that?” moment, it made me wonder about what Yamaha stated in their instruction manual. Much to my surprise (who reads manuals anyway?) the HS5 manual has a clear section on “Connectable Cables” that explains using TRS cables which in many years I hadn’t come across their use other than as a stereo connector - as mentioned at the start it just occurred to me that this could be a solution. OTOH my 1 metre cables fall within their “can probably be used without any problems”. The PreSonus monitors I replaced were hum-free with the same cabling so something about the HS5 tuned the cables into the SSD hum.
The UC44C manual just says “These jacks can be connected to phone-type (balanced/unbalanced) plugs” without explanation. Checking out a Behringer manual for a mixer, they show a TS cable for active speakers with no other advice.
Anyway, a lesson has been learned and hopefully this will serve as useful advice to other people.
Studiomonitors will always have a balanced connector, either xlr or trs, most of them do not even have unbalanced(cinch mostly) connectors.
Inteference hum will often be caused by the computer itself or the attached screens. Or the shielding within the speakers ampliers is not that perfect. With unbalanced cables, even very short ones, you can pickup this inteference when cables are running close to these appliences, so always better tp use balanced connections to be on the safe side.