What could be causing this spike at 60Hz?

[RenPa]

I have a 2010 Asus laptop and a miniDSP Umik-1 since 2015. All worked well with REW and Dirac 3.0 for my thousands of measurements done since then. Yesterday, during the night so in a completly silence environment ( during the day Dirac mic level reads -48issh dB but last night in a more silence room mic level was -41dB) this 60Hz appeared every where. It is NOT a Hummm. My Arcam AVR-21 is dead silent even if I push the main volume at 90 (usually 55-62). With one point measurement only the spike is in all channel but surround left and sub right. In a 9 point measurement withthe help of the propagation window, the spike is in all channels.
I know I can check with REW (need to find a moment for now)but in the mean time what is a probable cause? usb cable? mic itself? Dirac software? or worst of all my receiver?

Fronts

Center

Surrounds

Subs

 

[smygolf]

Do you use a lap top ?
If yes try to disconnect the power cable.

You can also have the power cable connected, turn of Dirac in your Arcam - start REW and use the RTA with pink noise and see if you see the spike.

 

[RenPa]

Do you use a lap top ?
If yes try to disconnect the power cable.

You can also have the power cable connected, turn of Dirac in your Arcam - start REW and use the RTA with pink noise and see if you see the spike.

yes a laptop older than 10 years. The power cable is a little exposed at connector and protected by electrical tape...
RTA + power cord connected confirms the spike either for noise floor or measurements. is it the mic or the laptop the culprit?

 

[smygolf]

I would say it is the power supply on the Pc - hence the suggestion to run on battery
It might also be on the grid to, a refrigerator, washing machine etc that are sending out crap.

A galvanic isolator might help but that is just a guess.

 

[RenPa]

I tried a quasi new laptop in a different room realy silent and his 2 usb ports= always there. With the new laptop and his internal mic the spike is not there

 

[Oddball]

Could be a whole can of issues.

Reinstall the Windows, then proceed. Nobody can tell you what went wrong as Windows really makes it very complicated with REW. At the end it might be the mic, but you won't know unless you clear the software path before that.

 

[smygolf]

Reinstall Win will not help here

I have two JBL 306 in my office connected with 3,5mm plug.
Connected to my work pc (lap top) and with power cable in the Pc i get all kind of interference.
And if i pull the power cable - no interference.

If i connect the 3,5 to my phone and charge the phone via usb to the pc - Interference

At home my pool pump also creates interference if i have the power cable connected to my home pc (lap top)

 

[RenPa]

Reinstall the Windows,

I will not. I have Win10 in my laptop where the problem arrives and Win11 in my son's laptop on Win11 and all the same.

 

[Oddball]

Oh gee, and I thought that my Mac REW was bad. Good luck with MS guys...I guess you will should create a separate thread to spare us of the greif. No pun intended thought. I still have my MS laptop but have not fired it up in ages as don't need MultiEQ-X any more...Not sure why I have it any more but a spare is always a spare.

 

[RenPa]

Report. New mic UMIK-1 and new usb a-c cable. New laptop. The 2-3 first RTA with REW meassurements were weid . Sometime the spike at 60Hz or not. Win 11 mic settings included a multi-mic by default and also an AUDIO recording enhancement (never saw it before).
I delited all those nic-nacs.
I didn't remember the resolutioin of Dirac DLBC . I choose 24bits 48kHz Studio quality. Is it wrong?
I remeasure RTA wihith REW and all seems good. DLBC seems happy too.
I am less familiar with the mic levels in the measurements settings for Dirac: it reads -73dB, I lower channel level to -6.0dB I raise master volume to -32dB and get -47.6dB to each channel.
I little incursion in the conspirationist world would drive to think that Microsoft put something in my old WIn10 now unsupported laptop to mess with me and force me to by a strong enough laptop to support win 11....but I am not a conspirationnist.

 

[smygolf]

I didn't remember the resolutioin of Dirac DLBC . I choose 234bits 48kHz Studio quality. Is it wrong?
There usually are an option to let different software take control of the unit, have that checked and you are good.

When i sweep with Dirac i am usually at 80dB or a tad higher (confirmed with REW)
If you go above 90dB there is a risk that room modes overloads the mic on different positions.

 

[smygolf]

For the Mic, exclusive mode
Pic from Swedish Win