Author Topic: Unwanted digital noise (Not the standard noise floor) from studio monitors  (Read 4979 times)

0 Members and 1 Guest are viewing this topic.

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Hi!

A few months ago i bought a pair of Yamaha HS7 studio monitors to use together with my desktop.
I will list my gear first so that you can form a picture of the situation as you read.

Tower: Cooler master Cosmos SE midi tower
Motherboard: ASUS Z170-E Socket 1151
Processor: Intel Core i7-6700K skylake
Processor water cooler: Corsair hydro series H115i
RAM: Crucial Ballistix Sport 16gb
GFX: GTX1080 G1 gaming
SSD: Samsung 850 EVO
HDD: Seagate Desktop SSHD
PSU: Corsair CX 600M 600W
Wifi: ASUS PCE-AC68 AC1900
Fans: 2x140mm in front, 1x280mm on top and 1x120mm in the back
External soundcard: Tested with both Focusrite Scarlett 4i2 (USB powered) and Focusrite Saffire 26 pro (Separate power supply and firewire connection)
Studio monitors: Yamaha HS7 active monitors
Cables: Standard power cables with ferrite beads. All jacks and XLR cables are balanced. Firewire cable is a IEEE 1394 compliant one.
Monitor: ASUS 24 inch LED
Keyboard and mouse: Corsair K55 and SteelSeries Rival 300S

When i plugged them into my Focusrite Scarlett 4i2 sound card (USB powered) there was this constant buzzing noise, which was emphasized whenever i moved the mouse or did anything that demanded power from my desktop. I tried changing the power outlet configurations to all different permutations with wall outlets, power strips (with and without surge protector), but to no avail.
I then tried to disconnect all the hardware on my machine except the processor and storage units, still no difference. I then checked that all the cables were properly shielded, although i haven't opened any of the components since my electronics skill isn't up to par. I have googled this for hours but nothing seems to work.
The only thing i can imagine it being is some kind of resistance issue in the power cable for my PSU, which makes it easier for the ground to go through the firewire, out in my monitors and down through the power cables there.

This is so frustrating, considering i have spent lots of money now on failed attempts, my recordings sound like crap (The buzzing affects my guitar pickups, so the closer i move to the machine the worse the sound gets) and it is impossible to use my monitors when playing games or such.
If any of you have any ideas, or want to help out i would be really grateful!

I will update this post continuously as i come up with more info, and take some pictures when i get home!

Thanks! :)
« Last Edit: November 25, 2019, 07:40:43 am by Vildhjarta »
 

Offline iMo

  • Super Contributor
  • ***
  • Posts: 5570
  • Country: va
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #1 on: November 25, 2019, 11:25:10 am »
How it works with your notebook?
Readers discretion is advised..
 

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #2 on: November 25, 2019, 11:36:28 am »
I will see if i can get my hands on a laptop today! If the noise is absent on the laptop, what would you suggest the issue is? :)
 

Offline magic

  • Super Contributor
  • ***
  • Posts: 7454
  • Country: pl
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #3 on: November 25, 2019, 04:41:02 pm »
buzzing noise, which was emphasized whenever i moved the mouse or did anything that demanded power from my desktop
Oh yeah :D

The only thing i can imagine it being is some kind of resistance issue in the power cable for my PSU, which makes it easier for the ground to go through the firewire, out in my monitors and down through the power cables there.
Yep, that's the thing, usually. Even if your ATX ground cabling has 1mΩ of resistance, that's still 10mV of ground bounce when the CPU turns on and off and draws 10A of current from the 12V rail. If the speakers have their own Earth connection then they see the signal riding on top of that bounce and can't tell them apart.

A cheap not-really-solution: load all CPU cores to 100% ;D

Do you have balanced inputs on those speakers?
 

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #4 on: November 25, 2019, 04:45:40 pm »
Yes, the outputs on both cards are balanced as well as the inputs on the monitors.
I tried the setup with a Macbook now. No noise with nor without the charger connected.
Do you think the high resistance resides in the PSU or in the power cable for the PSU?
Thanks for the reply!
 

Offline wraper

  • Supporter
  • ****
  • Posts: 17952
  • Country: lv
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #5 on: November 25, 2019, 04:53:27 pm »
Your sound card is crap if this happens. Did not utilize it being outside of PC and on external PSU. IMHO buy USB isolator or get rid of it and buy different sound card.
 

Offline magic

  • Super Contributor
  • ***
  • Posts: 7454
  • Country: pl
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #6 on: November 25, 2019, 04:58:51 pm »
This is indeed something that shouldn't be happening with differential signalling, in theory ::)

Is the noise still there when nothing is being played? Is it there if the cables are disconnected but there is ground connection between the PC and the monitors?

or get rid of it and buy different sound card.
Which one? ;)
Without that bit of information OP might as well make a new career as a sound card reviewer.
« Last Edit: November 25, 2019, 05:00:28 pm by magic »
 

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #7 on: November 25, 2019, 05:02:15 pm »
This is indeed something that shouldn't be happening with differential signalling, in theory ::)

Is the noise still there when nothing is being played? Is it there if the cables are disconnected but there is ground connection between the PC and the monitors?

The noise is there from the moment i turn on the computer, and is severe if i enter the BIOS or start up games etc.
I tried disconnecting the audio cables between the speakers and the sound card, and the noise vanished.

As i mentioned as well, the buzzing is there even when the sound card is turned off (The Saffire 26 with its own power supply)
 

Offline magic

  • Super Contributor
  • ***
  • Posts: 7454
  • Country: pl
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #8 on: November 25, 2019, 05:15:00 pm »
I tried disconnecting the audio cables between the speakers and the sound card, and the noise vanished.
Okay, but what if you add ground connection then? Take some wire, stick the ends into the appropriate holes in the XLR. Or dunno, stick pins into the holes and touch them with the tips of a guitar cable, whatever. Or touch some other connectors with exposed ground, if available, if you are worried about damaging the XLR.
It may be a star grounding fail in the soundcard, or it may be a star grounding fail in the monitors. If you get noise with only ground connection, you can be reasonably sure that changing soundcards won't fix anything. At this point it would be USB isolator or some weird trickery like manually converting USB to star grounding.
« Last Edit: November 25, 2019, 05:17:42 pm by magic »
 

Online David Hess

  • Super Contributor
  • ***
  • Posts: 17429
  • Country: us
  • DavidH
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #9 on: November 25, 2019, 10:36:04 pm »
If the buzzing is at the line frequency or a harmonic, then it might be RFI from the input rectifier in the ATX power supply.  A different power supply might fix this.

But I agree with wraper, install a USB isolator between your computer and the USB sound device.  USB is a real problem for audio because of its lack of galvanic isolation.
 

Offline Bassman59

  • Super Contributor
  • ***
  • Posts: 2501
  • Country: us
  • Yes, I do this for a living
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #10 on: November 25, 2019, 10:48:33 pm »
Are the monitors plugged into a surge-suppressor power strip? If yes, how old is that power strip? Try replacing it. The MOVs in power strips get leaky with age and "hits," and that can cause all sorts of noise.

Once upon a time, a friend and I were trying to track down a noise source in our rock club's PA system. Turns out that a power strip which had only Little-Lites plugged into it, was the culprit. That power strip was plugged into the same circuit as the console. With the power strip unplugged, silence. And yes, we unplugged the Little-Lites' wall warts first.
 

Offline NOON Design

  • Contributor
  • Posts: 31
  • Country: au
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #11 on: November 26, 2019, 07:55:12 am »
Some computers can have horrendous ground noise, for various reasons other people have speculated on. Your sound card is from a reputable manufacturer and is not likely at fault. You've likely got a ground loop happening.

Professional balanced audio connections are designed to handle this kind of situation though. The 2 signal leads are referenced to each other rather than to ground, which is just a shield. You can safely lift the ground from one side of the cable. It will probably be quietest if you lift it at the sound card end so the shield is coming from the speakers back, but only trying it will tell. Cut or desolder the shield in the XLR or TRS connector and see if it makes a difference.
 

Offline magic

  • Super Contributor
  • ***
  • Posts: 7454
  • Country: pl
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #12 on: November 26, 2019, 08:50:50 am »
This is a fine solution, but one caveat applies: if either end loses its earth connection through mains for whatever reason, things may go poof. It certainly is a danger with low voltage CMOS circuits and I'm not sure how resilient audio gear is.
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 39026
  • Country: au
    • EEVblog
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #13 on: November 26, 2019, 09:34:14 am »
Can you get the frequency of the buzzing noise?
 

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #14 on: November 26, 2019, 05:05:03 pm »
Thanks for all the replies!
But I agree with wraper, install a USB isolator between your computer and the USB sound device.  USB is a real problem for audio because of its lack of galvanic isolation.
The new soundcard is firewire, still the same noise.
Are the monitors plugged into a surge-suppressor power strip? If yes, how old is that power strip? Try replacing it. The MOVs in power strips get leaky with age and "hits," and that can cause all sorts of noise.
I have tried with many different power strips, and the surge suppressor strip is just a month old.
Professional balanced audio connections are designed to handle this kind of situation though. The 2 signal leads are referenced to each other rather than to ground, which is just a shield. You can safely lift the ground from one side of the cable. It will probably be quietest if you lift it at the sound card end so the shield is coming from the speakers back, but only trying it will tell. Cut or desolder the shield in the XLR or TRS connector and see if it makes a difference.
Kind of embarassing since i am asking for help on an electronics forum, but i am not confident with my skills enough to go inside components (Ref. the post below by magic) :-X
This is a fine solution, but one caveat applies: if either end loses its earth connection through mains for whatever reason, things may go poof. It certainly is a danger with low voltage CMOS circuits and I'm not sure how resilient audio gear is.
Can you get the frequency of the buzzing noise?
There seems to be many layered on each other, but the most prominent one when i run games is around 1830-1850Hz.
I will upload an audio clip. The first part of the audio is when i am ingame, and the last 5-6 seconds is just the "standard" noise with some mouse movement.
 

Offline rsjsouza

  • Super Contributor
  • ***
  • Posts: 6106
  • Country: us
  • Eternally curious
    • Vbe - vídeo blog eletrônico
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #15 on: November 26, 2019, 06:09:43 pm »
I used to have this issue as well, but it was with the built-in soundcard. Once I got one of those cheapie USB pendrive soundcards (Syba is the one I have) I could record dynamic microphones without problems.

The USB isolator will help with conducted noise but it will be less effective for RFI. If you have a metallic box, you can try to shield your soundcard. Also, check what are the effects of touching a metallic part of your system. Sometimes you get different behaviours by touching different components.
Vbe - vídeo blog eletrônico http://videos.vbeletronico.com

Oh, the "whys" of the datasheets... The information is there not to be an axiomatic truth, but instead each speck of data must be slowly inhaled while carefully performing a deep search inside oneself to find the true metaphysical sense...
 

Offline magic

  • Super Contributor
  • ***
  • Posts: 7454
  • Country: pl
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #16 on: November 26, 2019, 06:15:24 pm »
I won't say it sounds exactly like my PC's ground bounce but it sounds similar. Anyone (who owns a desktop PC, heh) can produce such noise by connecting headphones between the motherboard ground and chassis. Or insert a jack cable into the audio input, press the tip at the other end against the chassis and record.

You have 50Hz mains in Norway, right? So that 120Hz thing isn't from mains but some 7200RPM disk or whatever. Dunno, given that everything else is 900Hz and its harmonics I suspect it's ground bounce rather than RFI from the PSU. But ground noise really should be eliminated by balanced signaling :-//

Failure of safety ground is a rare occurrence, it has never happened to me yet. And if your mains wiring were faulty, there would be no ground loop ;) So it should be safe to try the ground lift at least temporarily to see if it makes a difference, even if I personally wouldn't make such installation permanent without adding some additional protection. You don't need to modify any equipment, only the cable. Use the lousiest and cheapest one you have ;)

Do you have a DMM?
« Last Edit: November 26, 2019, 06:16:59 pm by magic »
 

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #17 on: November 26, 2019, 06:32:15 pm »
You have 50Hz mains in Norway, right? So that 120Hz thing isn't from mains but some 7200RPM disk or whatever. Dunno, given that everything else is 900Hz and its harmonics I suspect it's ground bounce rather than RFI from the PSU. But ground noise really should be eliminated by balanced signaling :-//
I tried once more to disconnect my SHDD which is running at 7200rpm, but still the same. :/
Failure of safety ground is a rare occurrence, it has never happened to me yet. And if your mains wiring were faulty, there would be no ground loop ;) So it should be safe to try the ground lift at least temporarily to see if it makes a difference, even if I personally wouldn't make such installation permanent without adding some additional protection. You don't need to modify any equipment, only the cable. Use the lousiest and cheapest one you have ;)
I'll buy an extra cable set that i can experiment with.
Do you have a DMM?
No, definitely would come in handy now!
 

Offline madires

  • Super Contributor
  • ***
  • Posts: 8276
  • Country: de
  • A qualified hobbyist ;)
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #18 on: November 26, 2019, 06:59:02 pm »
Another possible source of the buzzing is a SMPSU powering audio stuff. In that case proper filtering of the audio gear's DC power input helps (common and differential mode noise).
 

Online Bud

  • Super Contributor
  • ***
  • Posts: 7276
  • Country: ca
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #19 on: November 26, 2019, 07:07:55 pm »
USB power bus is full if crap. Connect an oscilloscope and see it for yourself. If you power your audio from USB you should change to a standalone power supply as the first step. Eliminate that noise source before doing anything else.
Facebook-free life and Rigol-free shack.
 

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #20 on: November 26, 2019, 07:29:49 pm »
Another possible source of the buzzing is a SMPSU powering audio stuff. In that case proper filtering of the audio gear's DC power input helps (common and differential mode noise).
https://www.corsair.com/corsairmedia/sys_master/productcontent/corsair-psu-spec-table.pdf
If you search for CX600M. Can you get any clue from the specs?
It seems to me as well that the issue comes from the PSU.
USB power bus is full if crap. Connect an oscilloscope and see it for yourself. If you power your audio from USB you should change to a standalone power supply as the first step. Eliminate that noise source before doing anything else.
The sound card i use now has its own power supply, and uses a firewire connection to the PC.
 

Offline magic

  • Super Contributor
  • ***
  • Posts: 7454
  • Country: pl
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #21 on: November 26, 2019, 08:21:00 pm »
I tried once more to disconnect my SHDD which is running at 7200rpm, but still the same. :/
I presume the mic picked this noise straight from the air, not through the speakers. No point testing such things ;)

Another possible source of the buzzing is a SMPSU powering audio stuff. In that case proper filtering of the audio gear's DC power input helps (common and differential mode noise).
That audio stuff is powered by a normal transformer. And, tangentially, it is indeed earthed to mains.
https://www.head-fi.org/threads/yamaha-hs7-internals.745768/

By the way, you could do the headphone trick I described. Maybe use some cheap headphones, though nothing bad should happen unless something is terribly wrong with the computer. If you hear the exact same noise that comes from the speakers, we can be quite reasonably sure that it truly is ground bounce that gets into the speakers. I think.

And looking at those internal pictures really makes me curious what would happen if the ground of those speakers is connected to the PC's USB ground but there are no signal connections. You know what, it seems there are 1/4" jacks there in addition to XLR. So plug a jack cable in and plug any sort of USB cable into the PC. Take the USB plug at the other end and touch its metal part to the ground (sleeve) terminal on the audio jack. See if there is noise. BTW, if you touch any other terminal, there will surely be noise, and perhaps somewhat loud.
« Last Edit: November 26, 2019, 08:23:57 pm by magic »
 
The following users thanked this post: rsjsouza

Offline VildhjartaTopic starter

  • Contributor
  • Posts: 15
  • Country: no
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #22 on: November 26, 2019, 08:55:41 pm »
I tried doing the jack vs USB cable experiment.
And indeed, the noise was there, even worse.
In this audio clip i first only have the tips touching, then i move the mouse, and lastly i drag windows around on my computer.
 

Offline magic

  • Super Contributor
  • ***
  • Posts: 7454
  • Country: pl
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #23 on: November 26, 2019, 09:41:27 pm »
Hmm, I expected it to be exactly the same, not louder. Perhaps it's a matter of different resistance of the phono cable vs XLR. You are sure that you touched the ground part rather than some signal input?
https://connector.pinoutguide.com/3_pin_stereo_plug/

If that's confirmed then it seems that your monitors simply don't like ground currents flowing through them, simple as that, and the soundcards have nothing to do with it this time.

And I suspected that this may be the case because it looks like the monitors have plenty of ground loops inside, between the various boards connected with cables and screwed to the metal chassis.
That's :-- for Yahama.

Well, since this is balanced connection, you can disconnect ground in the analog cable, as others suggested. To protect equipment in the unlikely event that one side loses earth connection, a pair of diodes (one in each direction) could be wired between the two grounds where they are cut from each other. Diodes allow the two grounds to differ by a few mV, so the noise will almost certainly be stopped, but if one end becomes floating, they will ensure that this difference stays less than 1V. Maybe it's paranoia, but diodes cost peanuts so why not.

And there is another possible solution, which may also reduce noise pickup by unbalanced soundcard inputs. That is to modify the USB cable such that it takes its ground from the PC's chassis rather than the motherboard. You would cut open the external isolation of the cable, cut the shielding braid, cut the black wire inside the cable and tie its end to some screw on the chassis. USB will probably tolerate this hack, and the soundcard will have undisturbed connection to earth, coming straight from mains through the PC chassis.
« Last Edit: November 26, 2019, 09:45:41 pm by magic »
 

Offline EEVblog

  • Administrator
  • *****
  • Posts: 39026
  • Country: au
    • EEVblog
Re: Unwanted digital noise (Not the standard noise floor) from studio monitors
« Reply #24 on: November 27, 2019, 12:13:51 am »
If that's confirmed then it seems that your monitors simply don't like ground currents flowing through them, simple as that, and the soundcards have nothing to do with it this time.
And I suspected that this may be the case because it looks like the monitors have plenty of ground loops inside, between the various boards connected with cables and screwed to the metal chassis.
That's :-- for Yahama.

Googling shows similar reports from others, so yeah, maybe unforgiving Yamaha's.
 


Share me

Digg  Facebook  SlashDot  Delicious  Technorati  Twitter  Google  Yahoo
Smf