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Getting Rid of Sizzling in my Monitors

Discussion in 'Monitoring / Headphones' started by ian_lucero, Jul 31, 2007.

  1. ian_lucero

    ian_lucero Guest

    I've been trying to pinpoint where the noises are coming from. I run all my gear through a Furman that is hooked through a UPS (to be extra anal) and the buzzes and hums got a little better but I still get sizzling. Not crackling, but sizzling.

    Will hooking up something like a hum eliminator do the trick? I know it isn't a hum but could it be related?

    Gear is:

    Computer - Mac Pro
    Soundcard(via Optical) - Edirol FA-66
    Sub (from FA-66 via Balanced XLR) - KRK RP-10S
    L/R Monitors(from Sub via Balanced 1/4") - KRK Rokit 5

    I've tried hooking up the soundcard to the MacPro via Firewire but that just gives me all kinds of demonic noises. Optical has been the way to go for me.

    Anyone know how to solve this?
  2. Thomas W. Bethel

    Thomas W. Bethel Well-Known Member

    Unplug everything from your speakers do they still sizzle?

    Start plugging in equipment until they start to sizzle. You have found the problem.

    Sounds like it could be some hash from the UPS. Some UPS's are not true sine wave but are more like rounded square waves and this can cause audio equipment some problems.

    Best of luck and check back with more questions
  3. Boswell

    Boswell Moderator Distinguished Member

    Be methodical. Strip it right down. Do the L/R monitors on their own (no sub) when plugged into the FA-66 show the problem? Do you get it when the FA-66 is not connected to the Mac? Have you tried different monitors? Have you tried those monitors with a different source?

    A hum eliminator is unlikely to work for this type of problem.
  4. mark02131

    mark02131 Active Member

    Yes pinpoint the source, Easier said than done, I know....
    Sizzling is not a good sound. You may have a bad sound card.

    Plug some head phones into the Edirol FA-66 (sound card) just to check if its quiet.

    If the sound card is still sizzling and you have nothing but head phones plugged into it. It uses 9v for power. Hook it up to a 9v battery if it's still making noise its not your power.

    You also may take the sound card and phones to another room or even location and see if it's still Sizzling.

    If you sound card is quiet. plug the monitors directly into it skipping the sub, then see if it's quiet. You can also see if the monitors them self's are quiet with nothing plugged into them.

    You could try plugging some other source into the speakers just to check the speakers.

    and lastly it could be a digital problem coming from the PC, but unplugging the optical cable will tell you its the PC or the sound card.

    Just keep trying different things until you find it. -- Good Luck
  5. ian_lucero

    ian_lucero Guest

    It does seem like the Soundcard (FA-66) is causing the noise.

    Turning it off makes the hi-pitch sizzling go away. It is like "skipping sizzle" sound. Anyway... Using the card firewire bus powered makes it worse. There is a lower hum introduced. The sizzle is gone but now it has a bunch of overtones and humming. Weird.

    Plugging in just headphones, the card sounds quiet. So it almost seems it has something to do with the way it is routed.

    Ah ha! I unplugged the Optical cable. Sizzling is gone! But now how am I suppose to get sound from the mac to the soundcard? Maybe it's a crummy cheapo optical cable? Now I'm using a shorter more expensive optical cable, still the same, sizzle.

    So I'm guessing it is the way things are routed. Cables crossing things, a mix of cheap cables or something else. IF the sizzle goes away with the removal of the Optical cable - what do I do now? That is my only way of getting sound out of the computer to the soundcard. I don't want to use a firewire cable because there are worse sounds using that.
  6. mark02131

    mark02131 Active Member

    Good Job, You have narrowed the problem. A better optical cable most likely wont fix the problem.

    It sounds like there's a driver on the MAC that sending the sizzling to the optical outputs. and most likely you could plug in headphones into the MAC and get the same results. Its also strange that the firewire is worse, really that should work great. There is something going on with the MAC.
  7. ian_lucero

    ian_lucero Guest

    I figured a better optical cable wouldn't do the trick but I had one lying around and thought it give it a try.

    That is interesting your theory about a 'driver' being the culprit. I don't get any sizzling though through headphones. It is super quiet. It is only through the monitors that I get the sizzle.

    So now I'm wondering if this has anything to do with a subtle ground loop of some kind. I don't know if I use that term correctly. Basically all my gear is plugged into 1 outlet which isn't on its own circuit.

    I'm going to try plugging the mac into different outlet throughout the house to see if that solves anything.
  8. Link555

    Link555 Well-Known Member

    Listen to Boswell be methodical- go through your signal chain one step at a time. Start with the speaker themselves.
  9. mark02131

    mark02131 Active Member

    check all the audio devices you have on the MAC, Also check the volume controls for the output devices.
  10. ian_lucero

    ian_lucero Guest

    Thanks Bethel and Boswel for breaking it down, simply. On the entire chain I started with just the speakers. Quiet. I started plugging things in, and all was quiet up until I got to the optical cable. Something is fuzzy about that connection.

    Now when you say to be methodical and go through the chain - do you mean to also isolate each cable in some way?

    I really do think it has something to do with that optical connection. And if this is THE cause, what do I do to get sound to the soundcard? Do I just change the soundcard altogether? I can't tell if it is the connection on the Mac or the Soundcard.

    I have connected the soundcard to my MacBook, which is running off of battery and I still get the sizzling sound. Plugged into AC, sizzle remains but not any worse.
  11. ian_lucero

    ian_lucero Guest

    Ok so I have the soundcard with monitors connected to my macbook which ISN'T running off AC, just battery. Soundcard is plugged into its own power source.

    I do get a very slight buzz/sizzle.

    Now when I turn on my MacPro, which is sitting under the desk (soundcard sits atop a DV deck and that on the MacPro) the sizzling is back.

    (gonna try something)

    20 seconds later...

    I unplugged the LCD power source (which an older Apple Studio Display) and then I woke the computer from sleep. NO SIZZLE.

    (I'm going to try to plug the LCD monitor into a different power source (circuit) and see what happens.
  12. ian_lucero

    ian_lucero Guest

    A big problem is the LCD.

    It is an older ADC Apple monitor which mean I need a special 'transformer' adapter that feeds it power. That then plugs into the Mac. On older macs you use to be able to just plug the LCD right into the proprietary ADC out and be able to power the monitor, get the video signal and run USB. But now that macs all have DVI instead of ADC you need to first plug it into a DVI to ADC adapter then to the mac.

    Noise everywhere.

    I've had this annoying buzzing - sizzling problem forever and sometimes it disappears and then reappears. Now it is gone which seems like for good, but at the expense of me not being able to use my computer monitor. I do have another external monitor hooked up but it isn't nearly as big as it needs to be. This cheaper and crappier samsung monitor surprisingly does not cause any noise to the sound system.

    I have been wanting to get a new wide-screen for some time now. This will happen soon.

    Thanks for all the help.
  13. mark02131

    mark02131 Active Member

    Good job, You did all the work, I would also considerer still using the firewire or USB to get the data from the sound card, you may get a little better quality, I guess try both and see which one works best. Apple has some really nice new monitors, I wish I had one. -- Later.
  14. Boswell

    Boswell Moderator Distinguished Member

    It does sound as though the problem is with the Mac and/or its display monitor. It's not possible for the optical cable to pick up interference in the way an analog cable might, and if the data in the Mac is all digital, it's not easy to see where the interference is getting in.

    I've seen bad clock jitter on S/PDIF links cause strange interference, but normally the audio is affected as well. It might be worth going against conventional wisdom and trying an analog cable from the Mac into the sound card instead of optical.
  15. ian_lucero

    ian_lucero Guest

    Thanks mark.

    I don't think I will be able to afford another Apple monitor, although they are nice, for what I'm doing at this point which is video/audio editing, what I really need is a big desktop or 2 affordable wide-screens.

    As for the optical vs. firewire/usb i/o. Right now I'm using the soundcard mainly for Output of sound. I do not capture of audio through the Edirol. The pres are kinda crummy. So I don't see how much more clarity can be fed to the speakers and seeing that I still get noise via Firewire, I'm not going there. But if I really can achieve more info via firewire for better sound out of the monitors, then will try to make that work.

    @ Boswell

    Thanks for the help. I considered the analog route as well but the only Out I have from the Mac is Un-Balanced 1/8". So that would mean a 1/8" to RCA, which I have and will try, but man the quality can't be that good.
  16. Boswell

    Boswell Moderator Distinguished Member

    OK, but this is for diagnosis - do you get the problem when you use an analog connection?

    Of course it still could be the FA66 and its optical receiver. When there is no optical input, the receiver shuts down. As part of the diagnosis, you need to try plugging the FA66 optical input into the optical output of another device such as a DAB radio, minidisc deck or CD player, and see whether you get the noise problem when that source.
  17. ian_lucero

    ian_lucero Guest


    I'm using anologue input now and the sizzling / buzzing is gone.

    But I do want to try to find out if the optical connection is messed up.

  18. Spase

    Spase Active Member

    I would also make sure your connections are clean. I'm not sure what would be best for cleaning an optical jack. I would think Isopropyl Alcohol and a q-tipwould work, but maybe someone knows a better way to do it.
  19. Boswell

    Boswell Moderator Distinguished Member

    It can't be the optical connection itself or you would hear sync problems with the main audio material. Given what you've reported so far, it's much more likely to be the DACs in the FA66, which will be muted in the absence of an S/PDIF recoverable clock.

    I think you need to find another optical S/PDIF source and try the FA66 and monitors on that.

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