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Hi-pitched frequency from right Monitor?

Discussion in 'Pro Audio Equipment' started by Ardroth, Jun 19, 2007.

  1. Ardroth

    Ardroth Guest

    I can't figure out what is causing a very high pitched frequency to emit through my Right monitor only. It's very distracting. It is in a random pattern, on and off every few seconds. It's like morse code... sometimes it's longer (2-3 seconds), sometimes short (1-2 seconds), in intervals of 1-4 seconds. I can hear it from several feet away, and when you put your ear up to the speaker itself it is very evident. I've tried different things but I still can't get rid of it. I use the speakers with my DAW (they are currently hooked up to my laptop via a mini-stereo out to 2 mono 1/4" jacks). I have a feeling it is something to do with my laptop. Any thoughts on this?! It is incredibly annoying, and I just started noticing it a couple weeks ago, though I've had them for many months.

    Thanks.
     
  2. Link555

    Link555 Well-Known Member

    It could be interferrence problem. Do you have cell phone, modem in room? Or it could be your sound card in the laptop. Sometime digital noise gets coupled onto the power supplies rails which power the speaker drivers.
     
  3. Ardroth

    Ardroth Guest

    I do have a modem, about 5 feet to the left (actually closer to the left speaker than the right one). I have a cell phone too of course, usually in my pocket. I might try turning these things off to see if that's what it is. I can't figure out why it's only coming out of one monitor either... bizarre.
     
  4. Boswell

    Boswell Moderator Distinguished Member

    Obvious thing to try - switch the 1/4" jacks over and see if the HF noise moves to the other monitor. If it does, it's the laptop. If it doesn't, you have a problem with the power amp in the RH monitor.

    I don't think it's the modem or the cell phone.

    BTW, I think you should be considering D-A conversion by a means other than the sound card in your laptop.
     
  5. Ardroth

    Ardroth Guest

    I was just about to try that. I'll post the result. By Digital Analog conversion do you mean an external interface? I use a firepod to record, but when I edit I just plug the monitors right into the laptop. Would you suggest something else?
     
  6. Boswell

    Boswell Moderator Distinguished Member

    With a FirePod, use the CR outputs on the rear. These have the same signal as line outs 1 and 2, but with the volume controllable by the Main and mix knobs on the front. Configure your software to send audio out through the FirePod ASIO driver.
     
  7. Ardroth

    Ardroth Guest

    Ok... i did a little troubleshooting. When the cables are switched between the 2 monitors there is NO difference: still a hi-pitched sound coming from the right. I unplugged the stereo mini-out jack from my computer, and plugged it into my mp3 player. Guess what... no hi-pitched sound! So I now know it is something to do with my laptop... any ideas at what would interfere with one side of a monitor via a laptop?!
     
  8. Boswell

    Boswell Moderator Distinguished Member

    Wait a minute - you said that when you switched the jacks over the high-pitched sound still came from the right? Do you mean it remained in the right hand speaker, or it was on the RH channel from the laptop and it now came from the left speaker?

    Either way, if your speakers are OK with the MP3 player, then I would change to using the main outputs of the FirePod instead of the soundcard. This should solve your high-pitched problem and give you substantially better sound quality at the same time. Since the FP outputs are balanced and at a higher level than the soundcard, you will need to use balanced cables (TRS-TRS or TRS-XLR) into your monitors and may need to adjust the level controls on the rear of the monitors. Operational volume can be controlled by the Main control on the FirePod.
     

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