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Thread: Speakers Pop on Start Up - And Hiss / Buzz - Help?

  1. #1
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    Speakers Pop on Start Up - And Hiss / Buzz - Help?

    Heya,

    Finished the test installation of my PC yesterday and the PC boots up fine etc etc.

    The problem i've encounted is when i turn the ignition the speakers make a LOUD pop.. like really loud (stupid me had my ear to the speaker the first time it happened :P). The speakers alo make a constant hissing noise but i'll explain that later.

    With the popping i've done some searching across the forums and it seems it's because the amp is being turned on before the PC turns on. So basically i need to make the amp turn on after the PC.

    I came up with the following solution, could i use a 12v line from a molex on the Opus 150w as the remote line on the Amp?


    Regarding the speaker hiss, i never had this problem before i had the PC and when the speakers were run off the Head Unit. As soon as i put the PC in the ran the speakers off the amp this hiss became noticable.

    What i did was try different grounding points for the PSU and Amp, to no avail. I tried moving the RCA cables away from the power lines, still hissing.

    I eventually homed the source of the problem down to the amp as i totally unplugged the PC and RCA plugs into the amp so there were only the Remote, 12v, Ground and the 2 speakers going into/out of the amp. There was STILL a hiss, so the problem definately resided with the amp.

    As the problem was still around when the RCA cables were unplugged a ground loop isolator wouldn't solve the problem. I've tried grounding the amp to various different points around the car. Maybe i could try grounding it directly to the battery?

    Do you have any suggestions to the hissing problem?

    Thank for taking the time to read this,

    Regards,
    Rob.

  2. #2
    Takes it in the Rear kevinlekiller's Avatar
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    Yes you can use a 12v from a molex for remote turn on.

    Did you ground all at the same place? Try that.

  3. #3
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    You could use this delay timer http://www.cardomain.com/item/PERVT3

  4. #4
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    Tried grounding the amp and PC to the same place.

    I would try a delay timer but i live in the UK and i don't know where to get one

  5. #5
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    Right i definately know it's the amp as i removed ALL audio input into the amp. The only things connected to the amp was the power in.. remote line.. ground and one speaker.. STILL hissing.

    I tried grounding the amp to different places in the car, even tried directly to the battery but it still hisses.

    I've tried wiring the remote line into the PC instead of from the ACC line, the hiss seemed to get quieter but i don't think it's related.

    Any recommendations? Is there anything i can put in between the speakers and amp to remove the hiss?

  6. #6
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    Did some more testing and found out something very interesting.

    First off my amp as 3 modes.. HP, LP and FLAT. When you use speakers it's meant to be on FLAT. However when i change it to LP the hissing disappears, although no sound comes out of the speakers so thats useless. The hiss is still there on both FLAT and HP modes.

    Secondly i found out if i turn the Input Level on the amp to it's lowest and hiss becomes barely audible (but still noticable if you put your ear near the speaker). This is a great find as all i need to do it turn the volume up in windows and the sound levels are normal.. but the hissing on the amp isn't noticable because the amp levels have been turned down.

    This is an odd solution but it's only temporary, i still want to actually remove the hissing completely, i'd still appreciate some ideas and comments from the information i've been giving.

    Seeing as this seems to be an amp problem, would a better amp fix the problem? I seem to see pioneer amps have inbuilt isolators which may stop the hissing?

    Please give me some feedback,
    Regards,
    Rob.

  7. #7
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    Quote Originally Posted by m00ie
    Did some more testing and found out something very interesting.

    First off my amp as 3 modes.. HP, LP and FLAT. When you use speakers it's meant to be on FLAT. However when i change it to LP the hissing disappears, although no sound comes out of the speakers so thats useless. The hiss is still there on both FLAT and HP modes.

    Secondly i found out if i turn the Input Level on the amp to it's lowest and hiss becomes barely audible (but still noticable if you put your ear near the speaker). This is a great find as all i need to do it turn the volume up in windows and the sound levels are normal.. but the hissing on the amp isn't noticable because the amp levels have been turned down.

    This is an odd solution but it's only temporary, i still want to actually remove the hissing completely, i'd still appreciate some ideas and comments from the information i've been giving.

    Seeing as this seems to be an amp problem, would a better amp fix the problem? I seem to see pioneer amps have inbuilt isolators which may stop the hissing?

    Please give me some feedback,
    Regards,
    Rob.
    HP - High Pass
    LP - Low Pass
    Flat - No effect

    The three modes on your amp are selectable filters on the audio signal. Low Pass only lets the low frequency part of the signal go through. High Pass is the opposite, of course. The hiss that you are hearing is in the high part of the frequency cutoff, this is why you don't hear the hiss whenever you set the filter to LP.

    Make sure your PC case and/or motherboard are grounded properly. I had the same problem and only noticed the hiss whenever the computer was plugged into the power source.

  8. #8
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    Why dont you just get a ground loop isoloator. It will remove the noisee.....
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  9. #9
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    u tried the unbalanced/balance switch on your amp?

  10. #10
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    Nothing to do with the PC as the PC wasn't attached to the car/amp in any way and it still hisses.

    Also means a ground loop isolator won't work unless i can connect it between the speakers and amp, not the amp and pc.. and i donno how that'd be possible when the loop isolator has RCA plugs.

    Erm, i've tried all the switches and knobs i can find on the amp .

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