Results 1 to 8 of 8

Thread: Sub noise...frustrated

  1. #1
    Newbie bumpbmxsbc's Avatar
    Join Date
    May 2009
    Posts
    4

    Sub noise...frustrated

    Okay in this area im not a newbie even if this question sounds like it.

    I can usually track these issues down but im at the point where im frustrated so im probably looking past it so im asking for new eyes to look at the issue.

    Here is the scenario,

    I have two amps, a 3000 watt mono block for the subs and 1600 watt 4 channel for the highs.

    Everything is terminated with no copper exposed.

    Pioneer AVH-4200DVD

    The power wire is a 2g and it goes across the firewall and in from under the glove box.

    The ground is one of the bolts for the back seats, tested the ground with a multimeter.

    The remote and rca's are all run down the driverside and power is on the passenger.

    okay so now for the frustrating part,

    When you turn it up with the subs on (and the music paused)i get a thumping deep deep thumping. Its not a wine and its only through the subs. It sounds like the exhaust.

    I have checked every ground and they all are good.

    i just know its probably something extremely stupid and easy and its most likely because im just so frustrated that im looking past it.. so anyone have some input?

    http://www.youtube.com/watch?v=r2vH4...layer_embedded

  2. #2
    MySQL Error soundman98's Avatar
    Join Date
    Jan 2008
    Location
    on the border of northern IL/IN
    Posts
    5,848
    the good news-- you've only got a ground loop.
    the bad news-- it's a ground loop.

    in some cases, different amps are more sensitive to this then others, which might be the reason that your 4ch amp doesn't display any of the symptoms.

    you were right to first check the ground, though you might also need to check the wire resistance between the ground and the amp-- it could be higher..

    you can also try grounding the rca's, or grounding/powering the radio through the same wire the amps recieve power--sometimes the radio getting power from somewhere else can also cause these issues.

    those are the main things i can think of at this time, though there are tons of guides and other suggestions all over the internet if the ones i listed don't work..

  3. #3
    Newbie bumpbmxsbc's Avatar
    Join Date
    May 2009
    Posts
    4
    so ive been poking around in some forums and i came across the pioneer "pico fuse" issue. I hot swapped a rca cable and i think i damaged that fuse.. stupid me..

    http://www.diymobileaudio.com/forum/...vention-8.html

    look at post #193 by yellowmustang

    found this while i was researching the pico issue, pretty good idea thought it might be useful.. now only if i can get this stupid headunit apart

  4. #4
    Newbie bumpbmxsbc's Avatar
    Join Date
    May 2009
    Posts
    4
    Okay so ive been troubleshooting this for days, ive been posting my progress here http://9glancers.com/index.php/topic,13260.0.html ..

    today i tried EVERYTHING

    i tried rcas going striaght from the back of the deck, also i tired rcas from the rear and front

    EVERYTHING i do its still there...

    i also changed the grounds so they are a foot and a half, and grounded to the floor of the trunk.. sanded to bare metal and all.

    made sure that there are no exposed wires

    im out of ideas someone please help!

  5. #5
    Variable Bitrate
    Join Date
    Jul 2010
    Posts
    226
    Tried using power to the radio from the same wire that's powering the amp as suggested?
    Maybe also try running the ground wire all the way back to the battery? Ive read somewhere that can help..

  6. #6
    Newbie bumpbmxsbc's Avatar
    Join Date
    May 2009
    Posts
    4
    yes i did try that, just forgot to add it to the list.. and i dont have enough wire to run back to the battery. ill see if i can find someone who has some laying around.

    is there anything else i can try?

  7. #7
    Mod - all of it.
    Join Date
    Jul 2007
    Location
    Buena Park, So Cali
    Posts
    521
    You should try an RCA cable with an isolation transformer built in. Like this. It is a ground loop, and the only way to stop the noise is by eliminating the loop.

    Since both devices are tied to each other with an RCA ground, and to the same power ground one of the grounds needs to be lifted. Since we are working with only 2 conductor power and 2 conductor audio, the only way to do that is with one of these isolators.
    Last edited by drewbp; 05-22-2011 at 11:08 AM.
    CAR: 2007 G35 Sport Coupe 5AT
    HARDWARE: Dell D630 w/ dock, internal 80G HD, internal 320G HD, Verizon Wireless Card, iBlue GM-2 GPS w/iGuidance, OBDPros w/DashCommand, Visteon HD Radio w/ Home Made Cable, Current Version of RR w/ DFX Skin. My Install.

  8. #8
    MySQL Error soundman98's Avatar
    Join Date
    Jan 2008
    Location
    on the border of northern IL/IN
    Posts
    5,848
    dude, finding that diyma post might have just saved my old pioneer 7800.. i had attempted to 'lift' the ground temporarily to remove a ground loop by quickly applying power to the shield of the rca--which resulted in a constant 1khz tone...

    at this point, a ground loop isolator might be the next-best step..

Similar Threads

  1. So frustrated with powerdvd right now
    By BavarianBuilt in forum Road Runner
    Replies: 8
    Last Post: 12-29-2007, 06:21 PM
  2. Frustrated with RR and IG3 embedding...
    By Pseudo Nim in forum Road Runner
    Replies: 12
    Last Post: 08-19-2007, 12:43 PM
  3. Frustrated, out of ideas, please help
    By amthar in forum Input Devices
    Replies: 4
    Last Post: 09-04-2005, 04:31 PM
  4. IM getting frustrated
    By fallnangel in forum Input Devices
    Replies: 0
    Last Post: 01-06-2005, 11:20 PM
  5. :( So frustrated with my WRX car computer!
    By rabydanimal in forum General Hardware Discussion
    Replies: 8
    Last Post: 11-10-2004, 09:27 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •