Have a 2008 Honda Accord sedan...added a dual 200 watt amp with an elemental design 12 inch sub....factory stereo...ever since we installed we have this thumping sound periodically from the sub....like a "whump whump" not always constant and sometimes when it is constant you can give the car gas and it goes away for a minute..but always comes back....have the output for the amp going from the factory rear speakers and have tried a hi-lo converter as well as ground loop isolator and nothing has worked...help!!
Replies (8)
swez on 08/27/2009 15:50:06
What amp model # are you using and how large is the sub enclosure in this design?
With the present statements, it could be cone whop or the amp is gassing out as it does not have enough power to keep up. If your dash has a voltage gage, watch it for voltage drops. Some amps are very sensitive to low voltage, (Under 11 volts) and will do wierd things like this when starved for power.
Finally, double check your ground for the amp. Bare metal connections in the floor pan helps a lot in most cases.
Swez
jsloan37129 on 08/27/2009 19:59:27
thanks for the reply...it's a dual xpa2100 the enclosure is about 3/4 cubic foot...the amp has plenty of power to drive it, the noise is even there at low volume...we've moved the ground twice so don't think it is that..
swez on 08/27/2009 20:39:52
How about the HU grouding system? Most aftermarket HU's perform best when the HU ground is not the factory/dash panel ground.
If this problem persists, try a bench test of the amp and use a Car BAT and charger as the power supply and a Source Unit like I-Pod or a Walkman CD player. If the noise is still present in this test, your amp is probablly damaged.
Swez
jsloan37129 on 08/28/2009 10:07:08
it's grounded to the frame of the car....the amp has been replaced and a different make also tried, still have the noise...
swez on 08/28/2009 10:40:04
This car has no frame per-se. It's a unibody design and the floor pan is the grounding source for the entire electrical system. Where is the ground wire attached now? (A rear seatbelt bolt is often a good location when it's bare metal from a wire brush or sandpaper to remove all paint and whatnots from that location)
OK, the next step is to try this sub out on a known good amplifer system. Here, you can determine if the sub/enclosure are working well together.
If the noise is still present, contact e-Designs for details on this sub and box combo. It could be a defective sub or another amp type is needed for this sub.
What is the model # of the ED sub you have now?
Swez
PS Looked up the specs on your dual xpa2100 and it's a pretty modest amp. (50 watts RMS x 2 @ 4 ohms per channel and 150 watts RMS when bridged to a 4 ohm load)
http://www.retrevo.com/search?q=Namsung+XPA2100&rt=sp
Victor on 08/28/2009 23:51:04
Try grounding the RCA -ve ... and check... open the RCA jack and see if the +ve is loose, split or touching the -ve... if its a fixed type RCA try using another set and check.
set the gains correctly using this
http://www.clubknowledge.com/Car_Audio_FAQ/?t57
Also try grounding the amp directly back to the -ve on battery and check.
Victor...
PS: Check the LOC's as well ...
jsloan37129 on 08/29/2009 10:48:14
thanks for the responses...we figured it out finally....my car had bluetooth microphones in the front and back....had to disconnect them both and the sound is gone....
swez on 08/29/2009 10:55:06
Good catch as this is a new one we've not seen at CK before. It makes sense that RF noise could come in with a BT system.
Swez
Replies (8)
swez on 08/27/2009 15:50:06
What amp model # are you using and how large is the sub enclosure in this design?
With the present statements, it could be cone whop or the amp is gassing out as it does not have enough power to keep up. If your dash has a voltage gage, watch it for voltage drops. Some amps are very sensitive to low voltage, (Under 11 volts) and will do wierd things like this when starved for power.
Finally, double check your ground for the amp. Bare metal connections in the floor pan helps a lot in most cases.
Swez
jsloan37129 on 08/27/2009 19:59:27
thanks for the reply...it's a dual xpa2100 the enclosure is about 3/4 cubic foot...the amp has plenty of power to drive it, the noise is even there at low volume...we've moved the ground twice so don't think it is that..
swez on 08/27/2009 20:39:52
How about the HU grouding system? Most aftermarket HU's perform best when the HU ground is not the factory/dash panel ground.
If this problem persists, try a bench test of the amp and use a Car BAT and charger as the power supply and a Source Unit like I-Pod or a Walkman CD player. If the noise is still present in this test, your amp is probablly damaged.
Swez
jsloan37129 on 08/28/2009 10:07:08
it's grounded to the frame of the car....the amp has been replaced and a different make also tried, still have the noise...
swez on 08/28/2009 10:40:04
This car has no frame per-se. It's a unibody design and the floor pan is the grounding source for the entire electrical system. Where is the ground wire attached now? (A rear seatbelt bolt is often a good location when it's bare metal from a wire brush or sandpaper to remove all paint and whatnots from that location)
OK, the next step is to try this sub out on a known good amplifer system. Here, you can determine if the sub/enclosure are working well together.
If the noise is still present, contact e-Designs for details on this sub and box combo. It could be a defective sub or another amp type is needed for this sub.
What is the model # of the ED sub you have now?
Swez
PS Looked up the specs on your dual xpa2100 and it's a pretty modest amp. (50 watts RMS x 2 @ 4 ohms per channel and 150 watts RMS when bridged to a 4 ohm load)
http://www.retrevo.com/search?q=Namsung+XPA2100&rt=sp
Victor on 08/28/2009 23:51:04
Try grounding the RCA -ve ... and check... open the RCA jack and see if the +ve is loose, split or touching the -ve... if its a fixed type RCA try using another set and check.
set the gains correctly using this
http://www.clubknowledge.com/Car_Audio_FAQ/?t57
Also try grounding the amp directly back to the -ve on battery and check.
Victor...
PS: Check the LOC's as well ...
jsloan37129 on 08/29/2009 10:48:14
thanks for the responses...we figured it out finally....my car had bluetooth microphones in the front and back....had to disconnect them both and the sound is gone....
swez on 08/29/2009 10:55:06
Good catch as this is a new one we've not seen at CK before. It makes sense that RF noise could come in with a BT system.
Swez
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