Go Back   Home > Forums > >
Home Forums Rules Articles diyAudio Store Blogs Gallery Wiki Register Donations FAQ Calendar Search Today's Posts Mark Forums Read

Parts Where to get, and how to make the best bits. PCB's, caps, transformers, etc.

how do i fix my subwoofer
how do i fix my subwoofer
Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Thread Tools Search this Thread
Old 3rd January 2008, 02:34 PM   #1
wanky is offline wanky  Australia
diyAudio Member
Join Date: Jan 2008
Unhappy how do i fix my subwoofer

i bought a home speaker system second hand and it has really bad distortion throught the subwoofer channel, all the other speakers work fine. I opened it up and found 2 bulging and dried up capacitors with my ESR meter so I replaced them but the problem still remains. I dont know much about amps what else should i look for with this distortion .f rom what I see its using LM1875T amps for the speakers and using IRFP150 & IRFP9150 for the subwoofer, could these be stuffed? how do i test them?
thanks for help
Attached Images
File Type: jpg img_1731.jpg (97.0 KB, 106 views)
  Reply With Quote
Old 3rd January 2008, 07:59 PM   #2
DSP_Geek is offline DSP_Geek  Canada
diyAudio Member
Join Date: Aug 2003
Location: Santa Cruz, California
Recheck the other electrolytics, especially the large one beside "BAD CAP HERE". If two already went west, likely some others are on their last legs. You might also want to verify the solder joints under the IRF devices, as they looked a bit dodgy to me.
  Reply With Quote
Old 5th January 2008, 04:06 PM   #3
wanky is offline wanky  Australia
diyAudio Member
Join Date: Jan 2008
i replaced the cap but no difference. i measures voltages of the mosfets while playing audio and they dont change at all

IRFP150 Vgs 3.2v Vds is 49.4v
IRFP9150 Vgs -2.9v Vds -48.9v

should the voltages be the same? also shouldnt gate voltage go higher than that? plz help im trying to learn
  Reply With Quote


how do i fix my subwooferHide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off

Forum Jump

Similar Threads
Thread Thread Starter Forum Replies Last Post
subwoofer under bed Potato42 Subwoofers 7 13th January 2009 02:21 PM
subwoofer project, which subwoofer? Davlaf Subwoofers 12 9th November 2006 03:59 AM
Subwoofer crossover / subwoofer module design derMichi Subwoofers 4 20th April 2006 10:31 AM
how to connect a non powered subwoofer to a stereo system without a subwoofer output JSD777 Multi-Way 4 20th September 2005 03:19 PM
I need help with subwoofer deisign: HUGE inexpensive subwoofer hottyson Subwoofers 16 4th May 2004 03:51 AM

New To Site? Need Help?

All times are GMT. The time now is 08:19 PM.

Search Engine Optimisation provided by DragonByte SEO (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Resources saved on this page: MySQL 15.79%
vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2017 DragonByte Technologies Ltd.
Copyright ©1999-2017 diyAudio