PC subwoofer humming. Modify, repair or replace?

R Soul on 6/10/2015 at 20:04

I have some (http://www.pcdistrict.com/edifier-r202-prod132066.html) Edifier R202 stereo PC speakers and they work fine even after all these years, except that the subwoofer* has been making a noticeable humming/buzzing noise for quite a while. It's becoming too annoying to put up with, so I'd like to do something about it.

I've been looking online to see what I can do. I've tried plugging them into their own wall socket and using a different power lead, but to no avail. I've read something about ground loop something but I don't fully understand it, and nor do I want to buy a ground loop isolator if I'm not sure that's causing the noise.

I've also considered something like (http://www.overclock.net/t/363405/how-to-connect-your-xbox-360-to-your-monitor-speakers) this cable adapter to allow me to bypass the subwoofer.

This is the current setup:
(http://s912.photobucket.com/user/rsoulinternet/media/misc/speakers_current_zpsetwu4amr.gif.html)

Inline Image:

http://i912.photobucket.com/albums/ac326/rsoulinternet/misc/th_speakers_current_zpsetwu4amr.gif

At either end of the volume control wires is a normal 3.5mm jack (male). Each speaker wire ends with a male RCA jack.

The speakers themselves are fine, but bypassing the subwoofer would lose some bass, and I'm not sure I could compensate with software, so my other option is to get new speakers. If I did that I'd want to avoid having a large subwoofer because it gets in the way with my current desk. I've seen (http://www.amazon.co.uk/GOgroove-SonaVERSE-Multimedia-Side-Firing-Subwoofers/dp/B007HBRGMK) these speakers but would appreciate any other recommendations.

*Apologies to audiophiles if that's not the correct term for this.

TannisRoot on 6/10/2015 at 20:18

Depending on the ohms and the transformer, leaving the subwoofer unplugged might cause the rest of your speakers to blow (personal experience).

What kind of hum is it? Can the noise be heard when there is no sound coming through the speaker, but the speaker is still on with the volume up?

P.S. If you want to bypass the sub you'd need a dummy load to not blow the transformer (assuming it's not sophisticated).

heywood on 6/10/2015 at 22:18

From the pictures, it appears that the amplifier for the speakers is inside the subwoofer enclosure, so you can't bypass the sub.

Ground loops can cause hum, but they are connection dependent and don't usually appear as a function of age. Usually, when this sort of hum or buzz appears in an old component, it's caused by a failed or leaking electrolytic capacitor in the amplifier's power supply. The solution for that is to replace the caps. Replacing power supply caps is not that hard to do, but you would have to be somewhat handy with electronics to do this yourself, and it's probably not worth your time considering the replacement cost.

Did you try turning the bass control all the way down? If you did and it didn't affect the level of hum, then it's most likely a power supply problem. If it did reduce the hum, then it's possible that the problem originates in your computer sound card.

TannisRoot on 6/10/2015 at 22:37

Be aware: the power caps can hold a potentially lethal charge and need to be discharged safely before you stick your hand in there.

R Soul on 6/10/2015 at 22:58

The SW has two knobs - volume and bass. Neither of their positions has any effect on the humming. It also hums when the PC is turned off. For good measure I also removed all wires but the power, and it still hummed.

Four words that do not describe me are, among many others, "somewhat handy with electronics". I can assemble a PC but I'll let foreign robots do the soldering.

Vae on 7/10/2015 at 00:35

Quote Posted by heywood

Usually, when this sort of hum or buzz appears in an old component, it's caused by a failed or leaking electrolytic capacitor in the amplifier's power supply.

Yes, this is correct.

Quote:

The solution for that is to replace the caps. Replacing power supply caps is not that hard to do, but you would have to be somewhat handy with electronics to do this yourself, and it's probably not worth your time considering the replacement cost.

Agreed...not worth the effort.

At the same price-point, I would recommend getting the (http://www.amazon.com/gp/product/B00BXF5HQ8) Cyber Acoustics CA-3602FFP

R Soul on 7/10/2015 at 01:30

Unfortunately that subwoofer is too big. My desk has beam across the back that restricts how far back it can go, but I sometimes like to play a racing sim, for which I have pedals. There isn't room for both of them. I could make a stand for it so it go over the top, but then it would block some power sockets. With a height of 6 1/2 inches I could make a little shelf higher up, but still under the desk.

A smaller SW may not produce as much bass as a larger one, but with my current one I've never had the bass turned up very high.

Vae on 7/10/2015 at 06:53

To be honest, it's a little painful to parse qualitative differences at this price-point, due to the severe compromises...That being said, you'd be better off with the (http://www.amazon.co.uk/Genius-HF-500A-Channel-Powered-Speakers/dp/B00308FQWG/ref=pd_sim_sbs_23_3?ie=UTF8&refRID=0F1KTGX3V8Y0EHK089G0&dpID=51e84eXlNjL&dpSrc=sims&preST=_AC_UL160_SR160%2C160_) Genius HF-500A than the GOgroove SonaVERSE O2...

I believe there's a good price on these here...(http://www.lambda-tek.com/kye-31730905100~sh/B2084939) http://www.lambda-tek.com/kye-31730905100~sh/B2084939

R Soul on 7/10/2015 at 14:24

Thanks for your advice again. I'm going to try those speakers. :thumb:

R Soul on 13/10/2015 at 18:16

The speakers arrived today, and they're excellent, so thanks again for your advice Vae. The only snag is that I have to move my router because the wireless signal causes a tapping sound. A minor thing.

:thumb: