[quern]

All

Hello, I've been the proud owner of an ACI Force sub for many years.  This morning I woke up to hear a loud buzzing coming from downstairs.  I traced it to my Subwoofer.  I unplugged all the inputs but it was still there... so I had to turn the power off.

Curious if there are any suggestions to what may have happened.  Did the amp take a dump or maybe the woofer itself?

I'm not sure if I'm up for a total DYI on it but i just love the cabinet and the sound.  If repairing it is too much then I may end up looking for a decent replacement... 

Thanks in advance.

Jerry

[max190]

I found this info from Mike Dzurko regarding Force XL or Titan buzzing.

"Occasional a Force XL or Titan XL will develop a slight mechanical hum. The windings on the transformer have heated up and cooled down and have shifted ever so slightly and now are causing the hum.
It is simple to eliminate the hum. First, unplug the amp and let it set 5 minutes to allow all the energy stored in the capacitors to dissipate. Remove the six screws that hold the amp to the cabinet. You will notice that the round, torroidal transformer is held in place by a bolt that runs through the middle of the transformer and is terminated with a Phillips head in the middle of the heatsink area on the outside of the amp. You will need to loosen the nut with a wrench while holding the screw with a Phillips head screw driver. With the nut loose, rotate the transformer about 1/4" to the right or left and tighten the nut down onto the transformer. Secure the amp back into the cabinet, plug it in and you are ready to go."

[davek]

I have a Titan, and in my case the buzz was caused by a faulty electrolytic capacitor. Not too difficult to replace.

[quern]

I have a Titan, and in my case the buzz was caused by a faulty electrolytic capacitor. Not too difficult to replace.

Davek

How do I know if a capacitor went south?

[DaveC113]

Sounds like an electronics issue rather than a ground loop, especially if it's been fine for years.

It might be a good idea to have all of the electrolytic caps replaced. Sometimes you can see they are defective if the cap is bulged or leaking fluid but if they are just old and dried out it might not be clearly visible, in which case you'd need a tool to test them. But electrolytics have a finite lifespan and require periodic replacement...

[quern]

I have decided to take it to a local repair shop. They will diagnose it for $20. Hopefully it's an easy repair. I have always been amazed at this little sub.

[davek]

As the other Dave said, electrolytics have a finite life span, and in my case I had a bulge on top of mine to indicate it was the culprit. When I had my problem a few years ago Mike from ACI referred me to a tech familiar with the amps who said it was not uncommon, especially on older amps. In the titan amp there are 2, one each for the DC rails. I replaced both of them and it's been fine since.

[quern]

I'm excited to finally learn that the issue is with a blown Capacitor.  I told the shop to replace both (they were only going to replace the one).  So for about $100 total I get my Force back.  I can't wait.  My Atlantic Technology 350 THX's really miss the sub.  I have no bottom end right now. 

Jerry

[Dieterle Tool]

Well done Jerry. The ACI subs do not get the credit they deserve. Short of trying a Rythmik or GR Research, ACI is one of the best for musical tone and speed.
There are a few others of course, but from my experience, you would have had to spend a considerable amount more to get there.

-Dieter