PSW125 Problems: Heartbeat Noise, even with all cables out (except power).


I'm a UK customer with a sub woofer problem.

My PSW125 has started to make a regular heart beat noise again. This happened a couple of years ago, and I was sent a new amp for it. The new amp did exactly the same right out of the box, so I was sent a second one. This one has worked fine since then, but has started to pulse like the old one in the last week (it's just over 2 beats a second)

Any ideas what could be causing it? It can't be damage caused by a power surge, because my entire system runs through a UPS which regulates the output to a steady 230v pure sine wave, with full protection. I've unplugged everything from it (except for it's power lead), moved all other electronics away from it, even taken it to my friends (4 miles away) and plugged it in there, and altered all setting on the back in various configurations, and it still does it.
A colleague of mine (who's studied electronics), said he thinks it sounds like a cap charging/discharging incorrectly.

Unfortunately I can't remember the name of the company I bought it from, or the date. But if you keep records, I have the paperwork that came with the warranty replacements (see attachment). Hopefully this will show up in your records.

This appears to be a common issue, as I've seen many forums discussing it, but no one has yet found the cause (not that I've found anyway). If any of your techs or engineers know of the cause, and any fixes (i.e. repairing dry joints or replacing caps etc.), could you pass the information on to me? If not, how do I go about getting a new amp for my sub, and what can I do to prevent this happening again in another year or 2? I don't want to have to buy another sub every 2-3 years, or a different manufacturers, as all my speakers are Polk. I've been very pleased with the performance of the system, but this issue with the sub amp lets it down when it occurs.

I look forward to your reply.


  • KennethSwaugerKennethSwauger Moderator Posts: 6,846
    I'm sorry you're having a problem. Send an email to: [email protected] he will direct you to the proper person.
    Regards, Ken
    "They thought we were too loud, but shoot, I had four army blankets folded over my amp, and the volume level was on 2. I'm used to playin' on 10!" S.R.V.
  • Hello,
    I'm sorry you're having a problem. Send an email to: [email protected] he will direct you to the proper person.
    Regards, Ken

    Thanks. Email sent.
  • Hoping for a positive response. I have had this same problem with the heartbeat noise and now a hum. I have emailed Polk as others have done and received a free replacement amp for their subwoofer. I have not received a free replacement amp nor have i received a response to my email. It has been over a week and sent a follow up email and still no response. If I don't receive a response soon, I will be replaceing my subwoofer but sad to say it won't be another Polk product.below is the email I sent. Feeling very disappointed.

    via Web 04/07/2018 11:18 AM
    It has been over a week since I sent this email and have not received a response back. What is the normal time frame if which you respond. I would appreciate a quick resolution to the replacement amplifier board for my subwoofer. Thanks
    via Email 03/27/2018 10:50 AM
    I have a Polk Subwoofer that I received from my insurance company, (Liberty Mutual), after an insurance claim I made due to an electrical surge from lightning. Instead of paying me for my damaged equipment, they sent me comparative replacements for all my damages. I really loved this subwoofe but after a couple of years my amp developed a heart beat sound. I disconected the input to the amp and the heart beat sound was still present when power was the only thing connected to the sub. I have lived with this issue for a long time and now it has an intermittent hum. I recently went on the internet to see what might be causing this problem and ran across a forum and many others complaining about this same issues. and are just a couple for reference. Me reasearch has lead me to believe the problem is in the amplifier board. I tried pluging it into a different receptical at my mom's house and the heartbeat sound was still present. The model number is PSW125 Black 110v. The serial number is AM122507084. I dont have the receipt because it was issued by my insurance company. I love my polk audio and woud be very greatful to receive a replacement amp for my subwoofer as in the cases of the forums I have mentioned. My shipping address is
    My name is
    and my Phone number is
    Thank you for your time and I hope you have a Blessed day.
  • Update!!! I did receive my free replacement amp for my subwoofer and replaced it today and all is good. Thank you Ken Carter for your help when no one else would. You deserve a raise.
  • pitdogg2pitdogg2 Posts: 12,606
    Glad to hear.
  • Hi,
    I have a Polk Audio PSW 125 Subwoofer, serial #AM122513192. I purchased this speaker, two TSi300's and oneCS10. I bought them in Aug,2013. I have enjoyed them a lot. Now the Subwoofer has the heart beat sound. I found a website that claims there are 2 capacitors on the amplifier board that go bad. He shows a picture of the amplifier board with the 2 capacitors circled. Is this a good fix for the problem? If not is there a way I could get a replacement board from Polk Audio like some of the other people on this thread have recently done? Thanks. Rob .
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