Question about Jensen JHT525 System

10 Answers

Loud humming noise from subwoofer

When I turn the sub on it makes this loud humming like noise, all other speakers work fine, I opened the sub up and everything seems fine, nothing blown, any ideas?

Posted by on

  • 9 more comments 
  • Jaejr51 Nov 10, 2007

    I have a Harmon Kardon HKTS14 subwoofer with the same problem, although I also sometimes get a screeching "fax" like sound from it as well. I am using the original cables to connect from the receiver (AS630), which are color coded purple. Should I try new cables, since these should be shielded?

  • Anonymous Nov 15, 2007

    I have the same problem with the bassbite iii subwoofer that comes with the KLH HTA-4100 system. It has the humming noise no matter what I do or how high or low the volume control is. The sub worked before I moved and when I got to the new place i plugged it in and it just hums. My cables are all good and the same ones I used when it worked so I dont think it could be that. Opened it up looks good. Im going to try a much better branded cble 1st then im going to start replacing parts in the sub. Im an electrical technician so I should be able to get somewhere with it. Ill be sure to post again if i get any progress. _J

  • Anonymous Jan 08, 2008

    Using Yamaha DSP-AZ1 and IXOS prof cabling, there is still a humming noise raising the subwoofer's volume control. How can I be sure whether the amp of 78AS is working correctly?

  • jcarterd2 Jul 03, 2008

    hum when power cable connected & power is turned off, blows fuse

    worked for over 5 years, have made no changes to connection or cables, one day just started to hum.

    Using ONKYO TX-SR500 AV Receiver, which has digial decording, subwoofer pre out connection, no speakers connected to subwoofer

    Change electrical outlet, disconnected line-in cable (RCA), changed fuse,

    reconnected power cable, unit powered off, still hummed, powered on, fuse blown

    Is this repairable or fried?

  • Anonymous Jul 12, 2008

    Experiencing low level audible hum - MOST notable when the PC is "off" and the speakers are left "on."

  • ofa025 Sep 20, 2008

    I have a theater research worked well for two who years, untill one afternoon there was a bizarre sound comming from the subwoffer. Its a humming, buzzing type noise dont know what it is, if any does please reply

  • Anonymous Dec 25, 2008

    Hi I have the hum too I've tried moving the speakers, amp, woffer, different adaptors, I even went tried different outlets in all the rooms, still humming. Is it the amp itself?

  • John McKenna Mar 17, 2009

    Hi my problem concerns my 2.1 Fujitsu Siemens PC speaker set up. Speakers are really good and working fine after 8 years light use. Just recently my system suddenly started making an annoying mid range hum, which was intermittant to continuous. I believe I have traced it to interference from my relatively new BT broadband hub and powered ethernet network.

    I started analysing the problem by guessing that the DC power supply transformer had gone off due to being left on for too long and getting hot. But using and alternative transformer made no difference. Then I connected the speakers to my mini hi fi via the earphone outlet and the hum had gone?? The hi fi is in another room some way from the ethernet hub.

    So what and why do I get this when my speakers are connected to my either of my two PCs. The BT hub is in the room on top of the desk with the PC boxes under. Alsocould my LCD monitor cause interferance? I do not use the " Wireless" network option but I don't know if it is switched on or off and it is only recently after having the hub for 2 -3 weeks has this problem surfaced.

    Any ideas what to do next??

  • Anonymous Mar 30, 2009

    My dad has these speakers on his computer and the subwoofer has always hummed. It's annoying as hell unless you have music playing to cover it up. I also checked out Altec Lansing's website and recently tried plugging the subwoofer directly into the wall outlet (it had been plugged into a surge protector). This helped a bit but the hum is still there.

  • Anonymous Mar 24, 2014

    Aiwa DV-AV97
    I have a humming noise from my center speaker and rear speakers

  • praveen rao
    praveen rao Jul 29, 2017

    use 332 AFC capacitor for 47k volume contorl
    call 9036436418



10 Answers

  • Level 1:

    An expert who has achieved level 1.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

If it is a powered sub you should lift the ground. you can do this by adding a three prong to two prong adapter. you know, like when you go to plug something in and the cord your plugging in has three prongs and the outlet your plugging in to only has two. it doesn't have the hole for the ground so you go get a little grey adapter that has three holes on one side and two prongs or tabs on the other.if that doesn't take the hum out (actually, is keeping the hum from getting in) you have a problem with the amplifier.

Posted on Jan 27, 2007

  • Level 1:

    An expert who has achieved level 1.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 2 Answers

Hopfully you fixed your problem by now but just in case, in addition to what dannydan suggested you may also want to make sure you don't have a ground loop from the ac supply line(120VAC), try relocating the plug to a sepearte outlet on a seperate circuit if possible, or ensure your input cables are not runing next to some ac lines. The hum is usally caused by the EMI (Electromagnet Interference) from your ac lines. this is the 60 cycle hum we get from the 120 Volts 60 Hz lines.

Posted on Jan 19, 2007

  • Level 2:

    An expert who has achieved level 2 by getting 100 points


    An expert who has answered 20 questions.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

  • Expert
  • 56 Answers

I had the same problem with the relevant subwoofer. The problem could simply be about the placement of the rest of the speakers connected to your amplifier. You have to be able to place your fronts and rears in a position that doesn't cause any coincidence. The best placement for a 5.1 system is that fronts are towards you with the subwoofer in between, or next to the front-left, and the rears are just next to your seat. If you use a 2.1 (stereo with a subwoofer), it needs some fine-tuning on the subwoofer and the amplifier as well. I hardly stopped that irritating noise. Firstly, I set the frequency of the subwoofer to 100Hz; then turned the volume down to the quarter level. After all those, I turned up my amplifier's "subwoofer volume leveler" to maximum. I solved the problem. try it out..

Posted on Apr 15, 2007

  • Max Robes
    Max Robes Dec 12, 2018

    Room acoustics dictate where my dub sounds best.


  • Level 1:

    An expert who has achieved level 1.


    An expert whose answer got voted for 2 times.

  • Contributor
  • 1 Answer

You could either be using poor quality input cables or they may be damaged and hence pick up interference. I suggest you check your input cables for damage. Use shielded cables from your source to your subwoofer. Your cables might be picking up this interference and transmitting them to the subwoofer amp. This interference can be caused by other equipment (tvs, radios etc) emitting electromagnetic radiotionand Because the subwoofer has its own amp/powered (I hope I'm right in your case), the input cable might be picking up this interference and sending them to the amp alongside the music signal. The amp then does what it knows best:- amplify the input signal. Which in this case is full of interference. Hence the humming. Use good quality shielded cables.

Posted on Nov 12, 2006

  • Level 1:

    An expert who has achieved level 1.


    An expert that has over 10 points.


    An expert whose answer got voted for 2 times.

    Problem Solver:

    An expert who has answered 5 questions.

  • Contributor
  • 6 Answers

I have a Mission Sub-Woofer on my home cinema receiver that suddenly started producing a 'fax' like hum/screech. It has a two core power cable. Replaced the speaker feed cable to no avail. Moved it to another power outlet, same problem. Then noticed it starts exactly on 45 seconds from power up. even with no input cable attached.
I've dropped it into a local AV repair shop to see if they can check the Amp circuit for a dodgy capacitor or something..
Edit: They found a problem in the internal power supply unit circuit. They replaced the PSU, and it's been working perfectly since then.

Posted on Jul 24, 2012

  • Gerard Coughlan
    Gerard Coughlan Jun 21, 2014

    The AV repair guy located a fault in the power supply unit. He replaced something in this and it's worked fine since.


  • Level 1:

    An expert who has achieved level 1.

  • Contributor
  • 1 Answer

Hopefully your cables aren't damaged, because they're attached to the unit and very difficult to replace. I just had this same problem, and after reading the first suggestion checked my cables for damage and found nothing. However, a closer look at the back of my computer showed that the audio cable running between my sound card and my amp was only halfway in. After correcting the problem, the feedback disappeared. Good luck.

Posted on May 02, 2007

Gtyler in Solution 7 above is probably most correct. AC power often isn't picture perfect and signal conditioning isn't practical at home. When a powered Home Sub signal is amplified, sometimes the noise of fluxuating AC feed is picked up by the amplifier and sent to the speaker as a pop or a crackle.

Solution: If you know what you are doing, condition the DC signal between the converter and the amplifier with an EMI Capacitor. It will cost about $2.50 to fix the whole problem.

Posted on Aug 26, 2008

I work for Cerwin Vega and normally when this happens is ground looping problems, for the solution we would suggest our customers to purchase an adapter from a three prong to a two prong.

Posted on Jan 15, 2008

I had same problem caused by a poorly grounded cable TV line. Try disconnecting the coax cable (the one which comes in from outside) from the back of your cable TV converter box. If the problem goes away, you probably have poorly grounded cable TV service. A $50 ground isolater filter will fix this (see model Model VRD-1FF at: I installed one recently and it works as promised... No degradation to digital cable/data service and the annoying hum is gone.

Posted on Aug 29, 2007

It also depends on where you have placed the base unit - if it is too close to the amplifier or other electrical devices, this will cause humming. Try moving it atleast a couple of feet away from any electrical devices.

Posted on Jan 01, 2007

3 Suggested Answers

  • 2 Answers


Hi there,
Save hours of searching online or wasting money on unnecessary repairs by talking to a 6YA Expert who can help you resolve this issue over the phone in a minute or two.

Best thing about this new service is that you are never placed on hold and get to talk to real repairmen in the US.

Here's a link to this great service

Good luck!

Posted on Jan 02, 2017

SOURCE: Subwoofer just stopped working. There's power but no sound.

I have the same problem. My guess is that the subwoofer coil is messed up. You MIGHT have to get it recoiled. But before you do any of that get someone with a sub to play their sub in your car, if it works.... then your sub is messed up, if not.....then your amp is messed up ( trial and error ). Today i noticed my subs rubber surrounding is crooked, that may be the problem for me. Also when I press down on the sub it makes a sticking sound, like something came loose. So once i get everything opened and out ill let you all know the solution. Good Luck!

Posted on Apr 10, 2008

  • 2 Answers

SOURCE: my Jensen spx 17 sub makes a loud thump on turn

all the spx17 will do that, no it should not damage the driver.

We usually suggest to customers that it is best to leave the Sub in the Auto switch position as this will allow it to automatically switch on and off without the loud pop.

Posted on Nov 14, 2010

Add Your Answer

Uploading: 0%


Complete. Click "Add" to insert your video. Add



Related Questions:

4 Answers

Klh powered subwoofer model ASW10-120B... when you plug in to power... it makes a loud buzzing/humming noise

I would check the caps on the power supply. They are rather large electrolytic capacitors that will look like they burst and/or leaking. When these die, the caps ground and the sub will make a loud buzzing sound. If you are handy with a soldering iron you can replace them yourself. Replace them with the same voltage or a little bigger and same with the size.

If the cap. says 16v 4700pF on it, for example, a 20v 5300pF or a 16v 6200mF cap. will work for this application.




Jan 05, 2016 | Audio Players & Recorders

1 Answer

Loud buzz in sub woofer, soundbar sounds fine

How to Stop a Subwoofer Hum - HowStuffWorks
Would you like to learn how to stop your subwoofer from making a consistent low-frequent hum or buzz? Read this article to learn how to stop a subwoofer hum.

Aug 03, 2015 | Audio Players & Recorders

1 Answer

My acoustic research hd510 has a loud humming noise

check your audio line in connection, either L or R signal line floating may also cause humming noise. Sub woofer usually very sensitive. If your audio input not connected, do you still hear humming noise? in actual you should not hear such noise, unless volume at max then it is possible to hear little.

Apr 03, 2012 | Acoustic Research HD510 System

2 Answers

Subwoofer makes loud hum noise

4 possibilities:
1) ground loop or open connection on input.
2) close proximity to a CFL, or other flourescent fixture.
3) bad filter caps in the sub.
4) bad coax to the sub.

in any event, check wire routing. You can also track down the noise sources by using a portable AM radio tuned off station. it will pick all manner of RF noise around the house. Light dimmers are notorius noise makers.

Dec 20, 2011 | Audio Players & Recorders

1 Answer

Making loud humming noise only.but if you plug

If I understand this correctly: with NO input or cable attached it hums; with an RCA cable attached it works. (What does 'some' mean in this regard?)

You say that connecting the RCA cable improves its sound. That tells me you're supplying a ground through the RCA cable for stray voltage in the sub.

It seems there may be a basic power issue if it hums with no input. Sometimes a given power source in a home may be wired differently than others or may insufficient grounding, which can result in hum. Try reversing the sub's power plug or move it somewhere else.

Since the sub contains its own electronics it is also susceptible to strong external magnetic fields. Keep it and any signal cables leading to it some distance away from other electrical devices like TV's.

Apr 08, 2010 | Velodyne CT-100 Speaker

1 Answer

Speaker makes a rather loud humming noise.

You can go buy a audioquest SUB-X subwoofer cable with a additional ground wire on it an connect the ground cable to the ground slot of the receiver an the other end to a screw on the sub or into one of the high output terminals on the woofer if it has them an this will take that humming sound right away but the cable is around $90

Mar 28, 2010 | Velodyne HGS-10 Subwoofer

1 Answer

Subwoofer problem

Sound like a component inside the sub is overheating. Most likely will need to be replaced.

Jun 18, 2008 | Audio Players & Recorders

2 Answers

Sony Active Subwoofer noise

The circuit that should be turning the sub on and off based upon the presence of an audio signal is not working correctly and the sub is trying to reproduce 60 cycle hum. The unit needs service.

Mar 09, 2008 | Audio Players & Recorders

1 Answer

Cerwin Vega ve-28s subwoofer and new Cervin Vega 2-way satellites

I bought my VE-28s and it did exactly that crackled, cerwin replaced part in amp but few months later problem persisted. they then replaced entire amp assembly and its been fine. i really push it to and its been fine. to test it, unplug the connection from amp/ reciever and see if it persists. if so its the sub, if not its the amp/ reciever. dont dump it, these subs really crank and can put out some deep loud bass.

Oct 28, 2007 | Cerwin Vega VE-28S Subwoofer

1 Answer

Loud hum on subwoofer.

try another speaker on that channel if you get no sound or it hums then it is time to take your set to a tech your audio out put on that side is damage along with some caps.good luck.

Mar 30, 2007 | Polk Audio RT1000I Speaker

Not finding what you are looking for?
Jensen JHT525 System Logo

33,148 people viewed this question

Ask a Question

Usually answered in minutes!

Top Jensen Audio Players & Recorders Experts


Level 3 Expert

5683 Answers

Don Hart

Level 2 Expert

127 Answers

The Knight
The Knight

Level 3 Expert

76036 Answers

Are you a Jensen Audio Player and Recorder Expert? Answer questions, earn points and help others

Answer questions

Manuals & User Guides