Subwoofer "Humming" problem

[Leetheman]

Hey, Just Wondering if anybody here has the Sony HTDDW750 home cinema Kit and could help?

Well here's my problem, I got one for Christmas and during the quiet moments of movies you can hear the sub woofer make a slight humming noise and it's quite annoying. has anyone else experienced this? I think it must be the transformer in the sub (it‘s an active subwoofer) but should it be making a noise? It even hums when it isn’t plugged it to the amp and when in a different location away from everything else.

Also can anyone recommend an Active Subwoofer that is completely silent when switched on?

Thanks
Lee.

 

[Polkfan]

While don't specifically own the model of sub you have, my first guess is that it sounds like you may have a grounding issue. Most likely something internally is not grounded properly, or a wire/connection is loose.

Or maybe it is trying to sing, but doesn't know the words?

My PSW650 (Polk Audio) is completely silent when switched on.

 

[Leetheman]

Apparently not, I took it into my local electrical store to see if there was anything wrong, and they said “No, I can’t see anything wrong with it”

So I’m guessing it’s just badly designed!

Also have you got a link to where I could purchase your subwoofer please?

Thanks
Lee

 

[Rip Van Woofer]

Or maybe it is trying to sing, but doesn't know the words?

Dang, he beat me to it!

 

[Leetheman]

Well, That was helpful

 

[Polkfan]

If you are interested in the PSW650 specifically, I suggest doin' a search online to find a seller. It is now considered an older model and has been discontinued. I bought mine at Crutchfield last August. Polk has several newer models however. Depends on what you want to spend.

 

[Leetheman]

Which Subwoofer would you recommend from here?

http://www.hifibitz.co.uk/subcategory.asp?id=23

 

[Polkfan]

Dang, he beat me to it!

Sometimes I get lucky.


Leetheman:

I would try to audition the sub first if possible. Also, for opinions on products you can try this link:

http://www.audioreview.com/defaultcrx.aspx

 

[Rip Van Woofer]

Well, That was helpful

I've always found humor a good way to deal with unpleasant situations!

Anyway, there isn't much to add to what's been said. Likely a grounding problem - you're getting 60 cycle hum via the transformer. If it's under warranty, take or send it back before going to the trouble of shopping for another unit (assuming you're satisfied with it otherwise).

A less likely but still possible cause is bad AC. Voltage fluctuations can cause even a well designed and properly grounded power supply to hum audibly, though that problem is typically intermittent depending on how your AC is behaving at a given time. Also it's usually a "chassis hum" from the tranny vibrating and doesn't go thru the speaker(s). My otherwise excellent power amp does it sometimes.

And don't go back to that dumba** shop that saw "nothing wrong".

And if all else fails...teach it the words!

 

[jeffsg4mac]

My dad had a klipsch sub that hummed, I stuck an adapter on it that changed it to a 2 prong plug and it went away. Give it a try.

 

[Leetheman]

So what exactly did you do?

Please explain

Thanks
Lee

 

[jeffsg4mac]

Just go to your local hardware store or walmart and get one of these put it on your subwoofer and plug it back into the wall. Should set you back less than 2 bucks. I bet it will work. Or you can do like I did and just cut the dang thang off with a pair of wire cutters.

 

[Leetheman]

I'm from the UK so I won't need one, the plug on mine is a 2 pin one though but it's in like a UK 3 pin adaptor!

 

[jeffsg4mac]

Oh, hmm, I am not familiar with UK electrical standards. Can you remove the 3 prong adapter? If so try it without.

 

[Leetheman]

Yes you can but then your left with a 2 pin plug which you can use in the UK

Anybody know if it would harm it if I cut the 2 pin plug off and wire it straight to a UK plug?

Thanks
Lee

 

[Rip Van Woofer]

Mucking about with 240V mains would make me very nervous!

Anyway, removing or bypassing the ground prong could correct a "ground loop" fault which is one common source of hum. If you can do so without "surgery", try it.

I know electrical standards are very strict in Europe, but last time I was in the UK I think I remember places that still had two prong outlets (probably wired during Cromwell's time), so the danger can't be that dire.

And it seems to me that a product designed for the European and/or UK market that can't meet those standards without making unseemly noises is defective. If you can return the thing for refund or exchange, do so.

 

[Leetheman]

Someone has already taken it to a sony repair shop and..........

http://www.dvd.reviewer.co.uk/forums/thread.asp?Forum=211&Thread=324417&Type=1

 

[Leetheman]

Anyone know if this one is any good? and if it buzz's/Hum's or anything?

http://www.hifibitz.co.uk/subcategory.asp?id=23

 

[Leetheman]

Well anybody?

 

[Jdrumstik]

while im not a genius and im not sure if active is when its external amped or internaly, my sub, I used s ignal mono line from the reciever, but the cord was non shileded and sat ontop of a bunch of other wires and it hummed so I replaced it with a nice thick bluye cable with shielding and now its silent.