OK, so I've read a ton of threads on humming subs, and all seem to have an issue after hooking up their sub to the reciever.

My problem is the sub has a low hum as soon as I plug it into the wall outlet. It's an Onkyo SKS-750 (the one that comes with the SKS-HT750 set), eventually it will connect to an Onkyo 605.
I've turned it way down in the back and changed outlets to dispense any ground loop problem. It seems like as soon as there is power going into it, it starts to hum, without any connection to the reciever as yet. It's sort of irritating. Any ideas as to way it would be doing this?!!

Any suggestions welcome!

Thanks guys!

One thing to try would be plugging it in using a "cheater" plug (3 prong to 2 prong).

Wow, I clicked the link in your signature... Your HT room is amazing! Scratch my previous recommendation, I think you need to do your setup justice by upgrading to a "real" subwoofer :D

Hey, Thanks for the compliment!!!

The sub doesn't have a 3 prong plug. It's just a 2 prong polorized (1 fat / 1 skinney).

P.S. Wife thought the HTIB I had before was good, so getting this new reciever and speaker setup was a stretch...

Hey, Thanks for the compliment!!!

The sub doesn't have a 3 prong plug. It's just a 2 prong polorized (1 fat / 1 skinney).

P.S. Wife thought the HTIB I had before was good, so getting this new reciever and speaker setup was a stretch...

Well, I suppose the cheater plug isn't going to do too much then... That's all I had :(

And I know what you mean about the WAF coming into play, you always have to consult with the boss and just be happy she's let you get the toys you already have ;)

Do you have a cable box in the room? if so, detach the coax from the wall outlet and see if that stops it. Seems to cause alot of probs. isolation transformer will fix that up.

When you plug it in does the on light show?
If you wait, does the sub go into standby and stop humming?

If it does as above, you have a ground loop problems yet.

I had a similar problem not one forum could answer and when I finally found it I was dumb founded.

Let me just put this all out.

Phones are sometimes grounded to the water pipe of the house.
Water meters use a hall effect units to power the meter. What that is, is as the water passes in the meter it generates its own power by this spinning and oddly enough its a 60hz deal.
I actually had my water meter humming a 60hz signal when the sub was plugged in along with the sub doing this.
Then on top of this if you have cable and or a sat setup, this also creates sometimes a 60hz signal and depending on how everything is grounded at your home, you can create a giant ground loop on everything electrically connected.

How did I remedy this?
Phones on the house outdoor ground, along with the cable/sat one.
There is NO, NONE, NADA a metal connection getting to the receiver associated in any way shape or form from the cable/sat unit or the TV.

Optical onlu was my solution.
No using the receiver to up convert a signal from the cable box and so on.

Do you have a cable box in the room? if so, detach the coax from the wall outlet and see if that stops it. Seems to cause alot of probs. isolation transformer will fix that up.

Funny you typed your response as I did mine.

Isolation transformers don't solve more than they may create.
I tried that one and it ruined my On demand service along with ruining my signal, which cable then found that transformer and told me to toss it. They didn't have a solution for the hum, not there department they told me, but running the cable through anything will ruin a signal. I also had a Furman surge protector which the cable line ran through to clean the signal of any noise supposedly and it dropped the signal strength 9db!!!

Do you have a cable box in the room? if so, detach the coax from the wall outlet and see if that stops it. Seems to cause alot of probs. isolation transformer will fix that up.

I do have a Cable Box in the room. But I'm not sure how unplugging the coax from it will stop the sub from humming when the sub isn't even plugged into the reciever. It's only plugged into a wall outlet.

When you plug it in does the on light show?
If you wait, does the sub go into standby and stop humming?

If it does as above, you have a ground loop problems yet.

I had a similar problem not one forum could answer and when I finally found it I was dumb founded.

Let me just put this all out.

Phones are sometimes grounded to the water pipe of the house.
Water meters use a hall effect units to power the meter. What that is, is as the water passes in the meter it generates its own power by this spinning and oddly enough its a 60hz deal.
I actually had my water meter humming a 60hz signal when the sub was plugged in along with the sub doing this.
Then on top of this if you have cable and or a sat setup, this also creates sometimes a 60hz signal and depending on how everything is grounded at your home, you can create a giant ground loop on everything electrically connected.

How did I remedy this?
Phones on the house outdoor ground, along with the cable/sat one.
There is NO, NONE, NADA a metal connection getting to the receiver associated in any way shape or form from the cable/sat unit or the TV.

Optical onlu was my solution.
No using the receiver to up convert a signal from the cable box and so on.

When I plug it in, a light comes on (red) meaning it's in standby mode. When I connect it to the receiver, it turns blue when it receives a signal.
My water meter is actually out at the street in a pit. So I'm thinking that's not the problem.

Could it be my sub is bad?! Or are my ears sensative and every sub has a little hum to it when plugged in?!!

ok, i had a miserable humm that was caused from the coax. I tried an isolation transformer from parts express......POS. lost my on demand....and some channels. Jensen makes an excellent one and so does viewsonics. If you have digital cable use one of these, they work like a charm. Do try and unplug the coax from the wall and see if this is the problem...it is for many people........
PS: Blue Jeans cables have a transformer made for subwoofers too, it is possible your sub cable is the culprit....any electrical interference will do it.

A hum is a 60hz and as a signal running through a ground loop created will trigger the sub.
Even though the meter is at the street in a pit, it could be connected via the pipes and aiding to a ground loop.
Your furnace also has a transformer in it, also 60hz.
So many things, so many potential ways to create a ground loop when cable or sat comes into play.
Sat of cable has to be grounded, hence a ground loop possible creation that will flow through many different paths. Very complex for me to try to explain, but simply unscrew the cable connection and see if it goes away. If it doesn't it "could" be within that sub.

What I said may fix it.
Line to cable box, audio from cable box to receiver using optical cable only.
If you use a DVD player, it must also use optical. Why, because the line if a wire of any sort runs to the TV, receiver, through the cable connection you use for a video signal, it will end up ground loop yet.

Bobcel, and JAD2...

Thanks for the info. I will try disconnecting the cable, and running optical to the reciever.

It just seems weird that the sub has a hum without evn being plugged into the receiver.

BTW: Just to clarify, this is not a hum from all speakers when the system is turned on. This is a hum from the sub only when everything in the room is off.

Sean. I used the transformer, viewsonics, for a problem coming from my mains and worked great. Then I bought a new sub, Energy...S12.3. It started to humm too. bastard. I ordered a sub cable from BlueJeans and one of their isolation transformers for the sub. Low and behold the new cable did the trick. Never needed the transformer.... It very may well be the sub cable...anyways, keep us updated on what you find.....

Sean. I used the transformer, viewsonics, for a problem coming from my mains and worked great. Then I bought a new sub, Energy...S12.3. It started to humm too. bastard. I ordered a sub cable from BlueJeans and one of their isolation transformers for the sub. Low and behold the new cable did the trick. Never needed the transformer.... It very may well be the sub cable...

I was thinking that, but the sub cable isn't even plugged in. And it still humms.

If you disconnect the cable totally from the sub so nothing is going into it does it hum? If so it is probably the sub. OH, just reread your thread, guess it hums with the power hooked up... Just trying to be sure of the circumstances.

If you disconnect the cable totally from the sub so nothing is going into it does it hum? If so it is probably the sub.

Yes it does hum when no sub cable is attached. It's just plugged into the wall outlet.

I'm starting to think the sub is bad.

have you tried plugging it in another room/outlet.

have you tried plugging it in another room/outlet.

Yes. Into other outlets in the room, but not in other rooms in the house.

I was thinking that, but the sub cable isn't even plugged in. And it still humms.

OK, that wasn't clear before.

If you plug the sub into the wall, no line yet connected from the receiver and get a hum, it will be the sub. Cheap amp, touchy and water meter, furnace is creating it through the electric line. That you can't fix.

There are also various humbusting products available. Such as a.......... Humbuster.

OK, that wasn't clear before.

If you plug the sub into the wall, no line yet connected from the receiver and get a hum, it will be the sub. Cheap amp, touchy and water meter, furnace is creating it through the electric line. That you can't fix.

So call Onkyo, or trash it and beg an pleade the finance committee to let me buy another one?!

go get some flowers and let the brown-nosing begin!

So call Onkyo, or trash it and beg an pleade the finance committee to let me buy another one?!

You could go to parts express and buy another amp for something momma may not complain so much about like a new $300 sub might create.

Transformer hums can be just its insulation pack loosening up enough the plates move and this isn't fixed by a hum buster or such other product.

Check your local craigslist, lots of good deals out there.....

Yes it does hum when no sub cable is attached. It's just plugged into the wall outlet.

I'm starting to think the sub is bad.

Without reading past the post quoted...You have a bad amplifier in the sub...An internal ground is bad...Cut and dry...plain and simple...One other possibility to confirm this is to plug the sub into a power conditioner such as a Monster conditioner for example...Hum still ther...bad sub amp...Get it replaced...OR connectit to the amp and see if it still hums...If not then the sub is using the amps chassis for its ground which is a possibility...Personally i think its the former though...

Bought new Paradigm Servo 15 3 weeks ago, got it home just plugged in the power cord and it started humming. I tried unplugging the cable, different outlets in the room. I ran extension cord from the GFI outlet and the hum was almost gone. Started unplugging thing and found it was my Plasma TV causing the hum. Ran a cord from another room on a different circuit and the hum is gone. But I did notice that I get a little hum from the light in my daughter’s room (one of those halogen lamps).
Take the sub to another room or location and see if it hums. If the hum goes away plug it back in your room and start unplugging things till it goes away.

All sorts of things in the house can cause hum, and that's one of the damn few reasons a $500 power conditioner is good for. A good input transformer will force everything not on the primary harmonic of the 60 hz AC power to be filtered out, and the best power conditioners have one in them.

Greg

Actually, you can go a lot cheaper. I've been using a Furman PL8SII (mostly known for use in pro sound systems) for many years. Works like a champ and eliminated an annoying hum in the system.

I’m guessing there’s wire of bunch of wires inside the sub that is close to the transformer, open it up and have look to see if the cables are near to the transformer.

You could go to parts express and buy another amp for something momma may not complain so much about like a new $300 sub might create.

Transformer hums can be just its insulation pack loosening up enough the plates move and this isn't fixed by a hum buster or such other product.
I think this is the problem, a transformer hum. Because I got this set recently, I would assume Onkyo should fix it. There's no reason this should be normal, right?!
I’m guessing there’s wire of bunch of wires inside the sub that is close to the transformer, open it up and have look to see if the cables are near to the transformer.
I'm a little leary of opening this sub up as long as it is under warranty. I would be interested in seeing it though.

New sub.... Your sub is bad if you are making no other connection than the one to the ac outlet and it causes it to hum.

New sub.... Your sub is bad if you are making no other connection than the one to the ac outlet and it causes it to hum.

Ya, that's what I'm thinking. I'll be calling the Service Center!!