Buzzing sound in subwoofer

gacilu

Hi guys,

I have a Polk TSW 404 connected to a Sony receiver. The receiver is also connected to a TiVo box provided by Virgin Media (my cable provider here in London). As soon as I connected altogether the subwoofer started to produce an annoying buzzing sound. I started to unplug everything until I realised that the sound started when I connect the TiVo to the cable TV.

Is there anything I can do to avoid that? Is it a Virgin media problem? Any suggestions?

GA

Speedskater

Is everything connected to the same AC power strip/distribution block? (as it should be)

tonyb

A power conditioner may help, but also check your cable running from the TiVo to cable box. If it's an el cheapo, that certainly won't help.

Speedskater

Bill Whitlock writes on 'power conditioning' :

In reality, many of the benefits often ascribed to “power treatment” schemes are simply
due to plugging all system equipment into the same outlet strip or dedicated branch
circuit. For obvious reasons, this is always a good idea!

and

“Power Conditioning” has been a high-growth, and high-profit, business for nearly 20
years. Most of the claims made for such “conditioning” are never
substantiated in any meaningful or scientific way. Many of the claimed
benefits, as well as carefully contrived demonstrations, truly test the limits of
credibility in an engineering sense ... “deeper colors” ... “better soundstage imaging”
... WHAT?

Bill Whitlock, 9/4/2012 Overview of Audio System Grounding & Interfacing p188

http://www.jensen-transformers.com/apps_wp.html

Speedskater

The real problem most likely is that your cable TV provider is using a very different connection to Earth than the AC power to your audio system. One good solution is a cable isolator similar to the unit that Jensen (Bill Whitlock) makes:

"VRD-1FF Cable TV RF Isolator"
For Analog and Digital Cable TV and Cable Modems
Solves "Ground Loop" and "Hum Bar" Problems

http://www.jensen-transformers.com/iso_vid.html
http://www.jensen-transformers.com/faqs.html#faq7

tonyb

Speed,

Dude,your just plain wrong on the benefits of clean power.

gacilu

Thank you guys. I have bought a power conditioner that also contains a filter for the AV cable. Let's see if this solves the problem.

I do have everything connected to the same outlet strip, so I almost sure that the power conditioner should help.

Thank again.

tonyb

It can also be just as simple as a ground loop problem. A cheapo ground lifting plug from any hardware store for 2 bucks may work on the box, sub, receiver....try it in a few different areas. For 2 bucks, what have ya got to lose.

Irrenhaus

tonyb wrote: »

A cheapo ground lifting plug from any hardware store

Can he get one of those in London?

Or can he use a 3 prong power cable with a dummy ground.


Cheers

tonyb

London....yeah, my bad....heck if I know whats available in London. Look for any ground lifting device, I'm sure they have them too.

polk500

http://www.jensen-transformers.com/iso_vid.html

Hello gacilu,

I had the same issue and I tried several things including a cheater plug. Which worked but you are eliminating the ground and potentially destroying your equipment or hurting yourself. Now lots of guys say they have done this and never had a issue and no disrespect intended to the folks who suggested using one.

If the filter on your power conditioner doesn't work don't be surprise as they are not all created equally. My Cable company installed one and it didn't make any difference either. But the problem is with the cable company.

I pick up a insolator made by Jensen Transformer (speedskater provided the link) from a fellow Polkie. Problem solved they retail for $60.00 .

Cheers
Roger

aboroth00

Holland electronics offers up a similar product to Jensen's (http://www.hollandelectronics.com/catalog/catalog.php?product_id=CISP-Cable-Isolator_ . The Holland suffers from more signal loss than the Jensen. Some people experience loss of some channels due to the blockage of certain signals. Not sure about the previous claim I just mentioned, but when i was looking around for a product like this it was mentioned. The Jensen is a quality product but at a price. I have a holland CISP if you're interested. Just pay for postage and its yours. Do a little research on the product first to see whether it fits your needs.

aboroth00

polk500 wrote: »

http://www.jensen-transformers.com/iso_vid.html

Hello gacilu,

I had the same issue and I tried several things including a cheater plug. Which worked but you are eliminating the ground and potentially destroying your equipment or hurting yourself. Now lots of guys say they have done this and never had a issue and no disrespect intended to the folks who suggested using one.

If the filter on your power conditioner doesn't work don't be surprise as they are not all created equally. My Cable company installed one and it didn't make any difference either. But the problem is with the cable company.

I pick up a insolator made by Jensen Transformer (speedskater provided the link) from a fellow Polkie. Problem solved they retail for $60.00 .

Cheers
Roger

+1 on this. I used a cheater plug as well and I am still here... However, I wouldn't recommend it as there's a reason why that grounding plug exists. I would solve the problem where it's coming from, the cable line. The Jensen is a fantastic choice.

I had the cable guy look into it as well. The real explanation for the hum is a ground voltage difference. Usually cable guys just ground the cable on whatever is around: pipe that leads to the ground in my case. But the electronics are plugged into an outlet which is typically grounded at the house's breaker. The difference in potential voltage causes the hum you hear. So if you can get the cable guy to ground the cable at the same ground as the rest of your electronics, that would solve the problem at the root. However, I tangled with the cable company and the guy said, the regulations said he could ground it anywhere which is acceptable and claims it shouldn't cause a problem. So all in all he left and didn't do anything. If you could get the cable company to do something, great, if not the isolation transformers offer a safe alternative to your problem.

gacilu

Hi guys,

thank you so much for all your suggestions. I've received yesterday the power conditioner and it solved the problem. It is a bit bulky but I managed to hide it somehow. The buzzing noise was really unbearable and I had to keep the sub off all the time. Now I can enjoy it again.

This is what I've bought: http://www.amazon.co.uk/Belkin-Isolator-Cinema-Protector-Sockets/dp/B0002AG9SA/ref=sr_1_6?ie=UTF8&qid=1385047746&sr=8-6&keywords=power+conditioner

It costed about $50 and even though I am filtering also the cable, the problem was solved as soon as I plugged the power cords.

Thanks again!

polk500

Good to hear that you solved the buzz.

Cheers
Roger

badchad

Figured I'd bump this rather than start anew. Is a small amount of "buzz" normal for subwoofers and amp'd speakers?

My HSU sub produces a small buzz, even with the "cheater" plug to eliminate the ground loop. I thought it may be normal since the sub is always "on". I noticed the same with my RTiA7's after I bought my amp. I also leave my amp on all the time as well. Devices are plugged into different outlets, can't remember if they're different circuits.

tonyb

Not for me it isn't. Any buzz would drive me nuts.

Ground loops, which is what most "buzz" is, is from too many grounds on one circuit, most the times anyway. Try a good power conditioner, or move that cheater plug to a different piece. Just because the sub is buzzing doesn't mean it's from the sub itself. It could be traveling from another piece. Try it on the receiver or the amp.

Other things that contribute is poor cable quality, cable tv boxes are usually notorious for it too. A good power conditioner will help all around. If your outlets are old, originals, change them out to hospital grade available at any home depot.

badchad

Thanks. I have a good electrician, but I'm horribly non-handy. Will have him take a look next time he;s around.

aboroth00

tonyb wrote: »

Not for me it isn't. Any buzz would drive me nuts.

Ground loops, which is what most "buzz" is, is from too many grounds on one circuit, most the times anyway. Try a good power conditioner, or move that cheater plug to a different piece. Just because the sub is buzzing doesn't mean it's from the sub itself. It could be traveling from another piece. Try it on the receiver or the amp.

Other things that contribute is poor cable quality, cable tv boxes are usually notorious for it too. A good power conditioner will help all around. If your outlets are old, originals, change them out to hospital grade available at any home depot.

Any hum drives me nuts too. After battling a hum in my system, I've developed quite the ear for it. Ground loops are technically not caused by too many grounds on one circuit but rather if there's a lot of stuff plugged into the same outlet, there is more likely to be a difference in their respective ground potentials which can cause a hum. While a power conditioner sounds like a tempting solve all solution it may not necessarily solve your humming problem, (I know I bought two just to make sure when I had my hum). Tony is absolutely right that the hum may not originate with the equipment that is actually humming. They're all connected electrically after all. The cheapest and though tedious way to solve where the hum is coming from is to disconnect all of your equipment and connect each component one at a time until you hear the buzz again and that would be the equipment which is causing the hum.

Poor cable quality may contribute to a hum, I wouldn't look at it first as the problem. Cable boxes are not necessarily poor quality but they are usually the culprit in introducing hums to a system. As in one of my posts above, it's due to the cable guy grounding the cable at a different location than where your house is grounded causing a difference in the grounding potential and thus a hum. Another culprit that may not be as familiar is DC in the AC line. Usually your outlet is just AC current however, DC may leak into that line and can be heard as a hum in your transformer.

My advice first is to save money and try the free fixes first. There are a couple questions that I have that may help in diagnosing your problem.

1) Did the problem arise after you added your amp or another piece of equipment?
2) Do you have a cable box?
3) Does the buzz go away when you unplug the cable line?
4) If you plug everything into the same outlet, does the buzz go away?

Speedskater

aboroth00 wrote: »

Any hum drives me nuts too. After battling a hum in my system, I've developed quite the ear for it. Ground loops are technically not caused by too many grounds on one circuit but rather if there's a lot of stuff plugged into the same outlet, there is more likely to be a difference in their respective ground potentials which can cause a hum. While a power conditioner sounds like a tempting solve all solution it may not necessarily solve your humming problem.
*********************************
1) Did the problem arise after you added your amp or another piece of equipment?
2) Do you have a cable box?
3) Does the buzz go away when you unplug the cable line?
4) If you plug everything into the same outlet, does the buzz go away?

I'm not sure if there is a typo or if the thought is upside-down.
What you really when is to have all your equipment on one circuit (with the exceptions of big power amps and video projectors). It is even better to have all your equipment plugged into the same power strip/distribution block. That's why power conditioner's often solve problems, it's because all the units are plugged into the same spot. The less EGC/PE wire between units, the less difference in their respective chassis ground potentials which can cause a hum.

TNHNDYMAN

Quick question-

I'm dealing with a hum issue that just started yesterday while trying to incorporate my new to me HSU VTF3 subwoofer....

When you speak of #3 above, do you mean to unplug the coax cable going into the cable/sat box or unplug the power cord from the sat/cab box?



I'm trying to place the sub next to my couch as an end table of sorts, and while testing yesterday initially I had it plugged into the power strip with the pre, bdp 51, and other sources and while a hum was present, it was fairly low level and I could tolerate it. It was also noticeable thru the LSiM 703's which were silent before the sub was installed.

My real problem started when I tried to use the power outlet behind my couch and also in the corner of the room away from the entertainment rack. The hum is then quite pronounced and not something I can deal with. Very noticeable and has me concerned. Any suggestions?

aboroth00

Speedskater wrote: »

I'm not sure if there is a typo or if the thought is upside-down.
What you really when is to have all your equipment on one circuit (with the exceptions of big power amps and video projectors). It is even better to have all your equipment plugged into the same power strip/distribution block. That's why power conditioner's often solve problems, it's because all the units are plugged into the same spot. The less EGC/PE wire between units, the less difference in their respective chassis ground potentials which can cause a hum.

Sorry about the misunderstanding I was trying to address TonyB's statement that "Ground loops, which is what most "buzz" is, is from too many grounds on one circuit." But yes you are absolutely right that you want everything on one circuit. However if you have ttwo items that are plugged into the same circuit with a different ground potential, you may develop a hum.

aboroth00

TNHNDYMAN wrote: »

Quick question-

I'm dealing with a hum issue that just started yesterday while trying to incorporate my new to me HSU VTF3 subwoofer....

When you speak of #3 above, do you mean to unplug the coax cable going into the cable/sat box or unplug the power cord from the sat/cab box?



I'm trying to place the sub next to my couch as an end table of sorts, and while testing yesterday initially I had it plugged into the power strip with the pre, bdp 51, and other sources and while a hum was present, it was fairly low level and I could tolerate it. It was also noticeable thru the LSiM 703's which were silent before the sub was installed.

My real problem started when I tried to use the power outlet behind my couch and also in the corner of the room away from the entertainment rack. The hum is then quite pronounced and not something I can deal with. Very noticeable and has me concerned. Any suggestions?

I think you might have already answered your own question. If you unplug the equipment at the other outlet, behind your couch, and the hum goes away that may be the culprit. However could be other things contributing to the hum such as the coax cable from the cable line. You can try unplugging that and see if it adds to the hum. If the sub you added is causing the problem which it seems like it is, you can try adding a cheater plug to the sub and see if that solves the problem. This should be used as a test to verify the sub is causing the problem and not as a permanent solution.

tonyb

There is nothing wrong with using a cheater plug as a permanent solution. I've had one on one piece or another for years and years with no detrimental effects what so ever to anything. Granted that's the cheapest solution and many more expensive options are available, but why start with the expensive solutions. Start with the cheapest and work your way up if it doesn't work.

Power strips, while do what they do, do nothing to help the situation either. Believe me, been down your road many times in 40+ years, before realizing what a good....repeat...a "good" power conditioner can bring to the table. Or the simple benefits of a cheap cheater plug when 2 bucks is all ya got to spend.

aboroth00

tonyb wrote: »

There is nothing wrong with using a cheater plug as a permanent solution. I've had one on one piece or another for years and years with no detrimental effects what so ever to anything. Granted that's the cheapest solution and many more expensive options are available, but why start with the expensive solutions. Start with the cheapest and work your way up if it doesn't work.

Power strips, while do what they do, do nothing to help the situation either. Believe me, been down your road many times in 40+ years, before realizing what a good....repeat...a "good" power conditioner can bring to the table. Or the simple benefits of a cheap cheater plug when 2 bucks is all ya got to spend.

I will have to respectfully disagree with you here Tony. There's a reason why that grounding wire is there. Although it is unlikely, a wire may come loose and make contact with the chassis making the chassis "hot" without the grounding wire. And if you touch that hot chassis, it could prove fatal. There have been reported incidences of this and it is generally observed as unsafe to follow the cheater plug practice. You're essentially bypassing a safety mechanism of the product.

Sure, it is a very cheap fix but in my view, a unnecessarily dangerous one. If the problem is that different devices are causing a hum due to their different grounding potentials, you can ground all the chassis to one point with speaker wire. If the problem is the incoming cable coax line, buy a transformer isolation device which is ~15$. Use it to see if the grounding is the problem then find a proper solution to the actual problem. A cheater plug is just masking the problem. Please stay safe, and God forbid I hear a story about an audiophile electrocuting himself because of a silly cheater plug.

gp4jesus

If I read your (OP) posts correctly, at one time your system had a common power/ground source/point. Your system was fairly quiet though, pardon the pun, it sounds like your sub is inducing something to whatever powers your 703s, made worse when you power your sub from behind your couch.

My VERY quiet system has 4 power amps -- 3 different brands, plus a powered sub of still another brand. Everything uses the same outlet w/daisy-chained power strips; power amps having a separate one providing one switch to power them up/down.

That said, per post 23, the "behind the couch" & other outlet made the hum worse suggesting the other outlets are mid-wired or wired differently from your prime power source.

I wish you good, quick fortune on the outcome.

Read Isaiah 9:6-7, Luke 2:7-20 & have a merry Christmas!

tonyb

aboroth00 wrote: »

I will have to respectfully disagree with you here Tony. There's a reason why that grounding wire is there. Although it is unlikely, a wire may come loose and make contact with the chassis making the chassis "hot" without the grounding wire. And if you touch that hot chassis, it could prove fatal. There have been reported incidences of this and it is generally observed as unsafe to follow the cheater plug practice. You're essentially bypassing a safety mechanism of the product.

Sure, it is a very cheap fix but in my view, a unnecessarily dangerous one. If the problem is that different devices are causing a hum due to their different grounding potentials, you can ground all the chassis to one point with speaker wire. If the problem is the incoming cable coax line, buy a transformer isolation device which is ~15$. Use it to see if the grounding is the problem then find a proper solution to the actual problem. A cheater plug is just masking the problem. Please stay safe, and God forbid I hear a story about an audiophile electrocuting himself because of a silly cheater plug.

I've never heard of one in all my days, maybe you have so I can't dismiss that. The chassis can't get electrified because you have interconnects that would carry away that electricity to other components that have ground wires in their plugs. Now, if you don't have any other component with a grounded plug, then try using a cheater plug on the single one that does, that may cause a problem. Common sense however rules the day in these situations.