Question about Sunfire True Sub MK II Subwoofer

1 Answer

Loud audible hum,figured a ground loop issue discovered that when I unhook my tv cable hum disappeared,reappeared when cable was hooked back up.Would a better shielded cable help or should i call my cable company. Steve

Posted by on

Ad

1 Answer

  • Level 3:

    An expert who has achieved level 3 by getting 1000 points

    All-Star:

    An expert that got 10 achievements.

    MVP:

    An expert that got 5 achievements.

    Brigadier General:

    An expert that has over 10,000 points.

  • Master
  • 3,917 Answers

Hi,

No need to call the cable company as they would do the same. Please get a better shielded cable to help have better ground. This will remove the humming sound.

Thanks for contacting Fixya and please accept the solution if it has helped you.

Posted on May 29, 2010

  • slehtimaki May 29, 2010

    HI

    I purchased RG6 quad shield coax and installed it, I achieved a better picture but no change in hum.



    Steve

×

Ad

1 Suggested Answer

6ya6ya
  • 2 Answers

SOURCE: I have freestanding Series 8 dishwasher. Lately during the filling cycle water hammer is occurring. How can this be resolved

Hi,
a 6ya expert can help you resolve that 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.
the service is completely free and covers almost anything you can think of.(from cars to computers, handyman, and even drones)
click here to download the app (for users in the US for now) and get all the help you need.
Goodluck!

Posted on Jan 02, 2017

Ad

Add Your Answer

Uploading: 0%

my-video-file.mp4

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

×

Loading...
Loading...

Related Questions:

2 Answers

I hear a humming noise from my Sunfire subwoofer - occassionally. I bought a kit from Radio Shack that supposed to cut down on noise from the electric outlet - it didn't work. Please help!


How to isolate annoying background hum.

As long as the music or movie is playing, you can forget about it, at least until a quiet passage occurs, then there it is again: HUMMMMMMM! Be gone, bad hum, you think. But, like a bad odor at the back of the fridge, it takes some dogged persistence to track it down and eliminate it.

Hum is a constant low-frequency buzz, usually at about 60 Hz or 120 Hz, which results from voltage differences between true "ground" (what you'd get shoving a copper pipe into the ground) and the electrical "ground" of your receiver's chassis, the incoming cable-TV feed, or any video or audio components interconnected within your system, including powered subwoofers. When this voltage differential exists, it's called a "ground loop," and the hum it produces is darned annoying. You'll hear the hum mainly from the subwoofer because it's a low-frequency noise, but there will also be hum from your floorstanding front speakers or even compact bookshelf models.

First, try disconnecting your subwoofer from the coaxial sub cable from your AV receiver but leave the subwoofer turned on. Does the hum go away? If it does, then the ground loop is entering the system from your AV receiver and/or your cable-TV system set-top box (or satellite dish and decoder).

Disconnect the incoming TV-cable or satellite feed to a set-top box or to your TV and the A/V receiver. If the hum disappears (and you don't use a satellite dish) complain to the cable-TV company. They may know what you need and supply you with a ground-isolating transformer. If they don't know what you are talking about you'll need to order a video ground isolator and install it in-line with the TV cable before it enters your set-top cable-TV box. Axiom has special wide-band isolation transformers that will not interfere with any digital TV or HDTV signal. (N.B. You CANNOT use one of these with a satellite decoder box.)

Before you order one, you can try plugging your subwoofer into a different AC outlet in the room, ideally one that is not on the same circuit as your AV receiver and video equipment (TV, DVD player, sat or cable TV box, etc.) That may solve the problem. If it doesn't, see if the back panel of your sub has a "ground-lift screw". It will be labeled as such. Just remove it. That may remove the hum. If it doesn't and you have a standard cable-TV feed (not a dish), then order the ground-isolation transformer. (Axiom has special wide-band isolation transformers that will not interfere with any digital TV or HDTV signal.)
Axiom Audio Ground Isolator

If that still doesn't eliminate the hum, or if you use a satellite dish video feed, then you could try one of these from Radio Shack, which goes between the subwoofer and the coaxial cable from the receiver's subwoofer output.

With persistence, all ground-loop problems can be solved.

Hope it helped..

Have a nice day...

Feb 21, 2011 | Sunfire True Sub MK II Subwoofer

1 Answer

After a power outage I have a loud hum.


Hi, The Ground Rules Of all the annoyances that can afflict any audio/video home theater or even a simple stereo installation, the notorious "ground loop" may well be the most difficult and persistent one to track down and eliminate. A "ground loop" is caused by the difference in electrical potential at different grounding points in an audio/video system. (All the grounds in an A/V system should ideally be at "0" potential.) A ground loop typically adds a loud low-frequency hum or buzz as soon as you plug in any of various audio or video components, including subwoofers, cable-TV outboard boxes, satellite-TV feeds, TV displays, amplifiers, A/V receivers or turntables. The buzz/hum is a byproduct of the multiple power supply cables and a ground voltage differential within your system and its network of interconnecting cables.

Here are some methods to help you get rid of ground loops. Try these first and don't waste money on a power "conditioner" which, in most cases, won't help. (There is no need to "condition" the AC power for your system. Your receiver or amplifier already has a power supply with its own filters and transformers. No further filtering is normally required.)

If you get your system up and running and hear an audible buzz or hum, the first culprit to look at is either the powered subwoofer or your cable-TV or satellite-box feed at the entry point to your system.

First, the subwoofer: unplug the coaxial cable that connects to your powered subwoofer to see if the ground-loop hum disappears. If it does, it's likely coming in through your cable/satellite TV feed.

Reconnect your subwoofer's coaxial cable from the subwoofer input to your receiver's subwoofer output and disconnect the cable-TV feed (or satellite feed) from your outboard set-top cable box or satellite tuner. Be sure and disconnect the cable before any splitters. Now see if the hum/buzz from your subwoofer stops.

If that eliminates the hum, you can install one of these inexpensive in-line ground isolators from Parts Express or Bass Home. Note that these transformer-based ground isolators will work fine with analog cable-TV feeds, but depending on their design they may interfere with or block reception of HDTV signals via a digital cable or satellite dish feed.

Install the ground isolator between the cable-TV feed and the input of your outboard cable-TV box or satellite tuner (or the TV display's antenna or cable input if you have a set with a built-in TV tuner or a cable-card ready set). In many cases, the ground isolator will "break" the loop and remove the annoying hum or buzz by isolating the TV-cable ground.

If a hum remains with the TV cable completely disconnected from your system, or you don't want to risk degrading reception of HD signals from a cable or satellite system, then you may have to add a ground isolator like this Radio Shack Model 270-054 between the line-level coaxial subwoofer cable from your A/V receiver and the line-level input jack on your powered subwoofer.

In all cases, if your subwoofer has a ground-lift screw like some of Axiom's subwoofers, try first removing the screw (or replacing it) to see if it increases or eliminates the hum. It may or may not make a difference.

If you do not have easy access to the aforementioned ground isolators, here are a few more tips:

Try plugging the subwoofer into a different AC outlet in the room, one that isn't supplying power to your components (A/V receiver, TV, cable box, etc.). That might fix it.

Try reversing the AC plug for your A/V receiver or the powered subwoofer. If it's a 3-wire plug or a polarized plug, which has one prong wider than the other, you won't be able to reverse the plug. For safety, do not use a "cheater plug" to bypass the 3-wire plug.

With the power OFF, reverse the AC plugs one by one of any other components that have a standard 2-prong AC plug that isn't polarized. Each time you reverse a plug, turn on the system with the attached component and your subwoofer and see if the hum disappears. In some cases, reversing one or more plugs will eliminate the hum.

If you have a turntable, try connecting a separate ground wire to a chassis screw on your preamp or receiver and see if the hum disappears. If you already have a turntable ground wire, try removing it from the preamp. One or the other may eliminate the hum.

Finally, here is another solution that worked well for a member of our message boards who decided to discard his ground-loop isolator on his subwoofer: "I took off the ground-loop isolator I'd been using and connected a plain 14-gauge wire to chassis screws on the sub and the receiver then powered everything on. Although hum was still there, it was far lower than before. Next I unscrewed the ground-loop screw on the back of the sub and that took care of the hum completely."

Almost certainly sounds like an earth loop to me, but can be caused by a poorly made transformer or phase shifts on the mains supply. Visit some power conditioner web-sites like Isotek or Isol-8 (or google "earth loop") where there's plenty of advice on how to reduce/eliminate earth loops and other causes of mains-induced hum (transformer problems etc).

Hum on the speakers usually indicates that there is a DC voltage on the speaker line. DC voltage on the output lines would be caused by a shorted output transistor.


Have a nice day...

Feb 16, 2011 | Cambridge Soundworks BassCube 12 Speaker

1 Answer

Sunfire MK II Subwoofer hum. I have a Sunfire MK II subwoofer that hums when it is plugged in (it even hums when no signal is connected). I've tried multiple outlets on different circuits, but hum...


you have a ground loop issue you could purchase a ground loop isolator, jensen makes them for about 40 bucks.I have discovered that if you have cable tv, unplug the incoming cable in your cable box and see if hum disappears.

Nov 25, 2010 | Sunfire True Sub MK II Subwoofer

2 Answers

Bose lifestyle makes loud noise like a build up of


If you still have the speakers that the TV came with hooked up try unhooking the wires to them I had the same problem and it fixed the problem, Good Luck!

Apr 10, 2010 | Bose Lifestyle 28 System

1 Answer

I have Insignia ns-p42q-10a tv, there is a loud hum when the volume is on when you mute the volume it goes away? Any suggestions?


check other inputs AVI, HDMI,,

do you here the hum on all inputs?

The hum maybe from a bad ground loop,, unplug all pluged in inputs, [dvd,games,radio,ect] <--check for hum.

If the hum is gone, plug inputs back in one at a time and test,,

When you find the source of the hum, go get a ground loop isolator to fix.

Mar 25, 2010 | Insignia NS-P42Q10A Plasma TV

2 Answers

When I hook the system up. I an hear a humming or buzzing like noise in teh system


This is the bane of all home theater installations and its called the "60 Hertz Hum" Most likely coming from your cable company.. Simple test... Disconnect any Coax cables from the outside going into your cable box or tv. Hum disappears. Most likely this is caused by a "ground loop" problem.

The solutions are far and varied. Google "ground loop hum" to find different things to try


Aug 14, 2009 | Philips HTS 6600/12 Home Theatre...

2 Answers

Hum in the audio - 32'' Proscan 1080i


does the hum occur when playing a dvd or only when watching tv ? if the hum occurs only when watching tv, i would like you to disconnect the cable line from either the wall or the back of the cable box and see if this hum disappears. if the hum disappears call your cable company. you have what is called a " 60 cycle ground loop ". hope this helps.

Jan 20, 2009 | Televison & Video

2 Answers

Sunfire Subwoofer 110 Noise on input plugin


A few more questions-
Does the sub hum without anything plugged into it except for power? If it makes a real loud hum almost a squeal then I think the rca cable between the receiver and the sub is dead shorted and needs to be replaced. If it's more of a low level hum, then it's a ground hum caused by many things, ie........the receiver and the sub being on different power circuits in the house.......sometimes diconnecting the cable tv feed as it enters the room while the sub is connected and humming to see if it stops........the easy fix sometimes is using a 3 to 2 prong ac adapter but lifting the ground on such a powerful amp could be a fire hazard.

Sep 25, 2008 | Sunfire True Sub MK II Subwoofer

1 Answer

Humming sounds


You have a ground loop in the system. Unhook everything and then slowly add one cable back at a time. You will find the problem that way. Good luck.

Mar 22, 2008 | Televison & Video

1 Answer

Screen Issues


Grounding problem. Sometimes too much, sometimes too little, grounding is a hard one to wrestle to the ground. Due to the possibility of ground loops, too much grounding can be as bad as too little.

Try unhooking all your components and see which one causes this thing to happen when it's HU'd.

The most common offender is having cable hooked up, whose grounding can cause this phenom and also grounding hum in the audio. You can get an isolating filter for cable grounding that allows the cable signal to get thru without allowing the grounds to connect to each other. This usually solves the problem.


Mr Bob

Feb 02, 2008 | Samsung HCM5525W 55" Rear Projection...

Not finding what you are looking for?
Sunfire True Sub MK II Subwoofer Logo

Related Topics:

75 people viewed this question

Ask a Question

Usually answered in minutes!

Top Sunfire Audio Players & Recorders Experts

shaun taylor

Level 3 Expert

1525 Answers

woodzowl307

Level 3 Expert

652 Answers

Joseph Hoffmann

Level 3 Expert

1706 Answers

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

Answer questions

Manuals & User Guides

Loading...