AVS Forum banner

1 - 20 of 98 Posts

·
Registered
Joined
·
68 Posts
Discussion Starter #1
hey guys,


so im going crazy trying to figure out why my brand new THX Ultra 2 system is huming (KW120's) i've tried several different ac outlets, rca cables (cheap ones) and still no fix. i called Klipsch customer support today and they recommened getting a high end subwoofer cable like a Monster M1000 thats directional for replacing the KA1000 subwoofer amp with a new one.. does anyone know if the more expensive sub cable will fix it or if i need to get a ground loop isolater etc?


thanks!
 

·
Registered
Joined
·
5,049 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24523986


hey guys,


so im going crazy trying to figure out why my brand new THX Ultra 2 system is huming (KW120's) i've tried several different ac outlets, rca cables (cheap ones) and still no fix. i called Klipsch customer support today and they recommened getting a high end subwoofer cable like a Monster M1000 thats directional for replacing the KA1000 subwoofer amp with a new one.. does anyone know if the more expensive sub cable will fix it or if i need to get a ground loop isolater etc?


thanks!

I doubt a "high end" monster cable would do the trick.

http://www.avsforum.com/t/1425569/ground-loop-hum-and-feedback

Some good feedback on how to isolate the problem.
 
  • Like
Reactions: Woobieizer

·
Banned
Joined
·
15,491 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24524423


If that's the case then I'll try a power filter or isolator, or replace the sub amp
If the hum is there with nothing plugged into the amp then it's a bad amp. If it only hums when connect to the AVR it's a ground loop. That's fixed with transformer isolation, on the interconnect or sometimes the TV cable. Power filters don't do anything, an isolator might, this is an excellent source:
http://www.ebtechaudio.com/
Quote:
i called Klipsch customer support today and they recommened getting a high end subwoofer cable like a Monster M1000 thats directional
Snake oil, money down the drain.
 
  • Like
Reactions: oneeyeblind

·
Registered
Joined
·
68 Posts
Discussion Starter #5
The hum only occurs when the receiver end of the RCA/SUB cable outer flange touches metal, if I hold the pin of the RCA cable to the outer portion of the SUB RCA input of the receiver with the receiver plugged in and unplugged the hum stops, if the RCA is fully inserted the hum comes back
 

·
Registered
Joined
·
1,627 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24524637


The hum only occurs when the receiver end of the RCA/SUB cable outer flange touches metal, if I hold the pin of the RCA cable to the outer portion of the SUB RCA input of the receiver with the receiver plugged in and unplugged the hum stops, if the RCA is fully inserted the hum comes back

Welcome aboard!

You've just solved your own problem.. outer ring is shield/ground. Descriptive of aforementioned ground loop.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #7
So I have a faulty RCA cable then, am I right? This is my first set of Passive subwoofers so this ground loop humming noise is new to me, I owned a powered sub before this with no issues even with the receiver volume turned all the way up
 

·
Registered
Joined
·
1,627 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24524882


So I have a faulty RCA cable then, am I right? This is my first set of Passive subwoofers so this ground loop humming noise is new to me, I owned a powered sub before this with no issues even with the receiver volume turned all the way up

Your RCA cable is not the problem unless you modify it by removing the outer shield to rid yourself immediately from the ground induced hum. This practice is called lifting ground.


Bill Fitzmaurice pointed out a web site with this item.




Warning:

Your choice is to lift the ground by modifying your RCA cable
,


Getting to Radio Shack and purchasing a RCA/stereo ground loop isolator.. Mono only if you can find one.


Or searching all over for AC plug for the offending appliance causing the hum Via AMP's Sub out.


Me.. I'd Dremel off the shield clean and push my signal prong thru a piece of electrical tape to ensure the cut off flange was not exposed to touch. Ground Lifting


Edit: spelling/grammar
 

·
Registered
Joined
·
68 Posts
Discussion Starter #9
I have a "Snake Oil" Monster M1000 directional sub cable coming tomorrow, I'll test out the new cable and if it doesn't help then I'll start some dremmel work on the $8 RCA cable
 

·
Registered
Joined
·
1,627 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24525029


I have a "Snake Oil" Monster M1000 directional sub cable coming tomorrow, I'll test out the new cable and if it doesn't help then I'll start some dremmel work on the $8 RCA cable

Good first choice.. Snake oil or not. If it works with your expensive gear. LOVE ON IT!!!

Keep us updated please. Your solution is our merit.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #11
My last Klipsch sub was powered and connected with a "snake oil" directional cable and went with the sub when I upgraded, I thought I could get away with a cheap cable for $4,500 subwoofers so who knows.


It's seems allot of people have this same issue so I'll definitely keep you posted with my findings.


All the reviews on the "snake oil" cable I'm getting tomorrow all talk about how it eliminated hum noise and produced a solid THX deep note so I'm anxious to see what happens!
 

·
Registered
Joined
·
1,627 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24525074


My last Klipsch sub was powered and connected with a "snake oil" directional cable and went with the sub when I upgraded, I thought I could get away with a cheap cable for $4,500 subwoofers so who knows.


It's seems allot of people have this same issue so I'll definitely keep you posted with my findings.


All the reviews on the "snake oil" cable I'm getting tomorrow all talk about how it eliminated hum noise and produced a solid THX deep note so I'm anxious to see what happens!

Well don't forget to take a cold shower, that seem to help me.



Found this lil gem off Monster


Quote:
Why do the cables have directional arrows?


This is done for shielding purposes only, a design where we do not solder the shield on the signal's destination. This ensures that any noise picked up by the shield will not be transmitted into your signal path.


Break out the Dremel and cook tonight!
 

·
Registered
Joined
·
1,627 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24525410


Lol, I'll give it a shot and keep you posted.

No need I have my ELF-SD on and will know when you crank up the Klipsch
 

·
Registered
Joined
·
68 Posts
Discussion Starter #15
Yeah the dual Klipsch's do put out some power, watching "The Conjuring" you could feel wind hitting you in the face, can't imagine what a cleaner signal will produce
 

·
Registered
Joined
·
1,627 Posts
wondering how low can you feel or even hear this with the awesomeness you own?

Test[/URL]


Enjoy.. think I'll put on "The Conjuring" myself.
 

·
Registered
Joined
·
68 Posts
Discussion Starter #17
Well I did your test and as expected I didn't make it very far, only got down to 15hz before it cut out. Hopefully once I get the hum fixed I'll be able to hit 10 or 5
 

·
Banned
Joined
·
15,491 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24524882


So I have a faulty RCA cable then, am I right?
No, you have a fully functional RCA cable. That's what causes ground looping, because the sub is connected to ground by both the AC cable and the interconnect. Two ground paths= hum. Transformer isolation eliminates the second ground path. So does not having the shield make a connection. Or not connecting the cable shield to the connector on one end, either end, it doesn't matter which.
Quote:
wondering how low can you feel or even hear this with the awesomeness you own?

Bass Test
Not what you think you can. If the readout says 15Hz you're probably hearing the second harmonic at 30Hz.
 
  • Like
Reactions: oneeyeblind

·
Registered
Joined
·
68 Posts
Discussion Starter #19
I'm gonna try the snake oil cable today and if still no luck I'm going to send the amp back to Klipsch
 

·
Banned
Joined
·
15,491 Posts

Quote:
Originally Posted by MKSniper  /t/1524113/klipsch-kw120-ka1000-thx-ultra-2-humming-noise#post_24526569


I'm gonna try the snake oil cable today and if still no luck I'm going to send the amp back to Klipsch
I already told you, the amp is not the problem. The Monster cable might work, but if it does it's not because it's expensive, any cable with the shield connected at one end only would give the same result. This is why you're having a problem, and it has nothing to do with the amp:
http://www.rane.com/note110.html
 
1 - 20 of 98 Posts
Top