subwoofer/humming (1 Viewer)

[Hailan R]

Hi guys,
Prety new here but ive been reading a lot . Here is my problem. I get an annoyinh hum out of my subwoofer with 1 cable and not the other. I bought a paradigm ps1000 subwoofer a month ago, cause the sale rep told me it was a 1000watt rms, witch it aint, and well i got a ixos bronze subwoofer cable and well that subwofer wasnt cutting it for me(need louder) and well i found out that it was only 175 rms afterwards and decided to try another cable sumthin better. And bought an ixos silver series cable from a guy on this board and all I always get an annoying hum now out of the subwoofer.
what i did tried allready:
When i received the cable,I took it out of the box uncoiled it and plugged it in the back of my receiver and into the sub and i got an annoying humming sound all the time(yes its plugged in the correct direction ). I then proceeded to unplug it and try back my old bronze cable and boom the hum is gone. tried routing the cable differently, didnt work, tried coiling it didnt work, put the sub as far as the cable would let me, moving it away from any electronics, even putting a board under it all a no go, i always get that annoying hum. Any ideas on this or what i could try to do to solve it.
Also could it be that the cable is fubared :frowning:
thx a lot guys

 

[Saurav]

Did you try reversing the direction? I posted an answer to an almost identical question on the Speakers forum, but I think you've probably tried most of that already. It's possible that one of the cables is just shielded better than the other, but I don't know if that would show up as hum.

 

[Bob McElfresh]

Hailan: there are 2 different kinds of subwoofer cables
1) For an ordinary interconnect/RCA cable, the outer shield connects to the outer part of the plug ON BOTH SIDES. This can/does cause a HUMM sound when connecting to an external amp (which your sub contains). But you WANT this type of cable when connecting different non-amplifier devices together.
2) A "subwoofer" cable has the outer shield connected to only ONE plug. It usually has little arrows to show the signal direction. The "break" in the shield prevents the 60 hz ground loop humm you are hearing.
Your Bronze cable is type #2. Your Ixos cable is type #1.
The answer to your problem is obvious: use the Bronze cable.
Hope this helps.

 

[Hailan R]

thx a lot guys but the part i dont get is that both are subwoofer/mono cable..... And yes Saurav i tried both ways(the way the cable indicates and well as last resort the other :frowning. Looks like im going shopping again :frowning: need a longer cable :frowning:
just in case anyone is wondering the bronze cable is model # 1182(witch aint listed on ixos site but 1181 older rev is) and the silver cable(one causing the hum is 1181) ixos site

 

[Bob McElfresh]

but the part i dont get is that both are subwoofer/mono cable

Ahhh. Your coax cable is really 2 wires:

- The center conductor that carries the actual signal

- The outer shield that represents 0.0 volts/ground so both devices have a common ground/reference.

The Bronze cable does not tie the grounds of the receiver & sub together. This eliminates the "ground loop" humm.

Hope this helps.

 

[Hailan R]

So in other word(plain english hehe) i have dirty power and only way to solve this hum with that cable would be a power conditionner or keep using cheap cable.......

 

[Bob McElfresh]

i have dirty power

No.

Short Answer: The humm is caused because BOTH your receiver and subwoofer have a 3-prong plug and both of these tie the very sensitive internal SIGNAL ground to your AC power system. When you hook up your sub with the IXOS cable the entire system now has 2 different paths to the ground. A bit of electrical activity in one part is viewed by the other part as a voltage-difference aka - a "signal". The amps then do what the amps were designed to do: amplify the voltage difference. This is what causes the humm.

(Have you noticed that your receiver has a 3-prong plug, but none of your other devices do? This is deliberate.)

 

[Steve Sz]

I had the same problem w/my Klipsch KSW12. Simply replace the 3 prong with a 2 on the sub power cord and you should be OK.

 

[Hailan R]

hmmmmmmm,
thx for the tip Steve Sz but both the receiver and sub have a 2 way plug (no ground... maybe thats why...) i tried both in the same power bar and not the same and still no go, oh well i give/gave up :frowning: