Woofer Woes: Cabling

[Aikouka]

So, I was setting up my new subwoofer today and I purchased the follow cable for it from Amazon:

http://www.amazon.com/gp/product/B0001XGQTA/

But whenever I use this cable, I get a humming noise with the subwoofer. I went and grabbed one of my unused cables, plugged it in and it works fine. I also went and used the cable that I have for my subwoofer downstairs and that works fine.

Is there something that I'm missing with that Belkin cable? I'd prefer one of the monoprice cables, but given the shorter time I needed it in, I didn't feel like paying the very high shipping costs :\.

EDIT:

If you're curious why I'm not just using the unused cable that I mentioned, I need a long cable (hence the 25' Belkin cable) for positioning the unshielded subwoofer away from components with hard drives in them (xbox, etc).

 

[slashbinslashbash]

When you used the shorter cable, was your sub plugged in to the same outlet as your other audio equipment? And when you used the long Belkin, was it plugged in to a different outlet?

 

[Aikouka]

The subwoofer was originally plugged into an outlet with only my PSP charger plugged into it. I removed the charger and nothing seemed to change. I moved my SW over to my AVR so I could use the shorter cables to test. The shorter cables worked fine in this other outlet, which had nothing else in it, but the longer cable still produced the excess noise.

I went out to hhgregg today and bought a cable (I know... I got reamed price-wise ), but this 25 foot cable seems to work without a problem. I wasn't entirely sure if it was just a bad cable, because after some Googling (before I posted this thread), I saw things about improper cables, so I wasn't sure if I just got a cable that wasn't properly compatible. This sub is a little different than my other one since it doesn't have a dedicated LFE RCA port.

Appreciate your help, slash.

 

[Rifter]

For longer runs you really need a well shielded cable for RCA since it is not balanced, and dont run it near other cables if at all possible. For short runs any cheap cable will work, anthing over 15 feet is when quality comes into play for RCA.

This is why a Balanced connection such as XLR is much better for long cable runs, XLR will go a hundred feet no problem, thats why its the standard pro audio connection, and most high end home audio subs also have this connection, if you do then use it.

 

[Aikouka]

I suspected that length might have been an issue, so that's why I ran all cables from the same point during my testing with the 3 different cables. Even though the 25' cable is longer than the 6' cable, it simply sat on the floor next to nothing. The new cable I got seems to be just as good of a quality as the old cable (shielding-wise... at least from what I can tell), so I'm not too sure. Maybe the Belkin was just a dud?

Now I need to try and figure out some quirks I never discovered in my AVR!

 

[Howard]

Possibly a ground loop that disappeared because the shield was wired differently in the cables you tried. Sometimes unbalanced cables don't have the shield connected at both ends.

 

[Fallen Kell]

I was always told that you shouldn't have the shield connected at both ends to the ground, as that defeats the whole purpose of the shield.

 

[BassBomb]

I've got a 25ft RCA from monoprice (pretty thick shield) running from one corner of my room to the other, it passes with my cat5 network cable yet ive not noticed any problems with my sub (rare clicking turning on/off sleep mode when theres very little signal)

 

[Howard]

I was always told that you shouldn't have the shield connected at both ends to the ground, as that defeats the whole purpose of the shield.

Yeah, well, there're no hard and fast rules for unbalanced wiring (or even for balanced).

EDIT: It's complicated. http://www.rane.com/note151.html

 

[vi edit]

Get a cheater plug from Walmart for a buck that blanks out the ground plug on your three prong power adapter on the sub.

 

[Aikouka]

The sub only has a two prong power plug .