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Basically a thickly-shielded RCA cable, essentially intended for subwoofer use. Something like this one: http://www.monoprice.com/products/pr...seq=1&format=2 if your run is about 25 feet, or they've got the same thing in 50', 75' and 100' lengths. Run a cable to each subwoofer position, and then when you're hooking everything up you can either use y-splitters (such as this one: http://www.outlawaudio.com/products/cab_y_about.html , or you could buy a cheaper RCA y-splitter at radio shack) at the receiver/pre-pro end to hook all the runs up. Conversely, if you get a subwoofer equalizer such as a Velodyne SMS-1, then that unit has pre-outs for 3 subs (I think), and you simply hook the long sub runs to that, and then a short subwoofer cable from your receiver/pre-pro to the equalizer.
 

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Your are going to get a lot of suggestions to run RG6 coaxial cable. This seems to work for most people. What is often misunderstood is why. It's generally not the superior shielding of RG6. Unless you are running the cables close to AC lines, or live next to an antenna farm, steel mill, or substation, there really isn't a need for deep shielding in an average residence.


The most prevelant cause of sub woofer hum is ground loops. The best way to prevent this is to do what the pros do - use a balanced system. This is expensive however. Here are my tips for quiet sub woofers before resorting to a balanced system:


1) Run a single PAIR shielded cable like Belden 9451. That is TWO wires PLUS a SHIELD. Initially you would use just one of the wires and shield but if you ever need to go to a balanced system, you have the proper wire installed. This is just as good as using RG6 and better as it future proofs the system. Do not use CAT5 wire. This is a poor choice for analog audio signals.


2) Try to use a subwoofer with a FACTORY INSTALLED two wire power cord. Now don't just chop the third prong off a three wire power cord as that's not safe.


3) Keeping the sub on the same circuit as the AV receiver is a good idea but is not often helpful in eliminating ground loops. It all depends on how the room is electrically wired.


4) Don't get hung up on the "everything on the same phase myth". Ground loops have nothing to do with the AC phase. The reason I suggest the same circuit is that it may mean the ground wires are close to the same length.


5) Keep these runs at least 12inches minimum from parallel AC lines. Personally I would go 48 inches away. This does not apply to non amplified speakers that are immune to hum pickup.


6) Don't fall for fancy overpriced audiophile cables. A sub woofer is very undemanding in terms of frequency response. Even paramaters like excessive cable capacitance are irrelvant with a sub woofer.
 

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Glimmie- that's some good info. The only thing that I would add it to run an RG6 as well as the 9451. The reason? RG6 is pretty cheap (you can get a preterminated 50' run for $5!) and terminating the shielded pair requires soldering RCA ends, which isn't the easiest thing to do if you don't have experience.


CJ
 

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Quote:
Originally Posted by CJO /forum/post/16931292


Glimmie- that's some good info. The only thing that I would add it to run an RG6 as well as the 9451. The reason? RG6 is pretty cheap (you can get a preterminated 50' run for $5!) and terminating the shielded pair requires soldering RCA ends, which isn't the easiest thing to do if you don't have experience.


CJ

Come to think of it why not run 3/4 Smerf or aluminum Flex. Then you can replace the cable at will anytime. Sounds expensive up front but once you get the wall treatment up and have to add or change wires, it's a pretty small investment!
 
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