Axiom Home Page Forums General Discussion Home Theater Subwoofer cable vs stereo RCA interconnect?

Hi,
I have integrated amp which has L/R pre-out. So i want to connect it to a subwoofer. Since the sub will be at seating area, i need long cable (25 ft). My sub also has L/R RCA line input.

Question: Can i use 2 25ft subwoofer cables ( i have several extra ones)to connect pre-amp L/R pre-out to L/R RCA sub, instead of buying a pair of stereo RCA?

thanks.

Yeah, all audio, line-level, coax cables are designed to carry the same signal. In fact sub woofer cables are less demanding than the full audio range interconnects.

The only worry would be as to the quality of the shielding if it is being run near power cables or in areas with a lot of RF. Or for long runs is the cable is really thin.

Otherwise what ever you have will work.

Thanks for replying.
Right now, i'm just trying out the sub with 2-channel stereo. So, once i'm set, i will get the high quality cable. I need 2 pairs of cables (25ft long).

Which cable do you recommend? There are many out there in the market though.

thanks.

I like Blue Jeans Cable. Though they are overkill for most home setups; at least they are well-priced overkill.

Hi Audiofan,

Just thought I'd mention that the general consensus around these parts is that as long as the wire is of thick enough gauge to carry the current the distance you need to go, all is good. However, as somebody mentioned, shielding verses interference can be an issue and some coax and RCA cables are indeed shielded better than others.

I guess the point I wanted to make is that when you referred to "high quality" cables, I wouldn't worry about paying big bucks for crazy priced, audiophile brands. As long as the electrical signal gets there unimpeded, the sound quality will be the same.

I am pretty sure you just referred to some thicker, shielded cabling but thought I'd throw this out there, just in case.

What do you think about the monoprice RG-6 cables, Chris?

They're probably fine. I just don't shop at Monoprice. I find their website a jumble, and even when you do find a part that will fit, you don't know exactly what you're getting. I feel this way about every place I shop. I usually know the manufacturer's part number of what I want, I've gotten all the specs I need from the source; it's just a matter of finding a good place to buy it.

When I'm looking for something more generic, like wire, I often have to rely on the reseller to tell me what I'm getting. Monoprice fails in that respect, by providing next to zero technical information. Including statements like:


...makes me run away screaming.

But that's just me.

I've had good luck with them, although their premium connectors are pretty tight. And the miniplug->RCA cable I got from them is RIDICULOUSLY fat.

As one of my favorite geeks is known to say, "sewer rat may taste like pumpkin pie, but I'll never know." I can't get past their appearance (website) to actually order something.

If I were in the market for as cheap as possible, Chinese made cables, I'd just go with Tartan Cable.

Mmmm. Sewer rat is starting to sound better all the time.

I've ordered cables/wires from Blue Jeans and Monoprice. Been very happy with products received from both companies. Monoprice is definitely cheaper than Blue Jeans, but Blue Jeans isn't bad compared to others out there either.

a couple of years ago i got satellite tv in the house.
they use very good RG6 so when the tech had finished making the installation, i asked him if he would be willing to make up six 15ft. cables terminated with rf plugs, with rf to gold phono adapters at each end.

for me, it was a good thing to do, price/quality wise.

Can you run the pre-outs and line level speaker outputs simultaneously? I have not ever heard of someone doing that before. Never heard of a sub with both R/L digital inputs either. Sounds like a cool feature. What is your sub, just curious?

A lot of receivers can use the line and speaker level outputs at the same time, but the manuals almost always say not to. That's because of the way the circuit is designed. If the line output is connected to an amp, then the impedance of the circuit changes. That's fine if you calibrate the the line to output a strong enough signal to drive the amp to the appropriate level. But what happens then is the same signal is being used to drive the internal amp, and that can cause trouble.

I don't think he's saying that the sub has digital inputs, but left and right analog ins. I'd guess that about a third of all sub amps are set up that way. No uncommon. Some do get a 6 dB gain when both the left and right are fed the same signal. Again, not a big deal, but needs to be accounted for in calibration.

Michael,
i don't know what "line level speaker outputs" is.

there's line level outputs on preamps and on some prepros, but the signal output of an amplifier is not line level, it can go as high as around 100 volts, but on preamps/prepros line level is less than a volt and the max output can be as high as around 16 volts.

prepros have low level outputs that can't drive speakers (very small amperage/low current)
power amps have high level outputs that drive speakers (many amperes/high current)

that's why preamps consume only small amounts of electricity and why power amps can consume large amounts.

hope this is clear enough. :-)

the sub is SVS PC12+. you can find info on it here:
http://www.svsound.com/products-sub-cyl.cfm
the difference is that mine is last year's and it does not have DSP and the amp is a 525 Watt BASH.

I probably used incorrect terminology. By speaker line level, I was referring to the amplifier output to the speaker driver. I don't really know why I call them that other than that's what one of my subs calls them. I have not heard of a sub that had R/L RCA. All I've seen is a mono RCA and then the R/L speaker inputs with outputs for running a sub in between the amp and the speakers.

Thanks for the clarification.

Yeah, Mike; the terminology has gotten a bit tangled-up here. As Chris mentioned, there's no "digital" connection in question; these are regular analog left and right channel inputs(which some sub amps do have), as the input to amplifiers has to be(even for those class D amplifiers sometimes incorrectly referred to as "digital").

Also, the "simultaneous" connection isn't to the same speaker, but to the separate sub amp as well as the integrated's internal amp. There's nothing wrong with this, and it's just an internal "Y" arrangement, with one branch feeding the internal amp and a parallel branch going to the pre-outs. A parallel connection doesn't form a voltage divider, and voltage to drive both amps can be supplied without difficulty.

As to the original question about the cables, as has been noted, these are all coaxial cables with RCA plugs on the ends; it doesn't matter if they're called "subwoofer", "RCA", "stereo" or whatever. They do vary in the heaviness of their shielding against outside electrical interference, but the typical cables sold by low-cost providers such as MonoPrice(which I use) are fine for use in nearly all home audio environments. No special "high quality" has to be searched for, as these have all the quality needed for the job.

Michael, in case you want to know;
about my subwoofer, it has l/r line level phono inputs and outputs
AND l/r high level inputs and outputs (speaker connectors).

my 2-channel system is pretty much decent , i think : Plinus 9200, Totem Forrest, Ayre CD player. RCA is Discovery . THis cable i bought used but it's already expensive. I just don't want to spend huge amount of $ on subwoofer cable, but not cheap cable neither.

I have several extra subwoofer cables in the house and i will try it first. thanks.

Here's a tip: Sell the snake oil, Discovery cable and use the money to buy a whole line of sensible cables.