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Main => Audio/Jukebox/MP3 Forum => Topic started by: Taborious on May 01, 2006, 01:50:25 pm

Title: Audio Cable length
Post by: Taborious on May 01, 2006, 01:50:25 pm

I'm sure this is a noob question but I don't know the answer so I ask...

I would like to run a cable from my PC to my stereo system, is there a specification for cable lengths for line-in/line-out? How do I determine what a specific sound card will support for this type project?

Title: Re: Audio Cable length
Post by: Ghoward on May 03, 2006, 10:05:59 am

I think you would be able to use a long cable with no problems, as for sound card any will do as you only need one output from your card.

Gary

Title: Re: Audio Cable length
Post by: Taborious on May 03, 2006, 01:22:31 pm

So could I get away with a cable 100ft long? For line out or headphone jack?

Title: Re: Audio Cable length
Post by: D_Zoot on May 03, 2006, 02:47:35 pm

Due to capacitance, signal losses and the potential for noise, long unbalanced line-level runs are not generally suggested.

Now, having said that, I have made 100ft unbalanced line level runs without any problems at all (in a pro sound system setup no less!).  Use good quality cable and interconnects and you will be fine.


D

Title: Re: Audio Cable length
Post by: MonMotha on May 03, 2006, 04:28:56 pm

Transmission line effects at audio frequencies on even relatively crappy cable won't be evident at 100ft.  If you use halfway decent cable, you should be fine.  Be aware that most PC sound cards don't put out a great signal in the first place, though, so if you have problems with noise levels, you may want to put a small preamp to boost it up to "pro quality" line levels (which are generally much, much higher than that found on consumer gear) before running it through your cable run.  Most likely, the only factor on a run of that length will be attenuation.

If you still have noise or other problems, you can move to a balanced line, but then you'll need balun converters, and you probably don't want to bother.  You could also move to TOSLINK or other forms of optical audio transmission as they don't exhibit transmission line effects except on unusually long links with poor quality cabling.

Title: Re: Audio Cable length
Post by: richms on May 05, 2006, 11:51:31 pm

Biggest issue will be ground loops. They are solvable with a cheap isolator from anywhere that sells car audio.

Also PC outputs tend to be low impedance low level so they can drive a pair of headphones with some sucess. very few soundcards have a true line out which is why you have to crank the volume on the amp so much. There are some soundcards that let you swap the front and rear outputs, and the rear are usually proper lineouts so give that a shot if the levels are too low.