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Gear / Technical Help => Cables => Topic started by: BJ on February 01, 2005, 12:24:54 PM

Title: longest rca run from sbd?
Post by: BJ on February 01, 2005, 12:24:54 PM: If I was wanting to run a matrix, but the sbd is in the far back of the room...what is the longest I could run some rcas? is there a point where its not worth it? i.e >15 ft >30 ft? Or is it totally up to the cable i get? could i purchase 2 25 ft rca's cables from rat shack and join them for a 50 ft run and still be fine???

edit: can a mod move this to the correct forum....damn im still asleep..thanx
Title: Re: longest rca run from sbd?
Post by: JayinKC on February 01, 2005, 12:57:32 PM: I run a 50' RCA cable occasionally when I do a matrix so I can be well away from the crowd in front of the soundboard. I run them through the ceiling joists and drop them where I put my gear. You've got to be careful though, and try to not make your run come near any electrical cables because you can get a low-hum interference. There's a neon light in the place I record at that I turn off to get rid of the hum coming through my cable. I got my 50' RCA at TigerDirect.

Jay
Title: Re: longest rca run from sbd?
Post by: Nick in Edinboro on February 01, 2005, 01:03:02 PM: This looked interesting: http://www.audiovideo101.com/learn/askus/displayaskus.asp?questionid=140&List=9

It seems you might be better off buying some bulk coax cable, putting the f-connectors (standard "cable tv plug") and then buying the RCA adapters which screw right onto the f-connectors--or wiring the rca's directly the coax cable somehow..
Title: Re: longest rca run from sbd?
Post by: hexyjones on February 01, 2005, 02:55:03 PM: Quote from: Nick in Edinboro on February 01, 2005, 01:03:02 PM
This looked interesting: http://www.audiovideo101.com/learn/askus/displayaskus.asp?questionid=140&List=9

It seems you might be better off buying some bulk coax cable, putting the f-connectors (standard "cable tv plug") and then buying the RCA adapters which screw right onto the f-connectors--or wiring the rca's directly the coax cable somehow..

They're talkin' video in that article...video will run fine on a coax/cable-tv type wire with RCAs....true.

But for audio - no way...
Title: Re: longest rca run from sbd?
Post by: learning_towalk on February 01, 2005, 04:09:05 PM: i bought a VERY heavy duty 25' balanced RCA cable from partsexpress on sale for 12 bucks

can't wait to run it
Title: Re: longest rca run from sbd?
Post by: leegeddy on February 01, 2005, 05:00:35 PM: Quote from: learning_towalk on February 01, 2005, 04:09:05 PM
i bought a VERY heavy duty 25' balanced RCA cable from partsexpress on sale for 12 bucks

can't wait to run it

i don't think there is such a thing as a "balanced" RCA cable. RCA only has 2 conductors (tip + ground).

marc
Title: Re: longest rca run from sbd?
Post by: jpschust on February 01, 2005, 05:24:56 PM: you are going to start seeing problems in rca cable i would imagine at about 25ft or longer with delay issues.
Title: Re: longest rca run from sbd?
Post by: learning_towalk on February 01, 2005, 05:29:03 PM: i didn't think that a balanced RCA was possible either but I found one...

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-211
Title: Re: longest rca run from sbd?
Post by: leegeddy on February 01, 2005, 05:33:35 PM: Quote from: learning_towalk on February 01, 2005, 05:29:03 PM
i didn't think that a balanced RCA was possible either but I found one...

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=263-211

i see what they're saying. i don't think their "balanced" refers to the same balanced definition applicable to mic cables.

marc
Title: Re: longest rca run from sbd?
Post by: learning_towalk on February 01, 2005, 05:36:46 PM: oh ok....but I knew I wasn't crazy ;)
Title: Re: longest rca run from sbd?
Post by: BJ on February 01, 2005, 07:18:13 PM: Quote from: jk labs on February 01, 2005, 06:41:24 PM
Quote from: My Old Jerry on February 01, 2005, 12:24:54 PM
If I was wanting to run a matrix, but the sbd is in the far back of the room...what is the longest I could run some rcas? is there a point where its not worth it? i.e >15 ft >30 ft? Or is it totally up to the cable i get? could i purchase 2 25 ft rca's cables from rat shack and join them for a 50 ft run and still be fine???

edit: can a mod move this to the correct forum....damn im still asleep..thanx

I know you are after an answer in feet. However, a given cable will have a capacitance per foot. That means you loose highs at a rate that depends on Rout, the OUTPUT impedance of the source driving the cable. Here starquads are twice as bad as single conductor cables.

Others have mentioned interference. A good separate shield will help. A balanced feed is even better.

So it depends. While it is fully possible to run several 100s of feet of single ended RCA cable it might take some work to do so in your application.

Jon

yes i was after a measurment...of course ;D however..a good learning discussion for me is even better in the end...

so would it be better if i was to get (50 ft xlrs?) from the board and use adapters on my end to go into the ua5?? will this still be balanced?? damnit..i really dont even know what balanced is...HA...

johnny - as far a delay....will this apply to no matter what cable i use??

I guess i should explain further...the main music club here is about 75-100 ft long..from stage to back..and the sbd is near back far left wall( if you were facing out from stage) the is a pole about 10 ft from the stage that I want to clamp/boom from....and still try to get the sbd feed on some bands...

any and all rec's welcome...and +t's all around!
Title: Re: longest rca run from sbd?
Post by: bluegrass_brad on February 01, 2005, 07:53:12 PM: It would still be unbalanced since you are connecting a balanced signal (XLR from the board) to an unbalanced signal (Adapted to the RCA's on the UA5). A "balanced" wiring system is when you have two out of phase conductors and a common screen, reducing the effects of interference. If you have balanced equipment on both ends than any interferance affecting the cable is cancelled out, resulting in a cleaner signal.
Title: Re: longest rca run from sbd?
Post by: Jason B on February 02, 2005, 07:57:05 PM: Quote from: corkscrew on February 01, 2005, 02:55:03 PM

They're talkin' video in that article...video will run fine on a coax/cable-tv type wire with RCAs....true.

But for audio - no way...

We do this every day for in-wall cable runs installing professional dedicated home theaters. This is 100% acceptable. Put some RCA adapters on and go. You will be fine.
Title: Re: longest rca run from sbd?
Post by: hexyjones on February 03, 2005, 04:47:24 PM: Quote from: Jason B on February 02, 2005, 07:57:05 PM
Quote from: corkscrew on February 01, 2005, 02:55:03 PM

They're talkin' video in that article...video will run fine on a coax/cable-tv type wire with RCAs....true.

But for audio - no way...

We do this every day for in-wall cable runs installing professional dedicated home theaters. This is 100% acceptable. Put some RCA adapters on and go. You will be fine.

Fine for Audio? or fine for Video?
Title: Re: longest rca run from sbd?
Post by: jpschust on February 03, 2005, 05:05:43 PM: not entirely true about delay- we deal with delay in long runs of xlr's too, especially when running matrixes.
Title: Re: longest rca run from sbd?
Post by: Jason B on February 03, 2005, 11:10:24 PM: Quote from: corkscrew on February 03, 2005, 04:47:24 PM
Fine for Audio? or fine for Video?

Both. It doesn't matter.
Title: Re: longest rca run from sbd?
Post by: jbraveman on February 06, 2005, 05:01:04 PM: What about running long XLRs from the mics back to the board instead of long RCAs from the board to the rig?
Title: Re: longest rca run from sbd?
Post by: rokpunk on March 04, 2005, 12:37:22 AM: Quote from: corkscrew on February 01, 2005, 02:55:03 PM
Quote from: Nick in Edinboro on February 01, 2005, 01:03:02 PM
This looked interesting: http://www.audiovideo101.com/learn/askus/displayaskus.asp?questionid=140&List=9

It seems you might be better off buying some bulk coax cable, putting the f-connectors (standard "cable tv plug") and then buying the RCA adapters which screw right onto the f-connectors--or wiring the rca's directly the coax cable somehow..

They're talkin' video in that article...video will run fine on a coax/cable-tv type wire with RCAs....true.

But for audio - no way...

no way?!?! why not?
coax cable is a hell of alot more sturdy than a standard RCA cable is. just terminate the ends with RCA's and you are set.