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Discussion Starter · #1 ·
Hi All,


I'm considering a home theater arrangement in which my surround amplifiers will be located about 50 circuit feet from my surround processor. Running 200 feet of audio interconnects would be very expensive so I have been considering running the line level audio over CAT5 or CAT6 wiring.


Leviton makes a wall plate mounted connector that has an RCA connector with a punchdown terminal that will take CAT5/6 wiring.

RCA 110-Type QuickPort® Connectors


Would this be a false economy in which I would be seriously compromising the quality of the audio signals going to my side and rear surrounds?


Thanks


Larry
 

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IMHO - Yes.


50ft of RCA interconnects is going to pose some issues no matter what you use.


Balanced cables (XLR) would be a different story.


Consider building your own 'high quality' RCA interconnects. Some shielded coax will be appropriate. The Tweaks forum should have a bunch of information on this type of activity.


Roo
 

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I would just keep the amps close and run speaker wire. Line level signals are more likely to have interference problems than amplified signals. What is the advantage of moving your amps so far away?
 

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If you're stuck on the 'long interconnects, short speaker wire' myth, then using CAT5 rather defeats that whole theory, doesn't it? If you want to do it, you can purchase interfaces from Audio Control ( www.audiocontrol.com ) that will allow you to use CAT5. From the processor to line driver use interconnects, from line driver to line driver use CAT5, from line driver to amp, use interconnects.
 

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Discussion Starter · #5 ·
Thanks guys for the responses.


I guess I'd better rethink my approach about placing my surround amplifiers so far from my surround processor.

Quote:
Originally posted by rgladiator
I would just keep the amps close and run speaker wire. Line level signals are more likely to have interference problems than amplified signals. What is the advantage of moving your amps so far away?
Frankly after receiving these responses there no longer appears to be any overriding advantage, but let me explain where I was originally coming from.


Right now I've got all my amps located in an entertainment center along with most of my equipment and a rear projection HDTV. (Please click on my signature for a descritpion of my current arrangement.) I'll be moving and setting up an other home theater, and since I've pretty much run out of space in the entertainment center, I was thinking about relocating some of the equipment to a second location in the rear of the room where the equipment would be more accessable.


Ultimately I'd like to upgrade to a front projection configuration and relocate all the equipment to a common location. Since I can't afford to do this at one time, I was considering accomplishing this in stages.


As Andrew suggests I have started researching Do-It-Yourself interconnects, but the silver ones would still probably cost over a $1,000. Even if I went this route I'm wondering whether there would be a problem placing DIY cables inside the walls of a home theater. Since this is a new home could I run into electrical code issues if the wrong type of cabling is selected? Would I have to limit my cable selection to phelum types?


Finally if I bite the bullet and spent the money on expensive interconnects eventually they would be abandoned after all the equipment was colocated during the next phase of upgrading.


I'm not specifically familar with the "long interconnects, short speaker wire' myth" that Dennis aludes to, but I guess I must have independently fallen into that line of thinking, since I thought it might make sense to move the surround amplifiers closer to the the surround speakers. Of course this creates the problem of expensive interconnects. I had seen a few threads on using CAT5 for audio, and I was hoping that I might be able to solve the long, expensive interconnect problem with CAT5 wiring.


In following Dennis' lead here's an excerpt from the AudioControl web site:

Quote:

BVD-10â„¢ - Balanced Video/Audio Driver

BVR-10â„¢ - Balanced Video/Audio Receiver

Video/Audio to CAT-5 Distribution System



The BLD-10 Video Driver and the BVR-10 Video Receiver form the new AudioControl Balanced Video over CAT-5 distribution system. The BVD-10 accepts 1 or 2 composite video inputs or a single S-video input along with a two channel stereo audio signal and converts the signals to a standard Cat-5 cable. The BVR-10 converts the balanced Cat-5 signals back to their original format. The Active-Balanced circuitry design enables distribution of a high-quality video and audio signal up to 1000’ using inexpensive Cat-5 UTP cabling.


Key Features
  • Active-Balanced Circuitry Design for Maximum Bandwidth Performance
  • Extends High Quality Video and Audio Signals up to 1000’ on Cat-5 Wiring
  • Flexible Video Inputs: 2 channel Composite, Component

    or 1 S-Video
  • Two channel Stereo Audio
  • Adjustable Video Gain for Source Balancing
  • Active Cable Equalization for Sharp Video Images
  • Adjustable Audio Signal Gain
  • Converts Between Composite and S-Video
  • Standard EIA568 RJ-45 Cat-5 Connection Jack
  • Operates on 24 VAC Power Input
  • Compact Panel Mount Design: 4â€H x 5.2â€W x 1.2â€D
While it would seem that Dennis' solution would technically work, I assume the more common and economical use of this approach for whole-house audio applications, versus dedicated home theaters. I haven't been able to find a price for this distribution system, but I guess that it would be more expensive than interconnects.


So I guess its back to the drawing board.


Thanks again for pointing me in the right direction.


Larry
 

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Quote:
Originally posted by LarryChanin


Even if I went this route I'm wondering whether there would be a problem placing DIY cables inside the walls of a home theater. Since this is a new home could I run into electrical code issues if the wrong type of cabling is selected? Would I have to limit my cable selection to phelum types?

I think you meant 'plenum', and no, you don't need plenum rated cables which are pricey. For in wall/ceiling use, you need CL-2, CL-3 or 'riser' rated cables. Much cheaper than plenum.


I have always been a strong advocate of using the properly rated cables for in-wall use. Recently, I was checking out my neighbors basement finishing, and they had run lampcord type wire for speakers inside the wall. Worst of all, the inspector didn't even blink. :rolleyes:
 

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Robertmee, don't be too shocked. When I checked with local inspectors the only wiring codes enforced were electrical. I could wrap my low voltage wires in paper for all they cared.
 

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Discussion Starter · #9 ·
Quote:
Originally posted by Dennis Erskine
As I recall, the Audio drivers (not video) are in the $50-$75 range.
Hi Dennis,


Thanks very much.


Sorry, I should have referenced these AudioControl audio line drivers and receivers:

BLD-10 - Four Channel Balanced Line Driver

and
BLR-10 - Four Channel Balanced Line Receiver
  • Allows easy extension of high-quality audio signals up to 1000'(305 meters)
  • Utilizes standard category 5 unshielded twisted pair wiring
  • Perfect for separating amps and source units in multi-room audio installations
  • Driver converts unbalanced RCA to balanced audio signal
  • Receiver converts balanced audio inputs to unbalanced RCA
  • Active balanced circuitry eliminates audio transformers
  • Four channel operation
  • Includes 24 vac wall plug power supply


I'm not sure a consumer such as myself could easily purchase these. In a 1998 press release AudioControl states:

Quote:
Price: AudioControl Custom Installation products do not have a suggested retail price since they are part of a complete system.
However, I was able to find an Australian audio dealer selling a new set for $500 AUD which I believe equates to about $311. So maybe this approach is not totally out of the question.


Quote:
Originally posted by robertmee
I think you meant 'plenum', and no, you don't need plenum rated cables which are pricey. For in wall/ceiling use, you need CL-2, CL-3 or 'riser' rated cables. Much cheaper than plenum.
Thanks robert,


Yeah, phelum that's what I meant. Well, at least I didn't spell it "phlegm" :D


Thanks again for everyone's help.


Larry
 

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I haven't tried CAT5 for audio, but I am running an SVideo signal over 30ft. via CAT5 and it works great. I just soldered regular SVideo plugs to either end of 2 pairs of a CAT5 cable (BTW soldering an SVideo connector is a major pain!) I used a pair for the chroma signal and another pair for the luminance. No ghosting or interference I can see, but I have not yet calibrated my whole system. I am using it to watch a Dish network satellite feed on my NEC LT-154 projector. I have a 110" 16:9 screen, so defects in the signal should show up very well.


Seeing as a video signal is a much higher bandwidth than an audio signal, you may have success with it. I would try it outside the wall first to see if it's a go. If you can find some inexpensive STP (Shielded Twisted Pair) wire, you can wire up a balanced audio interconnect that should really be quiet. Just be sure to use a single pair as your signal + and signal - and then connect the shield to the signal - on the source side of the cable. Or if your amp has balanced inputs/outputs all the better.


A balanced signal is one with shield separate from the signal ground (signal -) connection. Similar to a 120V AC circuit (hot = signal +, neutral = signal -, ground = shield). Theoretically, having a shield separate from the signal ground keeps any of the interference that the shield picks up from dirtying the signal.


Try wiring it up without the line drivers first. You may be pleasantly surprised and save a bunch of money.
 

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Discussion Starter · #12 ·
Quote:
Originally posted by cgblack
I haven't tried CAT5 for audio, but I am running an SVideo signal over 30ft. via CAT5 and it works great. I just soldered regular SVideo plugs to either end of 2 pairs of a CAT5 cable (BTW soldering an SVideo connector is a major pain!)


I used a pair for the chroma signal and another pair for the luminance. No ghosting or interference I can see, but I have not yet calibrated my whole system. I am using it to watch a Dish network satellite feed on my NEC LT-154 projector. I have a 110" 16:9 screen, so defects in the signal should show up very well.


Seeing as a video signal is a much higher bandwidth than an audio signal, you may have success with it. I would try it outside the wall first to see if it's a go. If you can find some inexpensive STP (Shielded Twisted Pair) wire, you can wire up a balanced audio interconnect that should really be quiet. Just be sure to use a single pair as your signal + and signal - and then connect the shield to the signal - on the source side of the cable. Or if your amp has balanced inputs/outputs all the better.


A balanced signal is one with shield separate from the signal ground (signal -) connection. Similar to a 120V AC circuit (hot = signal +, neutral = signal -, ground = shield). Theoretically, having a shield separate from the signal ground keeps any of the interference that the shield picks up from dirtying the signal.


Try wiring it up without the line drivers first. You may be pleasantly surprised and save a bunch of money.
Hi Graeme,


Thanks for the idea.


Have you considered using this QuickPort connector to eliminate the hassle of soldering?

S-Video Connector over UTP Wire Instructions


Your discussion regarding fabricating a balanced audio interconnect may have gone over my head, but wouldn't it be a lot easier for me to use the RCA connector with a punchdown terminal that I mentioned in my initial posting to perform this experiment?

RCA 110-Type QuickPort® Connectors


Thanks for your interest.


Larry
 

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Discussion Starter · #13 ·
Hi Graeme,


I found a source for audio / video line drivers over CAT-5.

Audio/Video Over Twisted-Pair


Notice that the cheap $50 Unicom video/audio driver/receivers have an audio bandwidth of only 50Hz - 15 KHz.


I'm wondering that if an inexpensive active device is bandwidth limited, wouldn't any attempts at using passive CAT-5 interconnects likely have the same limitation?


Larry


By the way, notice a pair of AudioControl audio driver/receivers cost $300. I can't find their band width listed in their specs, but based on AudioControl's reputation, I'm betting there's no problem with them.
 
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