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#1
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Running Audio on Cat5 -- Possible???
Hi all,
I'm looking at wiring up my home with Cat5, and I have some rather odd questions. First every room will be wired with two pairs of Cat5 cable -- one definately for ethernet but the other I'd like to keep open for other applications, which is the purpose of this email. First... I want to run two phone lines on the Cat5 -- which will eat-up two pairs and leaves me 2 more pairs. Is it possible to run audio over those other two pairs? By audio, I mean wire-up a standard Left and Right (RCA) jack to either pair for stereo audio. Is this possible? I'll have a patch panel each cable will run to, so wiring-up some audio cables shouldn't be too difficult. I'm just technically not sure if audio will even run over a small gauge of wires for this length -- which I'm looking at 50-60 feet. Also I'm not sure if there'll be interference with two phone lines and two sets of audio cables running through the same Cat5 cable -- given the cables can support the audio. Thanks in advance for any ideas or suggestions. I'm just trying to make wiring my home both easier and as simple as possible. Take care, Ringo |
#2
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First... I want to run two phone lines on the Cat5 -- which will
eat-up two pairs and leaves me 2 more pairs. Is it possible to run audio over those other two pairs? By audio, I mean wire-up a standard Left and Right (RCA) jack to either pair for stereo audio. Is this possible? I'll have a patch panel each cable will run to, so wiring-up some audio cables shouldn't be too difficult. I'm just technically not sure if audio will even run over a small gauge of wires for this length -- which I'm looking at 50-60 feet. Also I'm not sure if there'll be interference with two phone lines and two sets of audio cables running through the same Cat5 cable -- given the cables can support the audio. What you are seeking to do is possible, but how well it works will vary. If you simply RCA-terminate the two audio lines and go right into your audio components, I predict horrible problems with crosstalk, and especially with hum. You'll probably end up with a severe ground loop. A better approach is to use a "balun" (balanced to unbalanced audio transformer) at each end of each audio pair in the cable. A 1:1 audio isolation transformer is really what you want... connect an RCA-plug-terminated audio coax cable to one winding, and the RF-45 wire pair to the other winding. Using such a device will have two effects: - It'll prevent ground loops, by providing galvanic isolation of the grounds in the two rooms. Ground currents can't flow across the insulation between the transformer windings. - It'll probably reduce hum and crosstalk, by using each twisted pair in a fully-balanced mode. You can buy commercial audio baluns (http://www.svideo.com/500019.html is one such), or try homebrewing your own using audio isolation transformers (e.g. Radio Shack #273-1374) and connectors and casing of your own choosing. -- Dave Platt AE6EO Hosting the Jade Warrior home page: http://www.radagast.org/jade-warrior I do _not_ wish to receive unsolicited commercial email, and I will boycott any company which has the gall to send me such ads! |
#3
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"Ringo Langly" wrote in message
oups.com... Hi all, Hi. I'm looking at wiring up my home with Cat5, and I have some rather odd questions. First every room will be wired with two pairs of Cat5 cable -- one definately for ethernet but the other I'd like to keep open for other applications, which is the purpose of this email. First... I want to run two phone lines on the Cat5 -- which will eat-up two pairs and leaves me 2 more pairs. Is it possible to run audio over those other two pairs? By audio, I mean wire-up a standard Left and Right (RCA) jack to either pair for stereo audio. Is this possible? It's possible. For line level signals, there will likely be some discernable cross-talk, especially near the high end of the audio range. I'll have a patch panel each cable will run to, so wiring-up some audio cables shouldn't be too difficult. I'm just technically not sure if audio will even run over a small gauge of wires for this length -- which I'm looking at 50-60 feet. Not a problem unless you are driving speakers thru those wires or hoping to get microphone input levels thru them without some noise pickup. Also I'm not sure if there'll be interference with two phone lines and two sets of audio cables running through the same Cat5 cable -- given the cables can support the audio. Interference (aka "cross-talk") would be my only concern. Thanks in advance for any ideas or suggestions. I'm just trying to make wiring my home both easier and as simple as possible. Take care, Ringo -- --Larry Brasfield email: Above views may belong only to me. |
#4
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"Ringo Langly" wrote:
First... I want to run two phone lines on the Cat5 -- which will eat-up two pairs and leaves me 2 more pairs. Is it possible to run audio over those other two pairs? Yep. By audio, I mean wire-up a standard Left and Right (RCA) jack to either pair for stereo audio. Is this possible? I'll have a patch panel each cable will run to, so wiring-up some audio cables shouldn't be too difficult. I'm just technically not sure if audio will even run over a small gauge of wires for this length -- which I'm looking at 50-60 feet. Also I'm not sure if there'll be interference with two phone lines and two sets of audio cables running through the same Cat5 cable -- given the cables can support the audio. Possibly, but if your on the phone, you shouldn't be as worried about the audio on the stereo. |
#5
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In comp.home.automation, Ringo Langly wrote:
First... I want to run two phone lines on the Cat5 -- which will eat-up two pairs and leaves me 2 more pairs. Is it possible to run audio over those other two pairs? By audio, I mean wire-up a standard Left and Right (RCA) jack to either pair for stereo audio. Is this possible? I'll have a patch panel each cable will run to, so wiring-up some audio cables shouldn't be too difficult. I'm just technically not sure if audio will even run over a small gauge of wires for this length -- which I'm looking at 50-60 feet. What you want is entirely possible using a KAT5 transmitter and receiver. http://www.kat5.tv/index1.html Although the KAT5 units are primarily for video, they convey an audiophile-quality stereo signal. The wiring is as follows: Blue (4&5) Left Audio Orange (1&2) Composite Video/S-video Luma Green (3&6) Right Audio Brown (7&8) 2nd Video Circuit/S-video Chroma/Digital Audio You can connect the audio pairs and leave the others unconnected. That's what I do, and it works perfectly. Alternatively you could use SPDIF and get *two* stereo signals down your two pairs. Also I'm not sure if there'll be interference with two phone lines and two sets of audio cables running through the same Cat5 cable -- given the cables can support the audio. I can't tell you about phone lines, but FWIW I have about 10 metres of cat5 fixed wiring conveying KAT5 audio and ethernet in the same cable. [To the structured wiring police: yes, I know, I know.] At each end there's a specially-wired dual-RJ45 wallplate, with one outlet labelled "LAN" and one labelled "Audio" going to the KAT5 unit. I've detected no interference. To ask about phone lines you could contact Keith Doxey, the KAT5 designer: http://www.kat5.tv/contact.html -- Mike Barnes |
#6
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"Ringo Langly" writes:
Hi all, I'm looking at wiring up my home with Cat5, and I have some rather odd questions. First every room will be wired with two pairs of Cat5 cable -- one definately for ethernet but the other I'd like to keep open for other applications, which is the purpose of this email. First... I want to run two phone lines on the Cat5 -- which will eat-up two pairs and leaves me 2 more pairs. Is it possible to run audio over those other two pairs? By audio, I mean wire-up a standard Left and Right (RCA) jack to either pair for stereo audio. Is this possible? It is possible to run normal line level audio signals through CAT5 wiring together with other signals. I have personally done this, typically with video signal on the same cable. But there shoudl not be any problem with telephone on the same wire either (some crosstalk from rign signal and pulse dial possible). There is on "secret" on running the audio signal through CAT5 wiring successfully: the signals must be balanced. Balanced signals can be transported nicely through twisted pair cables without considerable crosstalk or without picking much noise on the way. The CAT5 twistred pair cable is not a suitable medium for transporting unbalalanced audio signals (the signal transfer method used n consumer audio RCA connectors and such). If you wire unbalanced signal source to CAT5 UTP, you will get considerable crosstalk between the signals on different pairs and the signal will very easily pick up humming noise. Balanced signals are available directly from professional audio equipment and can be directly wired to CAT5 UTP. One audio signal takes one wire pair. For left and right audio you need two wire pairs. If you want to connect equipment that do not have balanced connections on them, you need to use audio transformers on the both ends of the CAT5 UTP cable to perform balanced-unbalanced conversion (from unbalanced RCA to balanced on signal source end and and back from balanaced to unbalanced in the receiving end). In addition to signal balancing such tranformers will provide galvanic isolation on the audio interconenction (without isolation many times conenctions from one room to another will pick up humming noise). Ground currents can't flow across the insulation between the transformer windings. Audio transformers are available as separate components and there are also commecially adapters that can convert RCA audio to CAT5 wiring and back. I'll have a patch panel each cable will run to, so wiring-up some audio cables shouldn't be too difficult. You need to wire those audio transforemers to your circuit as well between your RCA and wire on the wall. You just can't just patch-in the cable from the hifi equipment to your patch panel. I'm just technically not sure if audio will even run over a small gauge of wires for this length -- which I'm looking at 50-60 feet. Line level audio will run though this wire this distance quite well. Been there, done that. I have one system at my home where I run the audio and video trough CAT5e wiring from my computer room to my living room TV/hifi system. Cabling distance is about 15 meters. No problems. The adapters are homebuilt (my own design). The audio adapter part is built out of one of those RCA stereo audio signal isolators sold or solving ground loop problems. Basicly have opened one the device (it includes two audio transformr), cut out the original signal out cable, disconnected the audio transformer secondaries from original wiring completely and soldered to two pairs on the CAT5 wiring. Works very well, is easy to build (if you know how to solder), and cost is very reasonable (those RCA isolators cost around 10-20 USD). Just build two of theose adapters, one for each end of the connection. Or go to a shot and buy a ready made box at considerably higher price. Also I'm not sure if there'll be interference with two phone lines and two sets of audio cables running through the same Cat5 cable -- given the cables can support the audio. There is potential for some interference, but it could work well acceptably for you. Thanks in advance for any ideas or suggestions. I'm just trying to make wiring my home both easier and as simple as possible. Take care, Ringo -- Tomi Engdahl (http://www.iki.fi/then/) Take a look at my electronics web links and documents at http://www.epanorama.net/ |
#7
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On Thu, 03 Feb 2005 18:44:45 -0600, John Hines
wrote: By audio, I mean wire-up a standard Left and Right (RCA) jack to either pair for stereo audio. Is this possible? I'll have a patch panel each cable will run to, so wiring-up some audio cables shouldn't be too difficult. I'm just technically not sure if audio will even run over a small gauge of wires for this length -- which I'm looking at 50-60 feet. Also I'm not sure if there'll be interference with two phone lines and two sets of audio cables running through the same Cat5 cable -- given the cables can support the audio. Possibly, but if your on the phone, you shouldn't be as worried about the audio on the stereo. I expect the 'phone circuits, now or in the near future, may be carrying an ADSL carrier for broadband internet. |
#8
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Tomi Holger Engdahl wrote:
Line level audio will run though this wire this distance quite well. Been there, done that. I have one system at my home where I run the audio and video trough CAT5e wiring from my computer room to my living room TV/hifi system. Cabling distance is about 15 meters. No problems. The adapters are homebuilt (my own design). The audio adapter part is built out of one of those RCA stereo audio signal isolators sold or solving ground loop problems. Basicly have opened one the device (it includes two audio transformr), cut out the original signal out cable, disconnected the audio transformer secondaries from original wiring completely and soldered to two pairs on the CAT5 wiring. Works very well, is easy to build (if you know how to solder), and cost is very reasonable (those RCA isolators cost around 10-20 USD). Just build two of theose adapters, one for each end of the connection. Or go to a shot and buy a ready made box at considerably higher price. I went the ready-made route and got two of these: http://www.videocapturecard.com/svideobalun2.html They transport the A/V from my PC across a distance of ~30 meters to a stereo A/V modulator that merges the signal with my cable TV. It works very well indeed. Ximinez -- Our three weapons are fear, surprise, and ruthless efficiency... and an almost fanatical devotion to the Pope.... http://www.ai.mit.edu/people/paulfitz/spanish/t1.html |
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