HomePlug AV and wiring quality

Discussion in 'Home Theater Projects' started by Jon:M, Mar 26, 2004.

  1. Jon:M

    Jon:M Auditioning

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    We're building a new house soon, and my current plan is to distribute audio and video using CAT5. However, I've been reading a lot about the new HomePlug AV spec which was demoed at International CES in Vegas in January. This is getting 200Mbps in the lab, and supposedly 170Mbps in a home environment (the speed shown at CES), and is being billed as capable of supporting HDTV distribution. This leads me to believe they really expect to get most of that bandwidth under real-world conditions.

    The earlier spec, HomePlug 1.0 released around the end of 1999, had real-world bandwidth numbers of only about 15%-40% of the quoted peak bandwidth of 14Mbps. This clearly illustrates that the quality of the wiring (and probably other conditions) have a huge impact on actual throughput. However, if they're advertising HDTV support for the new AV version, it would seem they expect the intervening years' advances in signal processing capabilities to overcome most of those problems.

    Still, it can't hurt to be prepared, so I'm wondering if anyone here can give me suggestions about specifications I could provide to my builder that might improve throughput if HomePlug AV takes off.
     
  2. Bob McElfresh

    Bob McElfresh Producer

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    Hi Jon.

    I may be out of the loop, but the last time I looked (about 2 years ago) the Cat5 solutions could not handle standard-definition video very well, let alone HD video.

    Be very suspicious of any product mixing 'bandwidth' in the same sentence as "14 Mbps". One is a analog concept, the other a digital concept. Different things with different applications. And dont invest in a 'cable' system from a show unless some outside/independent company takes a look at it and says it does not compromise things.

    My advice would be:

    - Design a wire system that fans out in a "star" pattern using something like the Smart Home cable (2 rg6 coax and 2 Cat5 cables in a bundle) from a central location. This can handle your computer, CATV and Sat distribution needs. Terminate everything in standard electrical outlet box's with a face plate with modular connectors. (Panduit makes a nice system). The last time I looked, the SmartHome cable (by CoastCom or ComCoast) runs about $1.20/ft. I would ignore the version that includes a fiber-optic wire as well.

    - I really dont suggest you try to distribute HD video throughout the house, but if you do get 3 runs of RG6 HD video cable from Belden or Canare. This stuff sells for about $1.60/ft in bulk. The Canare stuff is V3-5CFB, and Belden has 3 different models that work, but I dont have the part numbers memorized.

    If you do run HD video, design your runs with enough coax to create a un-broken cable from source to destination. Resist the urge to get wall-plates with RCA jacks. Instead, buy blank cover-plates and drill your own hole for the bundle of coax. Later, you can cut the coax off and install face-plates with connectors if you must. But please, please use BNC connectors on the wall-plates and not the RCA barrel-connectors.

    To re-state the high-points:

    Smart Home Cable: ~$1.20/ft
    HD video coax (3 conductor): ~$1.60/ft

    While Cat5/Cat6e wires are cheaper per foot - both of these are trivial compared to the installation cost which should be nearly the same for both systems. Trying to save money on the wire is penny-pinching in the wrong place. (Yes, I know you are shocked at the $220 price tag for a 6' component cable. But you can take advantage of bulk prices for broadcast-industry coax that rivals/surpasses the performance of the $$$ retail cables.)

    Another thing you might do: contact CEDIA and get someone from there to design your wire plan for a few hundred bucks. This organization is trying to be THE place to certify people who install whole-house computer and electronic systems. They dont sell any product, but they license/train and put on shows for people who install the type of systems you are looking at.

    Would you also do me a favor:

    Keep a log/diary of everything you do, learn, are told, etc. in this process and come back here at times and give us an update. We have lots of people who are in the same position as you and could benifit from your experience (including all the things that go wrong).

    Note: We also have a fourm dedicated to HomeTheater interiors and another fourm dedicated to "Home Theater Builder" magazine - both could be great resources for you.
     
  3. Jon:M

    Jon:M Auditioning

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    I should clarify, CAT5 is not being used for AV in the networking sense, it's being used to distribute low-power baseband signals. Basically it's just lengths of raw UTP as far as the AV distribution equipment is concerned. I'm interested in CAT5 based on a huge amount of research I've done on the subject in recent months. Unless I find compelling evidence that says AV distribution over CAT5 simply doesn't work (and I've found mountains of what seems to be evidence to the contrary), I'm already committed to about 30-35 runs of CAT5 through smurf tube and junction boxes. I'm not too worried about getting what I need from the CAT5, I just mentioned it because it's my current direction. It'll just be ironic if HomePlug AV plays out, because most of that CAT5 will become instantly obsolete.

    Regarding 14Mbps, I do know exactly how slow 14Mbps is (inadequate even for a single HD stream), but again, that's the old 1.0 protocol from 1999. I'm a programmer with more than 20 years experience, and my current home has 13 machines on a 200Mbps FDX network, so I'm very familiar with issues like bandwidth and comm cabling and so on. The 1.0 protocol is about to be superseded by the 170Mbps AV protocol, which is where my interest lies.

    I appreciate the response and the attempt to point me in the right direction, but I'm really looking for some very specific information: what can be done to a household electrical system during construction to optimize it for use with a powerline-based system like HomePlug AV?

    I may not even pursue the HomePlug AV thing, but if there are things I can ask the builder to do, even if they're expense items (within a certain range), I'd like to know about them just in case. Can't hurt to ask, right?

    Now, if you have experience with CAT5 UTP baseband distribution, I'd certainly enjoy a separate discussion on that topic. I'm by no means done with my research, but so far it looks pretty good to me.
     
  4. TroySimpson

    TroySimpson Auditioning

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    Hey Bob,

    Can individuals become members of CEDIA? How much? I could not find this information. It looks like it is geared mostly to manufactures, distributors, etc.

    I think I would like to attend their boot camp. Is it any good? I would also like to learn how to become a professional installer of this type of stuff. I live in Raleigh, North Carolina.

    I am remodeling my home and wanting to run some wiring. Any recommendations on what equipment / products / tools / brands to use? I was considering using an open rack (19") system in the central wiring closet, similiar to what is used in a company wiring closet to distribute networking Cat 3/5/6 UTP.

    Thanks,
    Troy
     

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