Help with wiring!

[Rowdy S13]

Hey guys, I have a few questions about wiring a room for surround sound. What I am trying to do is wire my living room for 7.2 surround sound, with the equipment located in a separate area. Most of it is very straight forward, but I am looking for recommendations, tips, tricks, and so on. I also have some specific questions, starting with the subs. I have seen wall plates that are RCA/RCA, and also F-Type/RCA. I guess you can say you loose me at coaxial cable What kind should I run, how should I terminate, and so on. Can I get a spool of RG-6 and use that for the subs (plate to plate)? Next up is HDMI over CAT-6, who has experience with it? Anything/brand I should avoid? How far is acceptable? Anything else I need to know before hand? Last question is what should I run for the TV? I am thinking HDMI (over CAT-6), and two CAT-6 for networking (one for the TV, one for just in case). Should I run a RG-6 for anything (no antenna currently), what about a second HDMI, and if so which direction? I say which direction because all of the HDMI over CAT-6 I have seen are directional.

Any and all help is appreciated. This is in the planning stages right now, and I have not bought anything yet. I just want to be as prepared as I can be for this project so it goes nice and smooth! I dream of a room with floating TV, and speakers that are just plugged into the wall, except the surrounds which are just there with no visible wire



Thanks,
Sean

 

[Rowdy S13]

Wow, 90 views and no replies! Do you installers not want to share your secrets with me?


Sean

 

[Sgratien]

Have never used cat6 hdmi, so can,t comment. You can, however, use rg6 for sub wiring if you choose. Works just fine. As far extra cabling goes, it all depends on access to the space. If its easy, just run what you need now. If it,s difficult, spare hdmi in case one fails- high speed with arc, check out monoprice. Possibly rg6 for ota antenna. Cat5/6 for Ethernet. Your receiver does up-convert of analog so hdmi is all you need. Good luck.

 

[Speedskater]

An important thing about RG-6 co-ax cable. This is a very generic number. The "RG" means Radio Grade from back in World War II days. The "6" means a cable with a radio frequency characteristic impedance of about 75 Ohms and a diameter of about 1/4 inch. Different RG-6 cables are made for different use's. One cable manufacture makes over 40 different model numbers.
The RG-6/QS (quad Shield) is only suitable for cable TV signals. The RG-6 suitable for analog & digital audio and for video is a very different cable.

 

[avengineer]

An important thing about RG-6 co-ax cable. This is a very generic number. The "RG" means Radio Grade from back in World War II days. The "6" means a cable with a radio frequency characteristic impedance of about 75 Ohms and a diameter of about 1/4 inch. Different RG-6 cables are made for different use's. One cable manufacture makes over 40 different model numbers.
The RG-6/QS (quad Shield) is only suitable for cable TV signals. The RG-6 suitable for analog & digital audio and for video is a very different cable.

There's no reason to think analog audio wouldn't work with any of them. Some types are more difficult to work with though.

 

[BMXTRIX]

I use RG6 quad shield for everything, I find it works well for digital audio as well as analog audio, antenna, cable, etc. It does a good job. It is a bit pricier, but always seems to work just fine when I have used it.

Terminate to an F-connector, then use a F to RCA connection at the wall so you get a subwoofer friendly RCA connection at the end.

For HDMI:

What distance are you running? It is best to run a 30 to 50 foot HDMI cable if you can. They work well and look good and typically provide the 'best' possible connection. No powered HDMI baluns to deal with and cause additional headaches down the road.

But, it does sound like you have a good plan if you want to do all CAT-X as the solution.

Cat-6a/STP is best for running HDMI over if you can get it in place. It is not as straightforward as Cat-6a termination, so if you can use a pre-terminated cable (monoprice) for this, then that will save you some termination headaches.

The transmitter/receivers are certainly directional, but the cable itself is not. So, I would plan to run cat-5 or 6 for networking, then two or three pieces of cat-6a/STP for the video. One for immediate use and TWO as spares. Only run extras though if the run is difficult and you don't have easy access to add more cables later on.

Make sure to use good HDMI baluns. HD-Base-T or something from Pure Link. (HCE from Pure Link is great)

Oh, and I've personally tested the Monoprice HD-Base-T extenders at 300 feet with a 1080p signal.

 

[Speedskater]

There's no reason to think analog audio wouldn't work with any of them. Some types are more difficult to work with though.

Yes, any RG-6 will work with any frequency signal, but some part #'s are much more suitable than others for any specific frequency and situation.

For cable TV & CATV you need low loss at TV station frequencies and good shielding at those same frequencies.
For analog audio you need heavy braided return and good low frequency shielding.

 

[markw]

This is what they are taking issue with.

An important thing about RG-6 co-ax cable. This is a very generic number. The "RG" means Radio Grade from back in World War II days. The "6" means a cable with a radio frequency characteristic impedance of about 75 Ohms and a diameter of about 1/4 inch. Different RG-6 cables are made for different use's. One cable manufacture makes over 40 different model numbers.
The RG-6/QS (quad Shield) is only suitable for cable TV signals. The RG-6 suitable for analog & digital audio and for video is a very different cable.

FWIW, I've worked with wave giude in my earlier days working with microwave transmitters for the AF so I do have some idea of what you're saying.

Granted, RF frequencies do require different specifications than audio fequencies, but a cable that works well with RF can easily work at least as well with audio frequencies. Some may be cumbersome to handle, but it will work perfectly fine.

And, good shielding is good shielding. There is no "low frequency" shielding.

 

[avengineer]

FWIW, I've worked with wave giude in my earlier days working with microwave transmitters for the AF so I do have some idea of what you're saying.

Granted, RF frequencies do require different specifications than audio fequencies, but a cable that works well with RF can easily work at least as well with audio frequencies. Some may be cumbersome to handle, but it will work perfectly fine.

And, good shielding is good shielding. There is no "low frequency" shielding.

Good points. Just to add one, cable shielding is electromagnetic and electrostatic shielding, not magnetic shielding. A shielded cable can still pick up a hum field from a power transformer, just as an example. The shield is pretty much transparent to magnetic fields.

 

[markw]

Good points. Just to add one, cable shielding is electromagnetic and electrostatic shielding, not magnetic shielding. A shielded cable can still pick up a hum field from a power transformer, just as an example. The shield is pretty much transparent to magnetic fields.

It's for this reason that it's not recommended one bundle line (and lower) level signals with AC power cables.

 

[avengineer]

It's for this reason that it's not recommended one bundle line (and lower) level signals with AC power cables.

Yes, that's what's recommended and it's good practice. What they don't tell you is that power cords in particular are usually twisted pairs. Each wire has an electric and magnetic field around it, but twisting them together effectively causes them to cancel each other. There's very little AC magnetic field around a power cord, especially once you are a short distance away. Not true about house wiring, where individual conductors are not twisted and don't lay exactly together in conduit, though the conduit itself tends to mush the fields together and participate in cancellation.

Anyway, drifting off topic.... RG6 is great audio wire, in any flavor. You can get RCA compression fittings that terminate the stuff quickly and solidly and don't require any F adapters. Quad-shielded types are designed to keep RF from leaking out of the cable, or leaking in.

 

[Speedskater]

As to shielding and co-ax cable performance in general, I'll go with what the expert's write:

Henry W. Ott
Henry Ott Consultants
home page

Stephen H. Lampen
Belden Wire & Cable
books:
Wire, Cable, and Fiber Optics for Video & Audio Engineers
Audio?Video Cable Installer's Pocket Guide

Bill Whitlock
Jensen Transformer
Countless article's on countless web pages (countless = lots)
White papers
JENSEN TRANSFORMERS, INC. - APPLICATION PAPERS AND SCHEMATICS
UNDERSTANDING, FINDING, & ELIMINATING GROUND LOOPS IN AUDIO & VIDEO SYSTEMS
http://www.jensen-transformers.com/an/generic seminar.pdf

Jim Brown
Audio Systems Group
Mr. Brown is the AES committee chair on EMI/RFI and a Ham radio operator.
About 50 of his papers and Powerpoints on cable's and interference.
Audio Systems Group, Inc. Publications

Each and every one of these expert's point out the different model number cable's with the same RG number are optimized for different things.

 

[markw]

Well, now that the enema has taken full effect, rather than expect us to read through these tomes only to find you've misinterpreted something to suit your needs, please use your "cut and paste" function again, only this time to show exactly where they say quad shield is audibly inferior to other types of RG cable.

 

[Speedskater]

Each of that one manufacture's more than 40 different RG-6 co-ax cables is optimized for many different parameters such as:
Fire safety
Sunlight
Flexibility
Underground
and the big one 'best frequency range'.

It's hard to cut and paste a copyrighted print only book but.

Stephen Lampen wrote about:

Shields and Frequency

Each shield type has good and bad points. Most performance differences have to do with their effectiveness at different frequencies.


I'll look for Mr. Whitlock's example of up to 23dB noise difference between good audio frequency cable and the not so good.


Anyone interested in audio installation and equipment should read the above linked authors.

 

[Speedskater]

From the Bill Whitlock paper:

UNDERSTANDING, FINDING, & ELIMINATING GROUND LOOPS IN AUDIO & VIDEO SYSTEMS
http://www.jensen-transformers.com/a... seminar.pdf

This is about a co-ax cable very similar to Quad Shield:

page 12

Consider a 25-foot interconnect cable with foil shield and a #26 AWG drain wire. From standard wire tables (or actual measurement) its shield resistance is found to be 1.0 Ohm..
The resistance of the inner conductor is insignificant and is not discussed here.
If the leakage current is 316 uA, the noise voltage will be 316 uV. Since the -10 dBV reference level for consumer audio is 316 mV, the noise will be only 20 x log (316 uV ÷ 316 mV) = -60 dB relative to the signal. For most systems, this is a very poor signal-to-noise ratio. Replacing the cable with Belden #8241F, for example, would reduce shield resistance to 0.065 Ohm and reduce noise by about 24 dB!

 

[Speedskater]

Henry W. Ott on interconnects. Sorry you will have to read bits & pieces of the first 3 pages.

15. Balanced vs. Unbalanced Audio System Interconnections (pdf file)
http://www.hottconsultants.com/pdf_files/Audio Interconnections.pdf

 

[markw]

The cable you point to is RG-59, a thinner cable. What cable is he using as an example?

He states the resistance of the inner conductor is "not discussed here". That's great for short runs but, when you consider the lengths used in whole-house wiring are considerably longer than those used in typical, short, component-to-component interconnects, then it becomes a major factor, particularly when you consider these cables may well be used for other than the essentially low-demand audio range of frequencies.

Read my sig line, and comprehend it.

P.S. Your link doesn't work.

 

[Speedskater]

I seem to have trouble with this forum software and links (some of my posts never show up!)

Let's try this:
UNDERSTANDING, FINDING, & ELIMINATING GROUND LOOPS IN AUDIO & VIDEO SYSTEMS
http://www.jensen-transformers.com/an/generic seminar.pdf

As to the other cable, it's a "25-foot interconnect cable with foil shield and a #26 AWG drain wire."

 

[Alex2507]

I use RG6 quad shield for everything,

How about just regular RG-6? I thought BJC had an article about why QS isn't needed but I'm too lazy to search. The regular RG-6 is so much easier to work with and honestly for audio at reasonable lengths (maybe under 15') RG-59 is even easier to work with.

For cable TV & CATV you need low loss at TV station frequencies and good shielding at those same frequencies.
For analog audio you need heavy braided return and good low frequency shielding.

How about a cheat sheet on who's good for what?

• Analog audio
• Digital audio
• Video (composite, component)
• Subwoofer
• Cable TV

I've seen BJC spec's on various wire but didn't like psychoanalyze them. What wires do you use?

 

[Speedskater]

**************

How about a cheat sheet on who's good for what?

• Analog audio
• Digital audio
• Video (composite, component)
• Subwoofer
• Cable TV

I've seen BJC spec's on various wire but didn't like psychoanalyze them. What wires do you use?

The Bill Whitlock paper has tons of information about cables and power:
UNDERSTANDING, FINDING, & ELIMINATING GROUND LOOPS IN AUDIO & VIDEO SYSTEMS
http://www.jensen-transformers.com/an/generic seminar.pdf

Some thoughts:

a] Audible differences in cables are often caused by connections and connectors.

b] The cables at low price points are junk. In the big box stores you sometimes see cables with what appear to be major brand labels. But don't let appearances fool you! These cables are made out of cheap aluminum wires and shielding.

c] Good starting points for bulk wire are: Belden, Canare, Gepco & Mogami.


THE LIST

Unbalanced analog audio & subwoofer (RCA)
The only things that matter are good shielding (heavy braid or braid & foil) and low end to end resistance.
For longer cables the "Blue Jeans Cable LC-1 Analog Audio Cable" and the other cables on the page would be good choices.
Subwoofer Cables from Blue Jeans Cable

Digital Audio Cables
These are low radio frequency radio signals, so at longer cable lengths the Radio Frequency Characteristic Impedance starts to become important ( 75 Ohm).
Once again "Blue Jeans Digital Audio Cables" to the rescue.
Digital Audio Cables at Blue Jeans Cable

"Video (composite, component)"
These have the same requirements as Digital Audio Cables.
And yet again "Blue Jeans Video Cables"
Component Video Cables at Blue Jeans Cable
Note: if you are doing DIY component cables from bulk, make sure that the 3 cables are from the same roll and are all the very same length.

Cable TV & CATV(F connectors)
The popular (but not only) choice is RG-6 Q/S Quad Shield. This is a commodity product with thousands of miles sold each year. The tricky part is getting matching connectors and tools, then learning how to use them.
I just go to my cable TV provider and get another installation kit. It's good cable, it comes with installed connectors and doesn't cost much more than short lengths of bulk cable.

"On Blue Jeans"
While I have referenced Blue Jeans many times, I have never purchased or used any of their products! I just like the way they provide information.