RG6 for Sub plus "How are you doing your 7.1?"

[Johnny B. Galt]

I'm finishing my basement for a more dedicated HT space and am looking at doing my low-voltage wiring very soon. I'm not sure where the ultimate sub location will be so I'd like to run a couple of in-wall cables to the possible locations. What is best to use for this application? I thought I read somewhere that you can use RG6 or some other coaxial type cable for the low-frequncy subwoofer runs.

I'm using Dayton Audiophile (or some similar name) in-wall cable from Parts Express for the in-wall surround runs. I will be using Paradigm ADP390s for side surround speakers. I will not purchase a receiver until New Year's for this room (right now thinking Onko 607) . I currently have 5.1 upstairs (with rear surrounds).

I'm planning on going 7.1 and am wondering how others are using it- are you using side and rear surrounds (or a 6.1 with an additional rear center channel) or have you abandoned that to add the new "High" front channels that are above the front left/rights? Since I haven't purchased the receiver yet I'd like to make sure I'm covered by having cable run to right places. I suppose I could run lines every where (like the conduit I'm running for the projector that may not ever happen) but I'd like to avoid the long runs of cable if I don't need them. Thanks for your help!

[bfalls]

[QUOTE=I'm planning on going 7.1 and am wondering how others are using it- are you using side and rear surrounds (or a 6.1 with an additional rear center channel) or have you abandoned that to add the new "High" front channels that are above the front left/rights? [/QUOTE]

High front speakers have been around for some time. Yamaha has employed them on their RX-V line for many years. Both my RX-V2092 and RX-V2095 had front effects channels.

I haven't heard of using RG6 for a sub. Since RG6 has a characteristic impedance of 75ohms. I would be hesitant. The use of 75ohm cables for audio has been discussed here before. I'll let you search for the threads in lieu of restarting the discussion.

[markw]

I really can't recall anything logical being said against the use of 75 ohm cable for audio.

RG6 or RG59 are both fine for subs, as well as for other audio uses. RG6 might be a little stiff but it's no impediment to fine performance.

[Johnny B. Galt]

I'm sorry for the conrfusion. By "new high front" I was referring to the new Dolby ProLogic IIz (http://www.dolby.com/consumer/techno...logic-IIz.html ) which I recently became aware of.
My understanding is that it might be worthwhile to re-assign (if your receiver has the capability) two of your 7.1 channels to power the elevated fronts. My thought was that if rear and side surrounds weren't all that great (I'm currently 5.1) and that there aren't a lot of movies recorded in 7.1, I'd skip doing the cabling for the rear surrounds. I was curious as to whether people were using it.

[Sir Terrence the Terrible]

I'm sorry for the conrfusion. By "new high front" I was referring to the new Dolby ProLogic IIz (http://www.dolby.com/consumer/techno...logic-IIz.html ) which I recently became aware of.
My understanding is that it might be worthwhile to re-assign (if your receiver has the capability) two of your 7.1 channels to power the elevated fronts. My thought was that if rear and side surrounds weren't all that great (I'm currently 5.1) and that there aren't a lot of movies recorded in 7.1, I'd skip doing the cabling for the rear surrounds. I was curious as to whether people were using it.

I would skip Dolby PL IIz, as it is a gimmick. I would stick to the way 7.1 is mixed, rather than having a matrix create new panning positions. 7.1 soundtracks are created and mixed for three front speakers, two side speakers, and two left/right rear wall speakers. All channels are discrete, and there is no matrix steering information derived from other channels. When you venture away from this speaker setup position, you allow all kinds of spatial errors to creep in.

Unfortunately Dolby has gotten into the habit of creating enhancements that do not stay true to how things are mixed. If they were smart, they should have created a way to steer information to a ceiling speaker like Smaart did with their Circle surround processor. That is a much more effective spatial enhancement since there are no speakers in that position in the first place, and it would have been perfect for both music and movies. One of my hometheaters has this setup, and it works with all kinds of music and movies. I have never encountered any strange or weird spatial effects with this setup, it was always an effective enhancement to 7.1 and 5.1 music and film soundtracks.

I heard a demo of PLII-z at Pixar Studios recently. I found that the enhancement was not stable or consistant with different sources. Sometimes it was pretty effective, and at others seriously detracted from the presentation. Its steering sometimes sent spatial information to the wrong place, making things either exaggerated, or just plain unnatural. One music recording of a large orchestra, organ, and choir placed information so high over my head and with so much reverb and only in front of me that it was unnatural and distracting. You also noticed the sound was only coming from high in the front, as opposed to a centrally mounted ceiling speaker which is emmersive and natural sounding.

[Johnny B. Galt]

Thank you for input. I should have guessed that was the case (a processing gimmick) but fell for the "Dolby" name. So, if things aren't being recorded for it I may as well skip it. That was kind of my impression of DTS-Neo 6 (or whatever it was) for bringing in a rear center. Do you think that 7.1 is ever going to really take off? I'm tempeted to just skip running the cables for it.
Also, I read a bunch of back and forth on RG cable for subwoofer in-wall wiring. There are definitely two positions on it. I think I'll just skip it and run the PartsExpress 12-2 inwall speaker wire to the different positions. That way I'll be set if I want to add an additional sub. Each run is less than twenty feet so I wouldn't guess there'd be a problem.

[markw]

So, you'll be running speaker cable instead of coaxial for a subwoofer?

Whatever floats your boat...

Somehow, methinks that for all the reading you say you've done, none of it sunk in.

[Johnny B. Galt]

What sunk in was there are people who say it works great, others say it doesn't work at all, some say it is less than ideal and maybe its all about the connection, and then there are pissing matches over exactly what bandwidth and frequency the cable can or cannot handle.

I asked for input, Markw said yes and bfalls suggested I keep looking. I didn't find a lot for meaningful discussions in a quick search on audioreview.com. There were a couple nice broad overviews of what types of cables there are (this is a DVI cable, etc).

I Googled "RG6 cable subwoofer" and visited multiple pages of ecoustics.com, highdefforum.com, audioholics.com, satelliteguys.com (who seem to love it and think it should be used for everything) forums that were a mixed bag. I read a bunch of posted opinions, I came away feeling that whatever had copper and ran from point A to point B would work (as seems to be the argument against esoteric speaker wire).

I don't know cables. They aren't really a big deal to me. I got a bunch of Acoustic Research interconnects closed out online that seem to work. My HDMI cables came from monoprice. I bought some Canare speaker cables off Ebay a couple years ago just because they looked cool. They don't sound any different to me than the generic 10-2 cable that I replaced but were nice looking. I'm now putting most of the stuff in the wall so I don't care what it looks like- I just want it to work well. I need to place another order with Parts Express so I guess I'll just ask them what they recommend and go with that. Maybe I'll call twice to see if the next person that answers the phone has a different opinion!

[Sir Terrence the Terrible]

Thank you for input. I should have guessed that was the case (a processing gimmick) but fell for the "Dolby" name. So, if things aren't being recorded for it I may as well skip it. That was kind of my impression of DTS-Neo 6 (or whatever it was) for bringing in a rear center. Do you think that 7.1 is ever going to really take off? I'm tempeted to just skip running the cables for it.

No, PLII-z is a DSP based ambience generator that uses phase information to steer signals to those front height channels. Dts-Neo 6 is very good at creating a center rear channel, much better than EX IMO. The steering is cleaner, less prone to calapse entirely to the rear wall, and has better seperation.

Is 7.1 going to take off? My answer is yes. When you see post studios like Mi Casa who specialize in creating 7.1 tracks from 5.1 sources adding audio engineers to their staff while everyone else in cutting back, that means they have a lot of business coming. For music only applications, Surround Records has released some very good 7.1 high resolution classical music recordings encoded 24/96khz. They plan to release a lot more 7.1 recordings in the future.

I will be supervising the upgrade of two dubbing stages, and six audio effects editing rooms to 7.1 later this year, and I have converted all of my hometheaters to 7.1 That is how much confidence I have that 7.1 will grow moving forward.

[markw]

What sunk in was there are people who say it works great, others say it doesn't work at all, some say it is less than ideal and maybe its all about the connection, and then there are pissing matches over exactly what bandwidth and frequency the cable can or cannot handle.

I asked for input, Markw said yes and bfalls suggested I keep looking. I didn't find a lot for meaningful discussions in a quick search on audioreview.com. There were a couple nice broad overviews of what types of cables there are (this is a DVI cable, etc).

I Googled "RG6 cable subwoofer" and visited multiple pages of ecoustics.com, highdefforum.com, audioholics.com, satelliteguys.com (who seem to love it and think it should be used for everything) forums that were a mixed bag. I read a bunch of posted opinions, I came away feeling that whatever had copper and ran from point A to point B would work (as seems to be the argument against esoteric speaker wire).

I don't know cables. They aren't really a big deal to me. I got a bunch of Acoustic Research interconnects closed out online that seem to work. My HDMI cables came from monoprice. I bought some Canare speaker cables off Ebay a couple years ago just because they looked cool. They don't sound any different to me than the generic 10-2 cable that I replaced but were nice looking. I'm now putting most of the stuff in the wall so I don't care what it looks like- I just want it to work well. I need to place another order with Parts Express so I guess I'll just ask them what they recommend and go with that. Maybe I'll call twice to see if the next person that answers the phone has a different opinion!

I would be pleased to see any references there are to RG6 and RG59 not being suitable for subwoofer cable. Also, please make available any "technical" reasons as well.

At this point, it's fairly obvious that you don't know the differencen between coaxial cable and speaker cable. But, hey, it's your money and if you want to spend it needlesly, then feel free.

Sometimes, you have to spend a lot of money only to learn later you didn't have to.

Again, I look forward to seeing some reasons it's not suitable.

[Johnny B. Galt]

This is from the very first ecoustics thread I looked at (http://forum.ecoustics.com/bbs/messages/3/173582.html) The answer sounded credible to me based on my (admitedly) limited knowledge of the subject. Is the answerer off-base?

Q: "Why couldn't I run coaxial cable. If it's good enough to transmit a High Definition video signal from the cable company why isn't good enough to transmit good, clean, solid bass?"

A: Because it is two completely different tasks. CATV cable is designed to carry RF frequencies from 54 MHz and up, with very low current, over long distances. Shielding and capacitance are critical parameters, as conductors and dielectrics behave differently at different frequencies. Conversely, audio cables operate within the range of audible frequencies, nominally 20-20,000 Hz, and speaker cables in particular are tasked with carrying high current at low impedance, typically 4 to 8 ohms, with woofer cables carrying the most current and operating in the band of 20-200 Hz. Resistance is really the only important electrical measurement here, and since 12AWG has about 1-1/2 ohms per thousand feet, a 40-to-50-foot piece will have virtually unmeasurable resistance.

[markw]

Be careful of whose wagon you hitch your horse to. Did you ever hear the term "baffle them with bullcrap? That "mike butler" throws out a lot of terms but has no idea of how they relate to the OP's question. He just likes to throw 'em out in the hopes of impressing people who can't tell the difference. There's a lot of those in this hobby.

Try these on for size.

"RG6 works just fine if not better than traditional dedicated sub cables and for a lot less money!!"

http://www.hometheaterforum.com/foru...ubwoofer-cable

"the sub cable basically has the easiest job of all your HT cables because it's carrying low-frequency, low-bandwidth signals."

https://www.polkaudio.com/forums/showthread.php?t=78870

http://www.hometheatershack.com/foru...fer-cable.html

http://forums.audioholics.com/forums...hp/t-1082.html

http://www.satelliteguys.us/v-receiv...fer-cable.html

http://www.highdefforum.com/cables-c...fer-cable.html

http://community.crutchfield.com/forums/p/602/1954.aspx

Finally,

"RG6 Quad shield (RG6-QS) coax is a multi-purpose wire. This wire can be used for subwoofer interconnects, component video cables, digital interconnects, analog interconnects, and satellite/cable distribution. The best way to purchase RG6-QS is on a 250ft or 500ft bulk spool. The wire is un-terminated and you must have the proper tools for correct high performance terminations."

http://www.audioholics.com/tweaks/do...rect-wire.html

You might want to explore this last site a bit more. IT offers many, many tools to educate the beginner in it's "AV University"

Any more questions?

[Smokey]

This is from the very first ecoustics thread I looked at (http://forum.ecoustics.com/bbs/messages/3/173582.html) The answer sounded credible to me based on my (admitedly) limited knowledge of the subject. Is the answerer off-base?

Q: "Why couldn't I run coaxial cable. If it's good enough to transmit a High Definition video signal from the cable company why isn't good enough to transmit good, clean, solid bass?"

A: Because it is two completely different tasks. CATV cable is designed to carry RF frequencies from 54 MHz and up, with very low current, over long distances. Shielding and capacitance are critical parameters, as conductors and dielectrics behave differently at different frequencies. Conversely, audio cables operate within the range of audible frequencies, nominally 20-20,000 Hz, and speaker cables in particular are tasked with carrying high current at low impedance, typically 4 to 8 ohms, with woofer cables carrying the most current and operating in the band of 20-200 Hz. Resistance is really the only important electrical measurement here, and since 12AWG has about 1-1/2 ohms per thousand feet, a 40-to-50-foot piece will have virtually unmeasurable resistance.

As Markw mentioned, this guy "mike butler" got everything mixed up.

If we are talking specifically about subwoofer RCA cable, then that cable is low current (high voltage) connection-not high current as mike mentioned. And cable should be shielded.

Shielding is probably the most important aspect of a subwoofer cable. Since sub’s amplifier operate in the low frequency region (20-200hz)-and most household interference occur in that region (such as noise from your AC power cords)-then your cable need extra protection against interference in that region. And that mean coax cables with extra “padded” shielding.

RG6 Quad shield coax Mark mentioned is a good sub cable. So as Belden 1505F coax which have double braid shielding.

[Swish]

I have the Paradigm DP450s and they are stellar, creating a very nice 'wall of sound', especially while playing a nice DTS recording. I recently bought Studio 100s but had to dismantle my HT room when we moved, so I haven't had the chance to hear them with my 7.1 system. Hoping to be set up next year (sigh), I would skip the rear center and go with the sides.

[pixelthis]

What sunk in was there are people who say it works great, others say it doesn't work at all, some say it is less than ideal and maybe its all about the connection, and then there are pissing matches over exactly what bandwidth and frequency the cable can or cannot handle.

I asked for input, Markw said yes and bfalls suggested I keep looking. I didn't find a lot for meaningful discussions in a quick search on audioreview.com. There were a couple nice broad overviews of what types of cables there are (this is a DVI cable, etc).

I Googled "RG6 cable subwoofer" and visited multiple pages of ecoustics.com, highdefforum.com, audioholics.com, satelliteguys.com (who seem to love it and think it should be used for everything) forums that were a mixed bag. I read a bunch of posted opinions, I came away feeling that whatever had copper and ran from point A to point B would work (as seems to be the argument against esoteric speaker wire).

I don't know cables. They aren't really a big deal to me. I got a bunch of Acoustic Research interconnects closed out online that seem to work. My HDMI cables came from monoprice. I bought some Canare speaker cables off Ebay a couple years ago just because they looked cool. They don't sound any different to me than the generic 10-2 cable that I replaced but were nice looking. I'm now putting most of the stuff in the wall so I don't care what it looks like- I just want it to work well. I need to place another order with Parts Express so I guess I'll just ask them what they recommend and go with that. Maybe I'll call twice to see if the next person that answers the phone has a different opinion!

RG6 will work, it has better sheilding, probably, but unless your run is over fifty feet I
wouldn't overthink it too much, and just go with a standard cable with RCA connects
on each side.
You use coax cable and you will need an adapter, most likely, and having put in several
sat systems I can tell you working with RG6 is a pain.
Also sub freaks are low and will travel better than higher freaks.
Good luck, in any event.