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Author Topic: Question about speaker lines Gordon McLeod Film God Posts: 9532 From: Toronto Ontario Canada Registered: Jun 99 posted 09-28-2010 07:46 PM                     yup we just did a nine plex that way  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 09-28-2010 07:48 PM                     We still use twisted pairs (good to prevent crosstalk) but not the improper drill method of twisting. Belden has some excellent speaker cable with a high strand count too. It has red/black pairs down to 10awg. (1313A). They also have it in 4-cond versions (down to 12awg).  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 09-28-2010 09:58 PM                       Pray tell what is wrong with using a drill? Half the idea is the keep track of the pairs, the other half is hum rejection.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 09-28-2010 10:11 PM                     quote: Sam D. Chavez Pray tell what is wrong with using a drill? I was wondering the same thing..I have done many installs using that method with never a problem.  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 09-28-2010 11:06 PM                     There's no guarantee that the twisting is even or not too tight, thus breaking the strands, but doesn't it also fuck up the lay of the strands inside the insulation or something?  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 09-29-2010 12:20 AM                     Randy, "even" twisting is not a mandatory thing, (there are some who claim that varying the degree of twist over the length actually helps in noise rejection, I say it doesn't matter) but yes too tight can break strands, but my own tests have proven you REALLY have to overdo it to even get to that point..and the resulting over tight twist makes the pair "kinked" which is obvious. And the average degree of twist will NOT affect the lay of the strands within the insulation, which is extruded tightly over the strands anyways..any such event would cause visible damage. Like anything else it has to be done right but it's not rocket science.  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 09-29-2010 01:34 AM                     I see what you're saying. The reason I thought of it is because, if you take a microphone cable and twist it the wrong way, against the lay of the conductors inside the jacket, you can cause them to kink. Thus the reason why, if you want to coil a microphone cable well, you'll wrap it over/under. Of course, a microphone cable is different. It's not tightly bound in its jacket and it's got other things wrapped up inside like the paper packing and the strand for strength. There are a lot more things to get twisted up inside the relatively loose jacket of a mic cable. I was just extrapolating what happens when you twist a mic cable to what might happen when you twist speaker wires.  |  IP: Logged Steve Guttag We forgot the crackers Gromit!!! Posts: 12814 From: Annapolis, MD Registered: Dec 1999 posted 09-29-2010 06:44 AM                     Randy is correct. There is no way to use the drill and not mess up the lay and start over twisting the strands. It is absolutely an improper method of twisting cables. To visualize....take a length of cable you want to twist...use a marker and put a straight line down one of the cables (like the red one). Then twist the cables via your drill. Even after the very first twist you will have rotated the cable by 1 revolution (and started stressing the conductors inside). To get a proper lay, you have also rotate the cable at the same rate as the twist such that the line you draw remains straight, even after the twist. The drill method, though easy and common, is absolutely wrong and harmful to the cable. Just get it pre-twisted, properly.  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 09-29-2010 09:51 AM                       Oh Piffle, this is just anal retentention to an extreme. There are laxatives for this condition you know. We don't really know how Belden twists them do we? For all we know they are using some automated version of a drill to do the twist before slipping the jacket over them. The real issue is whether the twist does any real good.  |  IP: Logged Tony Bandiera Jr Film God Posts: 3067 From: Moreland Idaho Registered: Apr 2004 posted 09-29-2010 12:57 PM                     Thank you Sam for putting that reply a lot nicer than I would have. Steve, FYI the FACTORY makes its twisted pairs using a method just like using a drill but on a bigger scale, which BTW would be MORE likely to damage the wire. It was shown on the "How It's Made" TV show. (The actual twister was like a super long lathe with a special chuck.) Unless you're a gorilla and keep twisting beyond tight there is ABSOLUTELY NO WAY you're gonna even come close to damaging the inner stranding of THHN 14 or 12ga wire. And like I said before, any damage you would cause would be visible. I have done literally hundreds of installs over the years with that method and NEVER had a line fail.  |  IP: Logged Randy Stankey Film God Posts: 6539 From: Erie, Pennsylvania Registered: Jun 99 posted 09-29-2010 02:06 PM                     How is it Made: Electrical Wire http://www.youtube.com/watch?v=svgW0YYSSOA  |  IP: Logged Sam D. Chavez Film God Posts: 2153 From: Martinez, CA USA Registered: Aug 2003 posted 09-29-2010 02:25 PM                       I've done this with solid wire, THHN stranded, and with fine stranded machine cable that has 56 strands or so and never had an issue. The wire at the drill end tends to be more tightly wrapped and sometimes kinked but I waste the first few feet of that end anyway.  |  IP: Logged Richard Hamilton Phenomenal Film Handler Posts: 1341 From: Evansville, Indiana Registered: Jan 2000 posted 09-29-2010 03:10 PM                     quote: Sam D. Chavez I waste the first few feet of that end anyway. What?? Just kidding. When I worked for Megasystems, I would do site visits and meet with the electrical contractors. When I would arrive for the install, there would be an extra 25 feet of cable for each channel both behind the screen and in the booth. It was partially our fault because we would supply them with 1 or 2 1000' wooden spools of 2 conducter cable, and they had to pre cut it before pulling it thru conduit. I don't know how many feet of cable I've had to trash. A lot of the electricians took the scraps I had to cut off! 18 to 20 runs each install of 2 conductor 12AWG. Rick  |  IP: Logged Andy Frodsham Expert Film Handler Posts: 238 From: Stoke on Trent, Staffs, UK Registered: Nov 2006 posted 09-29-2010 03:35 PM                     As a student, I worked in a Hi-Fi shop where the owner, and at least one loudspeaker cable supplier, subscribed to the idea that cables were directional and should only be made-up in the specified way!!  |  IP: Logged Scott Norwood Film God Posts: 8146 From: Boston, MA. USA (1774.21 miles northeast of Dallas) Registered: Jun 99 posted 09-29-2010 04:02 PM                        The "directional" thing actually does apply to 2-conductor shielded cable used for unbalanced lines. The shield would typically be connected at only one end, and one would want the shields of all cables to be uniformly connected to either the sending or receiving ends. That said, pretty much all the other "audiophile" cable talk seems like a total load of crap. As soon as I hear about a recording studio, postproduction house, or broadcast facility that uses anything other than "normal" (Belden, Canare, etc.) cables, I will start to take things like $400 power cables and $1200 speaker cables seriously. I've never heard differences in cables except at the "total crap" level.  |  IP: Logged

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