Coax speaker cables? - Page 2 - diyAudio
Go Back   Home > Forums > Loudspeakers > Planars & Exotics

Planars & Exotics ESL's, planars, and alternative technologies

Please consider donating to help us continue to serve you.

Ads on/off / Custom Title / More PMs / More album space / Advanced printing & mass image saving
Reply
 
Thread Tools Search this Thread
Old 9th January 2013, 11:25 PM   #11
diyAudio Member
 
Speedskater's Avatar
 
Join Date: Sep 2002
Location: Lakewood, Ohio
In the past some people would use RG-11 for speaker cable. It was a 0.4 in. dia. 75 Ohm co-ax cable with a 18AWG center conductor. It was 20pF/ft. It was also very, very stiff.
__________________
Kevin
  Reply With Quote
Old 10th January 2013, 12:36 AM   #12
diyAudio Member
 
Join Date: Aug 2003
Location: Santa Cruz, California
I've had good experiences with coaxial cables, although it depends greatly on the speaker impedance (no surprise there) and whether you're downtown or in the suburbs. Why? City centres are a mess of electromagnetic interference, which twin-lead can carry back to the amplifier and then to the negative feedback point.
  Reply With Quote
Old 10th January 2013, 12:40 AM   #13
diyAudio Member
 
CharlieM's Avatar
 
Join Date: Feb 2008
Location: Savannah, GA
Quote:
Originally Posted by DSP_Geek View Post
I've had good experiences with coaxial cables, although it depends greatly on the speaker impedance (no surprise there) and whether you're downtown or in the suburbs. Why? City centres are a mess of electromagnetic interference, which twin-lead can carry back to the amplifier and then to the negative feedback point.
Does your good experiences with coaxial cables include driving electrostats?
  Reply With Quote
Old 10th January 2013, 04:43 AM   #14
diyAudio Member
 
Join Date: Nov 2009
Location: Los Angeles
Quote:
Originally Posted by CharlieM View Post
Does your good experiences with coaxial cables include driving electrostats?
If cable is the problem, mount the amp at the speaker and use almost none. If you're worried about the low level signal you could either use balanced line or use properly terminated coax transmission line.

G
  Reply With Quote
Old 10th January 2013, 06:24 AM   #15
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
Are you talking about using the cable to feed the panel on the stepped up side or feeding the transformer between the primary winding and the amplifier?

jer
  Reply With Quote
Old 10th January 2013, 09:04 AM   #16
diyAudio Member
 
CharlieM's Avatar
 
Join Date: Feb 2008
Location: Savannah, GA
Quote:
Originally Posted by geraldfryjr View Post
Are you talking about using the cable to feed the panel on the stepped up side or feeding the transformer between the primary winding and the amplifier?

jer
I was referring to using coax speaker cable between my amp and ESL step-up transformer(s); specifically, Mogami 3082 coax cable, which I believe is the same cable used in the ESL-specific speaker cables sold by Roger Sanders (although I'm not positive about that).
BTW, how's it coming with testing that 1206 tranny?

Last edited by CharlieM; 10th January 2013 at 09:11 AM.
  Reply With Quote
Old 10th January 2013, 08:34 PM   #17
diyAudio Member
 
Join Date: Feb 2008
Location: Jackson,michigan
Okay,Thanks Charlie.

I think that it is novel idea to use Coax for speaker cable.
Although it seems to be beneficial, I don't think that one would see any gain in the extra cost unless it was for a very long run.

We once got some $4 per foot Monster cable for a 6' run to use on the Apogee Duette's and I couldn't hear the difference.
It was some fancy made stuff with heavy gauge and twisted pairs all in one cable 99.99% pure oxygen free copper!!! Ahhhh,ha,ha,ha,ha

I did have an instance once were an amp became unstable when I used some 12 ga House wire for speaker cable for a rather long run of about 20 feet.
It was my BGW amp and not having a the third wire connect in a certain configuration acted like an antenna of some sort and caused to chirp and squeal everytime the cable was touch or moved just right.

I had a chart that showed the attenuation of the 12 GA house wire to be less than 1db to .5db right at 20Khz.
It was in a issue of Popular Electronics magazine I had and I found it on the web once.
They were also comparing some standard zip lead as well to the expensive Monster stuff that was out at the time.

I had thought about using Coax for short runs to feed the panels before, for the shielding of the HV.
But the added capacitance is of concern although there is some that has a much lower capacitance as mentioned.

Some heavy duty twin lead would be better than speaker wire as the larger the distance between the two conductors the lower the parasitic capacitance of the cable and would provide a equally balanced load along its length.
Again this would only be of concern at RF frequency's.

The Mogami cable has some great cable however it is very costly from what I remember from my days of messin' with RF transmission and it has one of the lowest attenuation factors for runs of greater than 100'.
But it is only beneficial at 30Mhz and above.

Here are some examples of different cable types,

50 Ohm Braided Coax Cable, RG58 Cable | TESSCO 800 472 7373

50 Ohm Braided Coax Cable, RG142, RG174, RG214 Cable | TESSCO 800 472 7373

http://www.timesmicrowave.com/downlo.../broadband.pdf

Here is the Mogami Data

Mogami W3082

Twin lead, Ladder, Balance line or what ever you want to call it has the lowest attenuation factor of any of the cable assembly type and can be run at any length without impedance mismatch for any frequency.

Being that it is balanced it is immune to any outside noise issues just the same as a twisted pair line.

I have considered using some shielded twin lead (Twinax) before but again it is costly and it was difficult to find some with a really low capacitance per foot.

After all of that I can't say that it won't make a difference but it surly does on the input low level side of things.
I have tried several different types of cable for long runs of only 20' to 30' and some sounded very much better than others and this was affirmed to those types with a lower capacitance per foot were the best.

I was using my guitar on a very high power amp system set on clean and you could instantly notice the better highs coming from my Strat using the lower capacitance cable used to wire my studio.

It was West Penn #291 and I have used it for everything from audio to RF and Video with no issues or degradation in the quality the signal.
The only problem I had with using it was the crackling sound it produces when it is moved around or stepped on.
This is caused from the Piezo effect due to its polyethylene jacketing.

This is were good ole' Belden Rubber jacketed cable wins !!

Charlie, I will be getting on the transformer data within the next week,Sorry for the delay.

I had got a new computer for Christmas and I had been getting it situated and my bench was cluttered up with it.
And now that it is pretty much done I can continue on with my ESL projects.

I am planning on a newer and more thorough easier to follow article on the testing of transformers as during the last one I was still learning my self and got a bit confusing.
I will be including a much more in depth look at the transformer than just finding its Capacitance and such.

One of the things I have to do is make some resistor dividers For x10,x100 and x1000 so that I can get some accurate voltage measurements.
Or least, more consistent ones because my DVM is slightly off when it is switched between ranges.
I discovered this when I was finishing up my HV supply design.

I did this the last time I measured my transformer and got much better and consistent results and was able to quickly measure several of my cores for consistency between them.

I will document this process in my style of full details !!
I plan on getting some THD measurements as well with a x1000 or even a x10,000 divider using my computer.

Cheers !!!

jer
  Reply With Quote
Old 13th January 2013, 03:26 PM   #18
diyAudio Member
 
CharlieM's Avatar
 
Join Date: Feb 2008
Location: Savannah, GA
I just finished a pair of 10ft Mogami 3082 cables and heard them for the first time a few minutes ago. Nothing profound to report at this time-- I am withholding judgement on their sound until I've had time to listen to them at length-- at least they didn't blow up my amps right off the bat. This week will be rather busy so it may take me a while to evaluate.

The build photos are here

Last edited by CharlieM; 13th January 2013 at 03:47 PM.
  Reply With Quote
Old 18th February 2013, 07:35 PM   #19
diyAudio Member
 
Join Date: Aug 2010
Check this coax cable out!

Ultra low inductance...
The UBYTE-2 Speaker Cable
  Reply With Quote
Old 19th February 2013, 11:38 AM   #20
diyAudio Member
 
Join Date: Nov 2010
Quote:
Originally Posted by CharlieM View Post
I'm seeking opinions on going with Mogami 3082 coax speaker cables for my hybrid ESL's.

I've read Roger Sanders' cable white paper and I also read this review of the Sanders cables, wherein, it says they use Mogami #3082 coax cable:
http://forum.audiogon.com/cgi-bin/fr...Speaker-Cable-

Mogami's spec sheet for 3082 cable (see below) states its capacitance is 77pf per foot, which may be low relative to its inductance, but is still higher than other [non-woven] cables I've read about.
MOGAMI® - W3082 Superflexible Studio Speaker Cables

Unfortunately, I'm a complete dummy concerning all things electronic, including the effects of inductance and capacitance on loading an amp and on the resulting sound of the speaker.

Asking for advice now is a bit like closing the barn door after the horse is out, since I had already ordered some Mogami 3082 cable and connectors to build a pair of 10ft cables. But that was before I found the spec sheet and noted the higher capacitance. And I'm also assuming the review I read is correct regarding the Sanders cables using the Mogami wire. It would ease my mind if I could be sure that accepting the higher capacitance for lower inductance is in fact a good and wise trade.

Any thoughts on that?
Many esl have horrible capacitive loads for an amplifier, why add extra capacity if it's not needed?
  Reply With Quote

Reply


Hide this!Advertise here!
Thread Tools Search this Thread
Search this Thread:

Advanced Search

Posting Rules
You may not post new threads
You may not post replies
You may not post attachments
You may not edit your posts

BB code is On
Smilies are On
[IMG] code is On
HTML code is Off
Trackbacks are Off
Pingbacks are Off
Refbacks are Off


Similar Threads
Thread Thread Starter Forum Replies Last Post
Balanced interconnect with 2 x 75 ohm coax cables? judderod Analog Line Level 56 4th March 2012 09:47 AM
Separate Coax Cables for + and - Signal? fred76 Digital Source 0 23rd May 2007 05:38 AM
AES/EBU coax cables sensitivity to cable length? miksin Digital Source 9 15th August 2006 12:16 PM
selenium coax speaker question darth_sanchez Multi-Way 113 25th March 2005 02:27 AM
cables for diy amps, preamps, and speaker cables ... paulspencer Solid State 5 3rd August 2004 07:14 AM


New To Site? Need Help?

All times are GMT. The time now is 07:44 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio

Content Relevant URLs by vBSEO 3.3.2