Greetings,
I'm looking for a DIY speaker cable design that will be suitable for my setup in a pretty noisy EMI environment...
There are many designs on the forum - from CAT5 based, COAX, braided silver plated wires etc... but I wonder which one will perform best sonically and still gives decent EMI/RF protection.
I'm afraid i might overdo the shielding and use cables that will eventually degrade the sound quality (too much capacitance? too little!?)...
.
I've used shielded cables for the rest of the system - CANARE starquad microphone cable for the interconnects (from the HTPC) and a Belden shielded power cable.
The only thing left is to replace my pretty decent 4X1.5mm Bi-wire speaker cable that still get noise from FL lights and the CRT TV near it...
I'll need around 1m-1.5m for L/R and preferably Bi-wire.
I don't need it to be too "heavy" since I'm using an efficient set of book shelfs at MAX RMS of 100W/8ohm.
I'll be happy to experiment with some Pure Silver/Silver plated wires that are pretty easy to source through eBay etc...
Also maybe play with the interconnects (braided silver/PTFE wires?)
So - what would you recommend?
A link to relevant references will be appreciated as well...
Gal
I'm looking for a DIY speaker cable design that will be suitable for my setup in a pretty noisy EMI environment...
There are many designs on the forum - from CAT5 based, COAX, braided silver plated wires etc... but I wonder which one will perform best sonically and still gives decent EMI/RF protection.
I'm afraid i might overdo the shielding and use cables that will eventually degrade the sound quality (too much capacitance? too little!?)...
.
I've used shielded cables for the rest of the system - CANARE starquad microphone cable for the interconnects (from the HTPC) and a Belden shielded power cable.
The only thing left is to replace my pretty decent 4X1.5mm Bi-wire speaker cable that still get noise from FL lights and the CRT TV near it...
I'll need around 1m-1.5m for L/R and preferably Bi-wire.
I don't need it to be too "heavy" since I'm using an efficient set of book shelfs at MAX RMS of 100W/8ohm.
I'll be happy to experiment with some Pure Silver/Silver plated wires that are pretty easy to source through eBay etc...
Also maybe play with the interconnects (braided silver/PTFE wires?)
So - what would you recommend?
A link to relevant references will be appreciated as well...
Gal
If you have to use special cable to shield from EMI for speaker cable youve got some BIG EMI issues.
The level of signal going down the speaker wire and the circuitry connected at one end and the driver at the other mean that EMI is not usually a problem, as the level of EMI is of a much much lower level than the signal, usually! Also EMI that is radiated that can cause problems again is a much higher frequency than audio (hence the prolifitation of ferrite beads on most hookup wires these days)..
I'd be interested where you are listening to music if EMI interference is that bad.
Some good links can be found here:
http://www.diyaudio.com/forums/diya...ng-interconnection.html?garpg=6#content_start
and
EMC Information Centre - The EMC Journal (Free in the UK)
The level of signal going down the speaker wire and the circuitry connected at one end and the driver at the other mean that EMI is not usually a problem, as the level of EMI is of a much much lower level than the signal, usually! Also EMI that is radiated that can cause problems again is a much higher frequency than audio (hence the prolifitation of ferrite beads on most hookup wires these days)..
I'd be interested where you are listening to music if EMI interference is that bad.
Some good links can be found here:
http://www.diyaudio.com/forums/diya...ng-interconnection.html?garpg=6#content_start
and
EMC Information Centre - The EMC Journal (Free in the UK)
Thank you for the reply...
It's not THAT bad - I just want to create new speaker cables and as an avid DIYer use the opportunity to experiment with an optimized cable design (just too many to choose from) and high grade materials (silver coated/PTFE lines!?).
I think most of the EMI pollution come from strong FL lights (Hi Tech aquarium) that goes On/Off in the vicinity of the cables and the second source is the big CRT TV adjacent to the speakers (the Center channel is actually standing on top of the TV and the front L/R are on stands very close to it...).
So - what will be the preferable design?
It may not have to be "heavily shielded" if you say it's usually not necessary - how about braiding an extra line to use as a "shield" that will be connected only at the source "ground" or something similar (saw it done in interconnects - but not too popular in speaker wires...)?
Any other suggestions for a good speaker cable design? (too many design debated with too many opinions out there - I just can't decide who makes sense anymore...)
It's not THAT bad - I just want to create new speaker cables and as an avid DIYer use the opportunity to experiment with an optimized cable design (just too many to choose from) and high grade materials (silver coated/PTFE lines!?).
I think most of the EMI pollution come from strong FL lights (Hi Tech aquarium) that goes On/Off in the vicinity of the cables and the second source is the big CRT TV adjacent to the speakers (the Center channel is actually standing on top of the TV and the front L/R are on stands very close to it...).
So - what will be the preferable design?
It may not have to be "heavily shielded" if you say it's usually not necessary - how about braiding an extra line to use as a "shield" that will be connected only at the source "ground" or something similar (saw it done in interconnects - but not too popular in speaker wires...)?
Any other suggestions for a good speaker cable design? (too many design debated with too many opinions out there - I just can't decide who makes sense anymore...)
Is it good as speaker cables as well? what about all this extra "capacitance" when braiding the cables? or is it negligible?
What AWG would you recommend for MAX 100w RMS and Bi-wire (shall I braid 4 inductors together or in two separated pairs and then twist them or something else?)
Gal
Don't braid, twist. You must twist as pairs, e.g. the positive and negative wire for one speaker. Then simply lay the two runs required for bi-wiring, you could braid these for looks.
Actually, if you are really worried about interference you would be better off using a single wire pair instead, just of thicker gauge. 18AWG would be fine for the length you need.
Actually, if you are really worried about interference you would be better off using a single wire pair instead, just of thicker gauge. 18AWG would be fine for the length you need.
Hmmm.... OK (whats the big difference!?) - how can I keep the "twist" from "untwisting" - with a heatshrink or something?
How much "twisting" - as dense as possible or just few per ft?
Would it be better to use a ready made twisted pair cables - there are quite a few with 2 twisted conductors and some kind of shield - would these be suitable for audio or too high capacity (like in the CAT5 designs...)
Gal
Just take a pair of wires and keep the end in one hand. Have your writing hand about 5cm further along holding the wires free. Now twist both hands in opposite direction like you would be wrapping a sweet (candy). You should find the wire has a tendency to twist at a 'natural' rate. The twist should stay in place by itself, but you could heatshrink segments or all if you wish.
It helps if you can work on the floor or other big clear space where the wires are free to flap around and will remain supported and level.
CAT5 cable is too thin and messy, having lots of terminations to do. A screened cable would be OK but for the screen to be any good it must be earthed (grounded) at both ends, something which you probably can't do. Earthing one end only is worse than no shield as it creates an antenna.
It helps if you can work on the floor or other big clear space where the wires are free to flap around and will remain supported and level.
CAT5 cable is too thin and messy, having lots of terminations to do. A screened cable would be OK but for the screen to be any good it must be earthed (grounded) at both ends, something which you probably can't do. Earthing one end only is worse than no shield as it creates an antenna.
O.K. - thank you for the TWISTING guide 
sound simple enough..
Regarding the shielded cable - why not connecting it to the ground (black) wire at each side?
And if so - why not using a coax cable (or a pair of them) and run the signal through the center with the shield connected as ground (Like many interconnect cables are made AFAIK) - any reason it's inferior to twisted pairs for speaker cables?
Gal
sound simple enough.. Regarding the shielded cable - why not connecting it to the ground (black) wire at each side?
And if so - why not using a coax cable (or a pair of them) and run the signal through the center with the shield connected as ground (Like many interconnect cables are made AFAIK) - any reason it's inferior to twisted pairs for speaker cables?
Gal
I have a personal preference for using woven cables like the designs by Kimber Cable
These cables were designed to cope with high EMI.
The story behind Kimber Kable
I have no idea if this really has a performance gain over twisted pairs, but I like the way that the cables hold together.
The tricky bit is the braiding process, but I have made bi wire cables of 8 metre long for my PA (with some difficulty!).
3 wire braid is easy. 4 wire takes some practice but a quick google search will get you some info on braiding.
If you are really suffering with EMI problems, You might also concider filtering the input to your amplifier and improved grounding.
Ben Duncan has a done a lot of work on EMI, and you can find some of his products here.
Store
These cables were designed to cope with high EMI.
The story behind Kimber Kable
I have no idea if this really has a performance gain over twisted pairs, but I like the way that the cables hold together.
The tricky bit is the braiding process, but I have made bi wire cables of 8 metre long for my PA (with some difficulty!).
3 wire braid is easy. 4 wire takes some practice but a quick google search will get you some info on braiding.
If you are really suffering with EMI problems, You might also concider filtering the input to your amplifier and improved grounding.
Ben Duncan has a done a lot of work on EMI, and you can find some of his products here.
Store
I also liked the design of these cables and would probably experiment with these and twisted pairs as well.
I'm talking about SPEAKER wires currently not interconnects or internal wirings (which I already have good results with CANARE StarQuad and shielded twisted pairs cables).
I've got some info regarding the shielded wires I considered using - they are multi-stranded silver plated cooper with PTFE and plated cooper wire shield + PTFE again:
1X26AWG 37pf/ft
1X24AWG 41pf/ft
1X22AWG 50pf/ft
1X20AWG 54pf/ft
It seems WAY too high considering I'll need to braid/twist few of them together (it's in capacitance for ft...) - right?
So no shielded cables for speakers...
I'm waiting for same data for the unshielded and twisted pairs variants which I expect to be better...
any insights?
Gal
Hello again,
I decided to go for twisted/braided design (will experiment with both).
Wires will be PTFE covered Silver plated copper - 19strands wires.
Any recommendations for required AWG ?
(I'm talking ~50W RMS, 91db, 50Hz-25kHz speakers).
I don't want to go to extremities - just some experimentations - so I'll look for something around 2mm inductors cross section per each lead (4 of these per speaker).
How many wires to combine for each Biwire cable?
As much as possible with smaller gage (high AWG)? or one thick multi-stranded wire 18-20AWG is enough?
Combine various AWG within each lead?
Making the ground thicker than signal?
Making the LF thicker than HF (I'll probably do that anyhow).
Please share your "recipe" with me
Gal
I decided to go for twisted/braided design (will experiment with both).
Wires will be PTFE covered Silver plated copper - 19strands wires.
Any recommendations for required AWG ?
(I'm talking ~50W RMS, 91db, 50Hz-25kHz speakers).
I don't want to go to extremities - just some experimentations - so I'll look for something around 2mm inductors cross section per each lead (4 of these per speaker).
How many wires to combine for each Biwire cable?
As much as possible with smaller gage (high AWG)? or one thick multi-stranded wire 18-20AWG is enough?
Combine various AWG within each lead?
Making the ground thicker than signal?
Making the LF thicker than HF (I'll probably do that anyhow).
Please share your "recipe" with me
Gal
The geometry of the cable is insignificant compared with the way most speakers are wired up inside, unless you have a really wide spaced pair like DNM. Too many speakers have widely separated wires to the drivers creating huge loops
If you don't want to fix bad speaker layout, you could try putting 100R in series with 1nF across the speaker terminals to reduce rf going into the amp
If you don't want to fix bad speaker layout, you could try putting 100R in series with 1nF across the speaker terminals to reduce rf going into the amp
The best method I've found for twisting (which I think came from Morgan Jone's tube amp construction methods), is to take the two wires of the same length, put the one ends in a vise or clamp them to a sturdy support. Stretch the wires straight and tighten the other two ends in a power drill chuck. Start winding with the drill, keeping modest tension on the wires. At first, the twisting wires will pull in slowly. At some point, they will start to pull in quickly, and if you continue, will bunch. Just at the point where they start to pull in quickly, stop twisting and give the wires an extra pull to "set" the twist. Unclamp the wires and let them relax. Done.
BTW, in the environment described by the thread starter, I'd be more worried about the stuff coming through the mains, than stuff coming through the air.
Sheldon
I would suggest coax, two per channel if you're running BTL. Common RG6 can carry plenty of current (7A or so). Also note that modern amplifier designs often have a few hundred nF in the output filter, so a few hundred pF is not going to be significant.
- Status
- This old topic is closed. If you want to reopen this topic, contact a moderator using the "Report Post" button.