Thin wide DIY copper foil speaker cable construction traps

[robmid]

I am a recent convert to thin wide diy copper foil speaker cables which I built to complement my CloneNote LDR passive preamp.

 

There seem to be varying theories about cable spacing and termination but I had no idea which was the best way to construct them.

 

My 2x 3 metre cables were purchased from Uriah Dailey of Clone Note LDR fame in the USA. They are 35mm wide and .25mm thick and insulated.

 

I couldn't find any 'first hand' experiences online so I tried a few variations of construction at my own peril.

 

It seems that foils perform best when far apart or close together, whatever that means. That's a wide set of options so I decided to start by keeping signal/return cables separate and hanging them horizontally separated by about 50mm of air space. They performed superbly and left good quality copper cable for dead. It was more like being within a performance rather than just listening through speakers.

 

It was explained to me that wide spacing is 'bad' so my new research came up with the suggestion of taping the foils together which is close...very close.  I used 30mm wide double sided tape. They looked impressive and were *easy to handle.

*Pairs of foils are very slippery together and seem to be alive. Mine have a tendency to try and strangle me when I am alone with them so be careful.

 

Now for an incredible audio experience I thought, so I powered up and started playing my favourite tracks. Upper treble was very clean and voices had a nice halo but after a while I realised that I was missing some enjoyment. Everything was clear and bright but tracks seemed to have lost some of their magic and I had to reduce the level of my sub which was sounding boomy. It was then that I realised the mids were 'blurry' which emphasised the 'voice halo'. 

 

A bit of research pulled up information about how low inductance is the goal and high capacitance doesn't affect sound quality so I decided to measure the capacitance of my cables. They are 3 metres in length and the capacitance was 33,000 pF according to my dmm. I don't know if this is good or bad but in my experience it is bad.

 

Something had changed dramatically, so further investigation informed me that high capacitance can affect signal timing and change the sq. That sounded logical so back to the drawing board and pull them apart. What a bugger of a job. They were stuck together like they were welded and didn't look like moving but I persisted and eventually managed to separate them without too much damage. The big problem now it that the tape was still stuck to one surface and couldn't be removed. My solution was to put paper tape over the old tape and leave 30mm gaps every 1/2 metre to attach the second cable and keep them under control.

 

Once again the cables were draped but this time they were spaced between almost touching to about 5mm.

 

The capacitance now reads 2,400 pF for 3 metres. There doesn't seem to be a recommended figure, but this worked for me.

 

The result? They are now absolutely incredible and have to be heard to be believed. Although they might look ugly there is no comparison with conventional high quality speaker cables.

 

My experience:

1. Foils with 50mm air spacing sound better than conventional high quality copper cables

2. Foils taped together, seriously alter signal timing and produce muddy mids and bloated bass on my system. (Holton 150 watt dual monoblock and KEF LS50's)

3. Foils with a maximum of 5mm air spacing produce an incredible sound stage and realism with holographic presentation.

 

TERMINATION TO COVER THE FOIL WIDTH

A neat and effective way to terminate wide foils is to use a length of silver plated copper wire.

1. Wrap wire around three fingers side by side about 10 times forming a long series of loops about 50mm in length

2. Twist 30mm of the wire for connection to speaker and amp sockets

3. The untwisted end should look like a series of circles on top of each other

4. Spread out the circles to the width of the foil and make sure they are flat

5. Lay them flat on the cleaned (sandpapered) foil

6. Take some solder from your reel, make a lump and lay it down so it covers all the wires

7. Take a small gas torch and melt the solder until it flows around all the loops onto the foil

 

I hope my experience helps somebody out there in audio land.

 

Cheers,

Rob

 

[tesla13BMW]

@robmid glad to see someone has tried the DIY Aurealis Silver Interconnects!  I built these in consultation with Geoff and said "you should make a DIY kit of these" and he did.  What RCA's did you use?  I used the KLEI Absolute Harmony on one pair and Pure Harmony on the other.  I find they have worked well from phono stage to pre  amp and CD to pre amp.

 

I like the idea of the foil cables but need to do more research as to their application to ESL57's where by they are actually supplying a transformer.

[Bilbo]

I have been using foils for all my cabling for a couple of years now. They are 40mm x 0.15mm for all cables. As you note they are a bit unwieldy but the sonic benefits are profound.

My reference cable uses annealed silver foil and I have not heard a better cable. This cable is used between my DAC and Tortuga preamp. The rest are copper foil.

I got mine through a couple of other audiophiles in town but the foil rolls they bought are finished and I need one more for my phono stage to preamp.

You said you got them from Uriah Daley but they are not on his web site. Was this a special order and are they available to others for purchase?

Here is a photo of mine.

 

Edited February 20, 2017 by Bilbo

[robmid]

1 hour ago, Bilbo said:

I have been using foils for all my cabling for a couple of years now. They are 40mm x 0.15mm for all cables. As you note they are a bit unwieldy but the sonic benefits are profound.

My reference cable uses annealed silver foil and I have not heard a better cable. This cable is used between my DAC and Tortuga preamp. The rest are copper foil.

I got mine through a couple of other audiophiles in town but the foil rolls they bought are finished and I need one more for my phono stage to preamp.

You said you got them from Uriah Daley but they are not on his web site. Was this a special order and are they available to others for purchase?

Here is a photo of mine.

 

 

It was a special order from Uriah. He also has some 5mm insulated foils. I have made some IC's and they are not only transparent but super smooth.

[Guest]

It is sometimes perfectly valid to tune a hifi system by balancing the sound of components and interconnects. Cables are subject to the laws of physics in relation to electromagnetic properties. Flat wide foil loudspeaker cables will change how things sound fairly dramatically - this is just fundamental physics - the amount of change is a function of the length of cable. I'm not sure why anyone would want their cables to change the sound of the signal going through them. Personally I am of the view that the ultimate objective for high fidelity performance comes from hifi systems where each component in the system is designed to minimally change the sound that was originally recorded. Otherwise it isn't high fidelity, it's just "fashion in sound". Sound fashion certainly seems to becoming a dominating part of 'hifi'.

 

 

[robmid]

2 hours ago, tesla13BMW said:

@robmid glad to see someone has tried the DIY Aurealis Silver Interconnects!  I built these in consultation with Geoff and said "you should make a DIY kit of these" and he did.  What RCA's did you use?  I used the KLEI Absolute Harmony on one pair and Pure Harmony on the other.  I find they have worked well from phono stage to pre  amp and CD to pre amp.

 

I like the idea of the foil cables but need to do more research as to their application to ESL57's where by they are actually supplying a transformer.

I can't get to grips with my KLEI copper harmonies despite trying to get good performance from them. I am now using the STAR RCA's that Geoff sells. They are surprisingly good.

[Zaphod Beeblebrox]

It is probable that your amplifier cannot cope with such high capacitance speaker cables. This is not unheard of, when using high global NFB amps. A wide spacing of the foils is not smart though. A possible solution is to make the foil narrower, but thicker. This will reduce capacitance, but keep the resistance the same. Model them on the very excellent Goertz MI-1 cables and you won't go wrong.

 

See if you can listen to a zero global NFB amplifier, as such amps offer greater stability with highly capacitive loads.  

[acg]

6 minutes ago, johnmath said:

It is sometimes perfectly valid to tune a hifi system by balancing the sound of components and interconnects. Cables are subject to the laws of physics in relation to electromagnetic properties. Flat wide foil loudspeaker cables will change how things sound fairly dramatically - this is just fundamental physics - the amount of change is a function of the length of cable. I'm not sure why anyone would want their cables to change the sound of the signal going through them. Personally I am of the view that the ultimate objective for high fidelity performance comes from hifi systems where each component in the system is designed to minimally change the sound that was originally recorded. Otherwise it isn't high fidelity, it's just "fashion in sound". Sound fashion certainly seems to becoming a dominating part of 'hifi'.

 

 

 

But which changes the sound less, wide flat foils or other wire variants?  Honest question.  How does one know the answer to that? 

[Guest]

47 minutes ago, acg said:

But which changes the sound less, wide flat foils or other wire variants?  Honest question.  How does one know the answer to that? 

 

I'll limit this reply to loudspeaker cables for the sake of clarity. An appropriately designed coaxial or star-quad loudspeaker cable will invoke the least change of sound quality per length of cable. A loudspeaker cable cannot *add* fidelity, only detract from it. For each increase in length any loudspeaker cable's influence will increase proportionally. The electrical parameters of the loudspeaker cable impact on the amplifier / loudspeaker interface, reducing the amplifier's ability to *control* the loudspeaker, and reducing the loudspeaker's ability to *see* the amplifier output, hence the best loudspeaker cable is a zero length one. The electrical and acoustic parameters of loudspeaker cables that increase proportionally to length are well defined by physics and can easily be measured. Because amplifiers are essentially *constant voltage* sources and loudspeakers are *variable impedance* loads, the most important cable parameters in order are: 1. resistance; 2. inductance; 3. capacitance; and 4. dialectric effects, with 3 & 4 being usually* much less significant than 1 & 2. The electrical properties of a loudspeaker cable are a function of the *effective* conductor cross-sectional area and conductor geometry. This is a consequence of the laws of physics no cable manufacturer gets an exemption from these laws. Flat parallel conductors are relatively quite high inductance, and that excess inductance absolutely affects the reproduction of sound. If the perceived effect of high inductance loudspeaker cables in an improvement in system sound quality, then there are serious defects in other parts of the system, or the listener is expressing a preference that is not directly related to sound fidelity. If someone has an alternative reality based view, I'd be very pleased to hear it.

 

*the exception being in the case of incompetently or poorly designed amplifiers.

 

Edited February 20, 2017 by Guest

[andyr]

1 hour ago, johnmath said:

 

Flat parallel conductors are relatively quite high inductance, and that excess inductance absolutely affects the reproduction of sound.

 

 

Sorry, John - but my understanding is that:

• a cable's capacitance and its inductance are inversely related.
• IOW ... if capacitance is high ... inductance is low.
• low inductance is the ideal in speaker cable ... bcoz inductance "opposes current flow".
• flat parallel conductors have extremely high capacitance - which might send your amp into oscillation - but are extremely low in inductance ... which is a great thing for speaker cables.  (Not so good for ICs.)

Andy

 

[acg]

57 minutes ago, johnmath said:

 

I'll limit this reply to loudspeaker cables for the sake of clarity. An appropriately designed coaxial or star-quad loudspeaker cable will invoke the least change of sound quality per length of cable. A loudspeaker cable cannot *add* fidelity, only detract from it. For each increase in length any loudspeaker cable's influence will increase proportionally. The electrical parameters of the loudspeaker cable impact on the amplifier / loudspeaker interface, reducing the amplifier's ability to *control* the loudspeaker, and reducing the loudspeaker's ability to *see* the amplifier output, hence the best loudspeaker cable is a zero length one. The electrical and acoustic parameters of loudspeaker cables that increase proportionally to length are well defined by physics and can easily be measured. Because amplifiers are essentially *constant voltage* sources and loudspeakers are *variable impedance* loads, the most important cable parameters in order are: 1. resistance; 2. inductance; 3. capacitance; and 4. dialectric effects, with 3 & 4 being usually* much less significant than 1 & 2. The electrical properties of a loudspeaker cable are a function of the *effective* conductor cross-sectional area and conductor geometry. This is a consequence of the laws of physics no cable manufacturer gets an exemption from these laws. Flat parallel conductors are relatively quite high inductance, and that excess inductance absolutely affects the reproduction of sound. If the perceived effect of high inductance loudspeaker cables in an improvement in system sound quality, then there are serious defects in other parts of the system, or the listener is expressing a preference that is not directly related to sound fidelity. If someone has an alternative reality based view, I'd be very pleased to hear it.

 

*the exception being in the case of incompetently or poorly designed amplifiers.

 

 

Thanks John.

 

I am not baiting you John not at all, I've never seriously looked into this stuff with speaker cables, but how does high inductance influence the sound (see the bold above), or the fidelity?  What do they sound like?  I have used ribbon speaker cables for several years now because they sound better than other stuff I tried, but stand to be corrected (my aim with my playback is not necessarily fidelity, it is enjoyment - fidelity may or may not come along for the ride)

 

 

Here is a question for those in the know (sorry for the off-topic).  I am building a very unusual bass speaker that will operate sub 100Hz, crossover will be line level (in front of its own amplifier) and may be first order or higher in slope.  The bass array (8 x paralleled 8R drivers) will present a nominal 1R load and perhaps as high as 5R at Fs and a special bass OPT has been wound to drive this load.  Into 1R the triode will be driving equal current and volts (3.16V, 3.16A for 10W).  How do the speaker cable requirements change when driving current?  Obviously I will have to keep cable resistance as low as possible or risk raising the nominal load too far, but can you think of anything else that I should think about (other than a psychiatrist)?

 

 

[Guest]

45 minutes ago, andyr said:

 

Sorry, John - but my understanding is that:

• a cable's capacitance and its inductance are inversely related.
• IOW ... if capacitance is high ... inductance is low.
• low inductance is the ideal in speaker cable ... bcoz inductance "opposes current flow".
• flat parallel conductors have extremely high capacitance - which might send your amp into oscillation - but are extremely low in inductance ... which is a great thing for speaker cables.  (Not so good for ICs.)

Andy

 

 

High capacitance and high inductance are not necessarily inversely related nor mutually exclusive. Inductance is the property of current enclosing an area between conductors where a magnetic field can form. Capacitance is the property of voltage across a space between conductors where an electric charge can store. Flat parallel conductors like those pictured above will have lower capacitance and higher inductance than a typical pair of closely spaced adjacent circular conductors. If the two flat conductors were sandwiched together on top of one another instead of being positioned like two bird's wings, the cable would have lower inductance and higher capacitance than a typical pair of closely adjacent circular conductors.

A four conductor 'star quad' configuration has low inductance, not because there is not space between the conductors for a magnetic field to form, but because the mirror image pairs of conductors create mirror image magnetic fields that oppose and largely cancel each other out.

 

A coaxial cable has low inductance because there is no net current flow outside the cable. The only place a magnetic field can form is inside the small gap between the outer conductor and the centre conductor. As the distance between the centre conductor and outer conductor increase, so does inductance, although it remains very small compared to two open conductors spaced apart. The capacitance is as always a function of the surface area of the two conductors (more = more), the closeness of the two conductors (less = more) and the dialectric properties of the insulator.

[Zaphod Beeblebrox]

11 hours ago, johnmath said:

 

 Flat parallel conductors are relatively quite high inductance, and that excess inductance absolutely affects the reproduction of sound. If the perceived effect of high inductance loudspeaker cables in an improvement in system sound quality, then there are serious defects in other parts of the system, or the listener is expressing a preference that is not directly related to sound fidelity. If someone has an alternative reality based view, I'd be very pleased to hear it.

 

 

 

 

Flat, ribbon cables, with VERY close conductor spacing offer the lowest inductance of any cable. Even my favourite RG213/U is comfortably eclipsed by the mighty Goertz MI-1 cable. 

 

RG213/U has the following characteristics:

Resistance -  0.0058 Ohms/M

Capacitance - 101pF/M

Inductance - 0.23uH/M

 

Your favourite cable is similarly specc'd

 

Goertz MI-1 has the following characteristics:

 

Resistance - 0.012 Ohms/M

Capacitance - 1,440pF/M

Inductance - 0.012uH/M  (!!!)

 

Goertz MI-1 is the most accurate speaker cable I've ever tested/listened to. Like any high capacitance cables, however, it cannot be used with all amplifiers. Naim amps, particularly, should be avoided with any high quality speaker cable, as destruction of the amplifier is a real possibility. 

[Guest]

11 hours ago, acg said:

...but how does high inductance influence the sound (see the bold above), or the fidelity?  What do they sound like?...

 

I wrote quite extensively about how different loudspeaker cable geometries 'sound' some time ago in this forum. (See link below). The thoughts I posted then still hold true for my experience. In conventional systems, high inductance cables cause apparent loss of bass depth and increase mid-bass muddiness. The loss of control over the driver can be visibly evident just watching the increase in excursion of the bass driver cone at the same power level. This is even more apparent for high powered passive subwoofer systems, which typically have large cone areas with high moving mass and hence high levels of stored energy in the moving parts of the system. I have not had a chance to play with the Goetz Ml-1 cable, but from Zap's description I would expect it to behave the way Zap says it does, since Goetz gets the same laws of physics to play with as everyone else.

 

The system you're contemplating falls outside of my area of confidence which relates to conventional solid state amplifiers driving loudspeaker loads directly. An output transformer changes the scheme of things by adding another frequency dependent, nonlinear component into the system, and I haven't contemplate how this will interact with the frequency dependent nonlinearities of a loudspeaker system other than to suggest that the *better* the design of the transformer, the more it will behave like a transformer-less system.

 

A colleague of mine, engineer and inventor Graeme Cohen, was a specialist in this area and had several recent patents covering transformer design for valve amplifier outputs driving loudspeakers, but sadly he left the planet last year and a great deal of the world's knowledge on the topic went with him. He has probably published some AES papers on the topic, but they would not encompass all of his knowledge and experience.

 

 

[acg]

1 hour ago, johnmath said:

 

I wrote quite extensively about how different loudspeaker cable geometries 'sound' some time ago in this forum. (See link below). The thoughts I posted then still hold true for my experience. In conventional systems, high inductance cables cause apparent loss of bass depth and increase mid-bass muddiness. The loss of control over the driver can be visibly evident just watching the increase in excursion of the bass driver cone at the same power level. This is even more apparent for high powered passive subwoofer systems, which typically have large cone areas with high moving mass and hence high levels of stored energy in the moving parts of the system. I have not had a chance to play with the Goetz Ml-1 cable, but from Zap's description I would expect it to behave the way Zap says it does, since Goetz gets the same laws of physics to play with as everyone else.

 

The system you're contemplating falls outside of my area of confidence which relates to conventional solid state amplifiers driving loudspeaker loads directly. An output transformer changes the scheme of things by adding another frequency dependent, nonlinear component into the system, and I haven't contemplate how this will interact with the frequency dependent nonlinearities of a loudspeaker system other than to suggest that the *better* the design of the transformer, the more it will behave like a transformer-less system.

 

A colleague of mine, engineer and inventor Graeme Cohen, was a specialist in this area and had several recent patents covering transformer design for valve amplifier outputs driving loudspeakers, but sadly he left the planet last year and a great deal of the world's knowledge on the topic went with him. He has probably published some AES papers on the topic, but they would not encompass all of his knowledge and experience.

 

 

 

Thanks John.  Very much appreciated, I will have a look at that thread.  The ribbon speaker cables that I have here are very closely spaced, as @Zaphod Beeblebroxmentioned above is important (but they are not Goertz cables) and the very thing that made them so attractive to me was the articulation of the bass which seems to correlate to your theoretical explanation, so that is a feel-good moment the theory and practice point in the same direction.

 

Regarding the unusual bass channel, the transformer is wound and tested in the circuit and has -3dB points at full power into 1R at something like 5Hz and 4kHz...which is extraordinary that it could get up that high...the speaker cables and binding posts are the thing concerning me right now.

 

Edited February 20, 2017 by acg

[robmid]

This post is turning into an interesting technical education into why it is impossible to predict cable performance within different systems. There is an enormous amount of knowledge on SN and it's much appreciated.

 

I'm currently reading the 1955 edition of the Radio Designers Handbook but my only experience in audio is through the enjoyment of listening to accurately reproduced music largely through DIY equipment and audio club demos.

 

My original post was initiated because I could find stacks of technical explanations about the benefit of foil cables but nobody was discussing the effects of spacing between foils which is obviously critical to the audio experience.

 

After hours of hunting the net I found a simple explanation of why cable capacitance can affect sound quality. The explanation was simply that a capacitor stores energy and in doing so changes the signal speed which can lead to signal timing errors.

 

As KEF owners appreciate, the LS50's are critical and fast, as are many other monitor speakers. The Holton amp is no slouch either. So it would seem to me there is a distinct possibility that the degradation of fine detail and bloated bass with extremely closely spaced foils was most likely due to timing errors created by the high capacitance.

 

I'm sure I will be corrected but that's why I am here.

[agisthos]

A friend of mine from years ago did extensive playing around with copper and silver foil cables, He claimed that the insulation effects the sound a lot with foils, that's why the small air gap is no doubt best, but only practical for DIY'ers.
He sourced an expensive teflon tape. A double sided teflon tape for the middle layer, and single side for the outer edges. He claimed it was much better than standard sticky insulation tape.

 

Also, foils can be the best speaker cable ever for 'some' amp/speaker combinations. For some amps and speakers it does not suit. Zaphod would know more about this.

Edited March 3, 2017 by agisthos

[agisthos]

robmid why don't you post a picture of your construction so others can follow what you have done.

[Zaphod Beeblebrox]

On 2/21/2017 at 10:51 AM, robmid said:

 

After hours of hunting the net I found a simple explanation of why cable capacitance can affect sound quality. The explanation was simply that a capacitor stores energy and in doing so changes the signal speed which can lead to signal timing errors.

 

Nope. That is incorrect. Capacitance is inconsequential. The only important factors are resistance (lower is better) and inductance (lower is better). SOME amplifiers do not cope well with high capacitance speaker cables however.

 

On 2/21/2017 at 10:51 AM, robmid said:

 

As KEF owners appreciate, the LS50's are critical and fast, as are many other monitor speakers. The Holton amp is no slouch either. So it would seem to me there is a distinct possibility that the degradation of fine detail and bloated bass with extremely closely spaced foils was most likely due to timing errors created by the high capacitance.

 

 

Nope. Nothing to do wit timing. More likely a stability issue.

[davewantsmoore]

On 20/02/2017 at 9:09 PM, acg said:

How do the speaker cable requirements change when driving current?

 

In your case...  No change.

 

The current flowing in the voice coil is what causes the speaker to move.... and so for a speaker playing a fixed SPL, the current flowing through the voice coil (hence the speaker cable) is the same no matter how things are configured.

 

[davewantsmoore]

On 21/02/2017 at 10:51 AM, robmid said:

After hours of hunting the net I found a simple explanation of why cable capacitance can affect sound quality. The explanation was simply that a capacitor stores energy and in doing so changes the signal speed which can lead to signal timing errors.

 

 

The capacitance of a speaker cable is too low to do this.

 

Typical capacitance of a speaker cable is inconsequential, aside from the ability to cause amplifiers to be unstable (in extreme cases).

[tygersmoke]

1 hour ago, agisthos said:

A friend of mine from years ago did extensive playing around with copper and silver foil cables,
He sourced an expensive teflon tape. A double sided teflon tape for the middle layer

 

If you are still in touch with your friend, could you ask him where he sourced double-sided teflon tape? I have been on the lookout for years for exactly this project, but can't seem to find anyone that sells it. Oh, and what thickness he found best? Ta!

 

Regards,

Phil