09-Jul-2022, 14:57 (This post was last modified: 10-Jul-2022, 17:52 by B4ICU.)
Hi
Speaker cables are a difficult topic. The truth is that no one really knows what cable would be best for your speaker. I do.
Unfortunately, the industry of speaker cables (actually all kind of cables) is included in my say. For years we get directions on topics that are non-relevant:
Cable direction, Cable purity, Silver over Copper, Cryogenic treat, Bi-wire and more. It doesn't take 4 years of engineering to figure it out.
However, different speaker cables sometimes sound better (some other times not!), and the endless buy and try is costly and terribly inefficient.
Actually, even though the cable is named after the speaker (Speaker Cables), it should be named after the Amplifier!
The cable is an extension of the Amp's Damping Factor (DF). The higher the DF, the thicker the cable needs to be. When it is a tube Amp. with DF as low as 8,
The cable is insignificant. But when it goes in the hundreds it is. When it is as high (and good) as of a Devialet Amp (8,000!), it is most significant.
I've heard critics of Devialet Amp demos that didn't do the wow factor. The blame is the speaker cable. I assume that they placed it right and used a proper source.
I have a friend in the US, who owns a set of Magnepans with a Devialet Amp. He had thickened his #0 AWG cable into a 4x #0 AWG (should have been x16 times!
And sound had improved dramatically. The #0 AWG improved dramatically, when he used with a PASS power Amp. replacing a #12 AWG cable.
I conducted an experiment, with a test group (on Audiogon) and also some local friend and it works. I calculated a friend, a set of #4 AWG for his PASS and B&W801D,
that broke when cleaned. With my demo #0 AWG and as predicted, sound didn't improve by a bit.
That’s interesting. Can you elaborate a bit more on the theory behind this?
Lifetime Roon, Mac mini, int. SSD, ext. HDD, tv as monitor, key board and track pad on bean bag as remote,Devialet 200, Od'A #097, Blue jeans speaker cable, Dynaudio C1 MkII. Jim Smith's GBS. Northern NSW Australia.
I just looked up an AWG to square mm chart. 0 AWG = 53.5 square mm. Hmmm….
Lifetime Roon, Mac mini, int. SSD, ext. HDD, tv as monitor, key board and track pad on bean bag as remote,Devialet 200, Od'A #097, Blue jeans speaker cable, Dynaudio C1 MkII. Jim Smith's GBS. Northern NSW Australia.
The theory is very straight forward: the cable is a pair of resistors (in fact more complex load as it is a combination of resistor and capacitors) that you put in series in the circuit formed by the amp and the speakers.
The thicker the cable, the lower the resistance. Therefore if you consider that not to be heard the added resistance needs to be less than 1/10 of the output resistance of the amplifier (don’t take 1/10 as a real value it’s just for illustration purpose), you would ‘need’ a cable showing 100 less resistance for an Amp having a damping factor 100 greater.
Or if I take the example given by @B4ICU a Devialet would benefit from a cable 1000 times less resistive than a tube amplifier would.
My two cents
Jean-Marie
MacBook Air M2 -> RAAT/Air -> WiFi -> PLC -> Ethernet -> Devialet 220pro with Core Infinity (upgraded from 120) -> AperturA Armonia
France
(10-Jul-2022, 08:18)Jean-Marie Wrote: The theory is very straight forward: the cable is a pair of resistors (in fact more complex load as it is a combination of resistor and capacitors) that you put in series in the circuit formed by the amp and the speakers.
The thicker the cable, the lower the resistance. Therefore if you consider that not to be heard the added resistance needs to be less than 1/10 of the output resistance of the amplifier (don’t take 1/10 as a real value it’s just for illustration purpose), you would ‘need’ a cable showing 100 less resistance for an Amp having a damping factor 100 greater.
Or if I take the example given by @B4ICU a Devialet would benefit from a cable 1000 times less resistive than a tube amplifier would.
My two cents
Jean-Marie
There’s very little resistance in a few metres of simple cooper cable so that’s impossible to achieve.
Lifetime Roon, Mac mini, int. SSD, ext. HDD, tv as monitor, key board and track pad on bean bag as remote,Devialet 200, Od'A #097, Blue jeans speaker cable, Dynaudio C1 MkII. Jim Smith's GBS. Northern NSW Australia.
10-Jul-2022, 10:44 (This post was last modified: 10-Jul-2022, 10:44 by Jean-Marie.)
Believe it or not, but I have been told by Pierre-Emmanuel CALMEL, that the actual output resistance of a Devialet is in fact the resistance of the binding posts given how low is the actual resistance of the amplifier itself.
The resistance of a cable being rhô * length / section, doubling the section halves the resistance.
Now is it audible, probably when you are a given threshold, probably.
What is that threshold, I don’t know and I would posit that it does not depend solely on the amplifier. I would suspect that the load itself (the speaker, especially the filter) have a big effect and therefore whether or not it makes any discernable difference to your ears and brain is up to you.
Jean-Marie
MacBook Air M2 -> RAAT/Air -> WiFi -> PLC -> Ethernet -> Devialet 220pro with Core Infinity (upgraded from 120) -> AperturA Armonia
France
10-Jul-2022, 18:12 (This post was last modified: 10-Jul-2022, 18:14 by B4ICU.)
(10-Jul-2022, 08:18)Jean-Marie Wrote: The theory is very straight forward: the cable is a pair of resistors (in fact more complex load as it is a combination of resistor and capacitors) that you put in series in the circuit formed by the amp and the speakers.
The thicker the cable, the lower the resistance. Therefore if you consider that not to be heard the added resistance needs to be less than 1/10 of the output resistance of the amplifier (don’t take 1/10 as a real value it’s just for illustration purpose), you would ‘need’ a cable showing 100 less resistance for an Amp having a damping factor 100 greater.
Or if I take the example given by @B4ICU a Devialet would benefit from a cable 1000 times less resistive than a tube amplifier would.
My two cents
Jean-Marie
Hi
DF by definition is pure resistance, regardless of the inductive or capacitance values. It is the speaker's impedance value (8 ohms) divided by the Amp's output resistor.
But it is a question how the Amp. gets its DF value?
Is it by low resistance design, or by an aggressive feedback. The two doesn't sound the same.
Feedback is not a bad word. But it has to be used wishfully.
In case of Devilate's an 8,000 DF, is equal to a 1/1000th of an Ohm output resistance.
If the cable's series resistance (twice the length, by AWG table) equals to 1/1000 of an ohm, the DF drops to half!
By the sonic results, on moderate DF of 500 +/- 100, it is quite dramatic. I assume that it has a bigger impact, the higher the DF goes.
Unfortunately, no Amp. manufacturer takes the incentive to tell it's customer what should be the cable AWG for a given length, lets say 3m (10 ft.).
For the speaker cable's manufacturer it's quite a shame. They sale this stuff in millions of $ without understanding the physics, nor the formula.
An other interesting part of this, is that the speaker doesn't play a roll. It is completely not important what speaker is hooked.
Just for the sports, if any of the members here is interested, I can calculate his cable, if the info. of the Amp's DF and length is provided.
At lest you will know how close or far you are from the optimum.
Just be please patient, because I'll leave for a week for vacation.
I added a picture of the devilaete Amp with the 4x #0 AWG cables. The calc. shows that a 16x #0AWG should be used...
(10-Jul-2022, 10:44)Jean-Marie Wrote: Believe it or not, but I have been told by Pierre-Emmanuel CALMEL, that the actual output resistance of a Devialet is in fact the resistance of the binding posts given how low is the actual resistance of the amplifier itself.
The resistance of a cable being rhô * length / section, doubling the section halves the resistance.
Now is it audible, probably when you are a given threshold, probably.
What is that threshold, I don’t know and I would posit that it does not depend solely on the amplifier. I would suspect that the load itself (the speaker, especially the filter) have a big effect and therefore whether or not it makes any discernable difference to your ears and brain is up to you.
Jean-Marie
Hi
Just a reminder, that the thread topics is the speaker cable.
However, the DF or damping factor, is a figure that describes the efficiency of damping the speaker (membrane). The higher the DF the better the damping.
Low DF amps, as tube Amp's have a very different characteristics than high DF SS Amps. The hybrid version, like McIntosh, is one I don't like at all.
The more realistic the speaker sound's (I own a Klipsch Forte II) the more impact a good DF has.
For this example, keeping in mind that the Forte II has an efficiency of 99dB/w/m SPL, it almost needs no power to sound loud. My Amp. has some power meters, that run at most to 3W peak, when it gets loud. Rest of the time it is about 0.1-0.01W...At 8 Ohm's it's no current or effort. Still the cables matter.
So it's not the power and also not the current.
(10-Jul-2022, 08:18)Jean-Marie Wrote: The theory is very straight forward: the cable is a pair of resistors (in fact more complex load as it is a combination of resistor and capacitors) that you put in series in the circuit formed by the amp and the speakers.
The thicker the cable, the lower the resistance. Therefore if you consider that not to be heard the added resistance needs to be less than 1/10 of the output resistance of the amplifier (don’t take 1/10 as a real value it’s just for illustration purpose), you would ‘need’ a cable showing 100 less resistance for an Amp having a damping factor 100 greater.
Or if I take the example given by @B4ICU a Devialet would benefit from a cable 1000 times less resistive than a tube amplifier would.
My two cents
Jean-Marie
There’s very little resistance in a few metres of simple cooper cable so that’s impossible to achieve.
Hi
How little?
if you got to the AWG table: https://www.powerstream.com/Wire_Size.htm
you can see, that a #12 AWG cable of 10 ft. (3m) which is actually 6m as there are two wires connected in series:
It's 5.2 Ohms per 1,000m, so it's 0.0312 Ohms.
The output resistance of a Devialet is 0.001 Ohms. So the cable would ruin the DF by 31 times. In other words, the DF would drop from 8,000 to ~560.
If the same cable would be used with amp. that has a DF of 500 (Emotiva typical DF) the actual DF would drop to half: 250.
The fact that such AWG wires are measure in 1/10 or 1/100 of an Ohm should not scare you.
So a #0 AWG cable is not so thick as you might think, When DF goes high. I agree that it becomes dificult to connect the cable of such diameter to a binding post,
but creative methods can solve it.
The improvement in sound worth the effort.
11-Jul-2022, 17:08 (This post was last modified: 11-Jul-2022, 17:09 by daniel.avasilichioaei.)
I'm not an expert, but, as far as I understand, we are talking about a circuit in which they are put in series:
- a power generator (amplifier)
- a resistor (speaker)
- the two connecting cables.
The speaker has a resistance (more precisely impedance) from about 4 Ohms and up.
What is the relevance of the resistance of the amplifier and of the cables, in the conditions in which it is of the order of 0.01 Ohm? The speaker has a resistance hundreds / thousands of times higher than that of the cables...
