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Degradation of sound quality by speaker cables with high loop resistances?

pogo

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Did you mean "the damping of driver motion" by "the swing-out behavior of a speaker"? If so, I do not believe it is a big factor with amplifiers these days and even with the CCA cables.
See also here and the following posts:
Link
 

Beave

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Not convincing when the very next post is "So totally irrelevant to your extraordinary claim. Come back when you have actual data."
 

pogo

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What is so clearly audible and has already been measured in the past needs no convincing from my point of view. I do not have a setup to perform such a measurement.
 

Beave

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Clearly audible? To whom?

Measured in the past? By whom? Can you share a link to those measurements?
 

pogo

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This is actually perceptible to anyone who changes their setup. One example was my previously linked NAIM/NAD test example. In my setup, there is also the fact that my low frequency range runs over a quasi 0ohm coil and therefore the differences become clearer.

Here is the measurement that was carried out, but from my point of view it was misinterpreted:
Link
 

KSTR

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We have to put things into perspective. A woofer with a 4Ohms Voice Coil DC resistance will see at least those 4Ohms as its termination resistance, governing electromechanical damping. On top of that is the series resistance of the crossover and the amplifier output resistance + cabling. Adding 0.2Ohms of wire resistance is a negligible change of only 5% damping resistance increase worst-case (and the voice coil itself will vary more just alone from self-heating). This does not change damping in any significant way, it is inaudible. Insert ten Ohms and then we're talking...

But there is a linked effect... and that's a change of frequency response, and that may be audible when it is larger than certain thresholds.

The key point here is that time-domain response and frequency-domain response are 100% intertwined as they are two possible forms of representation of the same thing, the transfer function. Which means here that when you re-establish the original flat frequency response at the speaker terminals by means of EQ, then the time-domain behavior is also the same as before, regardless of even about 1Ohm of added damping resistance.

You really have to go to extremes of electrical series resistance (10Ohms) for second order effect to appear which actually change behavior even though frequency and time response match the original case.
 

pogo

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And here spoken from the perspective of the real world (from playtime 7:30 in German):
Soundphile

My experience has been the same for the last 30 years.
Here exists a gap between theory and a complex musical signal ;)

And here is a measurement method in the real world:
Link
 
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JWAmerica

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I would anticipate the CCA wires to degrade faster than pure copper wires. The copper layer is doing most of the work and will oxidize in time (I hope they were manufactured recently). Once oxidation reaches the aluminum core the wire will measure even worse.
 

CapMan

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Bumping this thread - just took delivery of a Revel C205 and noticed the same rather catastrophic guidance about not exceeding 0.07 ohms in the speaker cable

For practical reasons I used some thin AWG18 wire with 0.82mm2 x section which is in the wall and exits under our TV. It’s about 3.8m long.

I calculate around 0.08 ohms of resistance and would honestly prefer not to try and pull this out of the cavity!!

Can it really be so bad as the manual would suggest - I imagine there must be some tolerance in their figure .
 

NTK

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Bumping this thread - just took delivery of a Revel C205 and noticed the same rather catastrophic guidance about not exceeding 0.07 ohms in the speaker cable

For practical reasons I used some thin AWG18 wire with 0.82mm2 x section which is in the wall and exits under our TV. It’s about 3.8m long.

I calculate around 0.08 ohms of resistance and would honestly prefer not to try and pull this out of the cavity!!

Can it really be so bad as the manual would suggest - I imagine there must be some tolerance in their figure .
I wouldn't worry too much about it. Since the speaker cables take round trips to and from the amplifier, the added resistance needs to be doubled to 0.16 ohms.

Assuming the minimum impedance of the speakers above ~200 Hz* is 4 ohms (using Amir's measurements of the C208), and you have an amplifier that has an output impedance much lower than 0.16 ohms, the attenuation due to the cable is: 0.16/(4.0 + 0.16) = 0.0385.

In dB, it is: 20 * log10( (1-0.0385)/1.0 ) = -0.34 dB. Therefore, those 18 ga. cables will cause a maximum deviation of 0.34 dB in the frequency response of your C205 in the worse case.


* Note: Below ~200 Hz the room will dominate the overall frequency response, and will dominate those effects from high source impedance (which includes the cables).
 

CapMan

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I wouldn't worry too much about it. Since the speaker cables take round trips to and from the amplifier, the added resistance needs to be doubled to 0.16 ohms.

Many thanks for picking this up. My wife would possibly kill me if I started fishing cables out of walls a few days before the relatives arrive for Xmas !!
 
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