Hi, The way I understand it when low impedance speaker cable is used (vs high impedance) the damping factor improves, as the load for the amplifier is lower. In that respect isn't low-impedance speaker wire always preferable (everything else being equal)?
I was not aware any speaker wire had an impedance rating. As long as the gauge is adequate, you are good to go. Speaker Wire
The wire has little impact on damping factor = load Z / output Z If amp output Z = 0.05 Speaker = 8 10' x 14 AWG ~ 0.04 w/o wire ~ 8/0.05 .= 160 w wire ~ 8.04/0.05 .~ 160.8 If considered an extension of the amp 8/0.09 ~ 89 damping factor is overrated, anything > 40 is ok imo Some cable R is good, it dampens reflected oscillating reactive power
Technically OP is correct. Lower load impedance means higher damping factor as damping factor is load impedance divided by amp output impedance. And the load impedance is speaker impedance + speaker wire impedance (resistance). Meaning that lower speaker wire impedance can will result in higher effective system damping factor. Hopefully the wire in you system is big enough to have little effect on this.
Since speaker cable is mostly resistive and not inductive, its resistance and impedance will be about the same. But yes this is a factor, especially with longer cable runs. With lower resistance/impedance the damping factor improves, but not because the load is less. (Actually with lower overall speaker/cable impedance the load will slightly higher, because there's less loss in the cable.) The damping factor improves because with lower impedance the drivers will respond more accurately to voltage changes on the amp side, especially at very low frequencies. The drivers will tend to "ring" (continue to vibrate) after a loud signal from the amp suddenly stops because with higher impedance, the zero voltage output from the amp is less able to arrest unintended speaker movements. Maybe speaker damping could be compared to the chain on a fixed speed bike. A steel chain with no stretch will immediately transfer power to the pedals, closely mimicking the rider's pedaling and braking. If the chain was made out of rubber power will still be transferred to the rear wheel but the response to "transients" (sudden changes in velocity) would not be as immediate or powerful.
My basic understanding: If damping factor = 100 Reflected power will be absorbed by the amp 100x more than the load. The actually ratio changes based on each junction, wire to speaker, and reverse Amp to wire and reverse But you get the point You want the reflected signal to not be reproduced by the speaker By adding cable R you increase the damping factor (load) by adding R you get more damping, ie, absorption of reflected reactive power as R increases so does damping factor, proportional
I’m not going to pretend to understand it, but planet10 (Dave) on the DIYaudio forum suggested I try it and I like it on one of my systems more than the other. You might go poke around there if you’re interested in understanding it better. It’s relatively cheap to try on your own. I stripped some strands of solid ofc copper cat6 or cat5e. In the grand scheme of things it was a subtle change. When he does it I believe that he sandwiches the two cables between two pieces of packing tape. Edit- two people smarter than me posted in the time it took to write this. They seem to have tge science down. Probably no need to look elsewhere.
From the above equation I draw 2 conclusions Keep L << C, increases damping factor By keeping L small you push out hi freq attenuation Xl = 2 Pi f L Ohms As f and L increase, Xl increases, therefore attenuation increases
It's interesting to note in all the threads about damping that it never seems to be brought up that different drivers have different mechanical damping. The more you rely on the electrical, the more the wire comes into play. Seems at times that the two types of driver damping would come up. Guess not... CJ
Speaker wire resistance is not impedance. Both are measured in ohms, but they are not interchangeable.
I like it. I use it. It is going to be higher cap, but if it's not rolling off audible frequencies, I don't hear a problem.
I thought so too but it's not that small, see this example: Calculate Damping Factor Take the nominal speaker impedance and divide it by your amp’s DF specification. Let’s say your amp has a DF of 300 and you have an 8 Ω speaker, your output impedance is 0.027 Ω. Then add the nominal impedance of your cable. A twelve-foot cable presents roughly .0016 Ω per foot. Double that to account for the “out” and “return” impedance from the amp to the speaker (flyback current). If we have a 20’ run on 12AWG cable we have 0.064 Ω of cable impedance (40 x .0016 = .0064). Add 0.064 to 0.027 and you’ll get a system output impedance of 0.091 Ω which is super-low. Then divide your speaker impedance by the output impedance (8/0.091) and you get a Damping Factor of 88 which is really good. The example is from KEF's web site: Damping Factor Explained
Thanks all for your answers. So if this is consideration where does this lead in-terms of speaker wire selections?
Wireworld Luna and Solstice. Pretty cheap, too. Here's a review of some of theirs with some measurements if interested. Wireworld Mini-Eclipse 7 Speaker Cables Review - HomeTheaterHifi.com
Probably not always and likely only when running tube amps. Tube amps always have a high output impedance (low damping factor).
It depends on how you look at it. I calculated it as a load and included with the amp. I lean towards a load since it is external to the amp and .<< speaker Z. It also absorbs power like the speaker, ie, a load supplied by the amp. But as I mentioned there are 3 segments Amp Cable Speaker And 2 junctions Amp to cable, and the reverse Cable to speaker, and the reverse since cable Z ~ amp output Z, it can be ignored as matched. To analyze it properly the surge Z (or characteristic Z) for each segment needs considered. It is Zo = sqrt(L/C) Inversion and x R/2 is the damping factor As long as the cable is sized properly for V drop the rest takes care of itself (as relates to audio speaker signals).
@Giacomo Belbo Your question is a good one so I thought this article from Galen Gareis that will explain how cables work with audio signals: TIME… – Iconoclast Cable
I have my reservations about that analysis. Z decreases with an increase in f? ( he actually posits it increases as f drops, same thing. A cable has 3 parameters R, L and C The v of propagation = 1 / ( c x sqrt(L C)) Z = sqrt((R+j*2*pi*f*L)/(G+j*2*pi*f*C)) Is reduced to sqrt(R^2 + X^2) j 2 Pi f L = Xl 1/(j 2 Pi f C) = Xc As f increases Xc gets smaller and Xl gets larger X = j(2 Pi f L - 1/(2 Pi f C)) As f increases the first term gets larger and the second smaller So X increases Since |Z| = sqrt(R^2 + X^2) Z magnitude increases Z = sqrt((R+j*2*pi*f*L)/(G+j*2*pi*f*C)) This can be simplified to conductance G = 1/R Z = sqrt((R+ Xl)/(1/R + Xc)) = sqrt(R^2 + X^2) baffled with ... imo a good paper https://www.pearl-hifi.com/06_Lit_A...ease_Lab_Notes/Kaye_Pease_Davis_on_Cables.pdf
I was solidly in "expensive cables are snake oil" camp but I definitely believed that different cables can and will sound different because of different R, L & C values. I didn't feel spending lots of money on cables will guarantee improvements in system's sound. My EE background & experience has been mainly in the digital world, so Galen's math is beyond my ability to completely grasp. I figured his 40 years' experience at Belden designing cables for all kinds of applications carried some weight, so I read about what he was trying to optimize for and why. If I understand correctly, the electromagnetic field generated by the audio signal in the cable affects the velocity of wave propagation which varies by a lot more in audible frequencies than at very high frequencies. The differences cause timing errors that we are very sensitive to. I gave up trying to make sense of the equations and decided to try a set of his cables myself. Even though there was no financial risk in trying, I was afraid of confirmation bias and also didn't expect to (actually hoped to not) hear a big difference. I asked my daughter to describe what she heard before I said anything. She articulated pretty much exactly what I heard. We were both blown away with the improvement. Based on my experience in my specific system, I can't argue with the results.
Lots I don’t understand really when it comes to cable impedance, Q factor etc… My cables say: SE cables are optimized for single ended amplifiers and high efficiency loud speakers. They are Golden Ratio, concentric, asymmetrical, coaxial cables. The smallest gauge size the speaker will permit should be used. SE cables do not have a high "Q" like conventional cables, because efficient speakers do not demand it. They have dramatically low energy storage for their size, which makes them ideally suited for horns and other highly efficient speakers. Outside Diameter: .195 Dielectric Type: Teflon® Q Factor: 4.4 Inductance: .058 uh/ft/loop Capacitance: 188 pf/ft Discrete Conductors: 113 Cable AWG: 15.5 Conductor Type: Golden Ratio, Constant Q, Crossfield, Pure Copper Litz What this all means (besides that they’re skinny little fellas,) I haven’t the slightly clue, but I appreciate the sound and the fact that they provide these numbers .
