Cables can make a huge difference...

[TonyW]

I’m guessing recording studios capture a good portion but not all of the phase information during a recording session. And even the most competent stereo playback systems likely reproduce only a portion of the phase information captured in the recording. I think our brains fill in what’s missing. The more phase information present, the more realistic sounding the playback. I bet our brains are able to work with surprisingly little phase information to paint a holographic sound stage but of course the less extrapolation the richer and more realistic the experience.

 

[MarkusBarkus]

Yes, sound waves move through the air at different speeds relative to frequency

...is this accurate?

 

[DaveC]

I’m guessing recording studios capture a good portion but not all of the phase information during a recording session. And even the most competent stereo playback systems likely reproduce only a portion of the phase information captured in the recording. I think our brains fill in what’s missing. The more phase information present, the more realistic sounding the playback. I bet our brains are able to work with surprisingly little phase information to paint a holographic sound stage but of course the less extrapolation the richer and more realistic the experience.

It's the reverb trails that are truncated by both recording and playback systems. This is why psychoacoustically correct electromechanical feedback is part of the key to an excellent system.

What happens is sound from the speaker is transduced back into an electrical signal by many different parts of the playback system. The most obvious examples are vacuum tubes and turntables. But lots of stuff is affected by the sound of the speakers... the entire structure of the house and floor for one. AC power devices, capacitors, etc... maybe not to the degree of tubes and vinyl, but it all makes a difference, and the resulting transduction of mechanical sound back into an electrical signal that will them be played back again through the speakers has a significant effect on what we hear.

This is why we use special racks, footers, speaker stands, etc. what we're really doing is trying to reduce bad vibrations and promote good vibrations. In this case good means what our brain expects to hear, and is thus psychoacoustically correct, and bad means what we don't expect to hear or what is fatiguing, like alert sounds that overstimulate our nervous system.

The other way we can do this is mechanically... I once sat through a demo of small mechanical resonators that were placed inside a horn. The designer and builder of these devices explained that they were excited by the sound made by the speaker, then the energy was released later, like a tuning fork, in order to extend the decay and restore the truncated information. Well... IT WORKED! I was surprised it could be accomplished in this manner. Vocals sounded more vibrant and real, and the soundstage improved. Exactly what you hope for when you increase the overall resolution and fidelity of your system.

So playback is really complex... we're actually not just reproducing what's on the recording. Best case, and what sets a apart a really magical stereo from something a bit more ordinary, is how the system handles the inevitable electromechanical feedback, a great system uses feedback to produce a more psychoacoustically correct presentation that's actually closer to what the brain expects to hear while mitigating noise and feedback that is not psychoacoustically correct.

 

[TonyW]

...is this accurate?

Good catch. I misspoke. Thinking about cables when I said that. The phasing of a live band is relative to the positions of the singers and instruments. But the point I was making is that phase shift occurs in cables relative to frequency due to the capacitance and inductance of the wire. This affects the realism and naturalism of playback. That’s my theory in a nutshell.

 

[DaveC]

Good catch. I misspoke. Thinking about cables when I said that. The phasing of a live band is relative to the positions of the singers and instruments. But the point I was making is that phase shift occurs in cables relative to frequency due to the capacitance and inductance of the wire. This affects the realism and naturalism of playback. That’s my theory in a nutshell.

I agree with your observations 100% but I'm not sure there's enough reactance in a typical cable to cause significant phase shift. In many cases the LCR of the cable is simply added to the components immediately before or after, such as a pramp that has a capacitor coupled output or the crossover in a speaker, which is typically going to have much more reactance than the cable its self.

I think the effect you're hearing is more a result of spatial cues experienced as room reverberations and cables effect is more a result of smoothing over these fine details and reducing overall resolution.

A couple posts back I went into feedback and how extending decay of these truncated reverberations improves the overall listening experience by making the reverb trails more psychoacoustically correct.

 

[DonH50]

Here is the response of an RCA cable (Belden RG-6 1530A, distributed transmission line model with RLC for conductor and shield) 10 feet long used as an interconnect in a fairly high-impedance system having 1 k-ohm (tube) preamp output and 100 k-ohm amplifier input.

Relative to 10 Hz (the start of the simulation), at ~20 kHz amplitude is down 0.002 dB and phase shift is 1.2 degrees. Group delay change is 68 ps. This is due to the cable alone; source and load impedances are ideal resistors. Adding reactive elements would hide the effect of the cable.

 

[Robh3606]

Here is the response of an RCA cable (Belden RG-6 1530A, distributed transmission line model with RLC for conductor and shield) 10 feet long used as an interconnect in a fairly high-impedance system having 1 k-ohm (tube) preamp output and 100 k-ohm amplifier input.

Hello Don

That mirrors when I did my measurement using CLIO in the "loop" nothing there to concerned about measuring a 2 meter low cost cable.

Rob

 

[DaveC]

Here is the response of an RCA cable (Belden RG-6 1530A, distributed transmission line model with RLC for conductor and shield) 10 feet long used as an interconnect in a fairly high-impedance system having 1 k-ohm (tube) preamp output and 100 k-ohm amplifier input.

Relative to 10 Hz (the start of the simulation), at ~20 kHz amplitude is down 0.002 dB and phase shift is 1.2 degrees. Group delay change is 68 ps. This is due to the cable alone; source and load impedances are ideal resistors. Adding reactive elements would hide the effect of the cable.

View attachment 135673

View attachment 135674

Thanks, I agree adding reactive elements would indeed swamp the effect of the cable.

I suspect speaker cables would also have a very small effect on phase, FR or group delay.

I believe that the differences we hear in spatial presentation between cables is simply a result of resolution. A good cable will truncate reverb cues the least amount possible, and those spatial cues are in part what our brain uses to recreate the soundstage. If you want a 3-D immersive "you are there" soundstage, it requires maximizing resolution. Interconnect cables have an especially large effect on resolution.

 

[TonyW]

Thanks, I agree adding reactive elements would indeed swamp the effect of the cable.

I suspect speaker cables would also have a very small effect on phase, FR or group delay.

I believe that the differences we hear in spatial presentation between cables is simply a result of resolution. A good cable will truncate reverb cues the least amount possible, and those spatial cues are in part what our brain uses to recreate the soundstage. If you want a 3-D immersive "you are there" soundstage, it requires maximizing resolution. Interconnect cables have an especially large effect on resolution.

I cannot find a reason to disagree with these conclusions and I appreciate the Bode plot posted by DonH50. But it makes me wonder why some cable makers have those “network” boxes inline with their cables.

 

[DonH50]

Thanks, I agree adding reactive elements would indeed swamp the effect of the cable.

My original sim included a typical amplifier input (RFI suppression) capacitor but that buried the impact of the cable. The cable model incudes distributed resistance (different for center conductor and shield), inductance, and capacitance.

I suspect speaker cables would also have a very small effect on phase, FR or group delay.

A speaker cable having too high impedance (e.g. too small, too long, or both) for the speaker's impedance will affect the frequency response (etc.), but the amplifier's output impedance usually dominates the numbers. I have an article about that but not really relevant here, and I did not plot phase or group delay that I recall (phase is usually uninteresting as long as it is linear so group delay is constant).

I believe that the differences we hear in spatial presentation between cables is simply a result of resolution. A good cable will truncate reverb cues the least amount possible, and those spatial cues are in part what our brain uses to recreate the soundstage. If you want a 3-D immersive "you are there" soundstage, it requires maximizing resolution. Interconnect cables have an especially large effect on resolution.

What do you define as resolution? Spatial presentation implies time resolution to me, though amplitude gets involved since "softer" may sound "farther", especially with no visual cues.

If not distributed RLC, what in the interconnects contributes to (decreases) resolution?

What does it need to be to be (in)audible?

Sorry if you've already answered, hoping this might tie things together for me. In addition to the source material (recording, mixing, mastering), I would have expected speakers and speaker-room interaction to dominate the spatial presentation.

 

[treitz3]

Okay, gentlemen. This thread will be closed for a while. There are so many reports to go through, I don't even know where to begin. The moderation team will take a look and decide which direction to go from here.

It would be nice if a topic such as this could just be a cordial, casual conversation where everyone shares their experience and observations without all of the riff-raff. We are better than this.

Tom

 

[treitz3]

Ladies and gentlemen, the thread has been scrubbed of all of the recent "jitter". All of the unwanted and unneeded posts, personal attacks and off topic posts are gone. We can now resume the conversation. That said, we would like to remind the membership of our Terms of Service that each and every member must abide by -

Terms and rules

You must agree to these terms and rules before using the site.

www.whatsbestforum.com

The main thing that was violated was that members did not post about the subject at hand, they directed their posting to talking about a member or what they considered to be a group of members, calling them by a derogatory name. This will NOT be tolerated. Any violation of this will be dealt with swift administrative action, and a possible involuntary vacation from the WBF.

We do not ban, nor do we censor certain members who hold a differing view from yours. Heated debates are certainly welcome but disparagement toward another member of this forum most certainly is not. Our goal is to have a friendly place where everyone shares ideas and information without the level of bickering and angst that other forums tend to create. We will do this with or without you.

Please keep this in mind prior to your responding to this thread. Thank you and have a great weekend.

Now back to our regularly scheduled programming.....

Tom

 

[Holmz]

I've given this some thought. I have a theory why cables are more important in a playback system than in the studio.
Imagine standing in front of a live, acoustic band. Close your eyes and you can place the location of each of the instruments. That is because of phasing. This live band with several sources of sound is a jumble of frequencies and phasing. But even though the phasing is different this is how we can tell with our ears location- left, right, up, down, front, and back of all of the different sounds. This jumble of phasing from all of the various sources on stage sounds natural to us because this is our physical world. Phasing does not change with distance. Only amplitude changes with distance. And yes, high frequencies get dampened faster. So we all find our favorite spots to sit in a concert venue. Some like the front rows for a louder, more engaging concert, others like the middle rows for a balanced sound and some prefer the back rows for a more relaxed presentation. It's a matter of taste. While everyone is experiencing either a brighter or more mellow sound depending on seating position they are all experiencing the same phasing of the sound.

Put this band in a studio with multiple mics and pickups and now the studio must faithfully preserve this sound in a recording. As long as the microphone cables and pickup cables are identical then the phasing should be preserved. Note that no high powered amplifiers are used in the recording chain. That is a significant difference between studio and playback. (I'm not counting the high powered amplifiers used in the cutting lathes for making vinyl records). As long as the studio preamps and equalizers preserve phasing then the fidelity of the recording is maintained. Of course patch cords between preamps to recording device play a significant role in preserving fidelity but only after the recording is down mixed from multiple channels to two channels. And I think power cords, quality of power coming into the studio is just as critical as it is in a playback system. Any phasing information, any detail that is lost during the recording process is lost forever. So one question is: How much care do studios take in the use of power cords?

Now the playback system has the task of reassembling not just frequency and amplitude information but the all too important phasing information. The quality of reassembling the phasing information directly correlates to the realism and naturalness of the reproduced music. Most, not all of that responsibility falls to the speakers with the second most important component being the cables. The cables, being wires can't help themselves. They move signals at different speeds relative to frequency. Yes, sound waves move through the air at different speeds relative to frequency but the proportions between electrical wires and air is much different. So cables can alter the phase information in the musical recording. To complicate that, any speaker that is not a one way design such as a Quad ESL, has a crossover network that splits the frequency range of music and directs it to different drivers design to reproduce a specific range of frequencies providing more challenges to the preservation of phasing of the original music. So our playback cables not only need to reject noise, interference from the outside, but also try to maintain phasing as these signals traverse the wire. We see cables with network boxes and others that use a blend of dielectrics and wire materials to preserve phasing. I think that we find some wires work better with certain speakers than others because the cables need to compliment the crossovers with respect to phasing and also frequency response.

This is somewhat simplistic but still too long. The magic of it all to me is how I hear a 3D soundstage (left, right, front, back, up and down) as if the band is right there in front of me. But at the same time some of our hifi systems sound more real than real. It's not really hifi then, is it? What I mean is I can feel, not just hear the plucks on guitar strings- maybe in real life I'm sitting 3 feet from the guitar player. Or I hear clarity beyond what can be heard at a live session. It is the same as watching our HDTV's. We all, at least I do, have the color saturation, the contrast and the sharpness cranked up so that the picture looks more real than real. HDR was supposed to give us a more true rendition of the scene. HDR stinks.

Many speakers do not maintain the phase, although the Quad was one that did.
And I would doubt that most here look at step function response.

Arguing for time and phase correct cannot really be easily moved to a cable argument, as the cable move the signal through them with almost no effect upon phase.

 

[TonyW]

Yes, DonH50 showed us a Bode plot of an RCA IC with virtually no phase angle change up to 20 kHz. This plot was under high impedance conditions. And I asked the question: Then why do some cable makers put network boxes inline with their cables?

Another thought: Amplifier to speaker is a complex relationship because speakers are motors. They generate back EMF, ie the speakers generate a reflected wave back to the amplifier. That reflected wave has to be affecting phase angle vs frequency between the amp output and speaker input. The question here is: How much influence does a specific cable design have on phase angle from amp to speaker from 20-20kHz? Two things I know: 1) A speaker and cable combination can in some circumstances cause amplifier instability and 2) Speaker impedance varies with frequency. Impedance and phase have a relationship. This is a difference between playback and the recording studio- no high powered amps or motors in the recording chain.

Some Bode plots of amp output to speaker input with different speaker cables would be interesting, I bet.

 

[Robh3606]

Two things I know: 1) A speaker and cable combination can in some circumstances cause amplifier instability and 2) Speaker impedance varies with frequency. Impedance and phase have a relationship. This is a difference between playback and the recording studio- no high powered amps or motors in the recording chain.

Are you saying they don't use high power amps in the studio? Any large format monitor has a woofer that is a beast WRT motor size. Not sure I am understanding you.

Many speakers do not maintain the phase, although the Quad was one that did.
And I would doubt that most here look at step function response.

That's true but there is a threshold for audibility WRT group delay and yes compared to a speaker cables have no comparable effect.

Rob

 

[Holmz]

These two statements seem to be 180 degrees apart from each other.

This one talks about truncating reverb:

…
I believe that the differences we hear in spatial presentation between cables is simply a result of resolution. A good cable will truncate reverb cues the least amount possible, and those spatial cues are in part what our brain uses to recreate the soundstage. If you want a 3-D immersive "you are there" soundstage, it requires maximizing resolution. Interconnect cables have an especially large effect on resolution.

This one talks about making reverb.

It's the reverb trails that are truncated by both recording and playback systems. This is why psychoacoustically correct electromechanical feedback is part of the key to an excellent system.

What happens is sound from the speaker is transduced back into an electrical signal by many different parts of the playback system. The most obvious examples are vacuum tubes and turntables. But lots of stuff is affected by the sound of the speakers... the entire structure of the house and floor for one. AC power devices, capacitors, etc... maybe not to the degree of tubes and vinyl, but it all makes a difference, and the resulting transduction of mechanical sound back into an electrical signal that will them be played back again through the speakers has a significant effect on what we hear.

This is why we use special racks, footers, speaker stands, etc. what we're really doing is trying to reduce bad vibrations and promote good vibrations. In this case good means what our brain expects to hear, and is thus psychoacoustically correct, and bad means what we don't expect to hear or what is fatiguing, like alert sounds that overstimulate our nervous system.

The other way we can do this is mechanically... I once sat through a demo of small mechanical resonators that were placed inside a horn. The designer and builder of these devices explained that they were excited by the sound made by the speaker, then the energy was released later, like a tuning fork, in order to extend the decay and restore the truncated information. Well... IT WORKED! I was surprised it could be accomplished in this manner. Vocals sounded more vibrant and real, and the soundstage improved. Exactly what you hope for when you increase the overall resolution and fidelity of your system.

So playback is really complex... we're actually not just reproducing what's on the recording. Best case, and what sets a apart a really magical stereo from something a bit more ordinary, is how the system handles the inevitable electromechanical feedback, a great system uses feedback to produce a more psychoacoustically correct presentation that's actually closer to what the brain expects to hear while mitigating noise and feedback that is not psychoacoustically correct.

^This^ is getting a bit magical for me…
Most ICs tend to sound similar, and are nothing like an effects box.

I cannot see how we can get reverb in a cable, but the time domain reflectometry is used to find the length, or where there is a break.
At some point, if the cable is rattling the signal back-n-forth, then don’t we get back to Ralphs 600 ohm matching impedance?

The cable is not a laser chamber, and I am unaware that there are reverbs happening… especially for ICs.


I am not even sure what is a “good vibration” versus a “bad vibration”. I suppose one could put a TT on top of a speaker, and the vibrations are going to come in. Or a microphone next to a speaker.

Or if there are “bad vibrations”, then it seems like we are getting back to @Atmasphere claims of 2nd and 3rd harmonics, as good, and higher order ones as bad.
But cables are not very choosy, and basically they just carry the signal from point A to point B. They are not adding in extra stuff (vibrations) , except in the rarest of cases. If they were, it seems like one could fondle the IC cable and get sounds out of the speaker… but I have not heard that happening. Or tap the IC with a stick… and I have not heard the tapping sounds coming of the speaker.

 

[Holmz]

Yes, DonH50 showed us a Bode plot of an RCA IC with virtually no phase angle change up to 20 kHz. This plot was under high impedance conditions. And I asked the question: Then why do some cable makers put network boxes inline with their cables?

Another thought: Amplifier to speaker is a complex relationship because speakers are motors. They generate back EMF, ie the speakers generate a reflected wave back to the amplifier. That reflected wave has to be affecting phase angle vs frequency between the amp output and speaker input. The question here is: How much influence does a specific cable design have on phase angle from amp to speaker from 20-20kHz? Two things I know: 1) A speaker and cable combination can in some circumstances cause amplifier instability and 2) Speaker impedance varies with frequency. Impedance and phase have a relationship. This is a difference between playback and the recording studio- no high powered amps or motors in the recording chain.

Some Bode plots of amp output to speaker input with different speaker cables would be interesting, I bet.

Certainly a speaker cable should be more interesting than a power cord or IC.
The inductance and the capacitance are higher, and the speaker impedance and amp impedance are a lot lower.

But even zip cord, or lamp wire, gets sound coming out of the speaker reliably.
So I’ll leave it to Don as to the plots.

But those network circuits seem like they should help with impedance and oscillations at RF.

 

[DonH50]

Yes, DonH50 showed us a Bode plot of an RCA IC with virtually no phase angle change up to 20 kHz. This plot was under high impedance conditions.

The phase change would be less under low-impedance conditions, though if the same high source impedance was used there would be a little more amplitude loss.

And I asked the question: Then why do some cable makers put network boxes inline with their cables?

My answer would be Marketing, a misunderstanding of engineering physics, or to compensate what is an inaudible error that looks better on a graph (back to my first point). I have read some of the descriptions and justifications in the past but they did not make much sense to me. But they add some equalization and filtering you may or may not find pleasing.

Another thought: Amplifier to speaker is a complex relationship because speakers are motors. They generate back EMF, ie the speakers generate a reflected wave back to the amplifier. That reflected wave has to be affecting phase angle vs frequency between the amp output and speaker input. The question here is: How much influence does a specific cable design have on phase angle from amp to speaker from 20-20kHz?

Reflections occur at a significant fraction of the speed of light, probably ~60-80 % for speaker cables and 80% to 90+% for interconnects. Any reflections are over long before they could cause audible issues, far too fast for any speaker to react, and absorbed by the amplifier's low output impedance. I wrote an article actually showing the reflections that may still be here on WBF (I have not looked). And again the dominant impedances are the speaker, orders of magnitude greater than cables, and amplifier output impedance which is generally on the same order of magnitude as short, heavy cables for a SS amp. A tube amp has higher output impedance so in that case the cables contribute less since the amplifier's output is so much greater than the cables (but the speaker is still the highest impedance in the system).

All assuming reasonable gauge cables that are not many tens of feet long.

Edit: Here is the article about reflections:

Radio Frequency (RF) Analysis of Speaker Cables/Reflections

This is an article our technical member @DonH56 kindly wrote on another forum and place. I am copying it here given the recent interest in its content: Apples vs. oranges, anybody? In this thread we’ll take a look at speaker cables from an RF perspective, not something usually discussed...

www.audiosciencereview.com

Reflections can matter for high-speed digital interconnections, though would have to be really bad to cause audible problems such as drop-outs and such.

Two things I know: 1) A speaker and cable combination can in some circumstances cause amplifier instability and 2) Speaker impedance varies with frequency. Impedance and phase have a relationship. This is a difference between playback and the recording studio- no high powered amps or motors in the recording chain.

The only time I have seen a cable cause a problem was long ago when a woven cable having very high capacitance was connected to an early class D amplifier and ESLs (Quad's I think, been a long time). But for the cable to push it over the edge the amplifier had to already be very near the cliff with just the speaker.
Impedance includes resistance (R) and reactance (LC). If reactance is not zero there will be phase shift through the cable, but interconnect or speaker it is very small, basically insignificant relative to the other impedances in the system (speaker input and amplifier output impedances).

Some Bode plots of amp output to speaker input with different speaker cables would be interesting, I bet.

The speaker cables are in the mud but here are some plots of different speakers driven by different amplifiers for reference (I do not think I plotted phase, however, and again the phase change just from the cable is orders of magnitude less than due to the amp or speaker load):

Amplifier Output Impedance (Damping Factor) and Speakers

This is a reprint of an article written ca. 2011-2012. I've been meaning to rewrite and update it, but Life and Work keeps getting in the way, so I am reposting the original as-is. Take it for what it's worth, an introductory take on one of the potential causes for differences in sound among...

www.audiosciencereview.com

Speaker cable mismatch: https://www.audiosciencereview.com/...ffect-of-speaker-cable-length-mismatch.20150/ (I tend to match lengths even though it is not really needed; my reason is to match the driving impedance each crossover sees, nothing to do with delay)

An old thread on interconnect bandwidth: https://www.audiosciencereview.com/forum/index.php?threads/interconnect-bandwidth.25441/

HTH - Don

Realized most of these threads are now ~15 years old, and derived from source material much older than that, makes me feel old!

 

[TonyW]

Cool stuff. Guess my theory doesn't pan out. Cables are not causing any phase change vs frequency. That seems to be the conclusion here.
I'm still mystified then as to why cables can go from neutral to warm to hot and even impact PRAT. In my mind I can understand how they reduce noise, but how do they then improve clarity, add detail, etc? All this tied to wire material, wire gauge, wire drawing process, wire plating, wire annealing and dielectrics. This is about analog cables.

And one difference still holds true: No high powered amps or motors/speakers are in the recording chain. (Studio Monitors are not part of the recording chain. They are part of the recording process.)

 

[Holmz]

Cool stuff. Guess my theory doesn't pan out. Cables are not causing any phase change vs frequency. That seems to be the conclusion here.
I'm still mystified then as to why cables can go from neutral to warm to hot and even impact PRAT. In my mind I can understand how they reduce noise, but how do they then improve clarity, add detail, etc?

Which cables?
ICs or speaker?

All this tied to wire material, wire gauge, wire drawing process, wire plating, wire annealing and dielectrics. This is about analog cables.
…

And geometry, which affects inductance and capacitance.

I my mind the order for an IC is:
1) Geometry
2) Dielectric
3) Metal

But that is mostly ordered by affecting the traditional electrical outcome.