Damping Factor - Actual listening tests?

[Jason Lavoie]

Re: Damping Factor - Actual listening tests?

Thanks for the articles.

So in a day I've gone from lost, to thinking I have it all figured out, and then back to 'I guess I need to test it and listen for myself'

It looks like there are three considerations (and #2 is really just a more specific way of looking at #1):
1) power loss in the wire
2) Frequency dependent attenuation (different power loss at different frequencies due to the impedance curve of the speaker) * explained well in Dick Pierce's article
3) Distortion due to the amplifier having less ability to absorb the back EMF from the woofer * explained in the powersoft article, but still hard to predict to what extent it will manifest given a specific set of parameters

#1 is easy to calculate
#2 is relatively easy to gauge the severity of (and I think easy to mitigate with EQ)
#3 must be the elusive subjective bit that everyone is always worried about

Jason

 

[John Roberts]

Re: Damping Factor - Actual listening tests?

Thanks for the articles.

So in a day I've gone from lost, to thinking I have it all figured out, and then back to 'I guess I need to test it and listen for myself'

It looks like there are three considerations (and #2 is really just a more specific way of looking at #1):
1) power loss in the wire
2) Frequency dependent attenuation (different power loss at different frequencies due to the impedance curve of the speaker) * explained well in Dick Pierce's article
3) Distortion due to the amplifier having less ability to absorb the back EMF from the woofer * explained in the powersoft article, but still hard to predict to what extent it will manifest given a specific set of parameters

#1 is easy to calculate
#2 is relatively easy to gauge the severity of (and I think easy to mitigate with EQ)
#3 must be the elusive subjective bit that everyone is always worried about

Jason

I am not worried about #3 unless you are using 8 ohms worth of wire, and then it will be subtle (like an old tube guitar amp). If you want to worry about it you have plenty of company, but maybe that is why several hundred foot speaker runs typically use constant voltage systems.

JR

 

[Frank Koenig]

Re: Damping Factor - Actual listening tests?

I am not worried about #3

I'm with JR -- I'd be a fool not to be -- and not worried about number 3 either. Numbers 1 and 2 are familiar small-signal (linear) problems, which we have been discussing up until now. Number 3 is a large-signal (nonlinear) problem that sounds to me equivalent to saying that amplifiers may have reduced output current into reactive loads. If you run into number 3 get a bigger/better amplifier. Confession: I didn't actually read the Powersoft article. -F

 

[Peter Morris]

Re: Damping Factor - Actual listening tests?

Not to quibble but if you look at that article's electrical model the voice coil resistance and inductance is in series, so the ability of amplifier output impedance to damp that motor mass could indeed make a difference between high output impedance tube amps, but low Z solid state amps will all be similar and dominated by voice coil impedance. Of course if you use 4-8 ohms worth of wire resistance it should matter.

Peavey (Sondermeyer) got a patent for an amp that used a feedback trick to deliver silly high damping factor. In fact we could actually deliver a negative output impedance, which could compensate for wiring losses outside the amp too. I didn't even try to market this (I was power amp PM at the time) since I feared Peavey customer's heads would explode. I am not smart enough to do this myself but think there might be some tricks possible inside a powered speaker to drive individual drivers from a negative source impedance, but that was even further from Peavey's sweet spot in the market

Peavey (Sondermeyer/Brown) also patented amps with variable damping factor for use inside guitar amps to help solid state guitar amps mimic tube amp's interaction with driver/cabinet resonances. IIRC the peavey guitar amp feature had separate HF damping and LF damping adjustments (while they didn't call it DF). So if you want to hear really low DF maybe check out one of those Peavey guitar amps. (Audibly these circuits would enhance speaker voicing resonances, a part of guitar amp design, but now with a "more" knob.)

I didn't read that paper word for word, but since it comes from a power amp company I suspect they are promoting their amps as somehow better in this regard. Crown was notorious for hyping DF well beyond useful amounts.

With the exception of Tom Danley's old servo woofers loudspeaker driver position is not strictly controlled, just accelerated in one direction or the other. Remarkable they work as well as they do.

JR

John, I'm not that old that I have ever used a tube amp for PA applications.:razz:

If the speaker cone is accelerating faster than it should then it will become a generator and the amplifier will put the brakes on so to speak, accordingly a low impedance output / connection is better brake. There is some control, but not to the extent you get with an active feedback loop e.g. servo-drive systems – I assume this is what you meant when you said "not strictly controlled"

Powersoft are actually using the DSP in their amplifiers to implement Active Damping Control, providing dramatically improved cone control with a virtually negative output impedance.

For Jason, a simple example is to tap the cone of your bass speaker before it’s connected to the amplifier. It will resonate. Connected it to the amplifier and tap it again. You will just get a dull thud. If you put a resistor in the circuit (at a guess 50 ohms) you will get a little bit of resonance.

For me in 2015 dampening factor is moot. All modern amplifiers have good dampen factors. I just use the biggest cables and shortest runs that are reasonably practical. There is nothing else I can do other than to be mindful that loading my amplifiers down to 2 ohms on long skinny speaker cables is not a particularly good idea …. and engaging the ADC on my Powersofts.

 

[John Roberts]

Re: Damping Factor - Actual listening tests?

John, I'm not that old that I have ever used a tube amp for PA applications.:razz:

I'm not that young and I have never used a tube Pa amp.

If the speaker cone is accelerating faster than it should then it will become a generator and the amplifier will put the brakes on so to speak, accordingly a low impedance output / connection is better brake.

How could a speaker accelerate faster than it should? Do you perhaps mean something like when the driving signal changes direction, and want's the speaker cone motion to stop or change direction ?

There was a good thread years ago on another forum related to the classic myth about speakers over-herating while standing still during square waves (they don't stand still from square waves and I'm sorry I repeated that). A speaker geek (much smarter than me) posted the equations controlling speaker cone motion, the short version is the voice coil voltage imparts a force in and out. Cone position is the the result of that force working on that mass, and associated spring compliances like speaker surround, air in the box, moon's tidal forces (kidding about that last one.)

There is some control, but not to the extent you get with an active feedback loop e.g. servo-drive systems – I assume this is what you meant when you said "not strictly controlled"

Maybe they didn't make it to your continent or it was before your time if you are a young pup, But Tom made a belt driven servo controlled LF cabinet where the speaker cone was literally driven from a low mechanical impedance. (ServoDrive Bass tech 7 or something like that).

Powersoft are actually using the DSP in their amplifiers to implement Active Damping Control, providing dramatically improved cone control with a virtually negative output impedance.

As I mentioned Sondermeyer made an amplifier that "could" deliver negative source impedance, way back last century. Patent may be expired by now. As I mentioned there might be some merit for use inside a powered speaker if you know all the driver and box particulars.

For Jason, a simple example is to tap the cone of your bass speaker before it’s connected to the amplifier. It will resonate. Connected it to the amplifier and tap it again. You will just get a dull thud. If you put a resistor in the circuit (at a guess 50 ohms) you will get a little bit of resonance.

The better tap test is to tap the speaker with amp connected, then tap the speaker with his 200' of wire. Not open circuit or 50 ohms. And that test still doesn't reveal much about how it will sound.

For me in 2015 dampening factor is moot. All modern amplifiers have good dampen factors. I just use the biggest cables and shortest runs that are reasonably practical. There is nothing else I can do other than to be mindful that loading my amplifiers down to 2 ohms on long skinny speaker cables is not a particularly good idea …. and engaging the ADC on my Powersofts.

Maybe you didn't see Jason's question?

OK here's another hypothetical null test. Take two identical subs, place them side by side and drive them with opposite polarity. Perhaps first listen with short wires feeding both, to see how good of a bass frequency null you can get. Then add your couple hundred feet of wire in series with one sub. Tweak the gains to compensate for level loss and see how close to the short wires null you can get. Any dynamic artifacts you hear that you can't EQ out, will be your damping factor phenomenon. While I don't expect you to find much, or anything that nasty.

JR

 

[Timo Ulkuniemi]

Re: Damping Factor - Actual listening tests?

With the exception of Tom Danley's old servo woofers loudspeaker driver position is not strictly controlled, just accelerated in one direction or the other. Remarkable they work as well as they do.

JR

Hello

I have pair of the older Servo-Drives plus pair of JBL-EVO - everybody is wondering about both of them - "What the hell are those?" - and everybody loves the sound - and everybody disappears when it is time to move them in ...

 

[Peter Morris]

Re: Damping Factor - Actual listening tests?

I'm not that young and I have never used a tube Pa amp.

How could a speaker accelerate faster than it should? Do you perhaps mean something like when the driving signal changes direction, and want's the speaker cone motion to stop or change direction ?

There was a good thread years ago on another forum related to the classic myth about speakers over-herating while standing still during square waves (they don't stand still from square waves and I'm sorry I repeated that). A speaker geek (much smarter than me) posted the equations controlling speaker cone motion, the short version is the voice coil voltage imparts a force in and out. Cone position is the the result of that force working on that mass, and associated spring compliances like speaker surround, air in the box, moon's tidal forces (kidding about that last one.)

Maybe they didn't make it to your continent or it was before your time if you are a young pup, But Tom made a belt driven servo controlled LF cabinet where the speaker cone was literally driven from a low mechanical impedance. (ServoDrive Bass tech 7 or something like that).


As I mentioned Sondermeyer made an amplifier that "could" deliver negative source impedance, way back last century. Patent may be expired by now. As I mentioned there might be some merit for use inside a powered speaker if you know all the driver and box particulars.

Maybe you didn't see Jason's question?

OK here's another hypothetical null test. Take two identical subs, place them side by side and drive them with opposite polarity. Perhaps first listen with short wires feeding both, to see how good of a bass frequency null you can get. Then add your couple hundred feet of wire in series with one sub. Tweak the gains to compensate for level loss and see how close to the short wires null you can get. Any dynamic artifacts you hear that you can't EQ out, will be your damping factor phenomenon. While I don't expect you to find much, or anything that nasty.

JR

Hi John,

I was trying to put things in simple terms for the broader audience.

“How could a speaker accelerate faster than it should?” A simple example is the result of the pressure from the bass speaker impacting on the midrange cone or the HF diaphragm. Perhaps I would have been better to use your words “when the driving signal changes direction, and want's the speaker cone motion to stop or change direction” for the sake of the explanation.

I was trying to avoid talking about underdamped and over damped response of a mechanical/electrical system, complex impedances and all that stuff.

With regard to controlling the motion of the cone it depends on whether the cone is mass loaded or pressure loaded – reflex speakers have mass as the dominate part of the equation while horn speakers are dominated by the air pressure on the cone. This translates typically to about 90 degree less phase shift with respect to the driving signal for the horn … as you implied, it get complicated.

Yes I know about Toms servo drive speakers, but I have never actually seen one – FWIW in a past life I made / designed many industrial servo drive systems with feedback loops, some electrical and some hydraulic; most were used in production line cut to length applications, we even made a low frequency hydraulic / servo device with a seismic mass for oil exploration. … somewhat more powerful than Tom's sub but with a very limited band width.

…. And yes I did read Jason question, but he went on to say “Now that i understand this it sounds like something that could be 100% counteracted with EQ. I had visions of the effect being something more dynamic and time dependent the way people talk about DF.”

What I was trying to explain is that it is more complicated (like his second sentence). The dampening provided by the amplifiers controls the speaker cone’s motion to some extent and EQ will not correct for that.

I completely agree with your "hypothetical null test" statement and like you, I wouldn't expect to find much ... I did say that "For me in 2015 dampening factor is moot ..."

Apologies for the poor explanation, I hope this adds a bit more clarity. ~~:smile:

Regards

Peter

 

[Jason Lavoie]

Re: Damping Factor - Actual listening tests?

Hi John,

I was trying to put things in simple terms so others can understand.

“How could a speaker accelerate faster than it should?” A simple example is the result of the pressure from the bass speaker impacting on the midrange cone or the HF diaphragm. Perhaps I would have been better to use your words “when the driving signal changes direction, and want's the speaker cone motion to stop or change direction” for the sake of the explanation.

I was trying to avoid talking about underdamped and over damped responses of mechanical system, complex impedances and all that stuff.

No need to dumb it down, I'm trying to quantify something that always gets dumbed down and dealt with in generic terms yet everyone agrees that it is an important factor

…. And yes I did read Jason question, but he went on to say “Now that i understand this it sounds like something that could be 100% counteracted with EQ. I had visions of the effect being something more dynamic and time dependent the way people talk about DF.”

What I was trying to explain is that it is more complicated (like his second sentence). The dampening provided by the amplifiers controls the speaker cone’s motion to some extent and EQ will not correct for that.

Apologies for the poor explanation, I hope this adds a bit more clarity. ~~:smile:

Regards

Peter

I think what John was referring to was you returning to the all-too often used mantra of 'just put short, fat cable on it and don't worry about it' when the whole reason I'm digging at this is that VERY often in my line of work I have no control over the length and more often than not I don't get to use cable that is thick enough to be able to ignore DF.

Jason

 

[John Roberts]

Re: Damping Factor - Actual listening tests?

Thank you Peter, I know you know...
======
Jason, not everybody thinks DF is an important factor... IMO it hasn't been for decades. The manufacturers who hype it still, have commerce in mind.

Regarding your 200-300' speaker run, common practice is to use a constant voltage (high voltage) distribution system. This step-up/down transformer approach reduces the sensitivity to wire impedance. I would estimate a weighting of factors regarding that preference as probably 80% reducing power losses, 15% reducing sensitivity to speaker impedance frequency response effects, and 5% other. DF is in that 5% other but not the only thing in there.

If still concerned do the null test I proposed, I doubt you will find much at all, and what is there will not be nasty. If you want the highest fidelity locate the amps at the speaker, otherwise do what makes the most sense for you.

JR

PS: I recall a fixed sound manufacturer promoting a system decades ago where the typical CV wiring was used to distribute power (DC if I recall correctly), with the audio multiplexed on top of the power. A small audio driver IC was located at each speaker driver. I don't think this system gained much traction, or that it works for you.

 

[Peter Morris]

Re: Damping Factor - Actual listening tests?

No need to dumb it down, I'm trying to quantify something that always gets dumbed down and dealt with in generic terms yet everyone agrees that it is an important factor



I think what John was referring to was you returning to the all-too often used mantra of 'just put short, fat cable on it and don't worry about it' when the whole reason I'm digging at this is that VERY often in my line of work I have no control over the length and more often than not I don't get to use cable that is thick enough to be able to ignore DF.

Jason

Hi Jason,

If you have not already, I would suggest you read some of the papers that have been referenced in this thread.

As requested here is a slightly more complex answer ….

You can represent a speaker as having 3 parts – the Electrical circuit, the Mechanical circuit and the Acoustic circuit - refer picture 1

If you apply a voltage to a speaker the voice coil will start to move in the magnetic field. The movement of the voice coil in a magnetic field will generate a Back-EMF.

This EMF will be seen by the amp’s output circuitry. The amplifier will be the main electrical load on the “voice coil current generator” and result in "damping".

For a given speaker, the amount of damping can be varied by changing the value of the external resistance Re (amplifier plus cables/connector) and consequently the value of the braking current.

There a point where things are critically damped. At this point transient distortion is reduced and the low-frequency response is more consistent. For a loud speaker this point is generally with Re as low as possible - remember that there is also Revc in the equation.

Think of your cars suspension. It’s a spring and a shock absorber (dampener) – a simple second order system. There is a point where there is the optimum value of the spring force and damping force. If the spring force is too high with respect to the damping force the car will bounce up and down too much when you go over a bump, if it’s too low the wheels will not return to the correct position as soon as possible.

The second picture is the response of a second order system. Critically damped is with T = 1

Loudspeaker systems are more complex than a typical second order system, but the principle is the same.

In simple terms if Re is increased too much the system will look a bit like T less than 1. In practice the simple answer in 2015 is keep your speaker lead resistance as low as REASONABLY practical. It shouldn’t be an issue unless you are doing something REALLY EXTREME.

 

[Jason Lavoie]

Re: Damping Factor - Actual listening tests?

Hi Jason,

If you have not already, I would suggest you read some of the papers that have been referenced in this thread.

Read em all, top to bottom

And I've taken a 4th year university level course on the subject and fully understand, but it's been over a decade and I haven't used that math in a while so I'm not able to churn out the numbers I'm looking for with confidence.

For a given speaker, the amount of damping can be varied by changing the value of the external resistance Re (amplifier plus cables/connector) and consequently the value of the braking current.
...
There a point where things are critically damped. At this point transient distortion is reduced and the low-frequency response is more consistent. For a loud speaker this point is generally with Re as low as possible - remember that there is also Revc in the equation.

I think we're all on the same page about the cause of the under-damped system and we all agree that it should have an effect.
I'm still trying to find a way to describe the effect in something other than DF so that we can relate.

In simple terms if Re is increased too much the system will look a bit like T less than 1. In practice the simple answer in 2015 is keep your speaker lead resistance as low as REASONABLY practical. It shouldn’t be an issue unless you are doing something REALLY EXTREME.

Call me "Mr Extreme"
I'm trying to say that I often have no choice but to operate at the extremes and I'm looking to quantify those effects.
Also sometimes when you tell a customer or an architect that we need to run $10,000 of new conduit or the damping factor will suck they tend to want more justification than 'look, the DF will be 2"
Or trying to convince them to give up some prime square footage in order to move the amp rack closer.

If it's as simple as you say, why hasn't anyone made a DF to %THD translation chart or something like that?
That's why I'm still digging.

Jason

 

[John Roberts]

Re: Damping Factor - Actual listening tests?

Read em all, top to bottom


I think we're all on the same page about the cause of the under-damped system and we all agree that it should have an effect.
I'm still trying to find a way to describe the effect in something other than DF so that we can relate.

Except that it is DF so that bast describes it. It is already quantified, but wrt to a resistive load. To put it in terms of a loudspeaker's deviation from ideal behavior we need to know more about that loudspeaker (VC mass, box alignment, etc??). Clearly a large sub will have more moving mass than a tweeter.

Call me "Mr Extreme"
I'm trying to say that I often have no choice but to operate at the extremes and I'm looking to quantify those effects.
Also sometimes when you tell a customer or an architect that we need to run $10,000 of new conduit or the damping factor will suck they tend to want more justification than 'look, the DF will be 2"
Or trying to convince them to give up some prime square footage in order to move the amp rack closer.

If it's as simple as you say, why hasn't anyone made a DF to %THD translation chart or something like that?
That's why I'm still digging.

Jason

OK Mr. Extreme. If you are stuck with hundreds of feet of modest gauge wire inside a conduit, and no power available at the speaker end to support locating the amps there, the obvious way to finesse the wire impedance is step-up/down transformers. You should recall from your engineering education that transformers "transform" the impedance by the square of the turn ratio. So a simple 1:4 step up transformer, with 4:1 step down at the far end, you will drop the effective wire impedance by a factor of 1/16th. Of course for running the signals in conduit you need to account for voltage if 4x the amp voltage exceeds wire insulation class.

I have seen large instals that stacked 3 70V transformers in series to send audio over miles of wire at 210V nominal. Getting audio transformers that pass very low frequency will not be cheap, but that seems like one way to skin your cat.

I repeat again, are you sure you have a problem? Or a problem worth this much expense and worry?

Good luck.

JR

PS I don't expect a meaningful back of the envelope calculation. Since you should have a speaker in mind, perhaps do some experiments with driving one through an elevated resistance.

 

[Frank Koenig]

Re: Damping Factor - Actual listening tests?

One way to explore this, at least for the case of bass reflex speakers, would be to model the system using any of the widely available box modeling programs, such as WinISD, and perturb the value of Re. -F

PS: In most engineering writing the loss in a resonant system is referred to as damping, not dampening, which is what happens when someone spills beer in your monitor.

 

[Peter Morris]

Re: Damping Factor - Actual listening tests?

One way to explore this, at least for the case of bass reflex speakers, would be to model the system using any of the widely available box modeling programs, such as WinISD, and perturb the value of Re. -F

PS: In most engineering writing the loss in a resonant system is referred to as damping, not dampening, which is what happens when someone spills beer in your monitor.

I know ... I know ... but I keep typing Dampening ..Doh :?~:-?~:???:

 

[Jason Lavoie]

Re: Damping Factor - Actual listening tests?

I repeat again, are you sure you have a problem? Or a problem worth this much expense and worry?

That's just it, I'm NOT sure. but many people's opinions of the effects of DF are telling me that I do.
So I'm trying to investigate and decide for myself.

the obvious way to finesse the wire impedance is step-up/down transformers.

Agreed. but if I have to use expensive transformers plus take the performance hit that those come with then I'd like to be sure that I'm not trying to avoid something that isn't really a problem.

Thank you everyone for the help!
If I do manage to run some tests I'll report back

Jason

 

[Ivan Beaver]

Re: Damping Factor - Actual listening tests?

That's just it, I'm NOT sure. but many people's opinions of the effects of DF are telling me that I do.
So I'm trying to investigate and decide for myself.



Agreed. but if I have to use expensive transformers plus take the performance hit that those come with then I'd like to be sure that I'm not trying to avoid something that isn't really a problem.

Thank you everyone for the help!
If I do manage to run some tests I'll report back

Jason

This is not to sound rude.

If if you had spent 1/10th of the time that it takes to read and respond to posts on this subject, and taken the time to do a couple of simple tests YOURSELF, then you would have the answer you seek.

Simply take a long spool of wire, hook up a short piece of wire and a long piece of wire and and listen yourself.

Have somebody switch the cables so you do not know which is being used, and see if the difference you hear is worth the extra expense.

That is the ONLY way you can prove it to yourself. Relying on the sonic opinions of others can lead to very "odd" results.

Different peoples opinions will vary greatly depending on their experience and opinion.

When somebody says the sound is punchy and tight, what does that means? As compared to what?

When in doubt-do your own tests.

 

[Jason Lavoie]

Re: Damping Factor - Actual listening tests?

This is not to sound rude.

If if you had spent 1/10th of the time that it takes to read and respond to posts on this subject, and taken the time to do a couple of simple tests YOURSELF, then you would have the answer you seek.

Simply take a long spool of wire, hook up a short piece of wire and a long piece of wire and and listen yourself.

Have somebody switch the cables so you do not know which is being used, and see if the difference you hear is worth the extra expense.

That is the ONLY way you can prove it to yourself. Relying on the sonic opinions of others can lead to very "odd" results.

Different peoples opinions will vary greatly depending on their experience and opinion.

When somebody says the sound is punchy and tight, what does that means? As compared to what?

When in doubt-do your own tests.

No offence taken at all. I hear ya.

As an install-only shop though I don't often have speakers sitting around and a venue to blast them at full volume.
And when I do have speakers and a venue we're usually out of town or under some other time crunch.
Hence why I was hoping someone had already done that, or at least had more info on what actually manifests.

If I worked in a rental shop I would have definitely just gone to the warehouse and tested it.

I'll have to wait until the right opportunity comes along.

Jason

 

[Rob Timmerman]

Re: Damping Factor - Actual listening tests?

This is not to sound rude.

If if you had spent 1/10th of the time that it takes to read and respond to posts on this subject, and taken the time to do a couple of simple tests YOURSELF, then you would have the answer you seek.

Simply take a long spool of wire, hook up a short piece of wire and a long piece of wire and and listen yourself.

Have somebody switch the cables so you do not know which is being used, and see if the difference you hear is worth the extra expense.

That is the ONLY way you can prove it to yourself. Relying on the sonic opinions of others can lead to very "odd" results.

Different peoples opinions will vary greatly depending on their experience and opinion.

When somebody says the sound is punchy and tight, what does that means? As compared to what?

When in doubt-do your own tests.

Perhaps, but sourcing the wire, amplifiers, and speakers to run the tests, not to mention actually running tests that are valid, takes significantly more effort (and likely time) than simply participating in a forum discussion. And while the tests might answer the question about sonic performance, they won't do anything to explain the theory behind damping factor, as well as possible mitigation approaches (both of which have occured in this thread).

 

[Ivan Beaver]

Re: Damping Factor - Actual listening tests?

No offence taken at all. I hear ya.

As an install-only shop though I don't often have speakers sitting around and a venue to blast them at full volume.
And when I do have speakers and a venue we're usually out of town or under some other time crunch.
Hence why I was hoping someone had already done that, or at least had more info on what actually manifests.

If I worked in a rental shop I would have definitely just gone to the warehouse and tested it.

I'll have to wait until the right opportunity comes along.

Jason

Back when I was in the install business, we had manufacturers all the time bring us gear to play with and test.

I under stand about not wanting to "driver hard" something that is going into an install.

But you can also do a test at an actual install and just add some additional length to the wire going to the amp in the amp room.

I have done quite a few installs in which we had 300' runs-even to the subs. And the sound was plenty tight and nobody complained about the "sound" of the subs.

Basically we would run as large a wire as we thought the customer could afford-and what could fit through the conduit.

We did one install in which the previous wire was 6 ga to each speaker. Even then, the runs to the speakers was not "recommended", even though it was 300' ish.

The original install was not cheap-when you consider that there were almost 450 separate runs. The conduit costs had to be really nice to the electricians.

It is all about compromise.

I personally think there are more important things to worry about.

 

[Jim McKeveny]

Re: Damping Factor - Actual listening tests?

Now that we have exhausted the (mostly academic) modern, in-practice irrelevance of Damping Factor, can we now revisit Slew Rate?