High Damping Factor and Bass Output

[MacManNM]

...in it's circuit there is some sort of electronic brake(in the guise of a small, potted network of sorts) to facilitate "immediate" stoppage of blade motion...as far as I know it has something to do with back-EMF stopping the armature's rotation...

Now I'm not trying to be difficult about this, only trying to understand what you have said previously. I can comprhend the equalization concept when dealing with pre-emphasis/de-emphasis or stating the RIAA playback curve in usec's rather than at specific frequencies, but I still fail to see how something more attuned to tonal balance using impedance feedback networks has anything to do with controlling cone motion. Maybe I'm just dumb.

With any sort of encode/decode "equalization" you are dealing with a known input and expect a specific output, whether it be for better S/N ratio as in FM or the ability to avoid over excursions of a cutter-head and still end up with a properly balanced frequency response from your vinyl.

Damping factor strikes me as a completely different animal, more akin to stopping my lawnmower blade. Music is different in that it's never "fixed"per se(as would be our inverse EQ curve)...Plucking a bass note(which one?) and bowing the same note, results in two different waveforms having the same nominal frequency but completely different rise and decay times.

Applying "equalization"(again as I understand term and have up until now have used it) would treat both the same way, although they are quite different. Our ficticious parametric equalizer still has a fixed frequency, amplitude and Q, not quite the ticket as far as I can see. Given the inherent randomness that is music, I still can't quite see damping as being an "equalization effect"...An amp with a lower output impedance and higher DF would simply seem to be more compliant(if that's the correct word) in it's ability to "react" and/or "control" the net effect of that back-EMF produced by the motor/generator effects of the load's voice-coil.

Can you (or anyone else) direct me to supporting documentation that will disabuse me of my current notions.

jimHJJ(...thanx...)

No, because there is none.

 

[WmAx]

...in it's circuit there is some sort of electronic brake(in the guise of a small, potted network of sorts) to facilitate "immediate" stoppage of blade motion...as far as I know it has something to do with back-EMF stopping the armature's rotation...

It all has to do with the source impedance of the circuit. The source impedance of the circuit determines all of this.

I can comprhend the equalization concept when dealing with pre-emphasis/de-emphasis or stating the RIAA playback curve in usec's rather than at specific frequencies, but I still fail to see how something more attuned to tonal balance using impedance feedback networks has anything to do with controlling cone motion. Maybe I'm just dumb.

It is simple: the tonal adjustment curve that is created by the high source impedance has a fixed curve. This is a simple analog frequency response abberation. It is minimum phase in nature(it's phase is directly related to it's amplitude), and therefor the inverse curve(with the exact opposite phase and amplitude) will precisely counteract this phenomenon.

With any sort of encode/decode "equalization" you are dealing with a known input and expect a specific output, whether it be for better S/N ratio as in FM or the ability to avoid over excursions of a cutter-head and still end up with a properly balanced frequency response from your vinyl.

Yes. And the curve here remains constant for a particular speaker(excepting extreme power ranges where the speaker is driven out of it's linear motor/suspension operation parameters), therefor it is predictable and correctable. You can even correct in the case of non-linear extreme operation, if using a dynamic parameteric equalization DSP.

Can you (or anyone else) direct me to supporting documentation that will disabuse me of my current notions.

I am not aware of a convenient all-in-one documentation regarding the matters discussed.

-Chris

 

[Resident Loser]

Which begs the dumb question...

No, because there is none.

...in a long and proud history of dumb questions...

Is it no, because there is no neat little package with a flip-top box for my convenience?

Or is it: No, because my understanding is reasonably okee-dokee?

jimHJJ(...or is it something completely different?...)

 

[mtrycrafts]

Mtry,

Where does Tom Nousaine and Ed Mullen stand on damping factor issues? They've contributed quite a bit to Secrets, which I'm surprised if it's such a voodoo issue. They're pretty well respected in the audio world.

Perhaps their stand on DF is not supported by all the facts??
I am a betting person, at times and would bet that Tom would support **** Pierce on this who has the same stuff on it as AH does. Wonder which came first?
http://groups.google.com/group/rec.audio.high-end/msg/1a35b2da043f01d5?q=author:DPierce@world.std.com+and+damping+factor&hl=en&lr=&rnum=1

But if you want, I can drop him a line and ask for 100% accuracy

 

[mtrycrafts]

.....I'll say this....a fair way to AB the damping factors of two amps is one pushing the rears, and the other pushing the fronts..

You think this is the best way to compare??? Speaker locations, rooms boundary acoustics would not alter the acoustic property enough???

I bet that this would be thrown out from a court of science

, but mids is where you hear the longness of low damping factor....McIntosh amps ring in at 100 damping factor,

http://groups.google.com/group/rec.audio.high-end/msg/1a35b2da043f01d5?q=author:DPierce@world.std.com+and+damping+factor&hl=en&lr=&rnum=1

"However, this analysis and any mode of measurement and
listening demonstrates conclusively that it is not due to the
changes in damping the motion of the cone at the point where it's
at it's most uncontrolled: system resonances."

Hard to argue with facts.

and I heard two different Mac amps sound long and thick in the mids, compared to the K2 on the fronts....I heard the damping factor be 100 on the rears, against 3000 on the fronts....at the same time....all you have to do is shift your head toward one and then the other, and you soon don't want the long version 100, you want the cleaner one....higher damping factor was related to me by a few I trust as the amplified signal gets, "on and off the voice-coil more quickly".....the amplifier is more in control of the speaker element......


Do you think a flawed experiment may contribute to unreliable results???

 

[mtrycrafts]

For the most part, the average mild capacitive/inductive loads generated by a typical loudspeaker will not have much effect on simulations using this calculated static source impedance value. To very accurately predict extreme reactive load conditions, however, you will have to also measure the amplifer voltage into varying controlled inductive/capacitive loads of known values to generate an additional set of data to account for this variable.

-Chris

The testing of amps by The Audio Critic, specifically David Rich, using that power cubed method measures the voltage out to 60 deg cap/inductive loads.
The A500 is most impressive

 

[mtrycrafts]

Besides

Mtry,

Where does Tom Nousaine and Ed Mullen stand on damping factor issues? They've contributed quite a bit to Secrets, which I'm surprised if it's such a voodoo issue. They're pretty well respected in the audio world.

If DF was such a big issue, wouldn't you think that amp DBTs over the past 30+ years would have all positive outcomes or most, supporting audible differences? After all, DF is all over the place. The evidence doesn't support DF through controlled listening tests.

 

[Resident Loser]

Well, here comes...

...dumb question two or was it three or...whatever...

...The evidence doesn't support DF through controlled listening tests.

Support? Of what? It's existence? It's importance(or lack thereof)?

I mean, it's not like it's the spec du jour...my old Pioneer SA-9100 integrated(circa 1974) had a high one and the mags of the time seemed to think DF was an issue of sorts...the only downside I've come across has been a high damping factor is usually associated with high levels of negative feedback, which seems to be a more recent "audiopile" concern...

If the amp has a low output impedance and therefore a high DF and a high DF results in better "tracking" of the signal and we use wire of sufficient gauge for an efficient signal transfer to and fro and...it's supposed to be straight wire with gain and...

jimHJJ(...this is all very confusing...did I miss a day or something...)

 

[mulester7]

Do you think a flawed experiment may contribute to unreliable results???

.....I honestly get the impression these guys you and others worship, Mtry, are tin-eared Neanderthals who took up meters and scopes....compared to my own hearing and comparisons, I couldn't care less what they think.....I think the biggest thing they were after was being published.....

 

[mtrycrafts]

.....I honestly get the impression these guys you and others worship, Mtry, are tin-eared Neanderthals who took up meters and scopes....compared to my own hearing and comparisons, I couldn't care less what they think.....I think the biggest thing they were after was being published.....

They may be, but you have not demonstrated that you are a 'golden ear' chap. Hence, I place more credence in them than you.

Oh, yes, they wanted to publish no matter what. At times you amaze me where you come up with these nonsense??

 

[mtrycrafts]

...dumb question two or was it three or...whatever...



Support? Of what? It's existence? It's importance(or lack thereof)?

I mean, it's not like it's the spec du jour...my old Pioneer SA-9100 integrated(circa 1974) had a high one and the mags of the time seemed to think DF was an issue of sorts...the only downside I've come across has been a high damping factor is usually associated with high levels of negative feedback, which seems to be a more recent "audiopile" concern...

If the amp has a low output impedance and therefore a high DF and a high DF results in better "tracking" of the signal and we use wire of sufficient gauge for an efficient signal transfer to and fro and...it's supposed to be straight wire with gain and...

jimHJJ(...this is all very confusing...did I miss a day or something...)

To make it clearer, that DF is an issue in modern amps, let alone having 3 digit DF, and audible anything over 10.
Besides, DF is of any concern only at the system resonances.
From my cited link:
changes in damping the motion of the cone at the point where it's
at it's most uncontrolled: system resonances

and
this analysis and any mode of measurement and
listening demonstrates

 

[mulester7]

Oh, yes, they wanted to publish no matter what

.....ya' heard it first here, Guys.....

 

[MDS]

This is a perfect chance to use mtrycrafts' favorite example:

When you place a steel pipe in a bucket of water, your eyes tell you the water bends the pipe. Now everyone knows that the water doesn't bend the pipe and nobody ever says 'I don't believe those scientists that publish on the topic of optics, because I believe what I see'.

Yet when it comes to audio, many people claim to trust their ears and discount any published studies that show that the ears cannot always be trusted.

That's a rather interesting dichotomy, no?

 

[mulester7]

This is a perfect chance to use mtrycrafts' favorite example:

When you place a steel pipe in a bucket of water, your eyes tell you the water bends the pipe. Now everyone knows that the water doesn't bend the pipe and nobody ever says 'I don't believe those scientists that publish on the topic of optics, because I believe what I see'.

Yet when it comes to audio, many people claim to trust their ears and discount any published studies that show that the ears cannot always be trusted.

That's a rather interesting dichotomy, no?

.....MDS, I say first it's not me making it a contest here....my ears do just fine making my system thrill me more every day.....beyond that, why should I care what some guy who got published thinks?....I'm my own quite adequate eco-system.....now, if someone asks me what I think about something, and all I can do is tell them what someone else thinks about the subject, I didn't have an opinion, did I?......

 

[mtrycrafts]

.....ya' heard it first here, Guys.....

Just take it out of context, why don't you.

Oh, by the way, did you ever find that remark of mine that was quoted by that other guy??? I cannot find it.

 

[Dan Banquer]

Damping Factor

There is an excellent article on damping factor riight here in the audioholics archives.
http://www.audioholics.com/techtips/audioprinciples/amplifiers/dampingfactor.php

The real issue is how reactive the output impedance of the amplifier is. Testing the output impedance at one frequency is NOT a complete picture. Testing for output impedance must be done over freqency and power to get an accurate assesment. Any "internet expert" who says otherwise hasn't done their homework.

d.b.

 

[WmAx]

Testing the output impedance at one frequency is NOT a complete picture. Testing for output impedance must be done over freqency and power to get an accurate assesment. Any "internet expert" who says otherwise hasn't done their homework.

d.b.

The output impedance is virtually the same in most amplifiers through the most important range(bass to midrange) with a rise being typical as frequency increases. The two primary reactive bands are the midrange where the crossover is located and the bass range where the bass alignment impedance peaks are located. The only examples I can think of where it might make a marginal diference in audible response is with a speaker such as a full range driver speaker that has a very significant inductance/rising impedance of high magnitude into the treble band. So, it's a detail that I find rarely worth mentioning most of the time.

-Chris

 

[Dan Banquer]

Damping Factor

"The output impedance is virtually the same in most amplifiers through the most important range(bass to midrange) with a rise being typical as frequency increases. The two primary reactive bands are the midrange where the crossover is located and the bass range where the bass alignment impedance peaks are located. The only examples I can think of where it might make a marginal diference in audible response is with a speaker such as a full range driver speaker that has a very significant inductance/rising impedance of high magnitude into the treble band. So, it's a detail that I find rarely worth mentioning most of the time."

Another ASSumption that no longer applies. You might try looking at these digital amps that have output filters with no feedback around them. You should take a look at most linear amps that have a choke at the output after the feedback loop. It's just amazing that the "internet experts" can feed this misinformation to the everyone else and not bat an eyelash. I guess that we have come to expect from the pseudo intelligentsia of consumer audio. which assumes that you don't need to know anything about electronics.

I am just so disgusted with posts like yours.
A warning to the rest of the forum; Follow this mans information at your peril.
d.b

 

[mulester7]

.....on and off the voice-coil more quickly....I don't think it applies, I KNOW it applies.....

 

[WmAx]

I am just so disgusted with posts like yours.
A warning to the rest of the forum; Follow this mans information at your peril.
d.b

My statements adhere, as stated, to most amplilfiers and in conjunction with most speakers. Exceptions in the minority do apply, as my statement never said 'all' , but instead 'most'. Also, will append the former statement to not include switching amplifers, as I have not examined the characteristic behaviors of typical switching amplifiers. I still forget that they even exist in some cases.

It seems you have been disgusted for a while now, based on your replies in the past few months. You have yet to substantiate your assertions from that point in time, in which you seemed keep alluding to mysterious factors that are unknown to the general population, but you refused to divulge the precise nature and audibility coorelation of these when asked for specific information on these factors.

-Chris