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Flat Vs Colored Discussion - Page 2

post #16 of 33
Quote:
Originally Posted by FlatNine View Post

Regarding the flat sound vs colored sound and how different components affect the sound in different ways. You know, tubes are warmer, Cowon's BBE adds depth, Ety's are flat and accurate, etc. The observation I have for discussion is this - how can you know? It is a long trip from a musician's instrument to the listener's ears. Say you have a recording of a rock guitarist. Many rock guitarists prefer tube amps for their warm overdriven distortion. Also, maybe the player prefers a touch of reverb. Overall, the original recording is going to have a very warm sound.

 

So - the point I am making is this - unless you were present at the live performance, you can't know where the colorization (is that a word?) of the audio occurs. This is true for other situations as well. If you have a live jazz recording, like my favorite Wes Montgomery's Smokin at The Half Note, you can't know if the warmth, or depth is being produced by your equipment or if it is on the original recording. The "flattest" gear around had better reproduce that warmth and depth or it isn't flat at all, right? Hmmmm.



We know because they've measured it.


Google Free Field Equalisation and Diffuse Field Equalisation.


Yes, it's going to give you the same sound as a flat speaker - which sounds the same as real life.

 

Of course there's no mastering standard, so what you're getting is the master sounding as it would if it was played in real life exactly flat.

post #17 of 33


 

Quote:
Originally Posted by Shike View Post


 

Originally Posted by JerryLove View Post

You play something which is a known and measureable quantity. Long sine waves come to mind.

 

And no: a good tube amp, driving a speaker within it's ability and not run into clipping will be flat.The "tube sound" is the effect of soft clipping.


That . . . has nothing to do with output impedance (damping factor).  You could have an amp that doesn't clip but exhibits poor output impedance/damping factor.


Bold changed for clarity.

 

I did not say that impedance was clipping, nor did I intend to imply it. I said that a amp being asked to operate with an impedance it was incapable of providing would be being asked to work outside its ability to operate.

 

The same would apply to amps with current limitations, or with insufficient capacitance to deal with sudden, transient, current spikes.

 

Dealing with the impedance curves of my N801s was a challenge; my amps were not clipping, but were not keeping the drivers properly energized either, and so there were signifigant sound issues to address.

post #18 of 33


 

Quote:
Originally Posted by JerryLove View Post

I did not say that impedance was clipping, nor did I intend to imply it. I said that a amp being asked to operate with an impedance it was incapable of providing would be being asked to work outside its ability to operate.

 

That doesn't make sense either in regards to output impedance.  You want a low output impedance which give a high damping factor (which improve linearity of the driver).  It has nothing to do with working outside its ability to operate as something with a high output impedance can still be operating just fine, however it exhibits poor control over the driver which can introduce minor to substantial linearity differences of the driver.

 

You are familiar with output impedance aren't you?

 

The same would apply to amps with current limitations, or with insufficient capacitance to deal with sudden, transient, current spikes.

 

That would be clipping.  If the amp can't provide necessary current for the speaker it clips and distorts.

 

Dealing with the impedance curves of my N801s was a challenge; my amps were not clipping, but were not keeping the drivers properly energized either, and so there were signifigant sound issues to address.

 

You're going to have to elaborate on this, as it doesn't make much sense.  If they weren't meeting the current or voltage requirements of the speakers then that would be clipping no matter how you look at it.  Was it another problem with the amps in general?

 

Responses in bold.

post #19 of 33
Thread Starter 


I'm probably in over my head here, and this whole thread seems to have taken a turn towards argument rather than educating and discussion.

 

My understanding of clipping: A given amplifier can produce output cleanly, up to a point. The total amplitude of the output AC wave is limited to a definite value, beyond which, the top (and bottom) of the sine wave lose the peaky curve and gets "lopped off", aka clipping. In a simple transistor amplifier circuit, as voltage from base to ground increases, so does the voltage from collector to ground, only at a higher level, hence amplification. The theoretic maximum of the collector voltage being equal to VCC. So, when a high base input causes the collector voltage to max out at an amplitude roughly equal to VCC, clipping occurs and the top and bottom of the output sine wave is flat.

 

On the other hand, overdriving is often done intentionally, by introducing an already clipped signal from the preamp into the power amp. Instead of having a clipped wave as the result of the power amp being pushed beyond its limits, a clipped wave is actually fed into the power amp, which then reproduces the distorted wave, but not because it is being pushed too hard. That's how you can get a nice overdriven sound out of many guitar amps without having to max out the power amp and rattle the house.

 


 

Quote:
Originally Posted by JerryLove View Post



Quote:
Originally Posted by FlatNine View Post


The way I understand it, the tube sound is more than just clipping, which is why solid state amps don't produce the same sounds as tubes, generaqlly speaking. It was explained to me by an audio engineer that overdirving tubes generally produces harmonic overtones that are even multiples of the original frequency, whereas solid state amps produce multiples on odd harmonics. This was in the early 80's when he explained this to me, and at some point my head started to spin as he got way deeper into it. I don't have the depth to really comment on that, but as a former rocker, I know that I loved the sound of tubes over solid state, even when the latter was overdriven. (But now as a jazz player, I prefer the solid state amps - mostly because they are lighter! LOL!)


 

What do you feel is the semantic difference between "clipping" and "overdriving"?

post #20 of 33
Quote:

Originally Posted by Shike View Post

 

That doesn't make sense either in regards to output impedance.  You want a low output impedance which give a high damping factor (which improve linearity of the driver).  It has nothing to do with working outside its ability to operate as something with a high output impedance can still be operating just fine, however it exhibits poor control over the driver which can introduce minor to substantial linearity differences of the driver.

 

Let me sum up what I am reading.

 

In order for amp A to properly drive Speaker S (to have a high driver linearity), A must present an impedance of O or lower.

A has an impedance >O

 

A is incapable of O

O is neccessairy for S to run properly.

 

Yet, you claim that A is capable of running O properly (the definition of "within its ability")

You simultaniously claim that S will sound bad because A can't drive it (being incapable of <O)

 

Is the required impedance for linear operation of the speaker in question within or not within the ability of the amplifier to provide? You seem to be arguing some odd semantics :(

post #21 of 33


i agree with this. in order to actually judge if something is colored or not is have experience first hand on an instrument. i never played live or any type of shows myself but i have experience with wide ranges of string and wind instruments from hanging with friends and writing tabs and so forth. i'm no professional by any means. i just love my music. also it can be hard sometimes to tell if your ears never experience multiple tunings of instruments before or tuned different tunings.

Quote:
Originally Posted by Uncle Erik View Post

There is no stereotypical tube sound across all amps. They're all different. Some add warmth and some are very flat. It depends on the circuit and tubes used.

I judge accuracy based on measurements (they have loads of value, despite what some would have you believe) and my personal experience playing several instruments in bands and orchestras. If you've spent ten years with a bass clarinet or tuba (my favorites) you know if a headphone reproduces it well or if it is adding bass that isn't there. When you play shows, you know what the sound is like in warm and cold venues. If the gear is adding sound that you don't get in real life, it's colored. I also have a good idea of what all the other instruments sound like since I've spent thousands of hours listening to them live.

The human voice is also a good indicator. We've all spent our entire lives listening to them. If a headphone sounds plasticky with vocals, that's easy to pick out.

Judging against personal experience with live music is the best way to gauge coloration.
post #22 of 33


 

Quote:
Originally Posted by JerryLove View Post

Quote:

Originally Posted by Shike View Post

 

That doesn't make sense either in regards to output impedance.  You want a low output impedance which give a high damping factor (which improve linearity of the driver).  It has nothing to do with working outside its ability to operate as something with a high output impedance can still be operating just fine, however it exhibits poor control over the driver which can introduce minor to substantial linearity differences of the driver.

 

Let me sum up what I am reading.

 

In order for amp A to properly drive Speaker S (to have a high driver linearity), A must present an impedance of O or lower.

A has an impedance >O

 

A is incapable of O

O is neccessairy for S to run properly. It still is technically running properly, but probably with deviations to the FR.

 

Yet, you claim that A is capable of running O properly (the definition of "within its ability")

You simultaniously claim that S will sound bad because A can't drive it (being incapable of <O) I never said this, I said it would modify the FR though.  To avoid the FR modification a high damping factor is needed -- assuming you want to avoid it.

 

Is the required impedance for linear operation of the speaker in question within or not within the ability of the amplifier to provide? You seem to be arguing some odd semantics :(

 

Running properly means just that it's being driven without distortion.  Effectively it still is, the amplifier just isn't exhibiting a lot of control over the driver and isn't outputting distortion.  However, by doing so it allows increases the FR to usually peak at areas of impedance increase more than usual.  This isn't adding harmonics so it isn't THD, but it is increasing amplitude.

 

Perhaps linearity was the wrong word to use in this case since it isn't particularly adding distortion but just modifying the FR characteristics . . . similar to using an EQ in the chain wouldn't be considered distortion.


Responses in bold.  Sorry if you feel its semantics, but there's definitely a distinction.

post #23 of 33

Hey Shike, coud you provide a link with the calculations relating to how the damping factor modifies the FR of the transducer?

Thanks.

post #24 of 33

Quote:

Originally Posted by khaos974 View Post

Hey Shike, coud you provide a link with the calculations relating to how the damping factor modifies the FR of the transducer?

Thanks.
 

 

Xnor discusses the problem here:

 

http://www.head-fi.org/forum/thread/493436/dampening-in-amplifiers#post_6660782

 

You can use a voltage divider calculator here:

 

http://www.raltron.com/cust/tools/voltage_divider.asp

 

Use one volt for simplicity, R1 is output impedance, and R2 is driver impedance.  You need damping factor in the form of output impedance.  From here you calculator the resulting voltage based off the average speaker impedance, and then one with the peak impedance.  Take the log of the first result (should get a negative amount), then multiple by 20.  Record.  Do the same to the second one.  Take the absolute value of each, and subtract the smaller of the two.  That's the difference in dB between those two frequencies.

 

Sample values:

1

8 (stays)

8/16

 

You should get a result around 2.5 dB

 

Now to see why a high damping factor (low output impedance) doesn't do this.  Put in something like 1 in R1 instead of the 8.  Should get something like a .492 dB increase instead.  Obviously the second instance doesn't modify the FR nearly as much as the first.  In some cases a difference of 4dB isn't unheard of.

post #25 of 33

Thanks. I thought there was another factor than a simple voltage divider, it's quite obvious that if the resistance changes depending of the frequency, the FR response is going to be affected.

 

I had hope for a more complete (?) model with some jwL and 1/jwC taken into account.

post #26 of 33
Quote:
Originally Posted by khaos974 View Post

Thanks. I thought there was another factor than a simple voltage divider, it's quite obvious that if the resistance changes depending of the frequency, the FR response is going to be affected.

 

I had hope for a more complete (?) model with some jwL and 1/jwC taken into account.



I don't know of such a model, if you find one it would be interesting to see.

post #27 of 33


 

Quote:
Originally Posted by Shike View Post

Responses in bold.  Sorry if you feel its semantics, but there's definitely a distinction.


It's honestly closer to a straw-man  or equivocation fallacy.

 

An amp not able to provide dealing with impedance required for a speaker to operate optimally (put out the best sound it could put out) is not being run "within it's ability", as I intended it when I said it, nor as I mean it now (since it's being asked to do something it is incapable of doing).

 

If you wish to use some definition other than I did, and then show why my sentence doesn't work with your definition, I don't really see the point. Your definition is also in direct conflict with other statements I've made in this thread (for example, my experience with the inability of some of my amps to keep the voice-coil on the N801 energized, which is not a clipping issue at all, but is certainly an indication that the requirements are outside the ability of the amp to provide).

post #28 of 33


 

Quote:
Originally Posted by JerryLove View Post


 

Quote:
Originally Posted by Shike View Post

Responses in bold.  Sorry if you feel its semantics, but there's definitely a distinction.


It's honestly closer to a straw-man  or equivocation fallacy.

 

I haven't misrepresented your argument, it's that your argument lacks context.  Are you arguing the ideal amplifier for the ideal speaker?  If that were the case then maybe what you said would have some merit, but we don't have such hardware in the real world.

 

An amp not able to provide dealing with impedance required for a speaker to operate optimally (put out the best sound it could put out) is not being run "within it's ability"

 

Okay, so if we use an EQ the speaker is not putting out the best sound it can put out right?  See how silly that sounds?  It's modifying the FR - which I agree I don't like - but is a different concept from being inadequately driven.

 

Are you sure you fully understand what output impedance is?  Your statement sounds like it's referring to speaker impedance only and whether an amplifier can drive it - which even with a low damping factor it can.  Once again, if you're arguing ideals that's something different, but the premise that something must sound bad because it's not based off ideals is another fallacy in your reasoning.

 

as I intended it when I said it, nor as I mean it now (since it's being asked to do something it is incapable of doing).

 

What is it incapable of doing, specifically?  What parameter is it causing to perform poorly exactly?  THD?  Transients?

 

If you wish to use some definition other than I did, and then show why my sentence doesn't work with your definition, I don't really see the point.

 

Which definition are you using?  Cite, please, where I've supposedly made this drastic misrepresentation.

 

Your definition is also in direct conflict with other statements I've made in this thread

 

Such as?  Once again, cite the definition I've supposedly made up that conflict with your statements.  Also realize, your statements are in conflict with what I originally said too.

 

(for example, my experience with the inability of some of my amps to keep the voice-coil on the N801 energized, which is not a clipping issue at all, but is certainly an indication that the requirements are outside the ability of the amp to provide).

 

How did you perform your test to confirm this hypothesis?  Was it not just a flaw with the amp?  What effect did this issue have on the speaker in terms of measurable impact?  Furthermore what relevance does this actually have to output impedance besides what seems an unrelated anecdote?


Responses in bold.

post #29 of 33
Quote:
I haven't misrepresented your argument, it's that your argument lacks context.  Are you arguing the ideal amplifier for the ideal speaker?  If that were the case then maybe what you said would have some merit, but we don't have such hardware in the real world.


You and I are using very different meanings of "within it's ability". We have been since you responded to my original use of the term it seems. I keep pointing this out, but I don't see that there's any effort for common ground on terminology, and nothing else is on topic.

post #30 of 33
Quote:
Originally Posted by Uncle Erik View Post

There is no stereotypical tube sound across all amps. They're all different. Some add warmth and some are very flat.


Yes I absolutely agree with this. The valve amps, as we call them in the UK, can be tremendously "flat". I will say that I have become very much one for Class A solid state amplifiers, but good engineering can be applied to valve or solid state to bring about something excellent.

 

The famous valve Studer tape recorders which were used in the 50s and 60s actually made recordings with no additional warmth whatsoever, they were beautifully neutral.

 

The odd thing about the valve amplifier renaissance which started in the late 80s is that some of the amplifiers produced unfortunately do valve amplification an injustice by playing to the stereotype of a warm sound.

 

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