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Why do Cab IR's seem lacking?
Old 20 hours ago
  #121
Quote:
Originally Posted by John Eppstein View Post
Oy vey!

You distortion "spec" is meaningless. It's nothing more tha a figure published by their advertising department to impress people like you.

What was the full spec, or did they even tell you? The "full" spec, such as it is, should be something like "0.1% THD @ 1kHz, 10 mW input" And your phones may very well do that. However, most people do not listen to phones with only a 1k pure sine wave, they don't listen at only one optimum level (chosen for lowest distortion), and that "spec" tell you NOTHING WHATSOEVER what those phones do when presented with a complex waveform containing may frequencies mixed together of at dynamically changing levels.

The 1kHz "standard" was chosen by manufacturers because it is a very easy frequency for most audio devices to reproduce and it's more or less in the middle of the perceived range of hearing.

In other words, a 1kHz sine wave test tone will make most audio equipment look good while actuality telling you much about how it behaves where it counts.

And that spec tells you nothing about the spectrum of the harmonic distortion being produced. I would be willing to be that you probably could not recognize distortion in a music signal with 10% THD if that distortion was all 2nd harmonic. you might very well notice a tonal difference, but you probably would not recognize it as distortion because 2nd harmonic is fully consonant with the fundamental, being the 1st octave harmonic. You might recognize it as a "warming up" or perhaps "fattening" of the sound, if you noticed it at all.

I also notice that Sennheiser doesn't say a thing about IM distortion, which might be a far more interesting figure.
10% THD you will easily recognise. Here's a video I've just created. This shows 3% THD, a second harmonic at -30 db below the first harmonic:


You can easily hear the second harmonic (I'm switching back and forth between the pure sine and the sine being overdriven). With a sine wave your ears should very quickly tell you if a signal is distorted. I can hear this happening even when the THD is below 1%. Not with music, only when a pure sine wave is played.

I am planning to do some testing with my guitar speaker cabinet. Unfortunately my Marshall is not in my studio at the moment, but I have a lovely H&K with a Greenback Celestion I can test. Upcoming...
Old 20 hours ago
  #122
Quote:
Originally Posted by John Eppstein View Post
I would be willing to be that you probably could not recognize distortion in a music signal with 10% THD if that distortion was all 2nd harmonic. you might very well notice a tonal difference, but you probably would not recognize it as distortion because 2nd harmonic is fully consonant with the fundamental, being the 1st octave harmonic. You might recognize it as a "warming up" or perhaps "fattening" of the sound, if you noticed it at all.
The second harmonic is not really fatening, it's an octave above the root. If the second harmonic is loud it will sound like an octaver. Far from fat.
Old 20 hours ago
  #123
Quote:
Originally Posted by Raaphorst View Post
The overtones are super, super low, because I can't detect any when using a pure sine wave on playback. So my ears can't detect it on my Equator powered monitors and Sennheiser HD600 headphones.

If there's distortion (sure, in a analog signal there's always a small amount of THD) it is so low it is ignorable.
Interesting. As it happens, I have Equator monitors too - two different models. One with the concentric mounted dome tweeter, one with the compression driver.

There is no way that I would ever claim that either one is "distortion free" - I'd have to laugh myself out of town. However, as with any monitor, I've
had to learn their quirks and I can work with them just fine.

Quote:
The only thing that might be interesting is some voodoo happening in 12" guitar speakers... But I think the one thing adds to the overtones: the power amp. It also adds compression (which is caused by overdriven circuit). And these things can easily be simulated digitally.
Well there is definitely some "voodoo" as you call it in guitar speaker design (it's only magic if you don't understand it), but that has nothing to do with amp distortion.

We are discussing speaker distortion here. That has nothing whatsoever to do with amp distortion. You want to talk about amp distortion, start a different thread.

Speaker and amp do both affect the final tone but they are not the same thing. It's like saying that flour and milk are the same thing because they both make up part of the recipe for a custard pie.
Old 20 hours ago
  #124
Quote:
Originally Posted by chris661 View Post
Your unwillingness to learn bewilders me.
Welcome to Gearslutz!
Old 19 hours ago
  #125
Quote:
Originally Posted by Raaphorst View Post
10% THD you will easily recognise. Here's a video I've just created. This shows 3% THD, a second harmonic at -30 db below the first harmonic:


You can easily hear the second harmonic (I'm switching back and forth between the pure sine and the sine being overdriven). With a sine wave your ears should very quickly tell you if a signal is distorted. I can hear this happening even when the THD is below 1%. Not with music, only when a pure sine wave is played.

I am planning to do some testing with my guitar speaker cabinet. Unfortunately my Marshall is not in my studio at the moment, but I have a lovely H&K with a Greenback Celestion I can test. Upcoming...
Jeeziz K-reist!

We are talking about speakers.

Speakers reproduce complex waveforms. YOU CANNOT TEST FOR BEHAVIOR WITH COMPLEX WAVEFORMS WITH SINE WAVES.

I said that I'd bet that you can not recognize 10% 2nd harmonic distortion in a MUSIC SIGNAL, which is a very complex waveform indeed in most cases.

Sure, you can hear it with a sine wave and nothing else. But that's not how speakers are operated in the real world.

And note that I didn't say that you couldn't hear a difference. What I said was that you would probably not identify it as distortion. I also didn't say that nobody could - but it would require a significant amount of specialized ear training. And if you had that you wouldn't be here doing this.

I seriously doubt that you have the necessary equipment to do the required tests and I'm damn sure that you lack the knowledge and expertise.

Here, you can start by reading this:
https://en.wikipedia.org/wiki/Intermodulation

It's not entirely aimed at audio, but it has the basics.
Old 11 hours ago
  #126
Quote:
Originally Posted by John Eppstein View Post
Jeeziz K-reist!

We are talking about speakers.

Speakers reproduce complex waveforms. YOU CANNOT TEST FOR BEHAVIOR WITH COMPLEX WAVEFORMS WITH SINE WAVES.
What would you suggest for measuring and analysing distortion?
Old 10 hours ago
  #127
Lives for gear
 
Yuri Kogan's Avatar
 

Quote:
Originally Posted by Raaphorst View Post
What would you suggest for measuring and analysing distortion?
At what frequency and level?
Old 9 hours ago
  #128
Quote:
Originally Posted by Raaphorst View Post
What would you suggest for measuring and analysing distortion?

This is the real issue. There is no good, standard test for analyzing distortion.

We have harmonic distortion methods that are pretty reasonable for modern hi-fi gear (THD+noise, and plots of individual overtones across frequencies). There is a standard IMD test, but it only tests with 2, fixed tones.

At this point, it's more of an art making guitar speakers distort consistently in a way that people like.



-tINY

Old 9 hours ago
  #129
Quote:
Originally Posted by Yuri Kogan View Post
At what frequency and level?
Full range, for all frequencies at all levels.
Old 9 hours ago
  #130
Quote:
Originally Posted by tINY View Post

This is the real issue. There is no good, standard test for analyzing distortion.

We have harmonic distortion methods that are pretty reasonable for modern hi-fi gear (THD+noise, and plots of individual overtones across frequencies). There is a standard IMD test, but it only tests with 2, fixed tones.

At this point, it's more of an art making guitar speakers distort consistently in a way that people like.



-tINY

So we can't measure it? That's ok with me. Means that we can only have subjective discussions about it.

I am fine with that. Use whatever you'd like I would say!
Old 9 hours ago
  #131
Lives for gear
 
Yuri Kogan's Avatar
 

Quote:
Originally Posted by Raaphorst View Post
Full range, for all frequencies at all levels.
Hmmm. Why do you think nothing like that is done by the manufacturers? Why are they only presenting a minuscule sample? How much variation in materials (cone, frame, magnets, coils, assembly precision) is there to guarantee even decent repeatability? And would those components behave even 50% as nicely as the computer model? I have some VERY expensive monitors here and the distortion is there even in the linear region. Guitars speakers, which are designed with low headroom distort at every level. Record DI and through a speaker and its obvious. And what about when the cone is flexing fast and the coil pumping to the full range? Do you think it will be even remotely linear, or repeatable. Why do you think people speak about "compressed" speaker sound?
Digital world is mainly additive, so as long you don't cross the -3db you are "clean" (which is an oxymoron in digital due to conversion quantisation error in the first place, plus all the other nasty's in the AD?DA processes). But puch an analogue mixer and it will still "squash " everything in - with a "compressed" sound. Ditto for speakers - analogue behaves differently from the digital stuff.
That's without going into the measurements, math... Hope this makes some sense. Use the best "meters" god gave you - listen.
Old 8 hours ago
  #132
Quote:
Originally Posted by Yuri Kogan View Post
Hmmm. Why do you think nothing like that is done by the manufacturers? Why are they only presenting a minuscule sample? How much variation in materials (cone, frame, magnets, coils, assembly precision) is there to guarantee even decent repeatability? And would those components behave even 50% as nicely as the computer model? I have some VERY expensive monitors here and the distortion is there even in the linear region. Guitars speakers, which are designed with low headroom distort at every level. Record DI and through a speaker and its obvious. And what about when the cone is flexing fast and the coil pumping to the full range? Do you think it will be even remotely linear, or repeatable. Why do you think people speak about "compressed" speaker sound?
Digital world is mainly additive, so as long you don't cross the -3db you are "clean" (which is an oxymoron in digital due to conversion quantisation error in the first place, plus all the other nasty's in the AD?DA processes). But puch an analogue mixer and it will still "squash " everything in - with a "compressed" sound. Ditto for speakers - analogue behaves differently from the digital stuff.
That's without going into the measurements, math... Hope this makes some sense. Use the best "meters" god gave you - listen.
I can't comment on what manufacturers do. But I think we can fully agree that it doesn't matter. Just listen, make your own choices.
Old 8 hours ago
  #133
Quote:
Originally Posted by Raaphorst View Post
So we can't measure it? That's ok with me. Means that we can only have subjective discussions about it.

I am fine with that. Use whatever you'd like I would say!

You can measure it. But, for anything meaningful, you'd need a lot of pages of graphs...

It's easy enough to do a two-tone IMD test. But, what do you do about the whole spectrum. You'd need to do a series of sweeps with one tone as you stepped the other tone through the spectrum - and you'd have to track sum and difference frequencies as well as sum and difference frequencies of the harmonics of each tone.

Or, you could make a series of spectral plots with various combinations of tones.

Either way, it's a lot of work to look at all that information and distill anything meaningful out of it for guitar speakers where the distortions are desired and you want to characterize them. For hi-fi, any distortion is considered a detriment and you can group them when you analyze the performance. Though, there are some audiophiles who like certain kinds of distortion too...




-tINY

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