Gedlee on distortion

[DDF]

Re: Gedlee on distortion

Even order distortion is "on the octave" and always "in tune", and the second harmonic is close enough to the fundamental to be generally masked. Higher order even harmonics do effect instrumental timbre. Odd order harmonics may be dissonant, and even the third is seldom significantly masked. Odd order harmonics do effect instrumental timbre.

It may have . . . um . . . not been (or demonstrated) quite what it purported to be (or to demonstrate).

Well, take a look at the spectrums JRT posted. It may have been that Arnie used musical signals that were more sensitive to 2nd order than 3rd.

BTW, are you saying Arnie's demo was flawed in execution, ie he made a mistake somewhere. If so, what was it?

[isaeagle4031]

Re: Gedlee on distortion

I think I along with many others understand your tone just fine.

[Deward Hastings]

Re: Gedlee on distortion

are you saying Arnie's demo was flawed in execution,

With the demo (and the methodology) NLA it's difficult to say. It's fairly easy to produce odd order distortion without even, more difficult to produce even without odd, and always open to question when a "distortion engine" is introduced in the signal chain just what it is actually doing. That's what leads me to speculate that "validity" might be the reason the demo was pulled. My own observation, where I've been able to imagine that I've teased the two apart, is that odd order harmonics are more noticeable (and objectionable) than even (all else being equal, which it never is).

[DDF]

Re: Gedlee on distortion

With the demo (and the methodology) NLA it's difficult to say. It's fairly easy to produce odd order distortion without even, more difficult to produce even without odd, and always open to question when a "distortion engine" is introduced in the signal chain just what it is actually doing. That's what leads me to speculate that "validity" might be the reason the demo was pulled. My own observation, where I've been able to imagine that I've teased the two apart, is that odd order harmonics are more noticeable (and objectionable) than even (all else being equal, which it never is).

Well, he pulled all his stuff, so I think we can agree there is no evidence that there was anything wrong with his demo.

I agree that there are many instance 2nd is less audible than 3rd. As I mentioned, I think this is more often true in the bass range based on my measures and listening. My point is that this isn't universally true so I think its wrong to downplay 2nd ord distortion as commonly happens (not that you said that, but others have)

[Deward Hastings]

Re: Gedlee on distortion

I think its wrong to downplay 2nd ord distortion as commonly happens

Even if not itself audible even order (2nd harmonic especially) distortion is a good proxy for other, more difficult to measure and observe, issues that may be more audible (like IM). But focusing too much on simple harmonic distortion tends to obscure and downplay the broadband "splatter" from sources like zero-crossing errors. While amplifier manufactures commonly boast about distortion figures at "rated power" only the rare few show curves at 100 milliWatt, which is where differences in amplifier "sound" are more likely to occur. It is not without reason that those with high efficiency drivers tend to choose Class A (or more recently Class D) amplifiers that may have relatively unimpressive distortion figures at high level but excellent sound at low. It's not just that the "first Watt" is where we mostly listen, it is also that the character of some low level distortion is notably audible, and notably bad (where simple harmonic distortion is not).

[Pete Basel]

Re: Gedlee on distortion

The term 'masking' has been mentioned a few times here related to the distortion discussion. Masking is cited by Toole (Sound Reproduction.... 2008), Chap. 19, pg 452 as the basis for his conclusion that traditional measures of HD and IMD are almost meaningless.

Carl, if you think about it, masking is fundamental to the audibility of distortion. The reason why there is a threshold below which the distortion becomes inaudible is because the fundamental is strong enough to mask the distortion. Speakers with say a tilted up response can unmask distortion that is already there in the recording, or make it worse. It was very common to use analog tape for compression by overdriving it so many older recordings have a lot of this distortion and it is quite audible.

[Jeff B.]

Re: Gedlee on distortion

An extreme example might exist in comparing harmonic overtones of soprano saxophone and clarinet, both similar in size but different in shape resulting in different harmonic overtone spectra, producing very different tonal qualities on the same musical notes. The clarinet approximates a closed end tubular instrument with mostly odd order harmonics, very low levels of even order harmonics. The saxophone approximates a truncated conical instrument with mouthpiece near the apex, and exhibits 2nd order harmonics near equivalent in level to the fundamental, and 4th order harmonics not far down from the 3rd order harmonics, etc.

http://www.phy.mtu.edu/~suits/conecyl.html

http://www.phy.mtu.edu/~suits/clarinet.html

http://www.phy.mtu.edu/~suits/sax_sounds/index.html

That's very interesting, I had never thought of these instruments in this way before.

[rickcraig]

Re: Gedlee on distortion

So, did Pallas' speakers exhibit any DIY effort? or where they of commercial origin?

I believe he has a mix of DIY and commercial - why not ask him? He had a young child sleeping and I didn't stay very long.

[Jeff B.]

Re: Gedlee on distortion

I'm not even sure how to ask this question...

How superior are high $$$ drivers to lower-cost offerings, when it comes to distortion that we can really hear, that is offensive?

And...

When it comes to distortions that we find audibly unpleasant, are we talking about smaller woofers (for example) being drive to extremes? Or are these distortions equally obvious on larger woofers operating well below xmax?

I'm not sure I even know what I want to know. Ugh.

Unfortunately, good motor design doesn't correlate real well to price. Looking at tweeters for example, the Scanspeak 9900 has the lowest distortion profile of any tweeter of any type that I have measured, and it is a pretty expensive tweeter. On the other hand, the Dayton RS28 series tweeters are way up there on the list of very good measuring low distortion tweeters, much better than some fairly expensive tweets, and these aren't expensive at all. To take it down another notch, the measured performance of the SB26STCN or SB26STAC are exceptionally good, and we're talking drivers that cost in the $30 - $40 range. You can spend a lot more money and have a tweeter than doesn't perform nearly as well. At the same time, there are some high-end tweeters that cost a lot of money and have nothing special to offer whatsoever, so selecting drivers is truly a case of caveat emptor.

It isn't much different with midwoofers, a while back I paid $280 for pair of 6.5" midwoofers from one well known company. The drivers were pretty, but the motors were really circa 1985 in my opinion (meaning typical for the time, not like Scanspeak motors of the time). These had no shorting rings or copper caps and 3rd order distortion was quite high in my opinion. Again, on the other hand, the SB17NRX is a driver with a lot of excellent features and very low distortion, so for a $60 driver, it is another excellent value.

Expensive isn't the metric, you have to dig deeper than that to find out what you are getting.

Jeff

[carlspeak]

Re: Gedlee on distortion

I believe he has a mix of DIY and commercial - why not ask him? He had a young child sleeping and I didn't stay very long.

i will ask him why he has not shared any of his DIY projects with the rest of us. I checked all of his threads and could not find any.

[monkish54]

Re: Gedlee on distortion

i will ask him why he has not shared any of his DIY projects with the rest of us. I checked all of his threads and could not find any.

Is he obligated to share? I haven't shared any of mine...

[carlspeak]

Re: Gedlee on distortion

Is he obligated to share? I haven't shared any of mine...

Obviously, no one is obligated to share their project, but aren't you just a bit curious as to why someone who writes so authoritatively should not have a great project or two I'd certainly love to see written up.
C'mon Pallas, let's see what you've got! :applause:

[monkish54]

Re: Gedlee on distortion

Obviously, no one is obligated to share their project, but aren't you just a bit curious as to why someone who writes so authoritatively should not have a great project or two I'd certainly love to see written up.
C'mon Pallas, let's see what you've got! :applause:

To be quite honest, I don't care either way. His ability or desire to design/build a loudspeaker doesn't refute or confirm his conclusion about distortion.

I find it a common theme:

Pallas makes a claim.

People disagree with the claim.

Rather than present evidence to dismiss his claim, we simply ask Pallas what he has designed and attempt to dismiss him by poisoning the well. Whether or not he has designed anything does not change the validity of his statements. I'll agree that sometimes Pallas can be condescending, but I'm not sure I blame him; when he claims something people disagree with they tend to get combative--often times before he does.

I think it would serve the discussion much better to ask Pallas for his evidence and to make an argument against his claim with counter evidence rather than dismiss him because he hasn't posted a build.

My 0.02.

Also, "PallasandhisToole" made me chuckle. :p

[blur]

Re: Gedlee on distortion

To be quite honest, I don't care either way. His ability or desire to design/build a loudspeaker doesn't refute or confirm his conclusion about distortion.

I find it a common theme:

Pallas makes a claim.

People disagree with the claim.

Rather than present evidence to dismiss his claim, we simply ask Pallas what he has designed and attempt to dismiss him by poisoning the well. Whether or not he has designed anything does not change the validity of his statements. I'll agree that sometimes Pallas can be condescending, but I'm not sure I blame him; when he claims something people disagree with they tend to get combative--often times before he does.

I think it would serve the discussion much better to ask Pallas for his evidence and to make an argument against his claim with counter evidence rather than dismiss him because he hasn't posted a build.

My 0.02.

+1

[carlspeak]

Re: Gedlee on distortion

To be quite honest, I don't care either way. His ability or desire to design/build a loudspeaker doesn't refute or confirm his conclusion about distortion.

I find it a common theme:

Pallas makes a claim.

People disagree with the claim.

Rather than present evidence to dismiss his claim, we simply ask Pallas what he has designed and attempt to dismiss him by poisoning the well. Whether or not he has designed anything does not change the validity of his statements. I'll agree that sometimes Pallas can be condescending, but I'm not sure I blame him; when he claims something people disagree with they tend to get combative--often times before he does.

I think it would serve the discussion much better to ask Pallas for his evidence and to make an argument against his claim with counter evidence rather than dismiss him because he hasn't posted a build.

My 0.02.

You are jumping to conclusions. I would not dismiss him. I'm just curious about what he's built.