George,
Since Derfy wimped out, the answer is that phase shift without amplitude change doesn't stand out as I presented an example way back and you and others couldn't hear it. Even though it was much greater than 5 degrees and lower than 20,000 hertz. So I am unable to confirm Schroeder's work.
However when the phase shift causes a change in the peak value by less than 10% that does stand out, even with high frequency hearing loss.
As to system distortion usually not a problem as in reality the harmonics from the system are on 2nd and 3rd harmonics. The second is one we don't tend to really perceive at modest levels and the third is much less than we generate with our test tones.
So Derfy, wimp...wimp...wimp... (Easy test with a computer at your beck and call these days.)
The key word here is 'without amplitude change'. However, at -3dB at 20Khz you would have (simple RC) -45 degree change. A lot more than 5 degrees.
Consequently, a much wider BW is needed to remain under 5 degrees.
THx-RNMarsh
Consequently, a much wider BW is needed to remain under 5 degrees.
THx-RNMarsh
Not kidding at all. You post vociferously here. With all your bloviating I was just curious as to your depth of judgement and evaluation of audio reproduction. Now I know pretty well.
Hi Robert,
Okay, whatever. When I see some of the guys, I'll ask if they can remember much about what we listened too. But in 2005 I was involved in a ad car accident and suffered memory loss and a host of other problems. Some stuff I remembered well, other things, especially recent things, I can't remember at all. That's the best I can do for you since you want to make this an issue. Personally, I think the exact answers have little value, but I can tell you for sure that I listened to some Triumph since I had been in on those sessions. I even got a credit on a CD. I can't remember which one it is though. You would think I should be able to remember that, wouldn't you? I can't, it's not a big deal really.
So, given your response, if I can get some answers together for you, I do expect an apology, right? I mean, if you're going to take that attitude, then you have to admit when you're wrong and fess up to same.
Hmm, I think there was some Tom Cochrane in that group too. I heard him lay down some tracks. Many others, but it never seemed important to remember this as we were always meeting people in the industry. We also had several famous musicians drop into our shop for repair work. Again, it didn't seem important to make an issue of their visits. There would always be someone else next week kind of thing, and they highly preferred being treated just like the next guy would be. Some of the guys would come out and make a fool of themselves. It was clear that the person at the counter was also uncomfortable about the adoring fan. Oh yeah, some members from Saga would drop in occasionally.
If visits from successful music people make you jealous, get a life. There are good ones, and bad ones just like in any other population you look at. It was a job for my wife and I. All they cared about was getting good work done without a lot of fuss.
-Chris
Okay, whatever. When I see some of the guys, I'll ask if they can remember much about what we listened too. But in 2005 I was involved in a ad car accident and suffered memory loss and a host of other problems. Some stuff I remembered well, other things, especially recent things, I can't remember at all. That's the best I can do for you since you want to make this an issue. Personally, I think the exact answers have little value, but I can tell you for sure that I listened to some Triumph since I had been in on those sessions. I even got a credit on a CD. I can't remember which one it is though. You would think I should be able to remember that, wouldn't you? I can't, it's not a big deal really.
So, given your response, if I can get some answers together for you, I do expect an apology, right? I mean, if you're going to take that attitude, then you have to admit when you're wrong and fess up to same.
Hmm, I think there was some Tom Cochrane in that group too. I heard him lay down some tracks. Many others, but it never seemed important to remember this as we were always meeting people in the industry. We also had several famous musicians drop into our shop for repair work. Again, it didn't seem important to make an issue of their visits. There would always be someone else next week kind of thing, and they highly preferred being treated just like the next guy would be. Some of the guys would come out and make a fool of themselves. It was clear that the person at the counter was also uncomfortable about the adoring fan. Oh yeah, some members from Saga would drop in occasionally.
If visits from successful music people make you jealous, get a life. There are good ones, and bad ones just like in any other population you look at. It was a job for my wife and I. All they cared about was getting good work done without a lot of fuss.
-Chris
What specifically do you want me to apologize for? Regarding being jealous about visits from successful music people I really don't know where you got that from, but since a very young age I have been around plenty of those types. My father was a session drummer here in Los Angeles. I have met, seen concerts from backstage and been to the houses and tagged along on tours of Frankie Avalon, 5 Dimension, Pat Boone and daughters, to name a few. All this before I was 12 years old.
Enough name dropping for now
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Robert, hang in there! Some people here have better or at least different hearing sensitivity than others. I can tell, for example, as to what they are happy to listen to at home. For me, almost everything is important, including open loop bandwidth (to reduce PIM). I just keep winning awards for my concern to do it 'right' and not settle with the status quo.
Thanks! I am clawing my way up to your level with every circuit change I can muster.
Well it warms my heart to see that no holds barred tribalism is still a thing. Who needs logic when you can out name drop and anecdote another person.
Yes, I agree not far apart & that is the alternate view - more accuracy & reduction of distortion - the problem seems to be we don't know what distortions & what reduction in levels are necessary for better perceived realism?
John, if you ever want to come and give a talk at the Hollywood Sapphire Group just let me know.
Hi Robert,
Well, that entire conversation went down the swirly hole. I'm not going to pursue anything with a response like that. It's clear where you are coming from, and that's okay for you.
-Chris
Well, that entire conversation went down the swirly hole. I'm not going to pursue anything with a response like that. It's clear where you are coming from, and that's okay for you.
-Chris
What is your opinion about class D using Bessel type filtering in the forward path to allow very high feedback over the audible frequency range even though the open loop bandwidth is limited? Does it follow that large open loop bandwidth is not necessary?
Do you disagree with the math in Bruno's article? John is going to continue to beat a dead horse. The question doesn't even need to be asked.
I think the question does need to be asked and I think John Curl has the expertise to provide a useful answer if he chooses to. I am assuming the maths is correct. I am hoping that John may also touch on why you don't see this sort of filtering used in linear amplifiers; it could be applied here too.
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