KP-302/3002 High Frequency Speaker - Intermittent & Scratchy Sound - Resolved, Bad Cap' Connection

[CWelsh]

6 minutes ago, Edgar said:

Yeah, I know. I was just in a foul mood. Apologies.

No offense taken. I knew you knew.

[CWelsh]

24 minutes ago, captainbeefheart said:

 

Well that's just it, many times these imperfections albeit are not suppose to be there and are not "faithful" to their inputs but sound good or are just benign. So you are correct in that even though technically it's an imperfection it's total effect on the overall acoustic output is either benign enough to not notice or the imperfection sounds good and adds something unique to the sound. Like harmonic distortion, not all distortion is dissonant, lower even orders are harmonious and somewhat benign, some even like the addition to 'warm' things up.

 

I build and restore electric guitars as a hobby and this reminds me of discussions I've had with friends about wanting "vintage reproduction" pickups to get that magical sound from the 50s or 60s. I try telling them that they will never sound exact because no machine can perfectly reproduce the imperfections and resulting distortion of something that was hand-made sixty years ago. Then I really piss them off by asking which one of the thousands of pickups wound that particular year do they consider to be perfect, because no two would have been exactly the same.

[captainbeefheart]

2 minutes ago, CWelsh said:

 

I build and restore electric guitars as a hobby and this reminds me of discussions I've had with friends about wanting "vintage reproduction" pickups to get that magical sound from the 50s or 60s. I try telling them that they will never sound exact because no machine can perfectly reproduce the imperfections and resulting distortion of something that was hand-made sixty years ago. Then I really piss them off by asking which one of the thousands of pickups wound that particular year do they consider to be perfect, because no two would have been exactly the same.

 

 What a wonderful hobby!! I sold my vintage guitars since getting a Collins Soco Deluxe, it's the only guitar I play anymore. And you are spot on, tell your friends they would have to most likely find the exact magnets used for those guitars, then hand wind the bobbin and pot in wax. Make about 100 of them and then test and play them all, they may find a few 'magical' sounding pups of the lot that fit the magic parameters of sounding 'good'. Honestly I think the ones that got the most turns on the bobbin ended up being the best ones as they will have more inductance and a hotter output. Now couple that extra output with some alnico magnets with the right BH curves where they slightly saturate giving off slight non-linearity and you got your mojo back baby!!

[CWelsh]

14 minutes ago, captainbeefheart said:

 

 What a wonderful hobby!! I sold my vintage guitars since getting a Collins Soco Deluxe, it's the only guitar I play anymore. And you are spot on, tell your friends they would have to most likely find the exact magnets used for those guitars, then hand wind the bobbin and pot in wax. Make about 100 of them and then test and play them all, they may find a few 'magical' sounding pups of the lot that fit the magic parameters of sounding 'good'. Honestly I think the ones that got the most turns on the bobbin ended up being the best ones as they will have more inductance and a hotter output. Now couple that extra output with some alnico magnets with the right BH curves where they slightly saturate giving off slight non-linearity and you got your mojo back baby!!

I'm not familiar with the Collings Soco Deluxe so I had to check it out. Man, is that ever a gorgeous guitar!

 

I always tell people I'm a better builder than player. I'm mediocre at best, but have a good sense of rhythm so I'm okay in a supporting role. One of the things I enjoy most about building and restoring is experimenting with the electronics to see what kinds of tones I can extract. My only attempt at winding my own pickups was a dismal failure, but I will try again once I get my shop set back up.

 

We sure have strayed far from the original topic of this thread 😄

[Chief bonehead]

11 hours ago, Edgar said:

 

Nothing at all, as long as it is accurately reproduced by your loudspeaker.

But should a speaker have constant phase?   

[Travis In Austin]

17 minutes ago, Chief bonehead said:

But should a speaker have constant phase?   

No, because it wouldn't sound natural. 

 

I'm guessing that FIR filters (and/or other digital processing) now allow for a speaker to have constant phase.

 

Thus, (still guessing) you can go too far with FIR filters?

[Edgar]

38 minutes ago, Chief bonehead said:

But should a speaker have constant phase?   

 

Well, I've designed filters for minimum phase and for linear phase, and for many phase characteristics in-between. (Loudspeaker model equations are identical to filter equations.) Zero-phase is a form of linear phase, but is noncausal. Constant-phase doesn't make any sense to me -- I cannot think of a single advantage that it might have. And it could be very difficult to implement.

[henry4841]

My thoughts are you want all the drivers in phase with each other and let the music take care of the musical phase shifts inherent in music. In real world, other then single full range speakers, it does not happen. Each and every component will create a phase shift of the original signal by the interaction of the drivers and or speakers with each other. Align 2 speakers in an appropriate box and throw in a capacitor on one of them and you will have some phase shift between the two speakers. Crossover designers, to my way of thinking, try and keep the phase shifts between the drivers to a minimal. 

[Edgar]

23 minutes ago, Travis In Austin said:

Thus, (still guessing) you can go too far with FIR filters?

 

Absolutely! Beyond a certain point it all just becomes "fun with numbers", and bears no resemblance to the natural world.

[Edgar]

@Travis In Austin, when you say "constant phase" do you really mean "constant delay"? 

[Travis In Austin]

3 minutes ago, Edgar said:

 

Absolutely! Beyond a certain point it all just becomes "fun with numbers", and bears no resemblance to the natural world.

I'm digging, and digging, and come to the realization I will never understand this in even the most basic terms. I went back to see what the giants have written about this, Klipsch, Delgado, Meyer, Heyser, Bell Labs, etc.

 

From a 1977 Dope From Hope:

 

Vol. 16, No. 8
September, 1977 
A NOTE ON LOUDSPEAKER IMPEDANCE AND ITS EFFECT
ON AMPLIFIER DISTORTION
(The following was submitted to the Audio Engineering
Society as a project note.)

 

"When a horn type tweeter is used with a direct radiator woofer, the power demanded by the
tweeter is in the order of 10 dB lower than that of the woofer. By using a matching transformer
instead of a resistive pad, the impedance in the tweeter range becomes almost ten times as hjgh
as the impedance in the bass range. Some critics deplore this impedance variation. But there are
advantages: the high impedance demands less power from the amplifier in the range where TIM
distortion is worst."

 

All of the greats, Newton, Feynman, Klipsch that I have read up on wanted to know why something existed in nature. Not just observe it, but truly understand the reason for it. With Paul Klipsch, a friend at Stanford told him that "a speaker always sounds better in a corner." From that comment, which he apparently agreed with, he set out to figure out why does it sound better. Not generally by observation, but at the root, literally at the quantum level (phonon). Twenty years later he had his first Klipschorn. For him, I'm not sure, the answer was linked to distortion and he pioneered the methods and means of measuring the multiple types of distortion and relating them back to his goal of accurate reproduction (High Fidelity). 

[Edgar]

3 minutes ago, Travis In Austin said:

All of the greats, Newton, Feynman, Klipsch that I have read up on wanted to know why something existed in nature. Not just observe it, but truly understand the reason for it.

 

I have informally concluded that we live in a 2nd-order universe. That is to say, essentially every resonant system in our natural world can be described by a 2nd-order transfer function (or, if you prefer, a 2nd-order differential equation). I can't claim that it's always true, but it certainly seems to show up a lot in the real world.

 

This is part of the reason that I object to extraordinarily steep, high-order crossover filters. I believe (without proof) that they sound increasingly unnatural as the order increases.

[Chief bonehead]

23 minutes ago, Edgar said:

 

Well, I've designed filters for minimum phase and for linear phase, and for many phase characteristics in-between. (Loudspeaker model equations are identical to filter equations.) Zero-phase is a form of linear phase, but is noncausal. Constant-phase doesn't make any sense to me -- I cannot think of a single advantage that it might have. And it could be very difficult to implement.

Minimum phase and constant phase are two different boneheads, as I am positive you are aware of. I’ve always said, you can’t fix acoustic problems electrically. You can only fix acoustic problems acoustically. So…..should a “well behaved” minimum phase response be a goal?  

[Chief bonehead]

3 minutes ago, Edgar said:

 

I have informally concluded that we live in a 2nd-order universe. That is to say, essentially every resonant system in our natural world can be described by a 2nd-order transfer function (or, if you prefer, a 2nd-order differential equation). I can't claim that it's always true, but it certainly seems to show up a lot in the real world.

 

This is part of the reason that I object to extraordinarily steep, high-order crossover filters. I believe (without proof) that they sound increasingly unnatural as the order increases.

My ears tell me otherwise……

[Edgar]

4 minutes ago, Chief bonehead said:

Minimum phase and constant phase are two different boneheads, as I am positive you are aware of. I’ve always said, you can’t fix acoustic problems electrically. You can only fix acoustic problems acoustically. So…..should a “well behaved” minimum phase response be a goal?  

Constant phase would be an anomaly. For example, one way to implement it would be to apply a Hilbert Transform to a signal, which will give constant 90° phase, and then scale and recombine that with the original signal to achieve any constant phase angle desired. But the resulting time smear would be horrible. And implementation in a loudspeaker is something that I would not even know how to approach.

 

I am personally in favor of "well behaved" minimum phase systems, because they concentrate as much of the signal energy as possible into the very beginning of the impulse response. Linear phase systems exhibit pre-ring, which can be very annoying.

[Edgar]

5 minutes ago, Chief bonehead said:

My ears tell me otherwise……

 

Ah, but there are so many other factors to be considered! So I do not disagree with you.

[Edgar]

2 minutes ago, Edgar said:

 

Ah, but there are so many other factors to be considered! So I do not disagree with you.

 

Continuing with that thought ...

For example, I have a system in my living room with vented bass. (Currently playing Linda Ronstadt.) A vented enclosure is inherently a 4th-order system. I can equalize it to any 4th-order system that I desire; Butterworth, Bessel, Chebyshev, etc. I can also equalize it to any 5th- or 6th-order system that I desire (or even higher, if I want to be absurd). The lower orders sound best. No doubt about it.

[mikebse2a3]

1 hour ago, Edgar said:

 

Continuing with that thought ...

For example, I have a system in my living room with vented bass. (Currently playing Linda Ronstadt.) A vented enclosure is inherently a 4th-order system. I can equalize it to any 4th-order system that I desire; Butterworth, Bessel, Chebyshev, etc. I can also equalize it to any 5th- or 6th-order system that I desire (or even higher, if I want to be absurd). The lower orders sound best. No doubt about it.

 

Considering the loudspeaker/room interaction variable do you try optimizing the loudspeaker locations with each filter change before judging which sounds best…?

 

miketn

[Edgar]

2 minutes ago, mikebse2a3 said:

Considering the loudspeaker/room interaction variable do you try optimizing the loudspeaker locations with each filter change before judging which sounds best…?

 

No, I only change one variable at a time. So perhaps I should say that the lower orders sound best in the current speaker locations.

[Travis In Austin]

3 hours ago, Edgar said:

@Travis In Austin, when you say "constant phase" do you really mean "constant delay"? 

The maxim: "No sound in nature has constant phase" is something I heard from a Bonehead. I wrote it down, word for word. For the last two years I have dabbled in trying to find out, first if it was true, and if it was, what is the significance when it comes to speakers, balancing networks, electronic crossovers (DSP). 

 

Why? Certainly not to try and design, improve, or change speaker systems. It's to try and have a better understanding of what PWK did from a historical perspective. To have a better understanding of what he did, and why he did it, and the impact that had on the audio and engineering world. He got a patent on a balancing network (described in the patent as a "crossover network."). How many people in the speaker, filter, network world can say that? Is it even possible today to get a patent on a balancing network? Or has the science and art run it's course?

 

The art and science of measuring speakers has a long, long way to go. Just google "M-Noise."

 

I don't know the difference between "constant phase" and "constant delay." I don't know what the Bonehead meant in the context of making the statement. The Bonehead would be able to answer that better than I could. I was just trying to understand why it is significant, in the most basic sense possible. 

 

I learn something new with almost every post in this thread. Sometimes it is that there way more to all of this then I will ever comprehend.