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

[billybob]

Sounds like you are on a good path for understanding, which will come...

[Dave A]

19 hours ago, captainbeefheart said:

 

For my work I rely on simulations a lot before going into prototype phase. For me it starts with an idea and scribbles with pencils and paper, circuits and calculations. Next thing to do is simulation to check calculations and also fine tune the performance. The prototype phase helps us improve my simulation phase also as if something needs to be moved on the board I need to either input or change parasitic properties into the simulation.

 

Besides designing and building things to put food on the table I have been making radios, amplifiers, TV's, speakers, crossovers, and many other electronic devices for the past 50-60  years.

 

Of course the listening aspect of this hobby is an important one and specs often don't tell the complete story, they can tell you a lot but after making something it always comes down to the listening test, I think we can all agree on that. As for simulations, they are only as good as the models you are using. Use a wrong model you end up with the wrong results, so it's important to know what the equivalent circuit is in order to model accurately.

 

As for this specific scenario, I don't see the purpose of any listening test. We are all on the same page that the acoustic response is the end goal but I feel many have lost sight of how this discussion got started. My original response was to folks choosing to use a film capacitor in the woofer circuit. The original design uses a general purpose electrolytic which has a much higher loss angle and subsequent much higher ESR. This extra resistance in that specific part of the circuit flattens the resonance out and so when changing to a film capacitor one may have to add the extra resistance in themselves to keep the electrical properties flat and more so keep the acoustic properties of the speaker the same as intended. In cases such as yourself you actually preferred the difference in sound so you liked the change in electrical properties and subsequent acoustic properties.

 

The discussion evolved into someone questioning the accuracy of the simulation without the voice coil reactance. Good question, crunching numbers tells us the average voice coil inductance really isn't going to have much reactance at frequencies below 500Hz but people were still concerned so I put the voice coil inductance into the simulation and voila no discernible difference as expected. It is a very simple exercise, inductors and their properties are quite well known and simply calculated but people are visual learners and all of us in here are not electrical engineers so it makes sense to post the two simulations showing the change with and without the inductance. If you find anything wrong with the simulation I am happy to rectify it, if one thinks the T/S parameters will make a difference I can calculate them into an RLC network and add it to the simulation but it should have no bearing on the series inductance and it's effects on frequency response. The simulation is only there to work out the electrical properties of the crossover network, not to be the end game acoustic sound form the speaker as once the crossover is worked out then move onto the measuring acoustic properties of the speaker system as a whole and critique it.

Always right I guess eh? Everyone else wrong I suppose also. Are your prototypes in cyberspace or do you have some physical samples to show?

[captainbeefheart]

I will try my best to explain the concepts better for people interested.

 

The statement I made about all the important stuff happens at the crossover frequencies is what I will go into depth about as phase seems to be the tough subject in relating electrical crossover properties to acoustic properties.

 

The problem rears it's ugly head near the crossover frequencies because this is where you will have two drivers in the speaker system contributing to the total acoustical output we hear. Around the crossover frequencies is where you will have the largest phase shifts and it's during transients where the phase alignment causes acoustic alignment problems. Because of the phase shift between two signals each driver will reach it's peak excursion at different times. For proper pulse wave transient response you want the signals reaching your ears at the same time, not different times. You can see if each driver reaches each peak at different times then the acoustic signals will not reach your ears at the same time.

 

Let's add some numbers for fun. At 1kHz it takes about .001 seconds to travel 12 inches. One way to resolve this is to physically adjust the alignment of the drivers until their acoustic centers are in alignment. Or you can use electronic phase delay for alignment. This is by far the hardest thing to get right in a multi driver speaker design and why many people have gone to full range single driver systems. Great speakers have coherent sound staging by having good time alignment between the different drivers. The further you get away from the crossover frequencies you are back to just the drivers own acoustic response and the crossover has little to no phase shift issues causing time alignment problems. 

 

Hope this makes phase a little easier to digest for the lurkers reading and not contributing, heck even the contributing members may learn something

[Dave A]

4 hours ago, captainbeefheart said:

I will try my best to explain the concepts better for people interested.

 

The statement I made about all the important stuff happens at the crossover frequencies is what I will go into depth about as phase seems to be the tough subject in relating electrical crossover properties to acoustic properties.

 

The problem rears it's ugly head near the crossover frequencies because this is where you will have two drivers in the speaker system contributing to the total acoustical output we hear. Around the crossover frequencies is where you will have the largest phase shifts and it's during transients where the phase alignment causes acoustic alignment problems. Because of the phase shift between two signals each driver will reach it's peak excursion at different times. For proper pulse wave transient response you want the signals reaching your ears at the same time, not different times. You can see if each driver reaches each peak at different times then the acoustic signals will not reach your ears at the same time.

 

Let's add some numbers for fun. At 1kHz it takes about .001 seconds to travel 12 inches. One way to resolve this is to physically adjust the alignment of the drivers until their acoustic centers are in alignment. Or you can use electronic phase delay for alignment. This is by far the hardest thing to get right in a multi driver speaker design and why many people have gone to full range single driver systems. Great speakers have coherent sound staging by having good time alignment between the different drivers. The further you get away from the crossover frequencies you are back to just the drivers own acoustic response and the crossover has little to no phase shift issues causing time alignment problems. 

 

Hope this makes phase a little easier to digest for the lurkers reading and not contributing, heck even the contributing members may learn something

Do you know Jeff Medwin by any chance?

[Edgar]

48 minutes ago, Dave A said:

Do you know Jeff Medwin by any chance?

 

I had decided to no longer participate in this thread, out of frustration. But at this point I think that we need to gain a little perspective, so I changed my mind.

 

captainbeefheart's understanding of the science is fundamentally correct. My frustration, and I suspect that of others, stems from his implication that his approaches to the problems are the only ones that are viable. There are as many viable solutions to a problem as there are people to formulate them, and each person seeks to optimize things according to whatever aspect of the problem is most important to them.

 

@captainbeefheart, if I am misinterpreting your intent, then I apologize. But that is the way that your messages come across.

[billybob]

May be a fair, for the sake of the curious, and if forum had no object, be beneficial to subjects of interest. Maybe possible for some to put their 

wares to hand in concept. LaScala or other  vintage model.

In other words, someone with the interest confer with the new member to see about building a crossover.

Maybe too ambitious...got the idea from a poster here.

[ClaudeJ1]

On 12/29/2021 at 1:04 PM, captainbeefheart said:

Of course the listening aspect of this hobby is an important one and specs often don't tell the complete story, they can tell you a lot but after making something it always comes down to the listening test, I think we can all agree on that. As for simulations, they are only as good as the models you are using. Use a wrong model you end up with the wrong results, so it's important to know what the equivalent circuit is in order to model accurately.

When I met and spoke with Tom Danley, he told me that he always had to go back and adjust his models to reflect what he measured and heard.

[ClaudeJ1]

15 hours ago, Edgar said:

if I am misinterpreting your intent, then I apologize. But that is the way that your messages come across.

Audible Significance are what come to mind about this whole argument thing about phase, capacitors, inductors, speaker boxes, horns, etc, which are all IMPERFECT components.

 

I use a combination of first order networks combined with acoustic measurements, with the driver voice coils aligned to well within the "industry standard" Quarter Wave between horn woofer and horn midrange. Then I let the DSP's in my Yamaha's YPAO microphone feedback system adjust for Room Acoustics to flatten it all out. Using a Hybrid approach renders all these argument (to my EARS) something I write off as academic BS. Now where is PWK's button............

 

Bottom line is. Make all electrical and acoustical things as good as you can make them, then apply the closed feedback loop, making use of all AVAILABLE technology for better sound.

 

Besides, it's the RECORDINGS that have the worst flaws, not the speakers!

[OO1]

Does anyone like Fishing 

[captainbeefheart]

16 hours ago, Edgar said:

 

I had decided to no longer participate in this thread, out of frustration. But at this point I think that we need to gain a little perspective, so I changed my mind.

 

captainbeefheart's understanding of the science is fundamentally correct. My frustration, and I suspect that of others, stems from his implication that his approaches to the problems are the only ones that are viable. There are as many viable solutions to a problem as there are people to formulate them, and each person seeks to optimize things according to whatever aspect of the problem is most important to them.

 

@captainbeefheart, if I am misinterpreting your intent, then I apologize. But that is the way that your messages come across.

 

Sorry you felt this way. I have noticed that although the internet and text messaging are great it also does not reflect the users tone and body language.  Nobody is ever going to 100% agree with one another, there were many times in my life where we had several engineers and we all had different solutions. Or, maybe two would agree on a solution while the other was feeling like he was being ignored, get frustrated and leave in anger. The bottom line is it's science, we are trying to solve the same issues, we all have that in common. In no way am I trying to tell anyone how to go about doing anything. For example I loved seeing a zobel network on your 1200Hz crossover network, great solution to a problem. I am not trying to tell someone to not use a film capacitor, I am only saying it most likely will exacerbate the resonant frequency issue.

 

 I think we are all here to do the same thing, to help and improve the sounds we love so much especially with Klipsch speakers that we also love so much.

 

I apologize to anyone if I came across as being a know it all, I don't know it all and I am still learning every day. I just want to help really.

 

 

[Chief bonehead]

5 hours ago, RandyH said:

Does anyone like Fishing 

I do!!!  I do!!!

[CWelsh]

2 hours ago, captainbeefheart said:

I apologize to anyone if I came across as being a know it all, I don't know it all and I am still learning every day. I just want to help really.

 

 

I believe you when you say this, which is the primary reason I haven't used the ignore function for you. I do believe that your intentions are good and there is nothing malicious in what or how you state your opinions, but as one of the non-contributing lurkers on this thread (and many other similar threads) I have to say, you often come across as smug and condescending. I don't assume you mean to, but...

 

Consider a couple of sentences from your next-to-last post. What I encourage you to do is try your best to put yourself in the place of other followers of the thread and understand how these might come across to them:

 

     "I will try my best to explain the concepts better for people interested."

 

     "Hope this makes phase a little easier to digest for the lurkers reading and not contributing, heck even the contributing members may learn something."

 

I was going to write a lengthy essay suggesting tools you could use to be a more effective (less offensive) communicator, but realized I was the one sounding smug and condescending, and that isn't helpful to anyone. Suffice it to say, I appreciate your contributions to these threads and feel I learn from you and others in the back and forth. I just encourage you to tone it down a little and engage in friendly dialog about this wonderful hobby of ours without feeling you have to instruct everyone else in the one correct truth...yours. We've got too much of that in the world.

 

Peace

 

 

 

[OO1]

bump-

[captainbeefheart]

1 hour ago, CWelsh said:

 

I believe you when you say this, which is the primary reason I haven't used the ignore function for you. I do believe that your intentions are good and there is nothing malicious in what or how you state your opinions, but as one of the non-contributing lurkers on this thread (and many other similar threads) I have to say, you often come across as smug and condescending. I don't assume you mean to, but...

 

Consider a couple of sentences from your next-to-last post. What I encourage you to do is try your best to put yourself in the place of other followers of the thread and understand how these might come across to them:

 

     "I will try my best to explain the concepts better for people interested."

 

     "Hope this makes phase a little easier to digest for the lurkers reading and not contributing, heck even the contributing members may learn something."

 

I was going to write a lengthy essay suggesting tools you could use to be a more effective (less offensive) communicator, but realized I was the one sounding smug and condescending, and that isn't helpful to anyone. Suffice it to say, I appreciate your contributions to these threads and feel I learn from you and others in the back and forth. I just encourage you to tone it down a little and engage in friendly dialog about this wonderful hobby of ours without feeling you have to instruct everyone else in the one correct truth...yours. We've got too much of that in the world.

 

Peace

 

 

 

 

I am always trying improve anything I do so I really appreciate the feedback. I will read my posts a few times before posting them to make better.

 

Those comments about explaining the concepts better for people was not intended to say "I know about this subject and you people don't". It was meant to try and reach people not having technical understanding of things, in this case phase which comes up a lot with many people I talk with which have a tough time with the concept. And rightfully so, it is not an easy subject for anyone. Your quote misses the emoticon in the last sentence about the contributing members even learning something, that was just a joke and not meant to be taken seriously which is why I added the winky face. Another example of things just not coming across through texting/messaging properly because it's just impossible to perceive tone and body language to know someone is just busting your chops as a joke.

 

I just want to move forward, I really like many of you I met on here and would hate to be looked at as a jerk. I am actually quite easy going and always joking in person. I use lots of sarcasm and busting chops is an sign endearment to myself and many of my friends, it's a regional thing (Boston) me thinks.

[OO1]

Yep , Boston

[CWelsh]

21 hours ago, captainbeefheart said:

I have noticed that although the internet and text messaging are great it also does not reflect the users tone and body language.

You've hit the nail on the head. And, I don't think you're a jerk. Let's face it...social media is a minefield for all of us. I know I've become increasingly touchy over the last couple of years and I think it is probably true for most of us.

 

Best wishes to all for a happy and friendly new year!

[geoff.]

Amen, brother.

 

...my thick head and thin skin doesn’t help either

[OO1]

bump

[Travis In Austin]

On 12/28/2021 at 12:25 PM, Edgar said:

 

It's in an enclosure.

LOL, I even understood that. Oh boy. 

 

I'm going to write a joke about this some day: "Three engineers go into a bar  . . . ."

 

I thought we were not supposed to call them crossovers? Or is that just dumbed down vernacular? 

 

Is a passive network patentable in this day and age? I was thinking about that the other day. I know that PWK had one a long, long, long time ago. 

 

When I read the responses it always leads me to two thoughts:

 

1. "No sound in nature has constant phase." Still trying to understand why that's important, but it seems to have some application here in the last 4 or 5 exchanges. 

 

When all else fails . . . .

2. "Don't worry about the horse being blind, just load the wagon."

 

Q: How many engineers does it take to change a light bulb? A1: None. They are all too busy trying to design the perfect light bulb. A2: Only the one with the instruction manual. A3: One. But she would insist that the way she did it was distinctive. A4: Three. One to hold the ladder, one to hold the light bulb, and the third to interpret the Japanese text. A5: Five. One to design a nuclear-powered light bulb that never needs changing, one to figure out how to power the rest of the USA using that nuked light bulb, two to install it, and one to write the computer program that controls the wall switch. A6: None. "According to my calculations, the problem doesn't exist."   A7 None, they simply redefine darkness at the new industry standard

[Travis In Austin]

On 1/1/2022 at 12:09 PM, ClaudeJ1 said:

When I met and spoke with Tom Danley, he told me that he always had to go back and adjust his models to reflect what he measured and heard.

That's what PWK called the "fudge factor" when he asked Roy to design a horn and Roy came back and told him the models/calculations were not matching. Paul said, "well what I didn't tell you is there's a fudge factor." Then Roy set out to do his own modeling software, you know the story. He was in search of something akin to the gravitational constant, his program started with 7 parameters, and I think he said, and 30 years later he is up to 21+ parameters. I never asked him how much he was able to narrow Paul's fudge factor