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Removing crossovers Chorus I ?


SonicSeeker
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  • Klipsch Employees
5 hours ago, captainbeefheart said:

Since foil caps need much thicker film layers, 5uM thickness compared to a metalized type of .05uM thickness they are going to be much larger in size. So it's certainly possible there is a difference in many regards to the properties of each. You'll get much more of the dielectric properties from a foil type since the layers are much thicker. I'll need to run a linearity check between a metalized type and a foil type and see if the foil has a more pronounced curve from the thicker dielectric.

 

I do know when they send out product documents listing applications foil types are sold for high pulse applications. The thicker film gives them more protection between plates.

 

The question @001 was asking about "voltage curve".  Since nobody is answering you I can't speak for what is inside their minds but I can give you my thoughts. Voltage curve is vague, but I assume they are talking about transfer function. Which a capacitor alone cannot really have a transfer function as it's a two terminal device. Typically when we talk transfer functions it's a comparison between in and out (2 ports, 4 poles). The crossover network can have a transfer function and they are most likely talking about amplitude vs frequency plots. So input is swept flat through the frequency range while we compare the output to it. Plotted out you'll see a specific shape known as the transfer function. The steepness or "slope" of the network is a transfer function. Phase shift is another transfer function of the network that can be plotted out, again the phase difference between input of the network compared to the output of the network. In theory if the outputs of the network look identical to what the original networks looked like then the amplitude vs frequency transfer function has been maintained and is their goal. It's possible using different types of capacitors that have say higher ESR will effect the transfer function of the filter, the higher frequencies going to the tweeter may be attenuated more than desired and so the transfer function plotted don't match up to the original intended networks. There is probably some papers the engineers have that show these plots for each of their networks and so they try to keep them performing the same when changing part types. So long as the output plots match then they should sound the same.

 

That's at least how I took what was said.

You are looking at it wrong. It’s the whole transfer function of the network. You need to start a new thread. 

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  • Klipsch Employees
4 hours ago, captainbeefheart said:

My E networks in my heresy are so simple with two 2uF caps, they came with the Tecate caps from JEM when I bought them last year.

 

I think it's probably just faster to test the network as a whole circuit and plot the output vs input with the JEM caps since we know these are sanctioned to be the "Klipsch sound".  Then I can swap various 2uF caps in and plot the filter outputs and compare the differences. This should show any and all differences between types to see if the specified caps do have a unique transfer function that is desired. It will probably be best to start an entire new thread for the sake of keeping the conversation kept to capacitor replacements for crossover networks.

 

I will already state that anything other than the JEM caps will be construed as a "modification" so that's how any cap other than the Tecate types should be referred to. Even if we achieve the same transfer function as them, they will still be considered a "modification" so please keep this in mind to respect Klipsch and JEM. The only sanctioned replacement parts come through JEM but we can at least be scientific about "modifying" the networks and showing the results from said modifications. There are others besides myself that are interested in other replacement capacitors besides the ones from JEM, so a database of how the plots may change may help determine which direction some people will go. If there is an audible difference then it should be measurable in one form or another. I'm also interested in possibly showing the linearity differences between different capacitors. Those will be different measurements on the capacitors alone outside of network. It may be prudent to also measure distortion at various output powers into a load through the networks and not just view amplitude vs frequency. Distortion results may clue us into some of the sonic differences.

I have done this. It might shed some light but once again start a new thread. 

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52 minutes ago, Chief bonehead said:

You are looking at it wrong. It’s the whole transfer function of the network. You need to start a new thread. 

 

How am I looking at it wrong? I said test the network. Or if it wasn't clear to you, that's exactly what I meant. Because like I mentioned you cannot test the transfer function of just a capacitor, we need it in the actual circuit.

 

 

5 hours ago, captainbeefheart said:

I think it's probably just faster to test the network as a whole circuit and plot the output vs input with the JEM caps

^^^^^^^^^^^This is what I said^^^^^^^^^^^^^^^^^^^^^^

 

I was going to test the properties of the capacitors (esr at various fequencies, leakage, series inductance, loss angle etc..) and also plot transfer function with them in the networks but testing the caps is a waste of time since all we are concerned with is it's interaction in the network.

 

 

And yes when I have some time to pull the E networks with the JEM caps installed I'll start a new thread with the results.

 

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  • Klipsch Employees
17 hours ago, Crankysoldermeister said:

Hi Roy, I'm too tired to wade back through the posts. There was something about why some hadn't used Klipsch branded capacitors and I said that being able to get these parts was a relatively recent thing. Randy said it's been two years, but what is two years compared to the almost 20 years some of us have been here, doing what we do because people had nowhere else to turn. A lot of work was done before those capacitors became available. That was all I meant.

 

As for mods, it's just the truth that some people like to modify their stuff, and they aren't much worried about what Klipsch thinks when they do it.  

 

When you asked me to stop calling my builds "upgrades" and to call them "mods", I did what you asked. You have said many times you don't care about the mods, just don't call them upgrades or Klipsch spec. I have respected that, so I don't understand why you're mad. I do think a mod or different network is required when someone starts yanking out tweeters, horns, etc.

 

There is no problem with me. I feel like I've been a voice of reason in this thread.

Yes you been the voice of reason. Sorry if I misunderstood. 

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3 hours ago, captainbeefheart said:

 

How am I looking at it wrong? I said test the network. Or if it wasn't clear to you, that's exactly what I meant. Because like I mentioned you cannot test the transfer function of just a capacitor, we need it in the actual circuit.

 

 

^^^^^^^^^^^This is what I said^^^^^^^^^^^^^^^^^^^^^^

 

I was going to test the properties of the capacitors (esr at various fequencies, leakage, series inductance, loss angle etc..) and also plot transfer function with them in the networks but testing the caps is a waste of time since all we are concerned with is it's interaction in the network.

 

 

And yes when I have some time to pull the E networks with the JEM caps installed I'll start a new thread with the results.

 

Please post here the link to the new thread when you do start one please.

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