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mboxler

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  1. I'm a little surprised that Klipsch authorized the use of electrolytic capacitors to replace the original film capacitors across the woofer. I believe Michael Crites did the same thing on the AK-3 he sells. Good to know!
  2. I mentioned in another thread that it appears Klipsch liked to have around 3mh inductance across the K-55M, hence the different parallel inductor values for the T4A and T5A. Seems to me that, in order to get the same 3mh using a 3636, one would need to use a 3.5mh inductor in parallel with taps 0-3 of the 3636??? I measure 20mh between taps 0-3 on my 3636.
  3. For me, dipping the end of the litz wire into solder flux before tinning really speeds up the process.
  4. Looks to me that the 5.6 ohm resistor across the K55 equates to a 4 ohm load on the .15mh/4.3uh components. That's already around 6000hz. Your 8 ohm driver appears to be around 10 ohms at 6000hz. If you put a 6.7 ohm resistor across the PRV D2200Ph you'll end up with a 4 ohm load, and can keep the other component values as is. The .3mh/2.2uh values on the ALK Universal are used for an 8 ohm load and are placed ahead of the autoformer to get the 6000hz low pass. Depending on your speaker, you may need to tweak the low pass to the woofer and high pass to the D2200Ph.
  5. It is an interesting circuit, as the 11.4mh inductance between taps 0-3 must have been too high to get the desired transfer function. The 2.5mh inductor is in parallel with the 5.8mh inductance between taps 0-2. That equates to around 1.75mh. That inductance, coupled with the windings between taps 2-3, equates to around 3.5mh. Oddly enough, I believe a 5mh inductor across taps 0-3 (11.4mh) would have worked as well, as that parallel combination also equates to around 3.5mh.
  6. I believe the 2.7mH indication on the schematic is the inductance between either end tap and the -6db tap. If you have an LCR meter, measure the inductance between each pair of wires. One pair of wires should measure around 10.8mH, so label one of those wires tap 5 and the other tap 0. Label the third wire tap 3. If all goes well the inductance between tap 5 and tap 3 should equal the inductance between tap 3 and tap 0...around 2.7mH. Mike
  7. T5A Seems identical to T2A, less the extra taps, as the inductance between taps 0 - 3 is 11.4mh on both.
  8. My brother and I spent half a day trying to figure out why one of his Klipsch subs didn't work. After measuring and swapping parts, it turned out that someone turned one of the knobs so hard that it twisted enough to touch one of it's legs to the leg of another knob. After straightening and tightening everything the leg was no longer shorted and the sub worked perfectly.
  9. The more I learn about crossovers, the more confused I get. When one refers to a crossover point, is one referring to voltage or SPL? Since a crossover can only control voltage, I took a wild guess. I tested the voltage across a Khorn K-33E with a 150uf shunt, and it came pretty close to a second order, 400hz filter. The filter had to be underdamped to get to that point, hence the slight bump in voltage before it drops. Not sure how it would blend with the first order high pass to the squawker, though. Mike
  10. I think it's actually more interesting than that. If the tweeter filter is connected before the 13uf capacitor, the load on the 13uf capacitor stays consistent, and the voltage drop across the capacitor will approach zero as frequency increases. Taps 0-5 will eventually get the full voltage. If the tweeter filter is connected to tap 5, the load on the 13uf capacitor becomes a bell curve, peaking out around 500-700hz. After that, the load drops quickly. At the rate the load is dropping, the voltage drop across the 13uf capacitor actually levels off, even though the frequency is increasing. That extra voltage drop never gets to taps 0-5. I'm guessing that's why Klipsch changed autoformers when they went with the elliptical tweeter filter. Since that filter is attached before the 13uf capacitor, it doesn't mess with the load on the capacitor, and more autoformer attenuation was needed.
  11. Sounds like you are trying to turn the tweeter filter to a 3rd Order Butterworth, like the Universal's filter? Then yes, the second capacitor is 3 times larger than the first. If you want to get the the Universal's 6000hz crossover point, simply changing the second capacitor in an AA to 6uf won't work. An ideal 6000hz 3rd Order Butterworth filter into an 8 ohm load would be 2.2uf, 160uh, and 6.6uf values. Since the first 2uf capacitor on the AA is in series with the 13uf capacitor, it effectively becomes a 1.75uf cap. A 1.75uf, 245uh, 6uf combination ends up crossing around 8800hz. In order to get a 6000hz filter, you would need to replace the first cap with a 2.7uf, replace the inductor with a 160uh, and replace the third cap with a 6.6uf. A 2.7uf cap in series with a 13uf cap is around 2.2uf. Keep in mind, the tweeter filter attached to tap 5 in a stock AA drops the voltage to the squawker (tap 3) by an extra 1.5db or so. Looks like changing the tweeter filter to the 2.7uf, 160uh, 6.6uf values will drop it another .5db. I think I got my simulations correct. Mike
  12. I was planning on connecting the common strap (and tap C) to squawker "+" and the 3619-ET output tap to squawker "-". Looking at Al's website picture of his Universal Economy, it sure looks like the 3619-ET tap "6" is connected to squawker "+". I assume tap C is connected to the common side of the "swamping" resistor and the common wire strap is connected to squawker "-". The picture is at a bad angle so I guess I'm seeing it wrong.
  13. I've read quite a few threads about this filter. Here's my uneducated take on it... I believe this is a three pole Chebyshev "Constant K" filter combined with a null pole. As I understand it, "Constant K" implies that the filter is designed for a circuit with equal source and load impedances. That's why the two series capacitors are equal. When this filter is used with a source impedance much lower than the load impedance, you get the familiar Type AA tweeter transfer function. I found this calculator which works great. Took a lot of trial and error to make it work. Someone smarter than me should be able to explain why it works. https://rf-tools.com/lc-filter/ For a high pass filter, I multiply the desired crossover frequency (-6db point) by 1.6. For a 6000hz cross, that's 9600hz. The screenshot shows the data entered. Note that the input impedance and output impedance are both set to 8 ohms (Constant K?). The Klipsch elliptical filter closely matches the computed component values. The 125uh inductor appears lower the crossover by around 300hz. The values for the null pole are pretty straight forward. Use the same value capacitor in series with an inductor that's 4 times the value of the Chebyshev shunt inductor. That would be a 2uf capacitor in series with a 460uh inductor, or in Klipsch's case, a 500uh inductor. The second screenshot shows both the Chebyshev filter alone and the Chebyshev filter with the null. I used the calculator's values for the simulation. The same calculator can be used to design a low pass filter as well. Instead, though, you divide the desired crossover frequency by 1.6. For the null, use the Chebyshev calculated inductor value in series with a capacitor that's 25% of the Chebyshev shunt capacitor. Again, I'm no EE. Mike
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