Al Klappenberger

John, 39 uF is 39 += 5% which is 39 +-1.95, so it could be 37.05 to 40.95 uF. You have 1 uF +- 10% across it which is 1 +=.05 or .95 to 1.05 uF. If you add the extremes it could measure anywhere form 38.0 to 42.0 uF. So.. your cap is good at 39.5. Al K.

Tony , John, Email me and we can decide what "reasonable" actually is to be. I still haven't heard from the seller. I will bug him again. alk@ezy.net Al K.

Hi guys. The picture below is an item up for bids now (March 26, 2001) on eBay: http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1224869985 I have not been able to confirm it from the seller yet, but I think all these drivers are the later version of the K55V having the phase plug modification done by PWK to smooth the frequency response. These can be identified by solder-on connections rather than push-on connections. If this is the case it represents 4 sets of drivers for home stereo speakers! The pictures seem to show solder-on connections, but I can't tell for sure. The price is probably going to go to high for me to buy it just to get one set of two. If four of us get together and buy it as a group, we could all divide the drivers between us (2 each at least). Would anybody else be interested if I can confirm that they are the later versiom K55V? Al K

Paul, Only the 3619 number is important on the transformer. The other number is just a production run ID number or something like that. It's different for every bunch I order. Al K.

Here's the AK-3: Al K

Jim, Ok.. Sorry I don't have any direct experience with the Heresy. The Cornwall is close and I do have one of them. It's has the K57-K squawker which does not need the P-Trap though. That only needed for K55V Atlas drivers. I got into this thread late because I just didn't see it soon enough! Sorry. Al K.

John, Do I detect a hint of sarcasm there? Al K.

Hi Guys, I managed to get very confused trying to follow what specific networks everybody has been talking about here, so I will make a few general points. Mainly that a second order filter can be made to generate a peak. This is what could be thought of a "Tschebyshev" (Spelling?) lowpass filter. It is possible to design for any peak you want by simply keying the desired correction factor, in dB units, as passband ripple into a filter syntheses program. This works because even order Tschebyshev filters exist between unequal terminations making an impedance mismatch at DC and coming to a matched condition at the peak. Any values of L and C can have any correction factor you need (dB) by selecting the termination impedance. The L and C values determines where the peak will be. The same values also determine where the crossover (of the network, at least) will be too. In short, there's a lot of interacting factors. A further complication is my "thing" of making constant impedance networks. I found that I can easily make a Tschebyshev response on the lowpass portion and a Butterworth response on the highpass portion of a second order diplexer if I assume perfect resistive terminations. Getting that takes some doing! It involves knowing the complex impedance of the drivers involved and correcting for it (Zobel). This gets even harder when there are two (maybe three) different bass horns involved (Khorn, La Scala and Belle). This is why I am using first order filters for the woofer / squawker transition. That way, the horns themselves determine the crossover frequency and frequency response. This is how the "AA" network did it (mostly) and initially what my network was inended to replace. Remember, when the AA network was in production, it was used in the Khorn, Belle and in the La Scala. Both the designs I have up on my web site are Butterworth designs and assume no passband ripples. This assumes a perfect resistive load by the drivers, which of course, isn't necessarily the case. Anyhow, no corrections of any kind are intended. The objective was a smooth transition form one driver to the next and a constant impedance load to the amplifier. The curves I have run so far show the response is not too bad. At this point I don't know if I can improve it by employing these methods or not. I need to do more testing to know. I have only had the equipment to do it for a little while and I should go over everything again to verify that I did it correctly. I am getting more proficient with the equipment now that I have been doing it a while. In any case, I think any improvements would be guilding the lilly. My main incentive for doing it would be that PWK did. If he thought it was worth doing, so should I! I would scan and post the curves I have made, but these are not sanitized and make things look bad when they are not. I don't want the average non- technical viewer to get the wrong impression of Klipsch speakers! Al K.

Blorry, Yeah! Give him a piece of you mind, the old one-two and then read him the riot act! . Seriously, he didn't sell it becasue his reserve was too high. The final bid he got was pretty-much the right price. That is, assuming the top didn't have the big dent! Maybe he has learned something on the first attempt. You might be seeing the listing again before too long. Al K.

John, You'r looking at eBay from the wrong point of view. What makes it great is all the stupid people who aren't as smart as you that you can take advantage of. Just be sure you are the smarter one! That's what horse-trading has been about since the dawn of humanity! Al K.

John, You got that right! You don't suppose that was to hide a huge dent in the top do you? Al K.

mdeneen, Thanks for the note but I am just thinking ahead. I will do that the day I get into home theater myself. It's a long term plan. I am not anywhere close to doing it yet! Thanks anyhow, Al K.

Safety, I baught a used LF-10 on eBay and it's super. I actually did a plot and it can be made to go flat down to 20Hz with ease! No air leaks in mine. Those passive radiators really move! Al K.

John, Good grief! What I need is a single Hresy to replace my Cornwall. Now that I have the LF-10 sub I don't need the extended bass of the Cornwall! I know.. Replace the flank Bells with Khorns! AL K.

Somebody was looking for a single Belle to use for a center fill speaker. There's one on eBya now (March 14) http://cgi.ebay.com/aw-cgi/eBayISAPI.dll?ViewItem&item=1221890608 Al K.

Elso, Let me shoot down a rather common myth here. The group delay of a Bessel highpass filter does NOT have flat group dealy! Only a Bessel lowpass filter will show flat delay. I have even tried to use computer optimization to flatten the dealy of a highpass filter. I have never been able to do it. The cutoff frequency simply moves down! If you scale normalized element values for Bessel response to a highpass filter you end up with an amplitude and impedance response (return loss) exactly as you would expect, but the delay is NOT flat! If you don't beleive it, I can post plots of any element values you suggest! Al K.

Johnny, Right, but there is a little more to it than shunting frequencies from one to the other. The "reactance slope" of each filter is mirror image to the other casing them to cancel leaving prue resistive impedance. If the values are not correct, or the opposing filter is not there, the reactance does not cancel. The number of element in the two filters in each diplexer must be nearly equal too. If not, you need computer optimization to make them work together. This is how I make an N=2 squawker filter work with an N=3 tweeter filter. Al K.

Johnny, You are quite right about the scale factors on the plots. The reason is that the scale factors are all automatic. I can't force the scale factor on the impedance channel. I can on the others though. Actually, if I did force the same scale, the impedance plot would be virtually a straight line. The program (PCFILT) was designed to display the results of analysis to display all the plots big enough to see. You are interpreting the circuit improperly when you try to series the 40 UF and the 2.2 uF. These caps are in different sections of the network. The 2.2 uFd (and the rest of the tweeter filter) works opposite the .3 mHy inductor (and the rest of the squawker filter) to form a 6000 Hz tweeter / squawker division having constant impedance. The 40 uF combination operates with the 2.4 mHy inductor to form a 400 Hz division, also of constant impedance. The entire tweeter / squawker division is way above the woofer / squawker division so the two do not interact. These are simply two different "diplexers" connected in series. Each is a separate entity. Al K.

Hi guys, I couldn't resist abusing the BB a little bit with a plug! Here's how the tweeter filter looks in my "ALK" network: Al K.

Fred, Here's the stuff I used on my Belle squawker horns. I used the same stuff on the tweeter horns too: I got this at the local "Sound Fx" car stereo store. The price was $19.99 a roll. The roll you see is totally unused. The scrap is what's left of another roll after doing both my Belles. Al K.

Fred, OOPS! Please do NOT imply from the picture I posted showing the Bi-Wire connections that I am promoting big wire for one and small wire for the other!!! The two different cables in the picture are to illustrate where the high and low cables are to be connected when the shorting straps are removed. They are just markers! I have no advice about what kind of cable to use. That decision is one that you will have to make for yourself! I invite discussion here about that very question. I have never tried Bi-Wiring myself! Anybody have any thoughts about it? Al K.

John, Testing the crossover points is difficult. Different methods give different results. I have chosen a method I use "in house" to compare two networks for left / right matching. The REAL crossover is determined by the speaker drivers as they work together. Even the autotransformer tap setting has an effect on it. If I were you, I wouldn't even bother to try it! It's not worth pulling your hair out over. AL K.

Hi Crossover fans, Here's some computer analysis studies on changing the 2.0 uF output cap on the AA network tweeter filter. Here's the stock AA (2.0 uF): With an intermediate capacitor value (3.3 uF): Last but not lease, with 6.0 uF: For comparison sake, I have moved the marker to 6000 Hz in each plot. Amplitude is in Green, simple impedance is in red, and group delay is in light blue (Cyan). Flat group delay is equivalent to linear phase. The analysis assumes a 0.1 Ohm source impedance, so the top reference line of the amplitued plot is of no interest. I will let the world decided if this is an improvement or not. Al K.

Hi Crossover A lot of people have requested Bi-Wiring for my crossover network so I have made the modifications necessary to do that. All the networks I make from now on will have this new feature. The design is unchanged otherwise. The new version (5) has been posted for download on my web site for anyone interested. The connections for bi-wiring are made by removing to straps that allow normal single (2 wire) cable connection to the amp. Al K.

Alessandro, All the details on my (ALK) crossover is on my web site at: http://www.web-span.com./alk Just look for the Klipsch speakers. Al K.