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JohnA

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Posts posted by JohnA

  1. I have a pair of Type ALs either of you can have. I'll take 1/2 of new. You should be aware that the Type AL is designed for a 109 dB, 16 ohm midrange driver, like the K-55-M. You can use it with another driver, but you may have to modify it. Several of us, esp. Al, can help with that.

    John

  2. Assuming the K-401 is the same as the K-400 and that my memory hasn't succumbed completely to CRS Syndrome, the lower cutoff is 263 Hz. However, it will have just about lost direstional control and diaphragm loading at that point. The best crossover point is one octave above that. I don't know about the K-55-M, but it should be similar the the 1823 or 1824 at 260 to 300 - 6 or 8k Hz. You will have to call Klipsch to be sure.

    John

  3. Hi Chris,

    Caps are capacitors. They are the small, tin plated tanks with 2 terminals on top. Back in the day, the paper in oil caps Klipsch used in the Heritage Series were likely the best there was. Now, more modern materials, found by research, have made capacitors more purely capacitive, with less resistance and energy stored and released as "ringing" or other distortion. Basically, a capacitor in series blocks lower frequencies. They can be used in combination with inductors to steepen the roll-off of either a high-pass or low-pass circuit. Klipsch used more modern caps in my KLF-C7, though not the $$$ expensive ones like Hovlands. It seems like I spent $110 for Hovland caps in each of my La Scalas.

    John

  4. Al has the button I was thonking about!

    My worst pair was a house brand from Dixie Hi-Fi (who knows who that is, now?). They were a 3-way with a 12", 3" & a 1". My brother and I bought them with lawn mowing money in High School. They made noise, I'm sure they sounded awful.

    After the 3rd pair failed, we added more money and bought a pair of U.S. made Marantz (7s?) speakers. My sister is still using those, way more than 20 years later.

    John

  5. I don't know anything about HPS. Since they changed the design, and the La Scala patent has long expired, I'm sure it's O.K. Since the site said the speaker was made for HPS, I think that's a clue. smile.gif Les brags on his La Scalas with the K-43 woofer having more bass, a 106 dB rating may well be possible.

    John

  6. Chris,

    Your tweeter can be repaired. Call Sam Stafford at Techstar in Nashville, Tennessee. The

    phone # is 615-242-2925. Their address is/was 750 Cowan St. #9; Nashville, TN 37207.

    Most any Pro Audio shop should be able to fix is as well. You need a diapraghm at @ $22.

    John

  7. "The capacitors they are using are very likely the most "bang for the buck" around!"

    Absolutely! The thing we are doing that improves the crossovers is the use of modern technology. Al's computer analysis and the newer cap and inductor designs all reduce the loss of signal or change in signal that any crossover network causes. In addition, the networks Al builds would probably have to sell for twice what he asks in a low production, retail environment. In short, the cost of each Heritage speaker would go up around $200, if Klipsch did the same thing.

    John

  8. I got another pair of La Scalas. They are 8734029 & 30. Today, I took the bottoms off to inspect the woofers and Lo and Behold, they are labeled K-33-E and have ROUND magnets. My first set are 81/82 models with K-33-Es with square magnets. The first set have K-77-M tweeters with rectangular magnets but the '87s have tweeters that look the same labeled K-77.

    Is this just normal production variations? Have the '81/'82 pair been "updated"? I thought the square K-33-E was the latest version.

    John

  9. DDick,

    You're right. I've already thought of that, but we need more info to see how the K-55-M is different from the -V Al designed for.

    BTW, I got them installed and calibrated this afternoon. The difference between these La Scalas and my old Bostons in the rear is really noticible. Better clarity and from the rear corners, plenty of dispersion for Pro-Logic. Rears matter. Size matters. We watched "The Sixth Sense"; spooky. Now I get to go upstairs and scare the living *&*& out of Cathy. :0

    John

  10. I found the problem! It was a loose wire from the + input terminal to an 8 uF capacitor. It was supposed to be clamped and soldered, but the red wire has never seen solder. I'd still like to get a copy of the Type AL schematic. This thing is needlessly complex. drobo sent me a copy of Types A, AA, and AL-3. I think the AL-3 may be the direction to go.

    Maybe I should have said "stole" rather than bought. I expected far worse problems.

    John

  11. I bought another pair of La Scalas for rear channels. They are '87 models, I think with Type AL xovers. One is fine. The other one has good drivers, but no sound comes from the squawker and tweeter, if you use the input terminals. Nothing is obviously wrong. This is the xover I never could quite sketch correctly. Does anybody have any ideas about what may be wrong? Do you have a schematic of a Type AL?

    John

  12. To All,

    Why isn't the 3" x 13" slot in a La Scala the "throat"? Mine begin an immediate expansion from there.

    Also, I sold my spare parts to Leonard Frisch (driver & xover). He's still short a K-400 horn. He didn't realize the driver was just the "softball" on the back. If anyone has an extra, he can complete his pair of La Scalas.

    John

  13. Peter, Ed,

    The idea is to build a J-shaped (L-shaped?), unfolded bass horn with the mouth against the floor, and place the HF section on top of that. The woofer would fire downward, its back air chamber would be between the HF section and the bass horn. I'd hope to make the footprint about 2' x 2' and have the left and right sides parallel. I'd try to vary the front and rear to achieve expansion. Since it would be tall, stability will have to be addressed.

    The killer for this whole project might be cost. If I can buy La Scalas for the same price, why bother? Even Cornwalls on stands would perform the way I want.

    John

  14. ED,

    I've got your spreadsheet. Thanks! I have a drawing that shows the slot the La Scala woofer fires through (throat?) is 13" x 3". That would give a compression ratio of 3.4. Is that accurate? I can't reach that far into the bass horn and it too much trouble to dissamble one right now to check. If so, I can build a 45" J-horn and set a La Scala top end on it and have a stunning rear surround. Your calculations are for a square horn, is rectangular expanding to square acceptable? It is most important that the area expand exponentially for the horn to have proper performance, is it not?

    John

  15. Gary,

    Al has a line on good components and a nice upgrade to the T2A autoformer. I'm sure the woofer could be run without an inductor, but PWK must have discovered it blends better with the mid using the inductor. A single element in a crossover gives a 6 dB/octave slope, not much, so the speaker depends on the the natural rolloff of the bass horn at higher frequencies.

    E-mail Al and be sure to orient the inductor and autoformer at right angles to each other to limit the influence of one on the other.

    John

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