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Bacek

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Posts posted by Bacek

  1. 14 hours ago, AudioDon said:

    Is there any servicing I can do to improve the sound? I was looking at Bob Crites site and see new diaphragms or the gasket between the driver and horn.

     

    For sure I would check the gaskets first. If those were K-55M not  K-55V then sometimes on Ms back cap was ungluing  itself, causing distorted sound. Also check if everything is screwed correctly, maybe it's mechanical buzz.

  2. 5 hours ago, dsmdylan said:

     

    What am I doing wrong here (Cornwall 1)? C1 seems close enough but C2 is obviously way off from the 2uF that's actually in the network.

     

    For a start auto transformer increases impedance seen by C2. And not sure  raw impedance's you have chosen are correct. For ex. K33 is 4 Ohm impedance speaker. Horn loaded it will be higher but it's not the case as it's Cornwall so judging by measurement around  400Hz it's closer to 5 or 6 Ohms. For other it will be similar + additionaly autotransformer impact.

    K33E_free-air_basshorn_R1.jpg

    K77 impedance looks closer to 7.5. And then other factors needs to be taken into consideration as actual frequency response and more. Calculator you have used is good only for ideal drivers with flat response and same efficiency.

    post-4254-13819264091062.thumb.jpg.e2fb764c1026db3605139836a0161836.jpg

     

     

     

     

    • Like 1
  3. For a long time I had 2 square magnet K33 laying in boxes. One is fine. The other had strange measurements, was lacking low frequencies when mounted in La Scala.  On closer examination it accrued that cone surround is "untreated", just clean fabrics that leaks air. To me looks like someone did recone but kind of wrong way. Cone part number seems to be same for both  451520-2, although one is R-451520-2 (R recone?).

     

    So question is if anyone knows if surround needs to be somehow treated/sealed on recone operation?

    Or maybe replacement cone should be "factory" treated and someone did something relay wrong with it?

    If possible I would like to fix that driver.

     

    First pic is faulty driver. Second one is working fine. You can clearly see treatment on second one. It glow slightly.

     

     

     

     

    faulty.jpg

    working.jpg

  4. Not sure where you are buying it but current APT driver is not the same as originally used in Klipsch mods. In the meantime (few years ago) Eminence changed to some Chinese supplier and this is actually different driver even though it looks similar. Somewhere here there is Bob Crites thread with measurements of this new one, and it looks inferior.

  5. Another thing I like about FIR filters that they don't change phase at crossover point. So signals from two drivers are always adding or subtracting (depending on a choice) and we avoid those strange wobbles near XO point where phase changes several times.

  6. 7 hours ago, HiFi Heaven said:

    Many Klipsch 8Ω-labeled systems use 4Ω woofers to boost bass output measurements by +3dB.

    But in LaScala or KHorn, horn loading increases impedance. So even if nominal free air or infinitive baffle impedance is 4 Ohm when placed inside of a horn enclosure, impedance raises, it can be even doubled.

  7. Tried to play little bit with FIRs and my crossover (Najda DSP). Unfortunately low frequency filtering has huge processing requirements. My XO allows only 1024 tapes per channel, mini dsp 2048. Good starting point would be 10k and more for sub. Anyway FIR's allow for very steep XO points. -90dBa is not a big deal.

    • Thanks 1
  8. 11 hours ago, Chief bonehead said:

    If the impedance is consistent, then an l pad will work because it will attenuate the freq response evenly. If the impedance if not consistent, then the lpad will not attenuate the freq response evenly. 
     

     

    Ok but while i remember correctly k55 impedance i k400  there is not more than 10% impedance variance in usable range. Does it this justify that large attenuation swing?

  9. 16 minutes ago, billybob said:

    And who is against their use and why?

    Thanks!

    This we actually know. Check  PWK article on previous page. Although I never understood this measurement effect and if it's something general or rather it was artifact of that particular test circuit.

    • Like 1
  10. 8 hours ago, tigerwoodKhorns said:

     

    If you put L Pads in Klipsch speakers they are no longer Klipsch speakers. 

    Does it mean that Klipsch does  not produce Klipsch speakers anymore? :) Or they again use autoformerts?

     

    Anyway from Chief bonehead comments on other topic, if you put anything into a Klipsch speakers they are no longer Klipsch speakers (key word is you, not LPAD, and I get this point of view).

     

    But I have trouble following this thread. What was actual question that started this topic? I miss some context in here. Who advises L Pads and for what purposes and where and in contrast to what?

    • Like 1
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