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Everything posted by mboxler

  1. In my uneducated opinion, wattage is pretty much a useless spec, except for the utility companies. I still can't figure out what an RMS watt is. Amplifiers have voltage, current, and thermal limits. Drivers have voltage limits at various frequencies. If any of these limits are surpassed, you have a problem. On to passive bi-amping. If your "100 watt" amplifier output voltage is clipping while driving the entire speaker, two of these same amplifiers, each driving its own section of the crossover, will still clip. On the other hand, each will need to supply less current...how much less depends on the crossover frequency. I've read that the actual music power 50/50 split occurs around 350 hz, depending of course on the music itself. So, unless you want more or less bass , make sure both amps have the same voltage gain. But definitely make sure each amp can supply the needed output voltage for the full range signal. Mike
  2. mboxler

    1985 Cornwall issue

    It's five o'clock somewhere! This will be fun. Bringing as much stuff as I can, not knowing what the issue(s) are. Even found the old diaphragms from my Heresy's K-52-H mids, just in case his contains the Heppner K-52-H as well and one or both are bad. Also a pair of K-77-M's. Hopefully it's something simple, but we'll see. Mike
  3. mboxler

    1985 Cornwall issue

    Looks to be in the Denver area. If you are reasonably close to the Golden area, I'd also be happy to help. Mike
  4. Thanks, Chris! Still learning, and I could never figure out what .zma files were. Opened it up in notepad and it became clearer. At first I thought the phase column represented the electrical phase shift across the driver. But it now appears that it is acoustical phase shift. Correct??? Again, thanks for the info. Mike
  5. Chris Am I reading the Crites .zma file correctly? Looks like the driver, at 800 hz, is 8.5 ohms and 38 degree phase (inductive). Seems as though a 1.7 mh inductor would be needed, or am I missing something. Mike
  6. You could try these https://www.parts-express.com/speaker-l-pad-attenuator-50w-mono-3-8-shaft-16-ohm--260-254 between the squawker output of the crossover and the BMS driver. You are going to need around 12-14 db attenuation, and they don't specify the maximum attenuation of the l-pad. Are you using the K-77 tweeter? Gorgeous speakers! Mike
  7. mboxler

    AA networks, A networks, E2 networks FS

    And which BMS mid driver...8 ohm or 16 ohm?
  8. That is old! If you want to stay at 500hz, 5mh should work. 6.4mh for 400hz. If you get a 5mh, you could wire it in series with the 1.3mh, giving you 6.3mh, and see if you like it.
  9. I was hoping you had the stock 1.3mh inductor, as that would be way too low, and would account for your measurements. But the 5mh should have been better. Any way to measure the 5mh to verify it's value?
  10. What value inductor are you using for the woofer? Looks like you would need a 6.4mh to cross a 16 ohm woofer at 400hz.
  11. mboxler

    Bi-Amping Cornscala

    The more I look at the picture, this may be easiest (and what you were suggesting). Is there enough of pin 5 exposed to allow a quick disconnect to push onto? If so, remove the wires you marked red from the input. Maybe wrap the spade with electrical tape to make sure it doesn't make contact with anything. Crimp a spade connect to one end of the wire and a quick disconnect to the other end. Connect to spade end of the wire to the input red. Push the quick disconnect onto pin 5. I think that should work. Mike
  12. mboxler

    Bi-Amping Cornscala

    Sorry for the late reply @Gints. Yes, that sounds correct, but if you want to modify the current crossover, I think this would be easier... Leave the 2.5mh inductor. Since the woofer will not be connected, no current will pass through it anyway. You can leave the 6.8uf cap in place IF you can run a wire from INPUT to pin 5 of the autoformer. This wire would be in parallel with the 6.8uF capacitor, causing very little current to pass thru the capacitor, like it's not even there. With this setup, the 3db attenuation would not be needed in the miniDSP. If you don't like the results, remove the wire, and you're right back to where you started. There shouldn't be any load issues. If you want a greater and more consistent load on the high pass amp, you could solder a 10 ohm resistor from pin 0 to pin 5. But I'd take it one step at a time. I always place an 8 ohm resistor across the tweeter output, a 13 ohm resistor across the mid output, and use a cheap amplifier to pass varying frequencies to the crossover input. Using a true RMS multimeter, I measure the voltages across everything just to be sure I didn't screw something up, then connect to the drivers. If you lived in the Denver area I'd be happy to help you with this. Hope all this makes sense! Mike
  13. mboxler

    Bi-Amping Cornscala

    Not sure how your DIY skills are, but the resulting circuit is quite simple... Autoformer 500uH inductor 4uF capacitor Here's an unfinished AB-4500 (type A, bi-amp, 4500hz) crossover just to give you an idea. I believe for your CS you would attenuate the hi-pass output of the miniDSP by 3db. The nice thing about this setup is you can attenuate the PD-5VH to match your CT-125, then attenuate the high pass output from the miniDSP to match the low pass to the woofer. Mike
  14. mboxler

    Death & Eternity

    Reminded me of this video... https://www.youtube.com/watch?v=MBRqu0YOH14 I realize this is 6 minutes of your life that you will never get back.
  15. Radio Paradise just released their lossless web player. And for any of you using MIchael Herger's Squeezebox server and Radio Paradise plugin, he just updated the plugin to allow access to the four FLAC mixes. Mike
  16. mboxler


    The T9A actually has -3db attenuation. The T4A has -4db attenuation. Looks like the T4A was used in the Belle AB-2 crossover. If using the T9A... Hook input - to 0 output - to 0. Hook input + to 5, output + to 4. Mike
  17. mboxler

    Basic KHorn XO Question

    Since the woofer is getting all frequencies, his crossover looks like a first order band pass to the autoformer/squawker and a third order high pass to the tweeter.
  18. mboxler

    Basic KHorn XO Question

    There should have been a 4mh inductor and two 70uf capacitors in the bass bin. If you removed them, and have only wire between the input and the woofer driver, than yes the woofer is receiving all frequencies.
  19. mboxler

    La Scala crossover

    Not sure if you want to know what the current rating of the stock 2.5mh inductor is, or how much current can pass through the inductor. I don't know the stock inductor rating, but... I believe the K-33 can handle 150 watts. If we assume the lowest impedance is 4 ohms, and use Ohm's Law, that equates to around 24 volts and 6.1 amps. Since the inductor is in series with the K-33, current through both will be the same...6.1 amps. Perhaps over simplified, but I hope that helps. Mike
  20. mboxler

    ALK universal crossover

    Oddly enough, I'm currently "rebuilding" my ALK Universal kits I purchased quite a few years back for my K-horns. It was my first soldering project, and it looked like gray gum wadded around the connections. I'm seriously considering replacing the 1.3mh woofer coil that came with the kit with the 2.5mh value used in the type A and AA. I know Al argued for the 1.3mh, but I find it odd that his Super AA upgrade keeps the stock 2.5mh woofer coil. While testing the rebuilt crossovers, I wanted to find out the frequency where the voltage across the 1.3mh inductor equals the voltage across the K-33 (the -3b voltage point). It turned out to be around 1400 hz! As it turns out, the impedance of a 1.3mh inductor at 1400 hz is 11.4 ohms, which must be the impedance K-33 at 1400 hz??? For fun, I hooked up a 2.5mh inductor between the amp and the K-33, and found the -3db voltage to be closer to 400 hz, or 6.2 ohms. Seems like replacing the ALK Universal woofer coil might be an interesting experiment. Mike
  21. mboxler

    Klipsch Balancing Network Mysteries

    Using this calculator http://www.pronine.ca/capimp.htm Change Capacitance to uF and Frequency to Hz. A first order rolloff (-3 db) occurs when the impedance of the capacitor equals to impedance of the series load. This occurs at a specific frequency. The tweeter capacitor ALWAYS has a 8 ohm load (the K-77). Using the calculator, plug in 2 uF and 8 ohms. When you click Calculate, the Frequency will show 9947.1875 Hz. That's the crossover frequency to the tweeter. Moving the tweeter tap will not change this, because the cap is after the autoformer. The K-55 cap (4 uF) is before the autoformer. Since it is using input 0-5 and output 0-3, the impedance of the K-55 appears 4 times bigger. Assuming the impedance of the K-55 is 15 ohms, the load on the 4 uF capacitor will be 60 ohms. Plug those numbers into the calculator, and you will get a frequency of around 663 Hz. If you change the output tap to 0-2, then the load is 8 times bigger, or 120 ohms. If you want to keep the same 663 Hz crossover frequency, plug in 120 Ohm, 663 Hz Frequency, and the calculator will determine that a 2 uF capacitor is required. Hope that helps! Mike
  22. mboxler

    Bi-Amp question / thought

    Interesting. Are you running a 400 hz low pass signal from the Xilica XP 4080 straight to the K-33, but a delayed full signal from the Xilica XP 4080 to the HP section of the original crossover? The 13 uf capacitor of the HP crossover is still the high pass filter for the K-55? Mike
  23. mboxler

    Bi-Amp question / thought

    What passive are you using for the mid to high crossover?
  24. mboxler

    Bi-Amp question / thought

    Not sure if this helps, but here's a Type-A-BA (bi-amp) crossover I'm working on. SInce the active crossover replaces the 2.5 mh inductor (low pass filter) and the 13 uf capacitor (high pass filter) of the Type-A crossover, all that remains is an autoformer and 2 uf cap. I even went so far as to reverse the function of the autoformer. Instead of attenuating the mid by 3 db, the autoformer passes a 3 db gain to the tweeter. Since I'm using the same amp type for the low and high pass, I run the low pass amp at full volume, and the high pass amp at around 12 o'clock. Mike
  25. mboxler

    Bi-Amp question / thought

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