rune Posted May 22, 2002 Share Posted May 22, 2002 Can I use a Type A x-over in a Khorn from year 2000? The reason I ask is that I'm thinkin' of buildin' the Type A,because I believe simple is better.And I understand that PWK also prefered the 1.order solution. But I think I have read that the A has x-over frequencies at 500 and 5k,is that correct?And the AK-3 has 400 and 6k? So does the A go with the drivers I have,or do I have to change the values on the type A to match todays drivers? I'm hoping someone could help me out here...... Quote Link to comment Share on other sites More sharing options...
JohnA Posted May 22, 2002 Share Posted May 22, 2002 I wouldn't advise using the Type A in a Y2K K-horn without mods. It has no HF roll-off for the midrange. The Type A was used with the K-55-V that naturally started rolling off at 4k. BTW, the crossover points for the Type A are 400 and 9k, but all are 6 dB/octave. try adding an inductor the roll off the squawker around 5k at 6 dB/octave. Otherwise, it will work fine. John Quote Link to comment Share on other sites More sharing options...
WMcD Posted May 22, 2002 Share Posted May 22, 2002 I can't quite agree with John here. He is being cautious, and there is nothing wrong with that. I'd think that as long as you're not abusing the little darlings, things will be okay. At least as okay as with the early design. The original and later design crossover in the mid are different because of the addition of the inductor across the midrange driver. However, that just converts it from a 6 dB high pass to a 12 dB high pass. Perhaps the 2002 design does have a something to limit the highs. But we're not talking about that. There is some question about whether the impedance changes with different drivers. I.e. the input impedance of the driver. But my guess is that it is not so significant to make the A type unusable or even in need of a different value capacitor. Regards, Gil Quote Link to comment Share on other sites More sharing options...
JohnA Posted May 22, 2002 Share Posted May 22, 2002 I think Gil's right (suprise!?). I looked at the schematic for the AK-3 that a Y2K K-horn would have and I believe the extra inductor steepens the squawker's high pass and it is run without a HF roll-off, just like the K-55-V. I had always thought the -M went a little higher than the -V. Based on my experience with both the -V and -Ms in my La Scalas, I'd expect the combination of the K-55-M and Type A to be a little more forward than the K-55-M/Type AK-3 combo. That's easily cured by changing taps on the autoformer. Be sure to use Solen FastCaps or Hovland Musicaps and good inductors in your homemade Type As and you'll be very satisfied. John Quote Link to comment Share on other sites More sharing options...
rune Posted May 23, 2002 Author Share Posted May 23, 2002 Thank you guys! I'm going with only the best sounding components,and I'm coming back with a report on the result!! Take care! Rune Quote Link to comment Share on other sites More sharing options...
rune Posted May 27, 2002 Author Share Posted May 27, 2002 New questione! In the Type A the transformer is called T2A and in AK-3 it is T4A....They are not the same are they? I'm thinkin of getting some custom-made so do anyone have the values for these transformers? By the way have anyone tried comparing these x-overs? Thank you for informing a newbie like me! Rune Quote Link to comment Share on other sites More sharing options...
JohnA Posted May 27, 2002 Share Posted May 27, 2002 The T2A has more windings than the T4A. The T2A was to be used in several different speakers. You should be able to use the T4A in place of the T2A, but I wouldn't. I'd preserve your AK-3 network. You can get the T2A under a different part number from UTC in Texas. I'm sure Al Klappenberger would also sell you a pair as well. He uses them in his custom xovers. They are pretty cheap. http://www.alkeng.com/klipsch.html John Quote Link to comment Share on other sites More sharing options...
rune Posted May 27, 2002 Author Share Posted May 27, 2002 Thank you John! I'm hoping Al or somebody else have the values on the T2A autoformer? Rune Quote Link to comment Share on other sites More sharing options...
Stig Posted May 28, 2002 Share Posted May 28, 2002 Tap values for T2A: #5-input, #4-32Ohm, #3-64Ohm, #2-128Ohm, #1-256Ohm,....0 tap is grnd note of confusion on T4A, the 'single tap' is labled #3 but uses a 13UF cap (along with 5MH coil for 12db slope) which corresponds to tap #4 on T2A. Do not use the 13UF value on a lower tap if you have one built. The math says it would be half of that for tap #3 (64-Ohms) but with the impedence variations... I don't know. Stig Quote Link to comment Share on other sites More sharing options...
rune Posted May 28, 2002 Author Share Posted May 28, 2002 Is that all the values I need to get one autoformer made? So basically I could just put a resistor in the x-over with these values? Quote Link to comment Share on other sites More sharing options...
Stig Posted May 29, 2002 Share Posted May 29, 2002 Sorry I should have added the following, tap #4 gives 3dB attenuation, #3 gives 6dB attenuation, #2 gives 9dB attenuation... The autoformer (T2A, T4A) is used instead of resistors. If you want to run the K-55-M WITHOUT the autoformer just find the series-parallel resistor circuit values for a 16OHM driver at somewhere between 3dB-9dB attenuation. Use a midrange cap value for 16OHM at 400 cycles. I have used series-parallel resistor circuit with the K-55-M... works fine ....but I found that the autoformer took the edge off the horns and seemed to just sound 'better'. You may like it...... Stig Quote Link to comment Share on other sites More sharing options...
rune Posted May 30, 2002 Author Share Posted May 30, 2002 Thanks a lot,Stig! Quote Link to comment Share on other sites More sharing options...
rune Posted May 30, 2002 Author Share Posted May 30, 2002 Thanks a lot,Stig! I'm probably gonna go with the T4A at first,until I get something like the T2A custom made... I'm coming back with reports.... Take care! Rune Quote Link to comment Share on other sites More sharing options...
rune Posted May 30, 2002 Author Share Posted May 30, 2002 By the way guys,is it possible to let out the autoformer,or would this kill the drivers? I'm thinkin' this with a biamp solution so one can regulate the volume on the bass and mid/tweet seperately.... Any opinions? Rune Quote Link to comment Share on other sites More sharing options...
JohnA Posted May 30, 2002 Share Posted May 30, 2002 Rune, The squawker's sensitivity is 107 dB @1 watt, the tweeter and bass horn ate 104 dB @1 watt. You need to reduce the squawker by 3 dB. Biamping won't be enough; triamping would. You can get an autoformer from Universal at: Universal Transformer #3619 P.O. Box 472 Farmersville, TX 75442 972 784-7700 voice 972 782-7000 fax I think they are about $US20 each. The different taps reduce the voltage to the squawker and cut it's output. The other alternative is a pair of resistors in an "L" shape called an L-pad. There are design calculators on the web to size the resistors. You can place the high-pass capicitor before or after the L-pad or autoformer as you desire, but you will have to select values to match the impedance the cap "sees" where ever you put it in the circuit. I believe the 3619/T2A is nothing more than the standard 70-volt line transformer used in distributed audio systems. If you buy one locally, be sure you buy a high quality unit. John Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted May 30, 2002 Share Posted May 30, 2002 Rune, The T2A can NOT be replaced by a 70V line transformer! The winding uses much to fine wire and will be very lossy. The taps are 3 dB steps as Stig mentioned. I suggest you try to get the #3619 from Universal Transformer Co. if you can. I think it will replace the T4 by simply finding the correct tap. Al K. Quote Link to comment Share on other sites More sharing options...
esker Posted May 30, 2002 Share Posted May 30, 2002 I've tried both L-pads and the Universal 3619. The resistors seem to take the life out of the music. The amp seems out of touch with the driver. Probably puts some humps in the frequency response, too. The 3619 is close to the sound of a direct connection to the amp. That would be the way to go. My memory must be playing tricks on me. I talked to Nancy in Tech Support five years ago, and I could have sworn that she said the new AK crossovers were incompatible with the old drivers and vice-versa, in part because the K-55-V was 16 ohm and the K-55-M was 8 ohm. You might make up the difference in impedance with the autoformer, but if you got the right attenuation on the same tap where the capacitor was the correct value, it'd be by sheer coincidence. Am I out of my mind? Is the K-55-M 16 ohm and the same sensitivity as the K-55-V? And like Stig said - if you change the transformer tap, you can't use the same 13uf capacitor. Every step down the transformer would drop the crossover by an octave. The transformer is between the cap and the driver, which is nice from a manufacturing standpoint because you can use a smaller cap. But it only works with the number 4 tap - too bad for tweaks, but there's a reason Klipsch did it that way. 99 people out of 100, given level controls, would make a royal mess of it. By the way, the 500/5k crossover went with the pre-1963 fiberglass K-5 horn (A High Quality Horn of Small Dimensions, J Acoust Soc Am, Vol 17, No 3, January 1946). The K-400 horn (A New high-Frequency Horn, PWK IEEE Transactions on Audio, Volume AU-11, November-December, 1963) had wider bandwidth with the same K-55-V driver, and took the A crossover at 400/6k The AA crossover was a response to high power solid state amps and blown tweeters. The tweeter slope was changed from 6 dB to 18 dB, and Zener diode protection was added. The result of the change was "a sight overall improvement in amplitude-frequency-response, and an inaudible difference on listening test." (Dope From Hope, Vol 11, No 2, July 1971). As far as "good inductors" are concerned, there was a study in "Speaker Builder" magazine around 1998 that looked at DC resistance, saturation, and several other factors. The best inductors for lower frequencies turned out to be: laminated iron! How 'bout that! Best of luck Rune - Mark Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted May 31, 2002 Share Posted May 31, 2002 esker, About transformers. Yes, "L" pads do exactly what you say, The take the life out of the music by divorcing the amps damping factor from the driver. That's why PWK went the extra expense of using them. He knew it! By the way, I have tested several K55-M drivers and a pile of K55-V drivers. They are IDENTICAL clones of each other. Both are 16 Ohms (13 actually) and both have IDENTICAL sensitivity. The K55M is NOT 8 Ohms! As to inductors, iron cor inductors have less DC resistance but their inductance actually changes with the level applied to them. The squawker transformer does the same thing, but as a transformer, that doesn't matter since it's inductance is very high. Al K. This message has been edited by Al Klappenberger on 05-31-2002 at 06:04 AM Quote Link to comment Share on other sites More sharing options...
esker Posted May 31, 2002 Share Posted May 31, 2002 Thanks Al K. I can accept that my memory is not 100% accurate. I am sure that Nancy said I couldn't mix pre-1983 with post-1983 elements. Now I wonder what she can have been talking about. That's interesting about the inductors. How much do they change value with how much power, and in which direction +/- ? Quote Link to comment Share on other sites More sharing options...
Al Klappenberger Posted May 31, 2002 Share Posted May 31, 2002 Esker, I did a couple measurements of the 2.5 mHy iron core woofer inductor on an AA network. I could only go up to 1.0 V RMS at 100 Hz. Voltage = inductance .02 V = 2.52 mHy .2 V = 2.63 mHy 1.0 V = 2.70 mHy Al K. Quote Link to comment Share on other sites More sharing options...
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