ssh Posted November 17, 2004 Share Posted November 17, 2004 To biamp my Kornerhorns using an active crossover, what are the recommended crossover points? SSH Quote Link to comment Share on other sites More sharing options...
Deang Posted November 17, 2004 Share Posted November 17, 2004 400Hz and 4000Hz with 6db/octave slopes (1st order). Quote Link to comment Share on other sites More sharing options...
ssh Posted November 18, 2004 Author Share Posted November 18, 2004 Thanks, Dean. Phil Marchand, who designed the crossover, recommended using a 24db/oct slope module. Is there any advantage to that change, & would that change the ideal crossover frequency? I can order the crossover (XM44-AA) with different modules. SSH Quote Link to comment Share on other sites More sharing options...
Guy Landau Posted November 18, 2004 Share Posted November 18, 2004 I think that it's 400 hz and 6000 hz. I don't think that the k77 tweeter can go down to 4000 hz. Quote Link to comment Share on other sites More sharing options...
Q-Man Posted November 18, 2004 Share Posted November 18, 2004 Guy, Your right it is 6000. Quote Link to comment Share on other sites More sharing options...
CaptnBob Posted November 18, 2004 Share Posted November 18, 2004 Electro Voice claimed the T-35 (for all intents and purposes a K-77) could cross over at 3,500 hz. I'm sure there's a reason PWK had his starting at 6 khz - greater power handling and smoother response come to mind off hand.. Quote Link to comment Share on other sites More sharing options...
Deang Posted November 18, 2004 Share Posted November 18, 2004 Sorry SSH. The new crossover points are 450 and 4500, and I gots myself all mixed up. Quote Link to comment Share on other sites More sharing options...
ssh Posted November 18, 2004 Author Share Posted November 18, 2004 Dean, I was thinking it was 6k, but I'm trying to get it confirmed before I order the crossover. Why do you think he suggested a 24db/oct slope? and Does that necessitate a crossover frequency change? SSH Quote Link to comment Share on other sites More sharing options...
sfogg Posted November 18, 2004 Share Posted November 18, 2004 "Why do you think he suggested a 24db/oct slope?" Less driver overlap, lower distortion, less comb filter, greater power handling...etc..etc... I'd go that steep (or even steeper) if you are biamping. What versions of each driver are you running? If it is the older K55s I'd probably try lowering the crossover a little down from 6k since they don't get up to there all that well anyway. Maybe try 5k or so, the steeper crossovers should allow this fine with the tweeter. Of course if you bi-amp with crossovers like this it opens the door to further mods such as different drivers all together very easily. Shawn Quote Link to comment Share on other sites More sharing options...
djk Posted November 18, 2004 Share Posted November 18, 2004 An XM44? For a Klipschorn you want: 12dB 400hz Q=1 low pass 24dB 400hz LR high pass 12dB 6Khz Q=1 low pass 24dB 6Khz LR high pass I also like a 31hz high pass Q=2 on the woofer section (this can be added to the woofer section because not all the poles are used for the 12dB 400hz Q=1 low pass). Quote Link to comment Share on other sites More sharing options...
ssh Posted November 18, 2004 Author Share Posted November 18, 2004 djk, Are you using this crossover? SSH Quote Link to comment Share on other sites More sharing options...
Q-Man Posted November 18, 2004 Share Posted November 18, 2004 DJK, Good idea. That 31 Hz high pass on the woofer would come in handy for home theater use. In home theater you can run the Klipschorns on the large setting and this filter will keep the low frequencies from the .1 LFE channel out. Quote Link to comment Share on other sites More sharing options...
ssh Posted November 18, 2004 Author Share Posted November 18, 2004 djk, What do you think of sfogg's 5k suggestion? I agree with the rationale, but don't know from experience. SSH Quote Link to comment Share on other sites More sharing options...
Deang Posted November 18, 2004 Share Posted November 18, 2004 Shawn's suggestion sounds reasonable to me. The AK-4 starts to cut at 4500 -- and I think it sounds great. Quote Link to comment Share on other sites More sharing options...
ssh Posted November 18, 2004 Author Share Posted November 18, 2004 Dean, I think I'll try 5k. I see that's reasonable, but I'm not on known ground here. Heck, I'm just tired of wondering about this, & am shooting in the dark anyway. Thanks for your help, guys. I'll keep you posted. SSH Quote Link to comment Share on other sites More sharing options...
Erik Mandaville Posted November 18, 2004 Share Posted November 18, 2004 SSH: I think the 6KHz figure is correct for the tweeter, but I like Shawn's idea for a steeper slopes -- certainly 24db/octave. I have been working on a design of my own using 18db/octave slopes, and think you've gotten good advice from Marchand. I am VERY CURIOUS about your impressions when all of this happens! Please let us know what you think, what differences you perceive between active and passive crossovers in the K-horn, as well, of course, if you try this in a bi or tri-amped system. An active network may really be (at least subjectively)the ideal way of dividing the frequency response between the 3 drivers. Very Interesting! Erik Quote Link to comment Share on other sites More sharing options...
D-MAN Posted November 18, 2004 Share Posted November 18, 2004 I would go with a 6K figure for the 12db to 18db xover point, mine are 6500Hz (ALK-A), lower xover point is 375Hz (6db). With high frequency divers, the lower the xover freq, the higher the probability of damage to the driver diaphragm due to excessive excursion or voice coil burn out from excessive heat. DM Quote Link to comment Share on other sites More sharing options...
ssh Posted November 18, 2004 Author Share Posted November 18, 2004 The frequency modules are inexpensive. I may start with 6k for safety's sake, then try 5k. I do not want to replace drivers. But, I'm getting itchingly curious. It's time to put my $ where my curiosity is. SSH Quote Link to comment Share on other sites More sharing options...
sfogg Posted November 18, 2004 Share Posted November 18, 2004 " the lower the xover freq, the higher the probability of damage to the driver diaphragm due to excessive excursion or voice coil burn out from excessive heat." That is only if the crossover slope is the same between the two crossover points under comparison. Compare a first order filter at 10,000hz and it will be putting more energy (12db) into the tweeter at 2500hz then a fourth order filter at 5000hz would. The steep slope will limit the amount of energy the driver sees even with a slightly lower crossover point compared against a higher crossover point and a shallow slope. I posted measurements I made of the K55V and K55M here a year or so ago and they really don't get up to 6kHz flat with the rest of their range. That is why I suggested lowering the crossover point somewhat. I've used a Marchand crossover for bi-amping an older center channel. It originally had a 3kHz passive first order crossover in it. Using a 48dB/octave active crossover I ended up lowering the crossover point to 1600hz (or 1800 I can't recall which I settled on) and the speaker sounded better then before and increased its vocal clarity from less interaction and beaming of the woofer. No problems at all with overdriving that tweeter (an expensive Scan-Speak) either, in fact it sounded cleaner this way at higher volumes then with the higher crossover point. Shawn Quote Link to comment Share on other sites More sharing options...
ssh Posted November 18, 2004 Author Share Posted November 18, 2004 Marchand XM44 ordered from Walter Wergrzyn (On Audiogon search Marchand), a Marchand dealer. For bi-amping, the only crossover point in contention is 400hz, since mid/high will both go to one amp (pr of monoblocks). Slope will be 24db/oct, as recommended by Phil Marchand & seconded here. Now, I'm wondering how to run the Marantz in multi-channel, using the Khorns. Another pr of LaS??? Thanks again for the help, guys. Pics will come in a couple of weeks. I'll be in serious need of good, & probably immediately necessary help. How did I get here? SSH Quote Link to comment Share on other sites More sharing options...
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