Modified Khorn crossover question

[kevinmi]

I have recently modified my Khorns using Crites cast woofer, Crites CT125 tweeter, and homemade wooden tractrix horns driven by the original k-55-V drivers. My question is : would I benefit if I changed the crossover points? I was thinking of crossing the woofer higher, like 450hz if the woofer could produce that high, and crossing over the squawker/ tweeter at 4500. I also want to implement the mid attenuation found in ALK's universals. I might try different mid drivers in the future, and it seems hard to find many drivers that go down to 400 hz, so that's why I was wondering if it is possible to raise the woofer limit. Thanks in advance for your advice! -Kevin

[Guest David H]

Kevin, moving the bass to 450hz is not an appreciable difference, I do not think this would benefit you in the least.

Sent PM.

[Invidiosulus]

with as many bends as the khorn bass bin has you wouldn't want to go higher with your crossover point. the mass rolloff for the k33 is already below the crossover point so the horn loading isn't doing as much as it could at 400 hz anyway, not sure about the crites woofer but you still have all those turns to get around.

[seti]

I've been told you may be able to push the khorn bassbin to 500 but with eq and crossover. 450 is as high as it should go. PWK developed the Jubilee to overcome this it has good performance out to 1khz but for voicing of vocals about 700 is the max you want to use. It has been said that the 400-600 is better. I have crites woofers in my khorns. They are great.

[Al Klappenberger]

kevinmi

You can extand the low range of better drivers down to 400 Hz safely by using a 400 Hz crossover having an rapid slope. Look at my ES400T extreme-slope network. The design is downloadable from my web site. It will also allow any impedance driver to be used and allow the level to be adjusted too.

Al k.

[khorn#1]

Al,

How is the extreme slope design coming along for Gregs vtrac - BMS mid driver setup? I am really looking forward to this becoming available.

Thanks,

Randy

[Al Klappenberger]

Randy,

The design and layout for the V-track network set is done. I expect to order parts to build the prototype shortly. Maybe next week. I will be sending it to Greg for a fit-test and evaluation. You will probably hear about it from him first.

Al k.

[Deang]

You and Greg going for the 300Hz transition point on that one?

[Al Klappenberger]

Dean,

Yes. It will be similar to the ES400 network but at 300 Hz and will have even steeper skirts. I posted computer plots on it earlier, in a different thread, but I don't remember which thread. Maybe somebody else can find it and post a link to it.

Al k.

[JohnA]

I have recently modified my Khorns using Crites cast woofer, Crites CT125 tweeter, and homemade wooden tractrix horns driven by the original k-55-V drivers. My question is : would I benefit if I changed the crossover points? I was thinking of crossing the woofer higher, like 450hz if the woofer could produce that high, and crossing over the squawker/ tweeter at 4500. I also want to implement the mid attenuation found in ALK's universals. I might try different mid drivers in the future, and it seems hard to find many drivers that go down to 400 hz, so that's why I was wondering if it is possible to raise the woofer limit. Thanks in advance for your advice! -Kevin

You can raise the woofer low-pass frequency to 500 Hz. Klipsch used a 500 Hz crossover early on, but the response is falling quickly, beyond that. The attached AES paper shows the bass horn's response on page 6. The bass horn needs some EQ.

Crossing the squawker to the tweeter at 4500 Hz would be a good idea. At 4500 Hz, the horizontal dispersion of the tweeter and the OEM squawker horn are more similar than at 6k. I don't know what the horizontal angle of your horn may be. The K-55-V with spring terminals (the most common one) does not really get to 6k. Be sure to use a low pass filter on the squawker to reduce the 9k response return; crossing at 4500 Hz will make that easier. Contact Bob Crites to see what high pass slope to use on the tweeter, but I'd recommend an 18 dB/octave filter. The networks commomly used by Klipsch are deliberately lossy to attenuate the output of the K-77. The Type AA, at least, also has some needed EQ "built-in", too. The K-77 has a rated output of 105 dB/w/m, but most speakers sound nicer with a "cool" tweeter. Bob showed a graph of his tweeter showing it had an average output of about 102 or 103 dB. Perfect. If it is what I think it is, it carries a 45 watt rating at 3500 Hz, so it is plenty tough.

Not knowing what your squawker horn is, it's hard to predict the output of a K-55-V on it. The standard attenuation through a T2A is 3.35 dB. On a K-400 that gives a pretty flat response curve. Maybe that is a clue. Get an SPL meter to test with. You can't trust your ears to get the levels closer than 3 and maybe more.

AES-Jubilee.pdf

[Daddy Dee]

Changing the crossover to 4500hz with the CT125 was one of the sweetest mods I ever made to my Khorns. Definitely a winner, IMO.