Klipsch Modded Super Heresy

[ClaudeJ1]

10 years ago, I used a Klipsch K42 pro Woofer in my Heresys, instead of the K22 that it contained in the original sealed box.
I was trying to improve the "handoff" to the "faster" K700 Horn midrange with the K-55 compression driver.
After a capacitor refresh on the Klipsch "E" network using Dayton Capacitors from Parts Express, I was ready to go.
Since the woofer is a high bl woofer with a huge magnet, I know that the bass response would be even thinner than the original.
So I ported it in the rear, since it was the only place to put it.
I also swapped out the Super Tweeter for a Small Machined Aluminum Horn Lens with a b&c DE-120 Super Tweeter Driver sold on Ebay as a drop in replacement for the original tweeter. It is known as the sMAHL and responsibe for the "Super" in the name of my Mod.
I has been built all over the world by enthusiastic modder and I have NEVER read any feedback that was anything but "WOW." AFAIK, not one single person ever went back to the original after doing my Mod.
I have lost the original curves as Proof, but I was amazed when those little boxes went down to 30 Hz. in my small bedroom at the time (mostly Cabin Gain).
I have attached a PDF of the recipe for those who want to try it with own pair of Klipsch Heresys from before 1982. If you create a new rear panel for the port, the mod is totally reversible. I know of no one who ever went back once they did it.
With the cost of new Heresy IV's at over $3,000 a pair, you can do this for your OLD pair for less than $800 total in 2025 dollars.
Have fun and enjoy superior sound if you do what Nike says "Just do it."

 

[J!m]

Interesting mod.

Welcome to the forum.

 

[ClaudeJ1]

Interesting mod.

Welcome to the forum.

Thank you.

 

[VSAT88]

Interesting if I had Heresys might have to try it. It seems I have read that .PDF before somewhere posted elsewhere. What I want to do is build a box using the K45 woofers I have from a set of KP-450's I had. I also have some EV-1824M's for the mids. Hell I even have the plywood. Just aint worth a damn at cutting a straight line and designing a crossover seems to be well above my grade.

 

[ClaudeJ1]

Interesting if I had Heresys might have to try it. It seems I have read that .PDF before somewhere posted elsewhere. What I want to do is build a box using the K45 woofers I have from a set of KP-450's I had. I also have some EV-1824M's for the mids. Hell I even have the plywood. Just aint worth a damn at cutting a straight line and designing a crossover seems to be well above my grade.

I can design you a box which you can cut with a 7 1/2" hand saw and a straight edge guide. Those woofers look great. Do you know someone who can measure the Thiele/Small parameters?

 

[VSAT88]

They came out of Klipsch KP-450 boxes and I think I have the .PDF that shows the old box size and that's about it. They should thunder. They are definitely what I would call heavy duty.

 

[ClaudeJ1]

They came out of Klipsch KP-450 boxes and I think I have the .PDF that shows the old box size and that's about it. They should thunder. They are definitely what I would call heavy duty.

It's a good start.

 

[VSAT88]

Here it is...

 

[ClaudeJ1]

You need to tell me what you want to end up with. Single driver box. If you own a pair of KP-450's then what do you want to end up with? 4 single woofer boxes, what?

 

[VSAT88]

Actually have only two of the 15'' drivers and two of the mids. I have the plywood or at least I think it will be big enough to build two boxes. Probably mess with it all later though. I really need to move some equipment out as the wife and I are about to downsize.

 

[ClaudeJ1]

Actually have only two of the 15'' drivers and two of the mids. I have the plywood or at least I think it will be big enough to build two boxes. Probably mess with it all later though. I really need to move some equipment out as the wife and I are about to downsize.

Will You be using a subwoofer between 2 smaller speakers? or Just the one pair. Using a sub for bass below 50-80 Hz? Will you mount the horn inside the box? Where will they be placed? Corner or wall? How wide is the horn? Also, do you have acces to an Ohm Meter? I need to get a DC Resistance reading to know what impedance I'm dealing with. If K-45's are just a front mounted version of a K-43 (4 ohms) then I would know they are used in series for 8 ohms, which is what I would do. If those are 4 ohm woofers, I would offer to trade you for an 8 ohm pair EVM 15 L's I have with equivalent performance and specs. You pay shipping for both, then you can use the same exact crossover with just one driver. Send me a Private Message. We should talk.

 

[VSAT88]

Would be proud to work with you on a deal or design however right now I just do not have the time. That's the way it always seems to be with me. I either have the time and not the cash or the cash and not the time. I really don't have the inclination right now to work on another set of speakers to be honest. I just have to much otherwise I need to get done. Thanks a million though.