pkeller

OK, I finally got around to swapping the stock heresy type "E" crossovers with the new ones mentioned a couple posts above. My Heresy's are 1978 (alnico) vintage and have had the "P trap" installed for the past several months. I have been changing other things in my audio system recently (amplifier mods), so I had to get familliar with the sound before I could make any meaningfull comparisson of the two crossovers. Now the results: First impression (installed 5 minutes ago) is that the tweeter has more detail and delecacy. There is a bit more transparency and detail across the entire audio range. Bass is more controlled and a tad stronger. Imaging and dynamics are enhanced. Now the down side. The midrange, while cleaner, is slightly too strong. Remember that this system does include the P-trap. This may be corrected by a simple relocation of the squawker "-" wire to the #1 tap on the autoformer, rather than the stock #2 location. This would lower the mid horn -3db and probably be about right. To be fair, these new caps have not had a chance to settle in and the excess mid might take care of itself in time. It's not too far off as it is, but could be better. Over all, the new crossover has much more potential than the stock unit. The much larger inductor and Zen polypropylene film caps are clearly superior to the 23 year old components they replace. As for the UTC autoformer, It's about the same size as the stock unit. Al Klappenberger made some measurments in it a while back and found it better, so I used it. I have a photo of the new crossovers, but I'm having trouble attaching it to this board. Can anyone tell me how? As I type this, the sound comming from the Heresy's seems to be getting better. Even more detail. Either the mids are settling down a bit or the highs are getting stronger and more in balance with the mids and lows. Just for refrence, Im using modified Heathkit EA-2(12 watt 6BQ5/EL-84) amplifiers. Efficiency is about the same as before. I won't be changing back to the old networks. I have about an hour of listening time now (I type slowly) and the mids are getting to be about right. Detail and transparency is increasing as time passes. I'm Jazzed. Hope all this helps. Paul Keller

I used solen heptalitz inductors .1mh and Northcreek Zen caps 3uf in my "P traps". They changed the Heresy's into much better speakers. I cannot recommend Northcreek Zen and Crescendo speaker caps highly enough. They increased the transparency a great deal in my Shamrock Audio speakers over more standard Solen metalized film caps. No I have not installed the new crossovers in my Heresy's yet. They have been completed for months but my time has been streched so thin, it has not been a priority. Mabee I should make the time and post the results. Paul

The EV speaker design that you compared Heresy's to has the mid and tweet at least 18" apart by your description. When you re-mounted them closer together with the woofer at one end, you vastly changed the polar readiation pattern. This is vastly more responsible for the improvement you experienced than verticle or horizontal mounting. And yes, that "does" make your comments invalid. Once again, we are talking about Heresy's and Heresy's only. Extrapolation of findings from other designs is not justifiable. Yes, Heresy's could have been a better speaker. The realities of the market and tecnological limitations of the day take their toll. But I, and I suspect most, don't want to hachet up a good speaker in search of better performance. I like to make sure any modifications are completly reversible. Give it a try "with Heresy 1's". Paul Keller

"At least" let's talk about the same kind of speaker. Comparing different baffle mounting locations, Mid horn flair, 3/4" of baffle thikness surrounding the horn opening (Heresy 1's), edge diffraction from the baffle / grill cloth recess, room acoustics (I bet you didn't measure that response in an anechoic chamber), driver characteristics, 15" -vs- 12" woofer, crossover points, extreem phase change from you having the mid and tweet drivers so far apart, are all significant changes from Heresy 1's. Your conclusion, while strongly stated, ignores that we are talking about a specific design. Buy some Heresy 1's and give it a try. Paul

Since we are talking about 1978 vintage Heresy 1's, the "E" network is the crossover in question. It has a 2.5mh inductor, two 2.0uf caps, and a 2TA autoformer. I suspect your looking at a different version or network. The "P-Trap" is added to the + of the squaker and eventually connects to the - terminal of the speaker. It's easy. Disconnect the lead at the + terminal of your squawker. Take your p-trap cap and coil and twist the ends in parallel. Take one twisted cap/coil combo end and connect with the + terminal of the squaker. Connect the other twisted end to the wire you first removed from the squaker + terminal. Totaly reversible and simple.

Here is the P-Trap info from an E-Mail I received some time back. "This crossover has no high cutoff for the mid. it depends on the acoustic response of the Atlas driver. It will die at 6k but most come back at 9k. This causes a harsh sound people think is caused by the horn. A simple trap will cure the problem . Parallel a .1 mh. coil and a 3mf. cap. connect this combination in series with the + terminal of the mid driver" I hope this helps (Use a Northcreek Zen or Crescendo cap) Paul Keller

I installed the P-Trap on my 1978 Heresy's and the results were huge. The vintage of the Atlas driver in your speakers has a lot to do with the effectiveness of the P-Trap mod. Klipsch just let the driver roll off at 6500hz with no electrical limit. Problem is, natural resonance of some drivers brought the output back up at 9000hz. This is the source of much of the "horn glare" many try to reduce with damping materials. I'm surprised you can't find the P-Trap mod in the archives. I'll look and post the site address in a following post if successfull. Otherwise I'll have to take the back off one of my Heresys and take a look. Paul

Perhaps I should explian in better detail. The Heresy mid and tweeter horns are of a "diffraction" type. That means that they have a wider dispersion prependicular to their mounted axis. Therfore, a vertically mounted set of Heresy horns will have less critical side-to-side listener location than if those horns were mounted horizontally (standard mounting). Heresy's, Cornwall's, and Bells used these horn designs. Klipschorn's and LaScala's did not. Early Cornwalls had their mid and high frequency horns mounted vertically for just this reason. The problem is, this requires individual left and right speakers to make a stereo pair. This created a huge inventory problem for Klipsch dealers and numerous shipping mistakes. They finally just rotated the horns horizontally and cured the problem at the cost of reduced imaging. Heresy's are the only one of the three designs that can easily be turned for vertical horn presentation. Give it a try. mine have remained on their sides since I heard about this and found such a great improvement. Paul

For vastly improved imaging, turn your Heresy's on their side with tweeter toward the middle. Adjust the angle facing the listener (you) for best time alignment. Trial and error works well. Also, on type 1's, install the "P trap" crossover mod detailed elsewhere on this board. Just search "P-trap" to find it. Report back and tell this board what you found. Regards: Paul Keller

When you buy the logos, make sure you get two. The logo in 1978, when your Heresy's were made, was the negative script type. It was a bunch of small horizontal lines with no lines spelling "Klipsch" in a negative process. The logo's you will receive these days are laquered copper with black "Klipsch lettering embosed in them. Paul Keller

Can the T2A transformer in the Heresy type "E" network be effectively replaced by a series of resistors? I understand that the taps are each 3db apart. I would like to build new crossover boards and not canibalize my existing "E" type boards. Klipsch does not have T2A transformers listed as available on their "web" parts list. I have used Ohmite 5 watt wire wound resistors in past crossovers with excellent results. Regards: pkeller@ix.netcom.com