Damping Plastic Tractrix Horns and Compression Driver Questions ??

ka7niq · January 22, 2003

Have 2 pairs of Epic s, and I wannt to damp the plastic Tractrix horn, or replace it with the fiberglass one from the Epic version 3.

Also, I have the KN 63 kn 2" compression driver apart, and to me, it needs some felt under the aluminum dome, on top of the magnet, whadda ya think?

How about filling up the whole inner dome chamber between the magnet and dome with dacron like they do on soft domes ?

How about damping the aluminum dome itself with damping compound ??

Someone told me to be careful, as these diaphragms are expensive ??

I am all ears asa to which direction to proceed in

WMcD · February 3, 2003

In my view, all these modications are ill advised.

It is fair to say that the engineers who designed the components probably did not leave out all these modification for the sake of cutting corners. If some corners were cut, it is difficult to believe a home builder is going to find the magic modification to improve things.

Gil

prodj101 · February 3, 2003

hey will, lighten up, it's just a simple question. maybe you could send HBDRbuilder an email? he's knowledgeable in this feild. but otherwise, the way I look at it you can always just take off the felt/put the old horns in.

ka7niq · February 3, 2003

----------------

On 2/3/2003 12:15:30 AM William F. Gil McDermott wrote:

In my view, all these modications are ill advised.

It is fair to say that the engineers who designed the components probably did not leave out all these modification for the sake of cutting corners. If some corners were cut, it is difficult to believe a home builder is going to find the magic modification to improve things.

Gil

----------------

Well, the K 63 used in the larger Epics is a pro sound driver, and maybe they felt the benefits of putting some damping foam , or felt under the dome would be outweighed by the rough handling it would receive in a pro sound environment ?

I have damped my plastic tractrix horns w/rope caulk, just one coat.

It made a diffrence.

Perhaps since it is a pro sound driver, they figured it would be equalized anyway, so why bother?

Von Schweikert Audio used damping on Aluminum Dome tweeters to extend the response out and damp resonances.

You are right though, it is going to be difficult for a home builder to try and improve on them, especially if you give up before you even try!

I may not have all the nice test stuff, but I have my ears, and if I screw up a diaphragm, so what?

35 dollars gets me 2 delivered to my door!

I have 2 pairs of Epics, diffrent series, and they are voiced TOTALLY different from one another.

The CF 4 series one is the large Epic w/ 2 12' woofers and Horn .

It has pro sound voicing, very much in your face type sound.

I have a small room, and the voicing is all wrong for me.

The horn in the CF 4 dominates its sound.

The CF 3 uses 2 10 inch woofers w/ the same k-63-kn driver and tractrix horn.

It is a totally diffrent speaker.

It souns very much like a vandersteen w/ balls !

It is warm , rich and musical w/tremendous imaging, it does not sound like a horn speaker at all.

I love them both, and yes, I have owned Bells, La Scalas and old Heresys.

I dont like them, at all.

I stumbled on the Epics by accident, the CF 3, and loved them.

I spoke to Roy Delgado of Klipsch, told him how much I liked the Epics, and he suggested the CF 4, but the original versions!

It seems the powers that be at Klipsch didnt like them, and made Roy redisign them to sound more like the old Klipsch.

You know whats funny ??

Guess what Roy Delgado has at home ??

OLD , original CF 4's !

Kinda makes you wonder, dont it?

Roy could have anything he wants and he has CF 4's.

I can tell you that I have been an audiophile for 30 years, and I love the both of these speakers.

I love them enough to try and take them to a level impossible to do in a reasonably priced affordable speaker.

A properly set up original CF4 driven properly w/ good a good recording will drop your jaw.

But, they are totally unforgiving, and you need tone controls for ****ty recordings.

The CF 3's, version 2 will always sound pretty pleasant, but they will never drop your jaw either.

Honestly, the original CF4 can sound Electrostatic like, and kick holy *** too.

I never got that kind of sound out of La Scala, Belle, or Old Heresey.

But maybe I did something wrong ?

Anyway,,I am just rambling on, thanks for your reply!

TBrennan · February 3, 2003

That's no prosound driver, not a serious one anyway. More along the lines of Gemini prosound, not JBL or EV.

horonzak · February 3, 2003

Give JBL & EV a run for you,r money? Not in your life time.

ka7niq · February 3, 2003

----------------

On 2/3/2003 5:50:35 AM TBrennan wrote:

That's no prosound driver, not a serious one anyway. More along the lines of Gemini prosound, not JBL or EV.

----------------

With all due respect to my Irish Friend up in Chicago, this certainly is a pro sound driver TOM !

Dont forget, many of the EV engineers worked for Klipsch !

Don Keele for one!

They brought their pro sound driver knowledge with them!

People freak when they encounter a neo magnet, they are used to the " boat Anchor" drivers of days past!

No, its not a beryllium dome TAD, but its a pro driver.

I just want to make it better

djk · February 3, 2003

", and if I screw up a diaphragm, so what?

35 dollars gets me 2 delivered to my door!"

The MSRP on a pair of #128011 diaphragms to fit the K63 used in the CF3, CF4, is $872!

"Posted by ka7niq (A) on January 16, 2003 at 20:36:36

Anyway, I GENTLY Massaged the aluminum dome in the Klipsch compression driver, Gently moving it ever so carefully until I managed to get a kinda crinkly appearance when I pushed in on it, VS a smooth one.

Perhaps this 'Massaging' pushed the resonance up higher in frequency, or loosened up the aluminum, I dont know, but the effect was not subtle."

ka7niq · February 3, 2003

I spoke to Parts, and he assured me they were only 17.00 dollars each?

Someone posted this same thing on Audio Asylum, can someone set us straight ?

How about it, St. Thomas of Chicago, patron saint of our Lady of the Horn, how much do these diaphragms really cost ?

Anyone know?

I am going to try and get Albert Von Schweikert to give me some damping he used on his damped aluminum diapraghms he commercially made.

Let us damp the dome, and lets see what happens, that is, as long as they dont cost 872 dollars!

WMcD · February 3, 2003

Okay, I was not my normal polite self. My post had an edge to it. Proj was correct to take me to task. Please accept my apology.

BTW, are we speaking to Mr. Tucker? It looks like a ham call sign.

Sometimes I get annoyed when someone posts a question to the effect of, "I'm gonna do X, Y, and Z, blindly and without any serious insight. Please give me all technical information on the merits of my course of action, the predicatable outcomes with four different variables, prices, and guarantees of performance, etc." As if we'd all done a Ph.D. thesis on the noodlings of any and all tinkerers.

Whoops, the monster is coming out of me, again. I'm sure KA9 didn't quite mean it like that. Get back in the dungeon, I renounce my evil self. (Did ya ever see "Forbidden Planet"?)

Back to the issue. I did some experimentation with an EV-1824 midrange driver some years ago. It is a bit similar to the midrange drivers used by Klipsch.

I also had an LMS system and an improvised tube to measure results without a horn.

One mod suggested by the Altec camp was to take out the bug screen on Altec drivers. It was described as a sure fire improvement. Measuring the EV unit, there was no change. Granted, it was not the Altec.

I investigated the innerds of the 1824. There is a dome with a small hole in it, covered with fine cloth, behind the driver. I took that dome out and found the overall response to be worse.

So I put it all back together and concluded that that hot rodders can't be trusted.

Now I'll admit that my conclusions regarding the hot rodders was not scientific, and an overgeneralization. Perhaps the changes they made did improve things in their equipment. Still, I'm very skeptical unless someone has a pair of SPL graphs showing an improvement, or at least a difference. Anyone can say, "I did X, Y, and Z, and it sounds terrific."

Further, I would not recommend a modification, myself, unless I can support it with before and after graphs.

Now, I do advocate and support, very much, tinkering and experimentation (which are the same thing). It is the beginning of the scientific method. The results should be measured by technical instruments to avoid subjective bias, though. Yeah, I know, it is expensive. (This leads to a divison of the people giving reviews; those with tech equipment and those without.)

One experiment being considered by KA9 was to put clay (Moretite) on the diaphragm, if I read correctly. Maybe there will be some merit to the results. None the less, it looked to me that KA9 was going to put a lot of goop on a delicate diaphragm and muck up the works. It seems contrary to good practice. Most designers are looking for the least massive of diaphragms.

What is the moral thing to say? If you say "go for it" you've lead the guy down a path to, perhaps, ruining his hardware.

If you have the time, spare parts, and money to do this, well enough. But it is hard to tell where someone is coming from.

Again, I'm backing away from my curt and impolite response, and also explaining my own disappointments which caused it.

I'm today reading about patent law. In some cases the inventor found an improvement by making modifications which were counter intuitive. Still, the results have to be be shown by an objective standard.

So, I say, in retrospect, go for it, and let us know what you find.

Gil, AB9BE, the tinkerer.

ka7niq · February 3, 2003

----------------

On 2/3/2003 10:00:12 PM William F. Gil McDermott wrote: