Good to see you on here Al.  I also was not attending for quite some time, when I came back and you weren't here it just wasn't the same.  Hope you can hang out for awhile.

Al,

Sorry to ruin this thread.  My last comments.......DIYers ought to look at the 403. 

Mike,

Good comments.  I agree that you can not compare something like the 402 to the 403........totally different sound.......and driver size.  Didn't know the technology actually...was modified tractrix.

Just saying that after hearing that 403 horn.........it has the unmistakable PWK Heritage sound.  Just my opinion that it is an overlooked made to order upgrade certified by the guy himself.  But there aren't any "real" ones around to copy.  I would buy that horn 10 times over before any of these wonderful sounding tractrix woodys that depart from the characteristic Heritage sound.  That's just me.

I'm not dissing any of the excellent horn craftsmanship that has recently showed up........so don't anyone think I'm being negative toward these in any way or the ALK trachorn.  I know they all sound very good.

Anyhow, I have become totally satisfied with my cinema setup and would find it very difficult to part with what's in my avatar.  I'm certainly not shopping for any horns.............just commenting because Al mentioned he has competition and it seems everyone has overlooked the obvious.  Noone seems to care about seeking out and building the 403...........and PWK was standing there in the original Jub shot with his hands all over it.  I was just suggesting it be considered.

Al Klappenberger:

 Mark,

The Trachorn is actually made by Bill Martinelli of www.woodhorn.com. It was designed by the software I just made public. The actual series of events began with a telephone conversation with Max Potter, the guy who brought us the "P-Trap". He convinced me to try a set of Latec 511b horns in place of the K500 horns in my Belle Klipsch. It didn't take but a few hours to realize that a new horn was needed for the Heritage sereis that wasn't an out of production eBay item! Max told me about the wood tractrix article by Bruce Edgar. Max actually talked directly to Bruce Edgar about doing one for the Khorn but Bruce has bigger fish to fry! Having many years of experience writing engineering design programs I began the project of writing a program that would duplicate the example in the article. The program trachorn.exe was the result. I am quite happy to know that I seem to have started a revolution of sorts. Now though, I got competition out the yin-yang!  [:'(]

 Jay,

The only thing Greg needed was to listen to a Khorn set he referbished for a customer that he added my Trachhorn and networks to.  He wanted to do an all-out 2 inch driver version. The V-Track is the result. I was asked about a 2 inch version of the Trachorn several time and concluded that there wasn't much of a market for it considering the expense of 2 inch drivers. It looks like I might have been WRONG! I did have a little input to the V-Trac. I got him to make a correct square to round adaptor for the driver. The spreadsheet program doens't tell you about that little detail!

Al K.

 

Thanks for the response, it looks like the v-trac might be the way to go?

Jay

I have not heard a 403, but I doubt it's any better sounding than the ALK Trachorn.  The reason I can say that with some certainty is because I know from my own experience that the difference between the K400 and the ALK Trachorn, while using the same K55 driver, was a lot less of a difference than going from the K55 3/4" driver to the BMS 2" drivers (both in wooden tractrix horns).   

It's not the horn that is making the enormous difference in sound quality in my own Khorns, it's the BMS driver. 

I'm not inclined to go to the effort of building a K403.  I would have a hard time marketing it now that I know how good the 2" format is.  My advice to anyone considering an upgrade for their Khorn mid is to wait until you can afford to go 2".  Once you do there's no turning back to the smaller formats, regardless of what shape the horn is, it's history, it's nostalgia, or certainly whether or not it sounds like Heritage (K55/K400 - Yuck). 

Greg 

 I'll take the K403. It sounds Heritage in a good way. One of PWK's last horns and it rocks. It is a shame it won't see the light of day.

seti:

 I'll take the K403. It sounds Heritage in a good way. One of PWK's last horns and it rocks. It is a shame it won't see the light of day.

So you're saying the K403 is like the Heritage sound (which I assume means the K55/K400), only it's better.  That makes sense to me, it's a larger format horn and driver.  I submit that it's not so much the horn that's making it sound better, it's the larger driver.  My Khorns right now sound like "Heritage in a good way" too.  There's nothing un-Heritage about my Khorns except for the lack of blaring, edginess that I used to put up with from the K55/K400.  They sound just like you'd want Khorns to sound if you could dial them in yourself.  Imagine one step up from the K403 (1.4' driver) to a 2" driver.  It's "Heritage in an even gooder way". 

BTW - I agree that it's a shame the K403 won't see the light of day, just like it's a shame that the Jubilee will never become the speaker PWK intended it to be. 

Greg

Amen.

Actually 'd like a collection of difffernt types of horns to roll on top of the Jubilee bass bin : ) I'd like to hear k403 on a khorn if that is possible. I've never seen any curves on it. The two way system has been very appealing to me.

seti:

Actually 'd like a collection of difffernt types of horns to roll on top of the Jubilee bass bin : )

I'm working on a set of my Fc260 horns with Beyma CP25 tweeters to go on top of my Jamboree bass bins.  The Jamborees are the best sounding bass bins I own, and my Khorn tops (modified) are the best sounding high end I own, so it just seems natural to marry the two together and see what happens.  Al helped me with a passive network that should work ok. 

The next step for me is to build a horn that can be used in a two-way setup on top of the Jamboree (or Jubilee) bass bin.  This is not easy to do though and will take me some time.  My goal is to do it in such a way that the electronics downstream of the speaker are no different than what you'd use for Khorns.  That way I can keep the very simple signal path that I currently use and maintain the "life" of the music right to the end of the line. 

Greg

Thanks Al,

Good to see you on the forum.

 The observations about moving away from the K55 driver is interesting to me. I am using JBL 2426h drivers on my Trachorns here. I think I changed to the JBL driver while I was still using Altec 811b horns. My reaction at the time was that the JBLs were better than the K55 but not as much better as moving from the K500 horn of the stock Belle to the Altec horn. The 2426 driver is really not a true 1 inch driver. Under its built in adaptor is the same screw-on thing as the K55 has. There isn't a lot of choice of good 1 inch crivers that will go low enough for use on the Klipsch speakers. If I had it to do over I would be using  Altec 902 drivers.I think the big advantage to the JBL 2426 is that they will handle a lot of power for PA applications. That isn't a big advantage in the average living room! Beyma makes a 1 inch driver that might do. I don't think anybody has evaluated it though. It's the CP350Ti

http://www.usspeaker.com/beyma%20CP350Ti-1.htm

Al K.

Al Klappenberger:

It's the CP350Ti

Al:  Great to see you back!  I still enjoy the heck out of my universal ALK's. I have taken great interest in the replacement mid horns after reading some of your work as well as Greg's.  I was recently added to Greg's V-Track demo program and cannot wait to have a listen. You are correct, those 2" drivers are pretty expensive.  I'm still looking around for any potential 2" driver that would be worthy of being used for a Heritage application. 

Welcome back!  We missed you.

 Dave,

The CP350 suggested crossover is 800 Hz. With an extreme slope network it's safe to run drivers a lot lower than that. They are thinking 12 or 18 dB / octave slopes when they make those recomendations. They say the same thing about the JBL 2426. Besides, how may of us put any real power into our speakers? One watt make me run for cover!

 I'll be looking at Gregs V-Trac horn and driver in a week or so. Not the entire demo, just the horn and diver. I plan to run intermod distortion tests at 100 dB SPL on both the V-Track and my Trachorn to see how much the 2 inch throat reduces it.

As to my being "back", you can consider it part time. It's against my better judgment. I always seem to get into some sort of hassle! I plan to stay out of what doesn't directly concern me! In this case I'm very interested in the 1 inch versus 2 inch throat thing.

AL K.

As to my being "back", you can consider it part time.

I hope that isn't the case.

Al, since you have led us in on your trachorn design, can you tell us what exactly was the Fc of the horn and was there any "shortening" of the horn to "fit" into your Khorn top hat arrangement.  With greg's horn...the attempt was for zero shortening (he knew his max size tolerance) with an Fc just under 260Hz.

FWIW, my opinion with horn vs driver difference.....I found that when using a K55 on an Altec 511 was a very noteable improvement of sound quality over the k400.   Changing to 902 driver...there was improvement but not as much as changing to the 511.  I think the biggest leap is the midhorn exchange from the heritage line.  With greg's current offered upgrade setup.....you have the biggest midhorn that will fit in the Khorn for a 3-way setup and a nice driver.  There is gonna be some happy folks who want to make that step.  You could even throw a TAD on there!  whew...

I've also heard a TAD on the K402 and this is a seriously awesome combo.  I really don't care for the K69 on there as much...and this is a 2" driver as well. 

jc

 JC,

You can see the cutoff frequency listed on the sample run I posted earlier of the Trachorn design. It's 309 Hz.

To verify it, I inserted my calibrated mike from the side right into the throat of the horn just in front of the driver and ran a curve. Dr. Edgar showed a family of curves for "Throat resistance" in his article that I really don't understand, but I assumed a simple frequency plot might, at least, show me where the lowest frequency where the horn loaded the driver. The plot seems to show it to be 295 Hz. BTW: The rise down low is becasue It was measured using the "Transfer function" mode of the analyzer. It goes bananas when the level drops way down becasue the mike is picking up room sounds that are not in the signal going to the driver. It computes it as a HUGE gain!The vertical scale is dB SPL for 1 W into 8 Ohms.