Trachorn 400

Klipsch Squawker horn upgrade


ALK Engineering upgrade for the Klipsch K400 and K500 squawker (midrange) horns.

FREE GIFT (While supplies last)

The book Paul Wilbur Klipsch, The Life.. The Legend, by Maureen Barrett and Michael Klementovich will be included with every Trachorn order!

Maureen A. Barrett and Michael J. Klementovich have collaborated on this thorough biography of the audio pioneer, Paul W. Klipsch. As engineer, geophysicist, entrepreneur, WWII veteran and musician, the authors trace the life accomplishments of this brilliant, yet eccentric man who besides founding the company that continues to be a leading manufacturer of loudspeakers, holds patents in the field of ballistics, acoustics and geophysics and is the namesake of the Klipsch School of Electrical and Computer Engineering at New Mexico State University. Apart from his notable professional accomplishments, the authors illuminate Klipsch's private side and idiosyncrasies -- he is renowned for wearing a small button that says "bullshit" and his devotion to his wife, Valerie. Well-written and scrupulously researched, the book is an interesting portrait of a unique individual.

Complements of Michael Klementovich, Bill Martinelli and ALK Engineering.

The curves below compare the frequency response of the Trachorn 400, the Klipsch K400 (Klipschorn and LaScala) and the Altec 511b "Voice-of-the-theater" horns all using the stock K55V driver.

Here though is an example of an area of acoustics where looking at frequency response curves and distortion measurements tell you very little. While the measurement on the new horn are slightly better then the stock horn the improvement in realism will knock your socks off! The square mouth of the stock horns does not launch the sound waves correctly into the room. The new horn has a rapidly increasing flare to the mouth which launches the sound wave gracefully. The Altec horn, with its curved mouth, does a much better job than the stock Klipsch squawker, but is very difficult to mount into the Klipsch top section requiring major woodwork changes. The Trachorn 400 comes with an all new drop-in front baffle and grill cloth.

The stock horns, especially the older metal ones, tend to ring adding a harshness to the sound. The new horn is made entirely of wood with a layer of damping adhesive between two layers of wood on each side. There is no way this horn will add any sound of its own to your music! The sound is very similar to the highly regarded Altec 511b with heavy damping material added to its outside surfaces.

The throat will accommodate any standard 1 inch driver (JBL or Altec) or the stock Klipsch K55V or K55M drivers with an inexpensive adapter.

The horn was designed to resemble those described by Bruce Edgar in an article published in Speaker Builder magazine using a well known equation for area expansion.

1 Inch or 2 Inch drivers ?

Should I spend the extra money for a 2 Inch throat driver and horn? They say that a 2 inch horn is supposed to be better. The truth is that this is quite true, but difference is hard to measure at normal listening levels. Look at the distortion plots of a 1 inch driver on the Trachorn versus a 2 inch driver on a similar horn at volume levels that most people would consider extremely loud. The small "spikes" on the bottom line are the distortion products. The difference between the two is between 45 and 50 dB below the test tones. Even at very loud listening levels in most listening rooms this is an insignificant difference.

An important consideration is the "coloration" added to the sound. This means the quality of the horn and driver is far more important than the size of the throat!

Yet another consideration is the driver. The K55 driver that Klipsch uses actually measures 0.85 inch across the bug screen in the throat. It is actually an Atlas PD-5VH PA system driver! There is virtually no good quality 1 inch driver that can be operated safely down to 400 Hz. in the Klipschorn. This is reason enough to move to a 2-inch throat horn.

The ALK Engineering 2-inch horn shown to the left will soon be available. It will come complete with a driver designed to be crossed over at 400 Hz for use in the Klipschorn, or without a driver. It will have mouth dimensions and mounting holes identical to the Trachorn 400 allowing any owner of the 1-inch Trachorn to easily upgrade. It will fit directly into the current grill frame of the Khorn or Belle Klipsch. The new horn will be designated the Trachorn 420.

Click HERE for a complete discussion comparing 1 and 2 inch horns.

How about an even larger 2-inch horn in the Klipschorn?
Offering an even larger horn that would operate down to about 300 Hz was considered and rejected. Such a horn would be very expensive and the required driver and crossover even more so. If used with the Universal. network the extra midrange extension below 400 Hz would just make the interference between the woofer and midrange even worse than using a 400 Hz horn as Paul Klipsch intended. The first order woofer crossover in the Universal network depends on the natural acoustic roll-off of the horns to do the actual crossing over. Horns with overleaping response will both be making the same sound at the same time causing major comb distortion due to time misalignment. The AP12-350 network could also be used. This is a 2nd order network which would reduce the energy below 400 Hz that would easily propagate through a large horn to some degree. It would still generate more comb distortion than when used with the 400 Hz horn it was designed for. The best situation would be to uses the ES400 extreme slope network. This would not utilize the reign between 300 and 400 Hz at all, so why should such a big horn be used?

The real intention is to allow a better driver than the stock K55 to be used. This is why a 2-inch horn is being offered, not to extend the lower limit of the midrange! There is simply no 1-inch driver that will do! Initially, the B&C DCM50 driver is the prime candidate for evaluation. It was designed for a 400 Hz crossover. The ES400 network will reject any bass below the 310 Hz cutoff of the new horn allowing ear-splitting levels without the distortion or driver damage caused by deep bass leaking through the filter.

What about a big horn in the Belle Klipsch or LaScala?
The Belle and LaScala provides much more flexibility in the choice of midrange upgrades because the woofer will go much higher than the Khorn. The Khorn woofer will only go to up 400 Hz compared to the Belle and LaScala woofers which extend to above 700 Hz. This gives you the choice of using a much smaller horn and a larger choice of drivers, including 1-inch drivers. The wider response of the woofer combined with a large midrange horn creates an even wider area of overlap than with the Khorn (maybe 300 - 700 Hz). This means a large horn that will extend the midrange lower is an even worse idea than in the Khorn. The Universal network will NOT provide significant isolation between drivers. A network having sharper skirts becomes even more important then with the Khorn. It makes far more sense to use a smaller horn and crossover at the 500 Hz point. The choice of a 1-inch or 2-inch driver is really a separate matter than the size and lower frequency limit of the horn it is mounted on. The recommended choices are a 2-inch driver (B&C DCM50) crossed over at 400 Hz or a 1-inch driver (JBL 2426j) crossed over at 500 Hz. Only the Belle or LaScala can use the second option. The Belle or LaScala certainly do NOT need a large horn that extends down below 400 Hz when their woofers will go as high as 700 Hz! Remember, the objective for considering a 2-inch horn was to find an upgrade for the stock K55 driver that was designed to work down to 400 Hz for the Khorn. The Belle and LaScala can be crossed over at 500 Hz which allows several 1-inch drivers to be used even though at reduced power (that is, if you want to call 20W maximum below 800 Hz for the JBL 2426 "reduced"). The 2-inch horn and driver becomes an option rather then a necessity! The Trachorn 420 horn will certainly be usable in the Belle Klipsch or LaScala though.

Martinelli Sound actually makes the Trachorn. Martinelli is a well known expert in the field of wooden horns. The build quality of the Trachorn is far superior to similar horns made by others. ALK Engineering will be doing the final customization and assembly.

Here are some of the Trachorn advantages

  • Top and bottom feature 3/4" Baltic birch ply with 13 laminated layers with no voids for the best damping properties. A very costly plywood to use but far superior to all others.
  • The side construction is comprised of two separate layers. The inside layer is Italian bending ply for a smooth inside surface. The outer layer is a thicker luan bending section for strength.
  • All braces and structural supports are also 13 layer Baltic birch.
  • The two side layers are bonded with a costly acoustical damping adhesive. This horn will not "ring" or add any sound of its own!
  • All components of the horn are mechanically fastened and bonded. Two different types of adhesive, crown staples and screws are used. All work together to give the most rigid and stable design with the best acoustical properties available. This horn will not come apart after a few years!
  • The driver plate is not left to any chancy hand work or hand shaping. The entire design is computer programmed and machined using a CNC machining center. The mounting holes will fit your compression drivers without worry or hassle. The transition of the throat is a fully machined square to round transition with such precise detail that there is no chance for anything but perfect sound transmission.
  • A gasket is provided at the junction of the driver plate and the horn mouth to ensure an air-tight seal.
  • The plain black finish is an Industrial Acrylic Enamel. It isn't intended to be pretty but rather it seals the horn and keeps the moisture out. This inhibits shrink and swell, thus eliminating any chance of failure from the climate changes we all live in.

Dimensions

Beware of the construction of the other horns. The curved sides of this type horn can cause coloration if they are too thin. Take note of what Dr. Bruce Edgars's original article has to say about an attempt to make a horn with thin, single-ply bendable wood. The Trachorn has two layers of different types of wood bonded together with damping adhesive. This is far more important than the throat size of the driver!

The new horn's height dimension was chosen to just fit in the top section of the Klipschorn. For the Belle Klipsch, raisers will lift the top section woodwork slightly. Entirely new front grills with matching grill cloth will be included. The horn can also be used in the original LaScala if the hole size is increased.

Mounting in the Klipschorn and Belle Klipsch will be done by positioning the new squawker horn to the left with the tweeter moved to the side. Vertical mounting of the Klipsch tweeter is in no way a compromise. This is the way that tweeter SHOULD BE MOUNTED! The entire assembly can be flipped over for mirror-image mounting. The speakers may by reversed left-for-right to change from "inboard" to "outboard" tweeter positioning. Brackets will be provided in the new grill frame for the Klipsch K77, JBL 2404 or the Beyma CP25 tweeters.

Quality drivers on the 1-inch Trachorn 400

The Trachorn 400 is made to accept any quality 1-inch throat driver. The motor-board is drilled to directly accept the JBL three-hole bolt pattern or the two-stud system used by Altec drivers. A very inexpensive adaptor is needed to use the stock K55 driver. Here's an example of a JBL 2426h mounted directly to the Trachorn. With a "true" 1-inch driver the sound path from the diaphragm to the mouth becomes a smooth expansion with no "bumps". The improvement over the K55 is quite noticeable but not the "jaw-dropper" you will get when you replace the stock squawker horn with the Trachorn.

Here's the first prototype Trachorn mounted in the frame for the Belle Klipsch. The tweeter is a Beyma CP25. The Klipsch K77 will be mounted vertically, in the same position but without the 3/4 inch setback.

The raiser lifts the top section to allow for the new horn. It becomes the same height as the Klipschorn top section. The grill cloth is a virtually identical match to the cloth used by Klipsch.

This pair is for the Klipschorn and is complete with black grill cloth and the K77 tweeter bracket.

Here's an installation in the new LaScala II.

Testimonials

Here are the comments of the first Klipschorn owner to install the Trachorns. Ms. "Golden-Ears" sings in the choir of a major symphony orchestra and knows what live music sounds like!

"The Trachorns took about two hours out of the box to install. As advertised, they just basically dropped in and brought my K-Horns back to the factory look. The cut-out and pre-drilled holes for the Beyma were spot-on and the Beyma mounted without any problems. I did not need to move the crossovers to accommodate the horns, so there was no problem there either."

"Ms. Golden-Ears and I spent about four hours listening last night. We both agree that the new horns are much clearer and more natural sounding than the Altec 511s. For the first time violins sound almost like what I hear at the concert hall. Voices are clear and very distinct. Al, this is a great product and one that every K-Horn owner should install. I have never heard the K-horns sound better... I don't think I've heard any speaker that sounds better! With the TADs, Beymas, ES crossovers and the new Trachorns these speakers sound wonderful."

Bob Lemker

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

"There is a good jump in clarity, and the sound is more open and relaxed sounding. Voices sound natural, and there is better articulation. When power levels are increased, the sound doesn't become constricted and pinched like the K-400/401. If you just imagine a very clean sounding Klipschorn, then you pretty much have it. The Trachorn also has a flatter response than the K- 400/401, especially in lower end of its response. This, along with the lower distortion and increased clarity gives the impression that the midrange is more pronounced than it was before -- which it is A 2db drop in the squawker's attenuation is all that's needed."

Dean Wescott

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

"Before considering installing the Trachorns in my Belles, I had already both spoken to and emailed Al regarding his Universal Upgrade to my existing Belle networks, which I bought. He gladly answered all my stereo related questions which were of absolutely no financial benefit to him. I found that refreshing. His advice was sensible, pragmatic and plain speak. With that in mind, I decided I just couldn't go wrong by getting the Trachorns. Not unexpectedly, his praise of them was understated. No more "bottom-of-the-well" sound. Great dynamics and "room presence". They just sound bigger. P.S. I have subsequently traded-in my ALK networks for Al's "Extreme Slope". If your budget allows -- this is a must. If you have gone to the trouble of getting the Trachorns I strongly recommend you go the extra distance. You will then have world-class speakers without having spent $20,000 plus."

Rainer Gunther

NOTE: The Trachorn will be available only from ALK Engineering, NOT directly from Martinelli.

Pricing & shipping 


 TRACHORN 400 .....................
   Horn will accept 1 inch diameter throat drivers with
        JBL 3-hole 1 1/8 Inch radius or Altec 2-stud 1 1/2 Inch radius.

   Set of two horns:
        Black ................................................. $480.00

   Two adapters for Klipsch K55V, K55M or K55X drivers (installed).
        1-3/8 Inch - 18 TPI round thread screw-on mounting
        (SELENIUM ADF25-25) ...................................  $12.00

   Set of two grill frames with detachable flush-mount tweeter bracket
        (black, no grill cloth)
        * Specify tweeter type: Klipsch K77, Beyma CP25 or JBL 2404
        for Belle Klipsch
             (Includes top section raisers and hardware) ...... $75.00
        for Klipschorn ........................................ $60.00

   Klipsch equivalent grill cloth installed
        * Specify grill cloth: Black or Cane. ................. $75.00

 Shipping:
   Complete set of two horns, grill frames and tweeter rackets:
   Box: 32 X 24 X 19 Inches. Weight: 30 Lbs.
   Professional packing cost: $33.00
     Estimate shipping cost

Go to ALK Engineering home page>

* Home *