With Respect
March 9, 1904 - May 5, 2002
** PWK's loudspeakers **
Klipschorn
Belle Klipsch
LaScala
The loudspeakers Mr. Klipsch designed are among the finest ever made. His horn-loaded woofers in particular are first class. We don't mess with them! No changes of any kind should be made. Don't try to put a better woofer driver in them. Don't stuff the back chamber with damping material or do any other kind of changes. You will be taking a step backwards!
However, some of these speakers have been in use for as long as 50 years. The state of the art has moved on making the high end ready for some improvements. The midrange (Squawker) horn and crossover networks in particular could use some improvements. To a lesser degree, the tweeter can also be improved. The upgrades we offer will make your Klipsch heritage speaker second to none!
A new policy
(This is why a credit card is the preferred payment method. I charge the card the day I ship.)
PayPal payments are accepted but I am forced to insist on these points:
About delivery time:
I do not have the networks built and in stock! I need to order parts for the network orders that are on my waiting list and build up and ship these before I order parts again. Getting parts takes time. I can not keep all the major parts in stock for such a variety of network options. Cash flow demands that I operate this way. Lead time will usually be between 4 and 8 weeks depending on your position on the waiting list and part availability.
I recently learned that the policy of Solen of Canada has been to wait until all of the parts I ordered are ready to ship before shipping anything. This has been responsible for holding up production for just a few parts. From this time on I will instruct them to ship what they have in stock. I can be building something while the remaining parts are made. I hope this will reduce overall waiting time but it will make it even more difficult to accurately estimate when a particular order will be filled.
About current delays (February 03, 2012):
Parts for the next batch of networks are on order. Parts from Solen of Canada have been shipped.
What's wrong with the stock Klipsch networks anyhow? Here's what!
======================
All our networks, except the Universal , are divided
into two separate modules to allow flexibility. Each module is a constant-impedance crossover formed by a high-pass and a low-pass filter of the same frequency. The high frequency
output of the lower crossover is fed to the input of the higher frequency
crossover. The diagram below shows the ES500T crossover connected to the ES5800 crossover. Any of the low frequency crossovers may be used in place of the
500 Hz network shown including one of the
AP12 series 12 dB / octave networks.
The Universal network
6000 Hz section can even be used in place of the ES5800 by connecting to its
Bi-Amp input. This lets you upgrade your speakers slowly, one module at a time!
Notes:
Are the old paper labels on the edge of your networks damaged or falling off ? High quality engraved replacements are available.
Available types 
These are available directly from my source:
Stan Holt
Our Extreme-slope filters reject at a rate beyond 120 dB / octave until they reach about 25 dB where the rejection levels off. The faster slopes yield a noticeably better stereo image.
The computer plots below compare the response of the normally used 12, 18 and 24 dB / octave filters (N=2,3 and 4) to each other. The plots are all shifted to illustrate how the crossover can be lowered with a sharper slope (higher order filter) and still maintain 20 dB of protection for the squawker driver from sounds at 200 Hz. Notice how the ES400 extreme-slope filter with a 400 Hz crossover is far ahead of the others providing over 25 dB protection all the way up to and beyond 310 Hz where the Martinelli Trachorn or the Fastrac K Edgar type tractrix horns cut off. Even the 24 dB / octave N=4 filter offers only about 6 dB of protection at 310 Hz! You can rest assured that you will not damage your mid-range "squawker" driver with an extreme-slope network!
This seems to be becoming a very popular project in the DIY community. It is the result of combining the WORST features of the Cornwall and the LaScala speakers into one. The LaScala has the BAD K400 squawker horn from the Klipschorn and the Cornwall has the higher distortion direct radiator from the Cornwall. So, the result is a speaker with the harsh midrange of the Khorn and the higher distortion bass of the Cornwall. It will go down to 30 Hz though, and this is probably what it's all about!
HOWEVER: With a few variations on the theme you can come up with a very good speaker. The very first thing to realize is that the K33 woofer as used in the Cornwall will operate higher than the 400 Hz upper limit of the Khorn woofer horn. This allows you to move to any of a long list of better mid-range (squawker) horns. Even with a 400 Hz crossover, anyone who uses the K400 horn for anything but a door-stop is crazy! It's a headache maker.
These are ALK's recommendations for a good Cornscala:
Al Klappenberger
Enlarge
This network is for the Forte I.
A nearly identical network for the Forte II is also available.
(The Chorus models are NOT compatible.)
These networks are available as a parts kit complete with a pre-drilled board for $150.00 or finished for $250.00 less the the transformer which can be removed from the stock network and reused. A set of 3619 transformers can be substituted for an additional $80.00.
Bi-amping is the practice of utilizing separate amplifiers to run the woofer and the high frequency drivers. It also requires an active crossover network AHEAD of BOTH amplifiers. This is a point beginners don't understand. Most of my crossover networks are NOT compatible with this procedure. If you have to ask why, you don't want to even consider bi-amping. It's a BAG OF WORMS! HOWEVER: A version of the AP15-6000 network is available for use with bi-amping. It will be designated the AP12-6000T. It will allow the squawker to be attenuated rather then the tweeter in a 3-way system.
These on-line audio forums exist for the financial enrichment of their owners. This is certainly the case with the Klipsch company forums. The long list of sales banners at the bottom of the AudioKarma forms is certainly evidence of THEIR agenda if not outright proof. Unless you pay them, a "vendor" such as myself can not mention his products without being accused of abusing the forum. In spite of care not to directly tout my products I have been repeatedly accused of it. When owners of Klipsch Heritage speakers post asking questions like why do my speakers sound great but give them headaches after listening for a while, I feel obligated to point out the reason, the K400 squawker horn! When an owner posts asking for ideas on how to upgrade his speakers I have two choices. I can to point to the items that I know need improvement and get accused of abusing the forms or I can say nothing waiting for other to suggest my products and later be asked why I didn't help! I considered sponsoring one of the forums but realized that doing so would not pay off. I do no paid advertising at all but rather depend on word-of-mouth to sell my upgrades. This is the best advertising there is and it's FREE! This is one reason I can offer my upgrades at reasonable prices. Paid advertising is expensive! After years of fighting the unavoidable I have concluded that I should never again join any of these forums.
As of Thursday, February 24, 2011, I again resign from the Klipsch forums.
The opposite extreme from forum moderators who will not tolerate anyone who is considered a vendor of products related to the subject are those who will not control vendors who take advantage of the situation peddling poorly designed products. In this case, only other forum members knowledgeable enough to identify the snake-oil they sell can perform the function. When such moderators come after these individuals instead, it is time to leave. The Klipsch forums have become such a forum. I have left by my own choosing!
UPDATE:
A test log-on June 21, 2011, out of curiosity, showed that I have been banned. I don't really care, I don't need that forum to sell my stuff! I think it clearly shows something about their thinking though. Would I have been banned if I criticized products made by BOSE? Everybody there does! Suppose Mr. Bose was a forum member? Would his products be protected from criticism then? Would criticism of his products be assumed to be personal attacks on him? Probably!
To be forced to not respond to quackery, as I have been, is similar to an itch you can't scratch! I wouldn't be able to sleep nights!
Here's an unrelated project for the "green" DIYer that I'm rather proud of: Take a look
Al Klappenberger