Klipsch Horn Woofer designs....

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If you're going to do a unity horn, consider a PPSL woofer.

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"I think that this is the worlds best subwoofer design. This is a Double 15" Push-Pull. I'll never build a bass horn again. "

http://i56.photobucket.com/albums/g196/dkleitsch/CoePA-2009.jpg

Apart from the purported decrease in even-order distortion, how would the output of that differ from a vented box of the same net size and Fb built with the dame drivers?

A TH offers the possibility of greater extension and great efficiency, at the expense of a larger box size for a given driver. Of course, if you start from the box size, one could argue that you might be able to get similar output if you use more drivers in a vented alignment, but no-one's going to just give you those extra drivers and the amp to drive them :).
 
Thanks for the option reminder...

Thanks DJK for the reminder. That tyoe of cabinet is very similar to that which William Cowan uses though his is two double 12 inch Peerless drivers in sealed boxes per channel in a vertical WMW configuration. I can not go as large as William did but I wanted to try and equal the Unity efficiency (or get as close as possible) at 100 db. There may be options available if I look hard. This style of cabinet is no worse than either the La Scalla or the Beck cabinet from a size point of view.
Brian one of the major advantages of the manifold cabinet design according to William is that the manifold has a dispersion pattern of 90 degrees at the crossover frequency of 370 Hz. which matches that of the Unity so a uniform power response is obtaind throughout the room at crossover frequency. The other benefits are lower distortion and vibration control. I plan to use multiple small TH's for the extreme low end. A TH alone would be an octave away from crossover to the Unity so an additional driver cabinet and crossover would be required not to mention an amp. So I would like to go with a bass mid that will run from 50-70 Hz. up to the unity at 370 Hz..
I am still interested to hear comment on the Beck horn if anyone cares to offer it as it looks to be a nice design. Thanks so much for the input and support. This is a big undertaking and I want to do it right. Best regards Moray James.
 
Where is information available on building a PPSL type woofer. I have seen these on several threads but no information on building one. I try to model one in Horn Response and it looks quite good but I don't know if I do it correctly. Unlike some sims I have seen I do remember to do the combined output part of the sim.

I am looking at two or three way with horns but don"t have room for the lowest horn. Would a PPSL be capable of going high enough to make a two way crossed about 600 - 700Hz. Just looking at it for some reason I don 't feel that it would so I am looking for input from the more experienced like djk. I am eagerly waiting for his development on the unity horn for this reason.
jamikl
 
"Apart from the purported decrease in even-order distortion, how would the output of that differ from a vented box of the same net size and Fb built with the dame drivers?"

It doesn't.

A 2 cu ft 2nd order sealed box with an F3 of 30hz can only be 0.18% efficient (84.55dB).
A 2 cu ft 4th order vented box with an F3 of 30hz can only be 0.36% efficient (87.56dB).
A 2 cu ft 6th order vented box with an F3 of 30hz can only be 0.90% efficient (91.54dB).



I use 6th order vented alignments for minimum box size and maximum bass extension. These boxes sound so different than regular vented that they may take some getting used to the clean sound.

"A TH offers the possibility of greater extension and great efficiency, at the expense of a larger box size for a given driver. Of course, if you start from the box size, one could argue that you might be able to get similar output if you use more drivers in a vented alignment, but no-one's going to just give you those extra drivers and the amp to drive them . "

A TH looks interesting, I have a PP TH design for a dual 12 that looks promising (although it is quite large). I use very inexpensive drivers, a pair cost less than one driver as used by Danley. Amplifier power is virtually free these days, especially if you can find what you want used ( I recently bought 8KW of Crest from a church remodel job for less than $800 ).
 
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"Where is information available on building a PPSL type woofer."

Do a Google search on PPSL and djk, there is quite a bit out there.

"I try to model one in Horn Response and it looks quite good but I don't know if I do it correctly. "

I use BassBox v6.0, and select my drivers to use with a 2-pole HP filter with a Q=2 at Fb.

I keep the plenum as small as possible, I don't want it acting like a bandpass enclosure.

"I am looking at two or three way with horns but don"t have room for the lowest horn."

No one does. If you try and cheat the size you end up with poor performance. The TH looks to be an exception, but the bandwidth is limited.

"Would a PPSL be capable of going high enough to make a two way crossed about 600 - 700Hz."

Maybe.

I have never tried to go above 250hz with my designs, Although Electro-Voice briefly made a model that crossed over to a pair of DH1 on an HP940 at 800hz. The ones Les Hudson made worked well into the 400hz~500hz range by minimizing the plenum dimensions. The EV was constructed along the lines of this sketch:

PPSLslantplenum.gif


A couple more photos of designs from Les Hudson:

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I don't know the details on this tall slim one (middle), but it looks like it crosses over to a regular compression driver fairly high in frequency:

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Les Hudson accepts e-mail from inmates at the Audio Asylum.
 
Perhaps a new thread

Jamikl: perhaps a new thread on a ppsl would be a good idea. I am in worse condition than you as I have not been able to fly the simulation programs to play with such a design. Not sure either if I know anywhere enough to make sure I was taking all necessary aspects into account. I would not trust me to do it right. I would be interested in seeing what you have done so far as it might help me to figure out how to do it myself. Perhaps Les might chime in as he has built a number of these. Thanks for posting and best regards, Moray James.
 
The Klipschorn is very much a different speaker from the Belle or La Scala. It was designed to be placed in corners, with the horn exiting to the side, and the walls form the final flares of the folded horn. Placed anywhere else the lower LF response is compromised.

I'm going by memory here, but I believe ideally the walls should be at least 16' long at each "corner" for response down to the 30's somewhere.

The other Klipsch folded horns exit forward, and are limited to about 45 Hz.
 
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Thanks J2B: yes that's why the gap between "Klipsch" and "Horn" in the title. The interest was the comparison between the La Scalla and the Beck designs. Seems that for my application the recommended cabinet design is a PPSL design rather than a horn. That said I still like the Beck as far as I can see right now it would look to be a good design which while a little larger than the 2'x2'x2' size of the La Scalla it seems to be a sooth and well extended horn. Worth keeping on file. The Beck might make a nice guitar cabinet with the addition of a mid horn and certainly offers an option for a slightly different profile cabinet as opposed to the La Scalla. As a horn it probably runs lower than a La Scalla does which I think stops horn loading the driver at about 100 Hz..
As far as the KHorn goes the Jubilee (PWK figured it was his finest horn design) is a less complex build and it is a better horn but still too large for my situation. Thanks for posting, are you running horns? I fell in love with horns as a kid A7 Altecs but a small bedroom and A7's don't agree with some parents. Then a set of Altec Valencia's still big and now a set of Klipsch Forte ll and am working toward a set of Unity Horns with PPSL bass and TH subs. In between there were a lot of electrostatics and thoughts of ribbons. All three share dynamics and low distortion but horns seem to deliver the most once you accept the dimensions. High efficiency is the gravy boat that comes with the horns. All the best Moray James.
 
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In a different life, a long time ago, I had a retail store; we were the largest Klipsch dealership outside the United States. Paul himself even came to visit once, just to see what we were doing differently than anyone else. We were also a JBL Pro dealer (a different line from JBL consumer). I'm familiar also with Voice of the Theatre's and the Tannoy coax 15's.

There is a lot to like about Klipsch speakers, including near-bulletproof reliability (we replaced a few tweeters; never any other part, and a lot of the stuff we sold was used in sound reinforcement). A lot of people think they are too bright; in reality that's an issue with step response, not really linearity. The HF leads the Mid and both lead the LF by a fairly long time by modern standards. But, Paul knew what he was doing before a lot of people figured it out ... he took a lot with him when he died.

You know, I never saw paper-in-oil capacitors in anyone else's crossovers, and I saw nothing but in his. Same with the marine-grade plywood (not "Baltic Birch" which can have voids) which moves the resonance frequency higher up into the audio band, where it takes more energy to excite it, than equivalent thickness MDF. Stuff like that he knew 60 years ago.
 
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Hey that's great someone with some interesting story's to share? I had a bud as a kid who's brother had a set of Belle Klipsch and I have always loved the look to this day. Have you taken a look at Greg Roberts site (Volti Audio) he has done some stunning rebuilds on Klipsch speakers simply beautiful work. I bought into the hype about horns only really being for PA (in my 20's) and chased dome tweeters for a while but the Altec and the past Klipsch experience stuck. Some 10 years ago a late buddy of mine bought a set of RF3's, I drove him home with them in my car (just barley) and he ran them off a set of British EL34 set amps I was stunned right out of the box they were very good. That got me thinking again that high efficiency and horns were a good thing. I just got a set of Forte ll in trade and figured I would refinish them and upgrade them while I was working on the Unity project then give them to my daughter. I gave my son a set of Tannoy 12 inch HPD's last year. The Forte are even better than the RF3's and I think they have a lot of potential. The tractrix mid horn really puts meat on the bones of vocals and mid range solo instruments they can do some wonderful things for a very domestic sized cabinet. Can you share your favorite Klipsch models with us? Did you do much with the pro or theater Klipsch? Can you tell me why Klipsch never built the reputation that Altec or JBL did? They seem like a heck of a company even today their support is fantastic. They (Klipsch) claim today that one of every two new theater installs in both North and South America is built by them. Where was your store and what was it called? Glad you decided to contribute to the thread. I imagine you have a wealth of knowledge on the brand. Looking forward to learning more. Regards Moray James.
 
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Lots of La Scala Pro's; used to put 4 of them, one in each corner, down-firing, in dance floors in bars. This would be places with a dance floor about 30 x 30' ... you could talk at the table but were pretty much forced to move on the floor ... it was loud in the pit. You didn't need any other speakers in the whole place; that's where the bar owner figured out you were saving him money and packing the place where it counted at the same time. Two Bryston 4B's and you never had to worry about anything breaking and getting a call at 2 AM. It was nice to pop in and "check out the system" every once in a while ... no cover, free drinks.

Altec was around 20 years before Klipsch, and were marketed to that industry. PWK marketed to the HiFi crowd; thus the veneers on Belle's and K-horns. James B Lansing worked for Altec before branching off on his own, so he took some of that reputation with him and was able to move into Altec's market easily. The 300B was invented for telephone use, but you could also call it a movie amp tube; Western Electric made all the theatre amps at first. No surprise they used horns to go with it.

With the movie theatres, this is not an industry where the owners actually listened to anything; they just bought what the studios told them to. Some of the theatres were owned by the studios, so you just tried to keep up with what they installed. It's not much different than Burger King saying you buy this for fries, you buy this for burgers, you buy this for shakes ... the movie theatre is the burger franchise of the early 20th century.

A lot of people don't know it, but current home theatre owes everything to movie studios from the 1950's ... by then 3 channel sound was on every reel (left, centre/dialog, right).

When the studios started featuring widescreen (eg cinemascope) those films had 5 and 7 channel soundtracks. This is all 1950's stuff, not last year. Not sure of the date **, I'd have to look it up, but the La Scala was the first Klipsch actually designed for theatre use, and it wasn't introduced until after all those theatres already had 7 channel systems installed ten years earlier.

** Just checked it out ... 1963.
 
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Beck's Horns in Hornresp

Hi moray james,

You asked for a model of the Beck Horn:

BEC2Biex

I modelled it and the:

15" Bahorn

in Hornresp. The speakers used are listed in the input screens. I used Nd for the 12" and OD for the 15" to reflect the difference in throat position. Both horns would benefit from more length and a larger mouth, but then, what else is new. They also are a tad wasteful in their use of internal volume, but should be relatively easy to build. Not as easy, or going as low, as jbell's SS15s though.

Hope you'll find this useful.

Regards,
 

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Thank you Oliver: they look ok and yes the JBell cube is an easier smaller build and does go deeper. I will file this away and keep them in mind for a guitar cabinet for later. I think I will take the advice of William Cowan and DJK and look into a PPSL cabinet to run with the Unity horn. The idea of adding some small 6.5 inch woofers with serious travel onto the unity such as is done with the Danley SH50 is also an attractive idea. Then all the drivers would be coaxially loaded down to well below 100Hz. and a sub such as JBells cube could handle the bottom octave and a half. Thanks for the help here. Lots to consider. Best regards Moray James. l
 
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