Thoughts on Lascala and PWK's philosophy

[WMcD]

Various collections of images of bass horns show that those designed for use outdoors (edit, or on a stage) usually are quite large.  Part of the issue is the very large mouths needed to make the horn work at bass frequencies. 

 

Regarding the mouth, it is fairly often said that K-Horns us the room corner as an extension of the bass horn.  The corner of the room becomes the "bell" or mouth end.

Attached is an excerpt of an article from 1931 where the author discusses the use of a corner as an extension of a straight bass horn.  Its a bit impractical but you'll get the idea.  Putting a folded bass horn (edit: with a relatively small mouth) in a corner is similar in concept.

 

 

Means_for_Radiating_(excerpt_re_corner)_by_Kellogg.pdf

[JohnA]

Very interesting article, Mr. McD!  I can just imaging Mr. Paul reading this in grad school and dredging it up later as help designing the X-1. 

[WMcD]

I had posted the full article about 11 years ago.  I thought it had been lost in some of the reorganizations /  crashes of the server.  But not so. Smile.

 

https://community.klipsch.com/index.php?/topic/68216-article-means-for-radiating-large-amounts-of-low-frequency-sound-by-ew-Kellogg/

 

WMcD

 

 

[HDBRbuilder]

On ‎3‎/‎14‎/‎2018 at 12:48 PM, Ray_pierrewit said:

I've owned my Lascalas for over ten years now and have just gotten around to identifying the serial numbers. It looks like they are from 1975, serial numbers 4N891 and 892. They've got AA crossovers which I changed with the Crites capacitor kit a few years ago. I also built the ported bass bins which really added more than it subtracted, so they are staying put for now. I may one day try the Qpie bass bins, we'll see.

 

They were my initiation into the world of Klipsch and have led me to buying Forté Is, Heresy Is and recently RB75s. They sound terrific and I'm not currently looking to upgrade any of the drivers or horns, nor changing the crossovers. Having said that, are there any recommended steps to insure that they are in tiptop shape? I'm thinking gaskets or tightening screws or anything else that may be pertinent to verify. Being from 1975, is it safe to assume that they are Alnico drivers? The k77s are round. 

 

Interesting side note, I've noticed that the internal wiring is all tinned copper, which Jeff Day has been advocating on his blog for a couple of years now. Seems that tinned copper is all the rage with those seeking richer tone over ultimate resolution. 

 

Lastly, I've got a couple of questions regarding PWK's 8 cardinal points to reproduction of which I just recently became aware. In his first point he states that "corner placement reduces distortion three fourths". Does this mean that by placing the Lascalas in corners it will reduce their distortion, or is he referring to the woofer in the folded horn? I'm no sure if that's clear. In point 2 he says that by placing the speaker in the corner it increases the effective size 4X. Just what concretely does that mean? Points 3, 4, and 5 are straightforward and logical. Point 6 is up for debate as I've never heard a system setup on the long wall of a room. I trust that it's amazing with a third center channel and very distant flanking speakers, as he suggests is best for imaging in Point 7. In point 8 I'm compelled by the "reduced shift in the virtual sound source for different listener locations" created by corner flanking. If I understand correctly, he means that there isn't a narrow little sweet spot but rather a large listening window for several listeners to enjoy... hmmm, must try that one day.

 

Thanks,

Daniel

 

 

PWK was a product of group listening...as in an AUDIENCE.  Keep in mind that he was a proponent of the Bell Labs' three-speaker stereo array long before EVEN A SIGNIFICANT MINORITY OF "AUDIOPHILES"  had graduated beyond monaural home listening.  His first successful speakers following the K-horn were considered (and marketed AS) SUPPLEMENTARY speakers to a mono main speaker which was generally positioned in a SINGLE corner of a room, with the "supplementary" speaker being positioned in the opposite diagonal corner of the same room or positioned in another room.  People in those days did not hog a central listening position with its "sweet spot" for listening, by and large, but would be spread throughout a room often walking about and visiting with each other.  This style of listening continued into the era of stereo listening, and with the three-speaker stereo array, no matter where a listener was positioned within the room he/she heard the music in stereo, albeit the sound from the left or right channel may be stronger than that of the opposite channel.  It was just how people listened to music.  With mono it did not make any difference since there was just a single output of sound.  Once people felt a NEED to be centered between the left and right speakers in a "sweet spot" they tended to ONLY WANT TO HEAR the sound THAT WAY.  That became even more important to "sweet spot listeners" as televisions became centered between a left and right stereo speaker pair.  Make sense?  Even today, most listening to a stereo system is done NOT between the speakers in a sweet spot, but as one is walking around doing what needs to be done in the home...this is how it is with the vast majority of listeners.  If you gotta wash dishes you can sing along or enjoy the music while doing it...cooking...whatever...and maybe even dance around a bit to break the monotony of chore completion.  And if vacuuming, you just turn up the volume and blow your tweeter diaphragms.  LOL!

 

[boom3]

WMcD,

Thanks for re-posting that. I find the roster of authors on the title almost a Who's Who of early audio.  Wente, Thuras, Olson, Kelogg, Sabine, Snow. A name worth noting, but not familiar to most folks, is O.B. Hanson. Hanson was the engineer behind the designs of the best radio and recording studios of the pre-WII era, and also supervised the placement of the early TV broadcasting antennae on the Empire State Building.

[MerkinMuffley]

great reading!

[Ray_pierrewit]

On 4/6/2018 at 6:35 PM, HDBRbuilder said:

PWK was a product of group listening...as in an AUDIENCE.  Keep in mind that he was a proponent of the Bell Labs' three-speaker stereo array long before EVEN A SIGNIFICANT MINORITY OF "AUDIOPHILES"  had graduated beyond monaural home listening.  His first successful speakers following the K-horn were considered (and marketed AS) SUPPLEMENTARY speakers to a mono main speaker which was generally positioned in a SINGLE corner of a room, with the "supplementary" speaker being positioned in the opposite diagonal corner of the same room or positioned in another room.  People in those days did not hog a central listening position with its "sweet spot" for listening, by and large, but would be spread throughout a room often walking about and visiting with each other.  This style of listening continued into the era of stereo listening, and with the three-speaker stereo array, no matter where a listener was positioned within the room he/she heard the music in stereo, albeit the sound from the left or right channel may be stronger than that of the opposite channel.  It was just how people listened to music.  With mono it did not make any difference since there was just a single output of sound.  Once people felt a NEED to be centered between the left and right speakers in a "sweet spot" they tended to ONLY WANT TO HEAR the sound THAT WAY.  That became even more important to "sweet spot listeners" as televisions became centered between a left and right stereo speaker pair.  Make sense?  Even today, most listening to a stereo system is done NOT between the speakers in a sweet spot, but as one is walking around doing what needs to be done in the home...this is how it is with the vast majority of listeners.  If you gotta wash dishes you can sing along or enjoy the music while doing it...cooking...whatever...and maybe even dance around a bit to break the monotony of chore completion.  And if vacuuming, you just turn up the volume and blow your tweeter diaphragms.  LOL!

 

Thanks for the reply. It does actually address one of my... irritants about hifi systems, in that the sweet spot is generally too narrow to be enjoyed by a crowd. It's happened to me all too often where an acquaintance comes over and wants to listen to some music. Wanting my system to be at it's best, I have my guest sit in the sweet spot and generally let them determine the volume based on their preferences. It never lasts very long, a couple of songs usually. They are impressed by the soundstage and imaging and music... but it remains inherently individual, not so much a group experience, like live music. That's why this idea of a "wide area of listening" conveyed in the 8 cardinal points is so compelling to me.

 

Since first posting I've moved my Lascalas into the corners. Bass has been reinforced, seeming more natural and expressive. What I wasn't expecting was for the shape of the soundstage to change like it has. I now perceive it as being more rectangular instead of circular and having slightly more depth in the corners. Imaging is still tight. I'm currently planning the construction of an outbuilding/artist studio which will have dimensions much better suited to group listening, 16x26x10. I found those dimensions on several acoustic related sites and lo, it resembles what PWK had as a test room which I read about in some Dope from Hope memos (I think his room was 16x25x10). I'll be sure to post updates and pictures when they come.