Article by PWK: Wide Stage Stereo

[WMcD]

Below is an article for your reading.

I usually post these for weekend reading. Thanksgiving got in the way.

Gil

[WMcD]

Here you go!

Please note he is discussing the use of a center channel.

Gil

Wide Stage Stereo.pdf

[Q-Man]

Shame on you for letting Thanksgiving interfere. I had extra time to do a little reading over the holiday too.

[mark1101]

William,

Thanks, a very nice article. I always thought the Heresy was PWKs center unit of choice. Here we see the old corn however.

I think the best point of the article was the improvement and degradation of being able to locate the source within the sound stage depending on the speaker placements.

The experiment makes sense. In the past there have been times when I thought I had wiring (phase) problems and such, when it was just a tweak of movement of a speaker to correct the sound stage. Sometimes 1 foot made all the difference in the world. Especially with my corns.

I have never tried using a center channel output on anything but my subs (and HT). But I will try on the 2 Ch. systems as I get some time. My old Scotts have the derived center channel.

Thanks again.

[Erik Mandaville]

Thanks for posting this article, Gil!

I enjoyed reading it, since the center channel is something I have been experimenting with, not to mention very much enjoying, these past few days.

All I had was the schematic for the minibox used for combining the L/R signals, so having the chance to read this was great!

Erik

[Parrot]

Mark 1101,

Paul W. Klipsch advanced his way of thinking over the years from Heresy or Cornwall center to La Scala or Belle. He became quite adamant about it, as a matter of fact.

Of course anyone is welcome to disagree. Indyklipschfan's Cornwall center for his Khorns sounded good when I heard it, and he preferred it to a La Scala center in its place, which he had tried.

Nevertheless, the master himself said in Dope From Hope, June 1976:

"We recommend our BELLE KLIPSCH or LA SCALA as a center speaker between our KLIPSCHORN, LA SCALA or BELLE KLIPSCH as flanking speakers. We do not like to use our HERESY or CORNWALL speakers between totally horn-loaded speakers."

. . . "Our HERESY exhibits lower distortion than any other speaker of its size and price. But it is still not an all-horn system. Having a direct-radiator bass unit, its distortion in the bass range is inevitably higher than that of our horn systems, and the cruel fact remains that the speaker system with the highest distortion determines the distortion level of the entire stereo array."

. . . "The perceived distortion is that of the poorest speaker in the array."

"When a customer demands totally horn-loaded flanking speakers, but asks for a less expensive center channel, simply suggest he settle for a two speaker array until he can afford the correct speaker for the channel."

[WMcD]

Thanks for the kind words. They are inspiration to keep on with what is becoming a tradition.

It is interesting to me that PWK took such a scientific approach. It was in the early ages of home stereo. Granted he was building on Bell Labs. None the less, he must have done it for his own enjoyment and sense of perfection and wished to share it with the customer and also prove it to the hard core engineers.

In one installation I use a center channel to listen to ordinary two channel. Sometimes the result is a full stage of orchestral music. On some pop music the vocalist gets very solidly planted in the center, sometimes up above the center speaker. It really makes an enjoyable difference.

Gil

[sfogg]

"Nevertheless, the master himself said in Dope From Hope, June 1976"

While that is probably true technology has advanced a bit from 1976. Paul's minibox had no manor of dealing with the bass response going to the center channel. In fact the center channel in that setup would be getting all the bass in the recording and something like a singleHeresy (or Las... or Belle...or CW) couldn't keep up with a pair of K'Horns in that regard.

Nearly 30 years later it is much easier to deal with this. Processors can redirect the bass that would have gone to the center to speakers (or subwoofers) better able to deal with it. Reducing the bass sent to something like a Heresy center is going to make its life easier and reduce its distortion.

Shawn

[Erik Mandaville]

I am looking very forward to trying a more up-to-date approach to this! Having used a Heresy/minibox arrangement in the very first attempts, I have found a different speaker -- full-range Lowther-based horn -- to be somewhat better. Lowthers are crossoverless loudspeakers that, despite having limited bass response (somewhat room-placement-dependent), have very fast transient response and transparency. However, I wonder that the improvement I heard may have had more to do with the fact that the driver, installed as it is in a tall cabinet, was closer in height to the midrange and tweeter horns of the Klipschorns on either side.

I am planning for a third (center)Belle or La Scala, which I think will be an improvement over the Lowther. I found the Heresy a great inroad into a derived center channel, and immediately thought the overall sound was sigificantly better than two channels alone. However, the Heresy did have a sort of dull or muddy quality on the low-end that the Lowther does not. Lowthers aren't known for strong bass response (for a variety of reasons), but what is there is always very tuneful and natural; and this may be the reason why I found them a better match for the Klipschorns.

Having said all of that, the 30 minutes I spent building the minibox was probably the most significant work I have done in the past several years in terms of the overall impact and positive change for the better in our system.

An even great and more important carry-over of the change had to do with the fact that the extra channel/s pulled more people into listening to music! Off-axis listening improved surprisingly, especially when I included the Heresy in a secend derived rear channel; and my wife commented several times on how much better, full, and complete music sounded to her while sitting totally off to one side on our futon sofa.

I don't wear a hat, but if I did, would take it off in respect to the great work done by Paul Klipsch!

[avman]

i haven't yet modified the 3rd KLF-30 i have to use as a center channel, and the receiver does not have a 3-ch./5-ch. stereo mode, however i do have an old ES receiver that does have 3-ch.stereo with external amp capabilities...

my intention is to use the pro-logic circuit in that receiver to derive a center rear (which i will use my existing C-7 for)placing it between my KSP-s6's and powering the center rear w/the L or R channel amp of that receiver(it has line out/in amp capability,and the center 'amp' is weak compared to the L,R amp). while i am at it, i will experiment w/the 3-ch. stereo front configuration. thanks for the info-if i like it,i will also look at the configuration Mr.Paul used to see if i can go that route,but the room is only 12ft. wide,and i am VERY happy w/my existing 2-ch.+RSW-15 stereo sound!

avman.

[Parrot]

[Daddy Dee]

Gil,

Thanks for posting another article on PWK. I really look forward to seeing the next thing you put up on the bbs.

Just one sanity check please. It seemed to me that over the Thanksgiving weekend I found one of your posts of Dope From Hope on PWK deriving a center channel with the minibox circuit. It included the schematic for the minibox(s) as well. Now that I am looking for it on the forum I can't find it at all. Did you post this? Perhaps someone else?

If Gil or anyone else could point me toward this post, or the loony bin, either would be appreciated.

In addition to this, another reason to question my sanity is that there are some posts I KNOW I have written and replies in threads that disappear after posting. Maybe the loony bin will be fine. I wonder if I can still get the forum from there.

[Parrot]

Sometimes entire threads have been taken down because of vile, nasty comments in a particular post.

[Daddy Dee]

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On 11/30/2004 4:31:10 PM paulparrot wrote:

Sometimes entire threads have been taken down because of vile, nasty comments in a particular post.

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

Yep, maybe that's what happened with this one.

Score one for sanity, I did find an e-mail I sent to myself with the pdf attached. It was from a 1981 Dope from Hope that someone posted. Not sure if Gil posted that one. However, he has kindly posted another center channel Dope from Hope from 1974 which also includes the minibox schematic.