Old School Center Channel with Klipschorns - Is it worth it?

[Chris A]

it occurs to me....is this going to be worth all the effort?

I think that a rule of thumb is something like 20-30 feet separation between the Khorns before the "hole in the center" phenomenon usually occurs. If the "hole in the center" occurs at less than this separation distance, then I'd recommend room treatments. The following excerpt is from PWK's article, "Stereophonic Sound With Two Tracks, Three Channels By Means of a Phantom Circuit (2PH3)*", JAES, April 1958, Vol. 6, No. 2:

SPEAKER PLACEMENT

"When this writer started experimenting with 2-channel stereo, experience at various demonstrations was unsatisfactory; insufficient separation or sharply focused point source effects marred the demonstration. Accordingly the approach was made using wide microphone separation and corner placement of speakers. It was found that, usually, placement of corner speakers against the long wall of a room was better than against a short wall. Thus in a living room 20 by 30 feet, the performance was better with the speakers 30 feet apart than 20 feet. But the wider the separation the more apt there is to be a 'hole' in the middle and this has been the subject of occasional adverse criticism. The phantom center channel has not merely filled this hole; it has satisfied the ear to the extent that there appears to be a solid curtain of sound rather than a group of point sources..."

Chris

[mark1101]

A few years ago I had a nice pair of Khorns. But my room dimensions were about 2 ft. too wide for the Khorns and the room was not deep enough so I had the classic hole and I adopted a PWK mini-box and used the 3 way stereo setup being discussed here. That fixed the hole and improved the situation. However, what then became noticeable was a smear because the listener was almost always closer to the center channel than the Khorns which were sitting further away in the corners. I found that I started positioning myself between the center and either a left or right. If you stood directly in the center you heard the smear of the khorns slightly later. Still, the 3-way setup was the better tradeoff because the hole in the sound field was the worse of the situations.

Back then a solution that was proposed was to use the rear channel of a HT receiver to power the center channel......which you could usually delay. That was one way to solve the smear. I never tried that.

Of course you could also use a speaker processor to both mix L/R and delay. Never did any of that back then.

[Chris A]

But my room dimensions were about 2 ft. too wide for the Khorns and the room was not deep enough so I had the classic hole

Maybe another approach would be to use false corners and move the Khorns inward a foot or so from each corner...?

...20-20 hindsight is easy...[]

[erik2A3]

Absolutely worth trying! There is quite a bit of information on this forum about a derived center channel, including contributions from me and others several years ago. It was without question the single best modification I had made -- taking me about half an hour one saturday morning to make and implement PWKs "mini box" . In fact, I am at this time working back toward that arrangment, though via some other unexpected changes....rather experiments. As others have said, it is a wall of sound, though meant in a very positive way. Absolutely stunning, actually.....I couldn't believe the improvement.

[JJkizak]

Never heard of a "smear" before. What is it?

JJK

[mark1101]

Smear.........same sounds coming from different drivers at different times. Time mis-alignment. Every Klipsch speaker with a passive network has it to some degree.

Edit: In the case of the 3 channel system the smear comes from the inconsistent distances between the L and C, or R and C to the listener. It's the same situation that leads to figuring the proper time delays for speakers in a HT system. If the listener was the same distance from the L as the C there would be no issue.

In a Khorn or a lascala (for example) the smear comes from the different horn lengths and no time compensation (delays). That is one huge improvement in systems such as the Jub (run with a digital processor as opposed to a passive network), or the MCM-grands.

[Mallette]

http://www.stokowski.org/Harvey%20Fletcher%20Bell%20Labs%20Recordings.htm

The above links to a really nice article, but the neatest thing is the 1931"Roman Carnival" STEREO recording.

However, the reason I was looking was for the Bell Labs experiments in stereo. That is where PWK referenced his reasoning for the center channel.

Do you need it? Easiest way to find out is to play a mono recording and listen from your sweet spot. The "image" should be absolutely dead centered. If you hear ANYTHING from your L or R speaker, you need to move them around until you do not. The sonic apparition of a phantom sound source should be absolute. I you cannot achieve this, you need the third speaker balanced until you do.

This has always been my system for setting up for best image. Whether in stereo or mono I've had people SWEAR there was full range music coming from the sub in the center and wouldn't stand down until they put thier ears to it and realized it wasn't so!

One easy way to get a good 2 channel mix is to locate an old Dynaquad box which has a center tap on board. I have a couple and still prefer them to any electronic "surround" decoder for listening to two channel music as they "organically" route out of phase information to the rear. The null balance works perfectly to set this correctly and if your rear speakers are well matched to the front (not necessarily full range, but sonically complimentary) the experience is marvelous. I have a DynaQuad LP that is more "natural" and convincing than all but the very finest modern surround when used with this originally 15.00 device...especially the "Flight of the Bumblebee" which literally flys around the room.

Dave

[o0O Bill O0o]

Ed,

From what I remember, when I was sitting in your living room, you have windows on the back wall and a good deal of nick-nacks and furniture. I figure that you cook and listen most of the time since the furniture wasn't laid out the best for listening. So my recommendation, what I would do, is to re arrange the furniture and make it WAF friendly. Like a conversation pit or a palor room, but with a Hi Fi flair. Chairs/couch opposing each other with coffee table,then one big chair at the "head" facing the audio system.

Then the idea of sliding in some custom furniture that matches the veneer of the Belle or Klipschorns is great, but it always falls short because of the custom nature and that you may block of more of the room. Therefore, create a playback workstation. Move your electronics to an area where putting on records/cd is between belt to chest level when standing. Then the pre-amp is at eye level.

like this:

here are some other photos I found doing a search

[Edroom]

This is my current set up....

only the small Mcintosh speakers and mc101 are gone.

[o0O Bill O0o]

Ed, yes, clear out the space between the Klipschorns. Place the Belle there. Set up your electronics in another location in the room. Then run wires to the speakers.

[ClaudeJ1]

PWK said it, I believe it...that settles it!

Dave

Well I purchased and read all the "Klipsch" papers, including the "Dope From Hope" newletters. I built the resistor box, but added a center channel potentiometer to the circuit to give me variable attenuation there. I had two oiled birch Khorns (style C without the risers) and a LaScala Center for over 30 years!! I have also built false corners according to PWK's drawings when my homes needed them.

Back in 1985, I spent a day with PWK and he brought me to his home in Hope. He had a huge living room, and he used TWO false corners and the same resistor box he wrote about. In other words, PWK actually did what he wrote and wrote what he did. His Khorns were standard Walnut, as was his center Belle. He played me his amazing recordings from his huge collection of reel to reel tapes, all of which, he recorded himself.

So YES, absolutely it's worth it if you can space your speakers 18 to 25 feet apart. As a "setup recording" I used to use "Mediterranean Sundance" from Al DiMeola's "Elegant Gypsy" album. It features Al on steel Ovation guitar on one channel and Paco Di Lucia on Nylon String guitar in the other channel.

It has a solid Right and Left channel image, so it's useful for setting the center channel attenuation, which is usually from -3 to -6 db from the flanks. I use sit and listen in my sweet spot, and just turn down the center until the images moved beween Left-Center and Right-Center respectively. It's pretty cool to be able to adjust the positions of the guitarists this way, and serves to make ALL recording image better. It does spread out the sweet spot quite a bit in a room. It works just like the old papers say it does.

I only gave it up because I live in a smaller space and went for 5.1 and 2.1 from the same setup, which is a good compromise.

Otherwise, for Stereo, it's the cat's meow. It's rarity has to do with it's lack of convention and expense, but obviously you are headed in the right direction!!

You will really enjoy it, so go for it.

[ClaudeJ1]

You WILL benefit from a center channel even if the spacing is only 13 feet.................but only if you sit CLOSER to the front wall. By way of perspective, this will broaden the sound stage for you. It will make adjustment of the center level more critical than in a larger room, but will give you similar benefits.

This is not a theory, but I have done it in differernt rooms from 6 different homes in over 30 years, starting with an expando living room in a mobile home, when I was just a kid (hey I FINANCED my Khorns, which were my very first Klipsch speakers). This is why I never "upgraded" for 30 years. LOL. I started at the top and stayed there.

it occurs to me....is this going to be worth all the effort?

I think that a rule of thumb is something like 20-30 feet separation between the Khorns before the "hole in the center" phenomenon usually occurs. If the "hole in the center" occurs at less than this separation distance, then I'd recommend room treatments. The following excerpt is from PWK's article, "Stereophonic Sound With Two Tracks, Three Channels By Means of a Phantom Circuit (2PH3)*", JAES, April 1958, Vol. 6, No. 2:

SPEAKER PLACEMENT

"When this writer started experimenting with 2-channel stereo, experience at various demonstrations was unsatisfactory; insufficient separation or sharply focused point source effects marred the demonstration. Accordingly the approach was made using wide microphone separation and corner placement of speakers. It was found that, usually, placement of corner speakers against the long wall of a room was better than against a short wall. Thus in a living room 20 by 30 feet, the performance was better with the speakers 30 feet apart than 20 feet. But the wider the separation the more apt there is to be a 'hole' in the middle and this has been the subject of occasional adverse criticism. The phantom center channel has not merely filled this hole; it has satisfied the ear to the extent that there appears to be a solid curtain of sound rather than a group of point sources..."

Chris

[Rhetor]

The Belle would be a much better center even for HT!

.............

Absolutely! Give it a try and let us know what you think!

Dennie

I love my K-horns for two channel, but unless I turn them up louder than my wife appreciates, there is a "hole" in the center of the from soundstage, maybe ecause the K-horns are only 24 ft apart. I have tried to fix the hole at lower volumes and for ht by using my existing RC62--never could get it to sound right. Did not want to spend a precious Heresy that way as a center--and seemed too small for K-horns. Missed out on a pair of challenged low-priced Cornwalls. Kept playing with the RC62. Ran across a pair of budget Belles--oiled oak rather than oiled walnut, only one sticker no longer attached, tape adhesive on the tops from packing tape, and a few small chips at a couple of corners, and a missing emblem/badge, but it is a dark room. Finally, after two months in storage, got the Belles out, cleaned one up and oiled it, checked caps and drivers again, took out the RC62 . . . I put the Belle between the K-horns and the Panny plasma on top . . . I am blown away by the balance I get on the front now! What surprised me was that I had turn turn the Belle down to -4db (I keep the K-horns flat) for the center to disappear and seamlessly fill in the front stage . . . The Belle disappears, but there is no longer a weak spot in the front stage. My wife asked me, "What happened? It sounds so nice in here. I will watch a movie with you now." (Of course, it was a chic flick.). Now I see what PWK sometimes demonstrated with a center channel! I still love the 2 channel direct for music . . . But I sneek in some 3.1 music listening now that the Belle is in the center. Seriously, it is hard to describe the improvement . . . now I get that SOLID CURTAIN OF SOUND. And I am not easily amazed! No, I am not selling the extra Belle. It is now going between the La Scalas in my wife's home office setup. It feels like the first day I bought and fired up my first set of Klipsch speakers . . . A pair of low budget black originally probably oiled walnut KG 2s (which I still have) . . . Amazing. Can't wait to see what kind of impact the other Belle has between La Scalas if it is this amazing between a pair of K-horns!

[Rhetor]

And, I realize even though I am physically using a third speaker, the Belle, between two K-horns, it is really still only 2 channel . . . I can argue the legality of it with the two channel police running around in my brain: simce I am just filling in a quirky "hole" between the K-horns to get that solid "curtain of sound" and not employing the Belle for any other reason. . . Think of the Belle not as a third speaker, but as a room treatment, like acoustical tile or something. :-)

[Dennie]

And, I realize even though I am physically using a third speaker, the Belle, between two K-horns, it is really still only 2 channel . . . I can argue the legality of it with the two channel police running around in my brain: simce I am just filling in a quirky "hole" between the K-horns to get that solid "curtain of sound" and not employing the Belle for any other reason. . . Think of the Belle not as a third speaker, but as a room treatment, like acoustical tile or something. :-)

Congratulations! It's sweet when it comes together like that. [<)]

And remember... "If it sounds good, it is good"!

It doesn't matter what name you give it, 2.1, 3.1, 3.0, 1, as long as you're enjoying it, that is all that matters!

Dennie

[richbarrett]

I have a similar set up with Mac2105, 2100, C28 Cornwalls and a La Scala Center. I recently got a deal on one Mono VRD tube amp . I am running the center with that. I previously used a PWK Mini Box with a Heresy as the center.It is worth it to experriment. I enjoy my system.

[psg]

I wonder if the minibox could be implemented within a miniDSP and amplified using an AVR's 6/8 channel input?

[ClaudeJ1]

I have a similar set up with Mac2105, 2100, C28 Cornwalls and a La Scala Center. I recently got a deal on one Mono VRD tube amp . I am running the center with that. I previously used a PWK Mini Box with a Heresy as the center.It is worth it to experriment. I enjoy my system.

The PWK mini box is very cheap to make with parts available from any Radio Shack.

[ClaudeJ1]

I wonder if the minibox could be implemented within a miniDSP and amplified using an AVR's 6/8 channel input?

With a mini box, You can just use the pre-outs, since the R and L are pass through. You just gain a mono R plus Left signal. so you could do anything you want with two Mini DSP's and just have an unused fourth channel. its' AtoAtoDtoA, eh?

[ClaudeJ1]

Selected quotes from Paul W. Klipsch, Dope From Hope, Vol. 15, No. 6, June 1976:

More and more people are calling and writing us about a three speaker array. 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. Thus, we recommend an all-horn system, like our BELLE KLIPSCH or LA SCALA for use as a center speaker between flanking all-horn speakers.

. . . . .

The center speaker reproduces center stage events, and the soloist, if there is one. It should be at least as good and clean as the flanking speakers.

KEEP IT CLEAN!