3-channel stereo revival

[ClaudeJ1]

I posted this in another thread, but I though it deserved it's own space for those interested:

<<wilbucd:

Anyone have their Khorns more than 20ft apart and have a
problem with staging? I am looking at about 26ft corner to corner and am
wondering how much it will affect the music.>>

The Khorns should really sing in that room with only a 20 Watt amplifier
(trust me on this). Also, you really need a mono center channel, with a LaScala
being the best choice. I may have another one available in a few weeks as I get
my new setup going in the next few weeks, along with a resistor box.

I learned this from reading the "Klipsch Audio Papers" which I
purchased for a nominal sum back in the 70's when I was still a teen. William
B. Snow and others (Paul Klipsh's heroes) had tested different combinations and
found that 3 channels were best for "wide stage stereo." A symphony
orchestra was the reference standard because it was the most difficult to
reproduce. Aside from using horns, they deternimed that creating a "phantom"
derived third channel from 2-channel recordings gave them the same
"perspective geometry" and "sound localization accuracy" as
3 discrete channels, which were impractical on the recording side. This is
called the 2PH3 method. You marry the right and left channels with a resistor
box to create the "mono in the middle" and add another amplifier.
Putting a potentiometer to attenuate the volume of the mono-middle
channel (-3 to -6 db) relative
to the R and L is like a "focus control." Whenever I would move to a
new house, I would set mine up using Mediterranean Sundace by Al Dimeola and
Paco DiLucia on acoustic guitar. Each guitar has it's own channel and I would
adjust the middle volume until the guitars moved closer together about 1/4 of
the way in on either side. My 3 channel setup was then perfect for 95% of the
recordings out there. PWK would not listen to stereo at home any other way,
period. I know because I was at his house in 1985 and heard his setup, which
was identical to mine. I did it exactly like he showed in his publications. He
only used two microphones for his own purist recordings of symphonic works and
they were spectacular in his living room. I think his speakers (2 oiled
Walnut Khorns and a Walnut Belle) were about 25 feet apart, with 4x4 foot self
standing false corners spaced aboout 3 feet away from his bay window in the
living room. The false corners were made with studs and plywood (or drywall)
painted..........very solid and heavy........had to build one of those myself
in one of my homes.

I had that same setup for 30 years, but the room I have now only allows 13.3
feet for my 2-channel, so I don't need the center anymore and have gone 5.1
with the rest of the room.

I suggested that they do a 3-channel demo to Jim Hunter at last year's
pilrimage. They finally did it this year and everyone who heard the setup was
impressed. Most voted it the best sound there. What's old is new again. I
gurantee that, with a 24 foot width, and a mono center, you would NEVER go back
to just 2 speakers after hearing the difference for yourself.

[Mallette]

Hmmm...never knew it went away. PWK handed me my copy of the 6card and I accepted as though given Holy Writ by a higher power. I've had a center always. I use a Cornwall as I've not found the single Belle or LaScala yet, but since I active amp the center I can adjust for the efficiency difference and it works well. What IS strange is when switch to pure 2 channel from my Dynaco and put on a 78, people have to put their ears to the Cornie to prove it is not working. I've found that one of the best tests of imaging is to see if a mono signal originates from a phantom center speaker.

Dave

[fenderbender]

Funny you mention that Dave,

The other day I had some folks over and was listening to a few of the new Analogue Production 45 lps...My Klipschorns are 15 feet apart and image wonderfully, I just so happen to have my Cornwalls right smack in the center of that wall (nowhere else to put them at the moment) I told my wife's freind to take a seat center stage, and she goes "I don't know why you need those big things in the corners....the ones in the center sound so good to me...the trumpet is right in front of my face"....you know the rest of the story!!!

[psg]

Funny you mention that Dave,

The other day I had some folks over and was listening to a few of the new Analogue Production 45 lps...My Klipschorns are 15 feet apart and image wonderfully, I just so happen to have my Cornwalls right smack in the center of that wall (nowhere else to put them at the moment) I told my wife's freind to take a seat center stage, and she goes "I don't know why you need those big things in the corners....the ones in the center sound so good to me...the trumpet is right in front of my face"....you know the rest of the story!!!

Funny indeed. And all too common. I could sell a lot of center speakers that way!

[fenderbender]

Hey Psg...do you have a shop in Quebec??? My wife's from Toronto and we visit 3-4 times a year and usually make the drive to Montreal at least once.....

[ClaudeJ1]

Hmmm...never knew it went away. PWK handed me my copy of the 6card and I accepted as though given Holy Writ by a higher power. I've had a center always

It may not have gone away, but it was never accepted by the masses. PWK only took the credit of carrying on the work of others in this area. I thought the spirit of it went away at KLIPSCH because at the pilgrimage, 2007, Jim Hunter had a demo of Khorns with no center channel (I was surprised about that one). Plus how many people do you know that have center mono in their 2-channel setup?? I'll bet it's only 0.001 percent of even the staunchest of the Klipsch afficionados. I had 3-channel at 20, 3 years before I got Khorns and a LaScala, and 30 years after that. I too believed in the old testament (William B. Snow). LOL.

[WMcD]

Let's not overlook this review of what was then called the Cornwall II http://www.klipsch.com/news-center/reviews-press/archived/details/klipsch-model-cornwall-ii-speaker-system.aspx

There is a link to a .pdf of the whole article which has a nice, if short, description of the center channel.

Wm McD

[Deang]

It may not have gone away, but it was never accepted by the masses.

Maybe you should go visit the HT section of the forum for a while.

[ClaudeJ1]

It may not have gone away, but it was never accepted by the masses.

Maybe you should go visit the HT section of the forum for a while.

The 3rd channel there doesn't count. It's a discrete channel to carry only dialog in movies, not music. I thought about making a 3-pole double-throw switch to take the speakers to true 3-channel and do double duty as 1/2 of a 5.1 system. But, with only 13.3 feet width, I don't need a center anymore.

[Deang]

From the web (of course):

"The Dynaco circuit is the predecessor to Dolby Surround, which was the first Dolby surround format used. (The original Dolby format was Dobly Stereo.) I indicated in another thread Ray Dolby took what David Hafler was willing to give away free in many articles and publications and Mr. Dolby has made millions and millions off the same circuit. The original Hafler/Dynaco circuit was, as John points out, all analog. It used the difference signal to create the back channels of ambient information. Since it was only difference signals it was exremely effective, given a good source, at keeping vocals from leaking into the rear channels. When Dolby took the idea and turned it into Dolby Surround it was using the same signals procesed digitally. When that circuit made its first change it became Dolby Pro Logic Surround. This added the summed signals (those signals that are alike) and focused them into the center channel. This was taken from an analog connection that was established by Bell Labs and later Paul Klipsch to create what is known as a phantom center channel. I believe you can still find that diagram on the internet also. (It amounts to hooking the two positives together.) Both circuits were very effective at what they tried to accomplish and, because they are analog, they don't have the tracking problems of the later digitally matrixed formats. They will not do what a true discrete format will accomplish but they beat the early Dolby products in many people's opinion. The box pictured in the link was the Dynaco circuit with the refinements that were made as the idea became more flexible. It allowed the surround circuit to be switched out and the speakers could then be used as two stereo pair. It also included a volume control for the rear channels instead of a fixed resistor value. It had a thrid control that allowed the user to adjust how much difference signal was injected into the rears which gave the user the ability to remove sounds that over zealous mixing engineers had panned and phase looped into a difference signal. The Dynaco circuit is from the late 60's. The phantom center channel circuit is from the 30's." -- J. Vigne

[JJkizak]

In 1965 My new Fisher amplifier (I believe model 202B) had a power derived center channel output with a separate volume control which I used to drive the Cornwall. Fisher (I believe) was one of the first companies to provide this option. Not sure what their inspiration was but it worked just fine.

JJK

[Mallette]

>It may not have gone away, but it was never accepted by the masses.

Nor were K'horns...

As to the Hafler circuit, I've had an original Hafler in my system for most of nearly 30 years and Hafler's work has had a great impact on my thinking. I hope to get it hooked up again soon, but it is complex as it requires a duplicate speaker connection system to isolate it from the HT circuits and I want it fed this time only by my Dynaco ST-70.

The original DynaQuad has a really neat null circuit for level setup, which is critical. You send a mono signal and use your balance control to achieve minimum sound. That tells you your phase recovery is dead on.

I also have the original DynaQuad demo LP that has material recorded specifically for the DynaQuad. "Flight of the Bumblebee" flys around the room in circles every bit as discrete as ProLogic II using only Hafler circuitry. I've done some noodling on how they achieved this in the recording and intend to use SoundCube to experiment someday. Anyway, the DynaQuad is superior to ProLogic in everyway when it comes to recovery of out of phase information from analog sources. I've compared the two A/B when I was last hooked up to do so, and DBPLII often scrambles the channels with falsely applied steering logic. Not surprising, sense the logic circuits make assumptions that certain signals are intended by the engineer to go certain places.

The DynaQuad makes no such assumptions and the out of phase info always goes right where it should from acoustic material. The only exceptions are heavlily mixed and/or electronically generated material like rock n roll or Firesign Theatre. However, it is still interesting since there is really no "right" place for such things. Firesign is particularly fun as voices and sounds appear left, right, above, behind and all over. Same for Pink Floyd.

Dave

[ClaudeJ1]

may not have gone away, but it was never accepted by the masses.

Nor were K'horns...

Good points. All the people here are in the minority, which is a good place to be when it comes to audio quests. Also, how many married guys have a wife that would let him (in the basement, of course) create an ugly but great sounding setup such as mine? LOL.

[mark1101]

I have a wife like that! She even puts up with stuff rattling upstairs in the kitchen.

On another note I have used a PWK min-box with my old Khorns and I tried heresy, lascala, and corn in the center. Preferred the corn. Sounded great and I did need it with my Ks about 24 ft apart. Too far for the short depth of the room.

I also have an HH Scott LK-72 from around 1960 and that has a center channel output with a volume control for it. I have no idea how it works, I never tried it. I use the amp all the time for 2 ch. Sometime I'll have to try the center channel.

One thing that could bring the phantom center channel more up to date would be to use an amp that has a delay. On various music I could here smear in my system because of the time delay differences. In my room I needed to have a delay on the center and at times I found myself standing somewhere between the center and either the L or R.......not in the middle of the room. This became auatomatic sometimes or I would just turn off the center altogether sometimes. Most of the time it sounded great but If I had had the delay I can't think of a reason that it would not have sounded excellent on every recording you through at it.

I sold my Ks and am using a narrower room now so no more need for the center but I am not selling my PWK mini box just in case. I would set that back up in an instant if need be but I would use a delay for sure next time.

Good topic Claude

[Mallette]

>Also, how many married guys have a wife that would let him (in the basement, of course) create an ugly but great sounding setup such as mine?

Got you topped. When I first got my 'horns they were in our bedroom! It was the only room in the house with corners. I would even have Hornheads over for listening back there. We've moved since then and she made sure there was a music room with corners and also choose the paint, cieling fan, crown molding, etc. to make it beautiful. THAT is why I refer to my wife as the PAW - Perfect Audiophile WIfe.

As I mentioned in a recent thread, her recent volunteer action was to choose a beautiful polished granite slab, 24X48 to support my 'tables. She's also volunteered as a test subject in my A/B comparision of "The Digital Fox" LP vs. the direct to disc Crystal Clear LP of the same material in the same venue made a month later. Report on that in a separate thread when it happens.

Dave

[sfogg]

"I also have the original DynaQuad demo LP that has material recorded specifically for the DynaQuad. "Flight of the Bumblebee" flys around the room in circles every bit as discrete as ProLogic II using only Hafler circuitry. "

Haflers passive circuit has roughly 3dB of channel seperation from rear to front. PLII has dramatically more (at least 10x that) then that and is stereo in the rears, not mono. Try the same test with something PLII encoded and the results will differ considerably.

The problem there isn't in the decoders, it is in the source. PLII needs good phase information between channels to function properly which LPs can't really provide all that well. As such that wandering phase (and phase shift between L/R on LP playback) trips up PLIIs steering.

"I've compared the two A/B when I was last hooked up to do so, and DBPLII often scrambles the channels with falsely applied steering logic."

If you have PLIIs 'Panorama' adjustment on turn that off. That takes too much info from hard left/hard right and wraps that into the surrounds which throws off imaging. You can also adjust the centers steering with the 'Center Width' and the front to rear steering with the Dimension control. If you were using default settings you should try using those adjustments as they have a pretty large influence on the resulting sound.

"Not surprising, sense the logic circuits make assumptions that certain signals are intended by the engineer to go certain places. "

It makes assumptions that phase/amplitude combinations will be heard as coming from specific locations in 2 channel. The basics are in phase equal amplitude between L/R would image from front and center so that is what gets steered to front and center... the center speaker. Out of phase equal amplitude between L/R images as diffuse material that sort of surrounds you so that would be sent to the surrounds. Differing combinations of phase/amplitude in the source gets steered appropriately.

Shawn

[Mallette]

>Haflers passive circuit has roughly 3dB of channel seperation from rear to front. PLII has dramatically more (at least 10x that) then that and is stereo in the rears, not mono. Try the same test with something PLII encoded and the results will differ considerably.

They do. DBPLII scrambles it mercilessly. It is interesting, but not what was intended. I'll not debate the measureable channel separation, as that is irrelevant as many measurements are to what the ears hear and like. The apparent separation and positioning of the demo record is as precise as the very best of modern electronic intensive decoding. I've a theory about how this was achieved that I intend to test.

>If you have PLIIs 'Panorama' adjustment on turn that off. That takes too much info from hard left/hard right and wraps that into the surrounds which throws off imaging.

I do not use any of those things. Just the 'Music" setting which I prefer even for HT use. Actually, one of the things I always appreciated about DynaQuad was it's freedom from twiddle. Just works, at least for two channel.

None of the above is pushback, Shawn. I have immense respect for DBPLII and derive a lot of pleasure from it. It was the first circuit I heard that could compete with DynaQuad on derived rear channels from 2 channel sources. Wish I could recall (maybe you can remind me) the enigneers name. He designed the original circuit with vacuum tubes...my kind of guy!

I did not mention that on about one of 20 LP's, the DBPLII routes EVERYTHING to the rear for some strange reason. Switching to Neo6 fixes it on all but maybe 2, which appear on the rears with either decoder. I might be able to twiddle fix it, but I usually just switch to 2 channel as I want to listen, not twiddle.

Dave

[sfogg]

"They do. DBPLII scrambles it mercilessly. It is interesting, but not what was intended. "

If it was PLII encoded what you are getting with PLII decoding is exactly what was intended.

"I do not use any of those things. Just the 'Music" setting which I prefer even for HT use. "

All of those are settings within DPLII Music. So unless you have checked them you don't know where they are set.

"I did not mention that on about one of 20 LP's, the DBPLII routes EVERYTHING to the rear for some strange reason. "

Like I said... LPs poor phase response really toys with steering decoders. One of the reasons quad failed....

"Wish I could recall (maybe you can remind me) the enigneers name. He designed the original circuit with vacuum tubes...my kind of guy! "

Jim Fosgate. He did it with tubes as he is an analog guy. The circuit was 'ported' to digital code by Dolby themselves.

"Switching to Neo6 fixes it on all but maybe 2, which appear on the rears with either decoder."

NEO6 is horrible IME.

Shawn

[oldbuckster]

My Scott 299-D from around 1960 was a trendsetter with a center channel input ................. pretty amazing ...... EH !!!!!

[Mallette]

Crikey, Shawn...

>If it was PLII encoded what you are getting with PLII decoding is exactly what was intended.

Duh. However, we are talking about LP's here. I've not heard of any that are DBPLII encoded.

>All of those are settings within DPLII Music. So unless you have checked them you don't know where they are set.

Duh again. Except for the speaker type, distance, and such that is part of initial setup everything is default and works perfectly.

>Like I said... LPs poor phase response really toys with steering decoders. One of the reasons quad failed....

I've a number of quad discs and they all work perfectly with DPPLII. Poor technology was not why quad "failed." In fact, it did not as DBPLII is just quad on steriods. However, that is another story and I lived it and we knew it was not going to fly from day one. As to "LP's poor phase response" you'll have to educate me (and I KNOW you will []) as I don't even understand the statement. Out of phase info is either there or not. It's qualities are determined by type and number of microphones and/or mixing, overdubbing, etc. A simple two mike, no mixer recording exhibits excellent out of phase information that is well separated out by either a DynaQuad unit or DBPLII.

Thanks for the reminder on Fosgate. Superb mind and audio genius.

As to Neo6, either you've a bad one or just hear differently. I default to DBPLII but have found occasional situations where Neo6 worked better. In no event did it ever sound anything like "horrible." You want "horrible," you should have heard the noisy, nasty, Sansui outboard SQ decoder I finally threw in the trash.

Dave

PS - I've returned as I realize this is getting way off topic. Apologies to all for an unintended hijack. Hope you will tolerate a reply from Shawn which he is due. I do not think I have anymore to say on this, but if I feel it warranted I'll start a new one. I now return you to the "3 Channel Rivival" thread...