[borism]

Thank you Jim! I guess I shouldn't install any drivers on top of my Jazz Modules - just kidding.

[Duke]

I have been following the LCS technology with great interest and have a simple question for Duke. Would drivers mounted on the top plate of the speaker provide similar benefits or is the additional time difference of sound travel from the drivers close to the floor (estimate ~ 3 feet difference) crucial?
Thanks,
Boris

Jim pretty much covered it.  Not saying there would be no benefit from upfiring drivers on top of a regular-height speaker (a la Linn Isobarik DMS from the 80'. or a la one or two non-Walsh Ohms from the same era... and I remember seeing a dual-Lowther speaker with one upfiring at CES about ten years ago). 

Jim mentioned the 10 millisecond time delay that has been my target.  I don't remember exactly where that came from but I was using that number for SoundLab setups before encountering Toole's book.  I will try to retrace my steps.   I can remember some of the articles and papers I read which taught me principles if not specifics, and then I may have started using 10 mS as my own rule of thumb.  I can remember experimenting with different distances out from the wall for my SoundLabs and that seemed to confirm that 10 mS was a reasonable target. 

My first work with building what I then called a "dual array" speaker was back in the late 80's.   I even submitted an article to SpeakerBuilder Magazine on the subject, but they rejected it, which in retrospect I'm glad they did because I still had a long ways to go.   

Edit:  I found this paragraph in an undated paper written by Earl Geddes:

"The earlier and the greater in level the first room reflections are, the worse they are. This aspect of sound perception is controversial. Some believe that all reflections are good because they increase the listeners feeling of space – they increase the spaciousness of the sound. While it is certainly true that all reflections add to spaciousness, the very early ones (< 10 ms.) do so at the sake of imaging and coloration. There is no contention that reflections > 20 ms are positive and perceived as early reverberation and acoustic spaciousness within the space. In small rooms, the first reflections from an arbitrary source, mainly omni-directional, will never occur later than 10-20 ms (basically this is the definition of a small room), hence the first reflections in small rooms must be thought of as a serious problem that causes coloration and image blurring. These reflections must be considered in the design and should be also be considered in the room as well." [emphasis Duke's]

I first contacted Earl back in 2001, so he may have mentioned 10 milliseconds to me way back then.   I don't think it's a hard-and-fast threshold; rather, I think it's a point along a continuum.   One could draw the line at 6 mS or 12 mS, and in general reflections arriving after are more beneficial than reflections arriving before.

Toole sees early lateral reflections as more beneficial than Earl does.  Earl also maintains that early vertical reflections do not degrade the imaging.  That might be one of the reasons why Jim's LCS configuration works well. 

[roscoeiii]

What sort of  room requirements do these have?  Very interesting stuff!

[Larkston Zinaspic]

The Mighty Led Zephrin! On we sweep, with threshing oar!

Congrats, Duke. 

Would love to hear some of your more recent creations someday.


~Greg

[Duke]

What sort of  room requirements do these have?  Very interesting stuff!

The Zephrin 46 should be as room-adaptable and placement-friendly as my monopole speakers, which do pretty well in that respect, but we'll know more after I have the crossover parts to finish them up and test them as a stereo pair.   That hasn't actually happened yet! 

The Mighty Led Zephrin! On we sweep, with threshing oar!

Congrats, Duke. 

Would love to hear some of your more recent creations someday.

Well compared to my former abode in New Orleans, I probably could claim that these come from the land of the ice and snow!

The LCS arrays that form half of the Dream Maker LCS system can of course be added to existing speakers.   Or I could do a scaled-down version, that would probably work too.   Might have to get a bit creative on how to drive them, but that can be done.  Just saying, the LCS concept doesn't render my previous speakers obsolete - they can still form the nucleus. 

[Russell Dawkins]

So am I correct in understanding that the Zephrin 46, in order to comply with this 10ms rule, should be more than 5 feet in front of a reflective wall behind the speakers? It looks like there would be a substantial rearward reflection of the output from the the two rear 6s and the four domes, as they reflect from the backward angled midsection. I can see how the reflection from the ceiling to the listener would be well over 10ms.

[Duke]

So am I correct in understanding that the Zephrin 46, in order to comply with this 10ms rule, should be more than 5 feet in front of a reflective wall behind the speakers? It looks like there would be a substantial rearward reflection of the output from the the two rear 6s and the four domes, as they reflect from the backward angled midsection. I can see how the reflection from the ceiling to the listener would be well over 10ms.

Excellent question!   

Placement close to the wall is okay because the early "backwave" reflection energy ends up being quite weak at the listening position in the midrange and treble regions.

The primary axis of the LCS array is straight up, and yes the patterns aren't real tightly controlled, but in the upper midrange and treble regions the energy travels in rays instead of behaving like waves in a fluid (like at low frequencies), so most of it is still strongly angling up after its first wall bounce.   The four little dome tweeters are semi-horn loaded, so they're somewhat directional, which helps minimize the treble energy that bounces off the wall at a shallow angle. 

Then the enclosures itself casts a "shadow" that blocks much of the energy that reflects off the wall from reaching the listening area after only the one bounce.  Also relatively little (if any) of the energy that misses the "shadow" will be going straight towards the listening position (toe-in angle will play a role here).

At low frequencies, where the energy just wraps around and pretty much doesn't see the enclosure like waves around a piling, we have reflections off the wall from the front woofers and the rear woofers arriving at slightly different times.  This helps to de-correlate the bass energy a little bit, resulting in smoother in-room bass than we'd get from just having one bass source.  Of course in the bass region the energy is interacting significantly with all the room boundaries, but still having the bass sources spread out a little bit (in all three dimensions too, once the speaker is toed-in) improves things. 

So we don't totally avoid early reflections off the wall, but we do significantly minimize what arrives at the listening position after one bounce relative to say a dipole or more conventional bipole in the midrange and treble regions, and we make some improvements in the bass region as well.   Perfection (if it exists... yeah right) hasn't yet trickled down to $4500, but we think significant improvement has. 

[James Romeyn]

Much of the "work" I did leading to LCS (I use this term euphemistically, as this is more of a passion) was experimenting with six identical Dynaudio Esotec monitors.  I built six monitors, 2 required per each LCR channel for Trinaural Processor based system.  The monitors are much improved clones of some of the best stand mounts I ever heard, the wonderful French ASA Pro Monitors I purchased on John Marks' recommendation.  The clones are rear-ported classic mid-size, HWD about 14.5x10.25x11.75.   

It was work, but it was also fun experimenting over time with different physical orientations between two matched monitors.  Every iteration started with one stand-mounted monitor set up in classic fashion, firing forward, with various toe-in angles.  The "Effects Speaker" eventually made it's rounds to every imaginable location, firing in every direction, with polarity same and inverted vs. the Mains.

Duke optimized the Effects radiation for best performance, exceeding that of any regular monitor w/ one tweeter and one mid bass.  Even flush against the front wall Zephrin 46 will outperform a mono pole, dipole, or bipole placed in like manner.  At the earliest convenience, after Zephrin 46 arrives in my sound room, I will set it up in such fashion and report on the results.  At Newport I presume we'll site Zephrin 46 spaced a few feet from the front wall.  I'll consider the performance difference, and won't necessarily cross off the idea of short front wall spacing, though Tony Chipelo has last say on everything in Newport. 

Ideal spacing, a few feet, provides the best overall listening "stereo" experience ever, by huge margin.  I presume, but could be wrong, that flush front wall reduces depth.  But who knows, maybe depth is similar or equal.       

Based on experience with Dream Maker LCS, I believe even with Zephrin 46 flush against the front wall, front wall acoustic treatment is unnecessary.  I will listen with it flush and spaced and report results.
   
I spent many years listening in a LEDE room, both my own and another room owned by a full time professional speaker designer.  After this journey, I am much less a fan of LEDE.  I did notice in VMPS' LEDE, with his best and largest towers, and especially systems with separate huge floor to ceiling subs, pretty good spatial effects at times.  But not even in the same ball park compared to the overall spatial excellence of LCS with a much smaller speaker. 

A moderately live room seems ideal, with select treatments placed at the usual suspect locations.  This room has wall to wall carpet.  Several years ago I covered the rear 60% of the carpet with plastic and paper tarp, which very much seemed to improve every performance aspect.  I moved the tarp forward and backward in 6" intervals, and was amazed at how audible were such changes.  Based on that, if I was building from scratch, I'd place heavy pad and carpet over the front 40%, and hard reflective surface on the rear 60%.   

[Russtafarian]

Our dear Duke will be in Newport in spirit only.  Myself, Tony Chipelo, and Jack Elliano would be honored to meet you.     

I look forward to it James.  I may even pop in on Thursday just to say hi and introduce myself.  Thursday participation is one of the perk of being a board member of the sponsoring audio society.

Russ

[Brian Walsh]

Regarding the grille, I'm leaning towards a super-Velcro to hold it in place, along with a bit more breathing room underneath the edges of the grille than what you normally see (credit to Brian Walsh for helping me out with this).   The grille may or may not happen before the Newport Beach show.   

Although grilles often affect performance, I'm on a mission to help Duke come up with some that do so minimally and at the same time greatly improve the appearance. So if the speakers at the Newport show don't have grilles, just picture them with them, along with some other niceties. Wish I could be there but have other commitments.

[James Romeyn]

Duke dropped off the Zephrin 46 this afternoon around 6pm MDT.  Zephrin 46 had been played for only about an hour.  They sound magnificent.  We listened to an old Telarc SACD, large, swinging, powerful big band music.  First on Dream Maker LCS (two boxes per channel, $8800/stereo set/four boxes), then we switched to Zephrin 46 in the exact same location as DM LCS.  The sound was remarkably similar, especially the spatial effects. 

For all lovers of the original Jazz Module, now a cult classic BTW, I would say, well, this is very much worth a listen.  As already mentioned, you can't and won't get this type of spatial sweetness and lush presentation with any mono pole, no matter how exotic and costly.

I'll play them continuously till they pack for the trip Tuesday.

   

[James Romeyn]

Duke delivered Zephrin 46 with only one hour playing time on them.  Since he left I continuously played a Telarc Sampler SACD at low-moderate level, and I must say, these sound absolutely mahvulus!  Bass cutoff is adequate, and down to cutoff, the eight user-tunable ports (open or plugged) and natural mode-cancelling feature provide smoother bass than any system lacking such features. 

Spatial performance wise, no system I know of regardless of cost matches Zephrin 46's mesmerizing performance capabilities.  In this regard it is remarkably close to it's much larger and twice-as-costly 2-box sibling, Dream Maker LCS.   

[James Romeyn]

post deleted

[Duke]

Thank you Jim for running these tests.  I didn't really expect the 32 ohm configuration to be practical with solid state amps, but I guess what you end up with, in effect, is a 25 watt amp with a monster power supply.    Sort of like turning your 100 watt receiver into a 25 watt Accuphase... well not really, but at least it seems to be a step in that direction.  Certainly bodes well for use with amps that start out 32-ohm friendly, like Ralph Karsten's S-30 and M-60.    The little S-30 puts out 50 watts into a 32 ohm load, with naturally lower distortion, and longer tube life.  Might even be feasible to pull tubes and run it at reduced power.

The limitedup-against-the-wall testing I did before taking the speakers to Jim's house gave positive results as well.   That's good news for the home team too.

The only bad news so far is how much labor is involved.   So the $4500 price is the introductory price, and the day will come when it goes up to $5000.   

[James Romeyn]

...The only bad news so far is how much labor is involved.   So the $4500 price is the introductory price, and the day will come when it goes up to $5000.   

In effect, Zephrin 46 is two related but quite different loudspeaker systems per channel, or four total loudspeaker systems per stereo pair.  Each of the two systems is uniquely designed to tackle their different purpose.  Even though there are "only" two total enclosures, one can see the enclosure is remarkably more exotic and costly to make vs. the ubiquitous rectangular box.

One of the fruits of the labor and materials list is the previously unknown ability to wire the system for either 8 Ohm or 32 Ohm (see my comment above for a real-life benefit of this feature).  If you think a 32 Ohm load is a joke, an anomaly, or of no good use, please let us know your experience in this area.           

Taking a look around at whatever is available for $4500/pr MSRP, it's not a big surprise to hear that that price is not long for this world.  I honestly don't know what compares performance wise to Zephrin 46 even up to $10k/pr.  In fact, I'd be happy for a direct comparison.

After taking Zephrin 46 down to pack for Newport, I just re-installed Jazz Module 2.0 (Main Speaker of Dream Maker LCS system).  Call me if you're interested in my impressions of comparing these two spectacular loudspeaker systems. 

"Get 'em while they're hot...and before the price jumps!" 

[James Romeyn]

http://www.stereophile.com/content/show-2014-day-2-afternoon#comment-538946

"...The way the speakers' LCS Late Ceiling Splash radiation pattern, which was invented by James Romeyn and Duke LeJeune (implementing reverberant field theories by Dr. Floyd Toole and Dr. Earl Geddes), threw images way high, as well as their amazing three-dimensionality, was quite impressive..."

Jason mentioned the Patricia Barber cut was a "too rich," likely referring to its hot treble presentation, endemic to the software. 

[James Romeyn]

Side wall spacing is the same but baffle to front wall reduced from 76.5" to 19", no toe-in, wall and speaker parallel.  There's only 5" between the front wall and Zephrin 46 rear panel. 

If anything, bass and PRAT improved.  Bass quality and timing improved, apparently from less bass mode effects.  Definitely stage depth decreased, but not flat.  Certainly overall spatial performance beats any non-LCS speaker placed similarly.  It seems like vertical spatial dimension increased but this might be an illusion resulting from less depth perspective (hypothesis: all other things being equal sensitivity to stage and image height increases by magnitude similar to actual loss of stage depth).   

Increased hash in upper mid-range but tolerable, likely easily fixed with toe-in similar to before and side wall first reflection treatment as before.

Happily surprised similar overall joy and pleasure, likely resulting from increased bounce and dynamics via more precise bass timing/less modal effects.

I'll take a photograph before increasing toe-in and increasing front wall spacing.

This is highly encouraging for space-challenged audiophiles!

After Newport Show and now working with Zephrin 46 in my 3300cf sound room, I unequivocally recommend tube power from 10-15W up or SS as low as 20-30W.

[jwlaff]

Just read a nice write up  on "The Absolute Sound" by Robert E. Greene

[Duke]

Just read a nice write up  on "The Absolute Sound" by Robert E. Greene

Thank you....  and welcome!! 

Here's the link:

http://www.theabsolutesound.com/articles/2014-newport-beach-show-report-speakers-under-15k/

Apparently we made REG's "Top five under $15K" list.   Sweet!

[tdinut]

Congratulations!


I need to check these out. They look awesome too.