The Poor Man's IRS V Revisited

Way, way back in the Jurassic, when men were men and giants trod the earth, I wrote a description of paired Eminent Technology LFT8's titled The Poor Man's IRS V. Herewith is the original description with an update appended.

Original Description

The Poor Man's IRS V or Stacked Eights

For the longest time, the Absolute Mound's Harry Pearson used the IRS V as his reference loudspeaker system to the point where it became a designated audiophile icon. (HP has since moved on to the Genesis One, also designed by Arnie Nudell.) If you've always lusted after this particular audio icon but couldn't find the necessary spare change between the cushions of your couch, be it known that two pairs of Eminent Technology LFT 8A's make a reasonably good (yet affordable) approximation. Put side by side, two LFT 8A's are just about the size of an IRS V panel: thus, a Poor Man's IRS V, if you will. Furthering the analogy, the midrange and tweeter on the LFT 8A are quasi-ribbons, a similar technology to the IRS V panel drivers. (In a true ribbon, a strip of pure aluminium drives the air as well as carrying the signal. In a quasi-ribbon, a panel of the ultra-light plastic, Mylar, is used to drive the air with the signal

being carried by metal strips bound to the Mylar. In the case of the LFT 8A this metal is etched onto the Mylar in very thin (hence desirably light) strips, resembling a printed circuit trace.)

The LFT 8A tweeter sits beside and is horizontally centered on the midrange. To form a single speaker (or channel) of your Poor Man's IRS V, put two LFT 8A's together with the tweeters on the inside. This gives rise to a glass half-full/half-empty situation. If your glass be half-empty, this arrangement could be viewed as an MTM array (midrange-tweeter-midrange) against whose evils, our own Lynn Olson inveighed in Positive Feedback Vol. 7, No. 1 (Pay No Attention ...) and again in Vol. 7, No. 2

(Reverberations on P. 10-11.) On the other hand, a recent guest in my listening room had a glass that was decidedly half-full. He opined that the paired ET 8A's should be viewed as a giant coaxial driver. With the midranges extending above and below the ends of the two tweeters in the center, you could imagine that you are looking at a giant tweeter surrounded by an even more gigantic midrange: a virtual Tannoy as it were. (The midrange driver is about three inches wide and forty two inches tall, the tweeter is one half inch wide by twenty inches tall.) For the bass, the LFT 8A uses an 8 inch cone driver which sits below the quasi-ribbon panels. The "A" designation indicates an upgraded cone driver and crossover from the original LFT 8 model. Of course, this means we are without the huge IRS V bass towers (six drivers per side!) which are the true glory of that system. But this is, after all, only a Poor Man's IRS V.) But enough of theory, how does it sound?

Words like meaty, beaty, big and bouncy spring to mind. Sounds like the Unabanger Bio, doesn't it?. It is indeed a big, nay, huge sound. And meaty in extremis. No anorexic planar sound here of the Martin-Logan CLS or Audiostatic ilk. The ET 8A's stock in trade is Palpability with a capital "P". Yea, worthy even to be described, in that infamous phrase, as packing a terrific wallop. On the Mars track from Holst's Planets (Mehta conducting), I thought I was about to be invaded, so weighty was the blast from big brass. We're talking actual physical pressure on the pit of the stomach. One is literally pinned to one's seat, rendered immobile by the sheer sonic impact. This is aside from any musical impact you understand. I'm talking pinned to the seat by wave upon wave of sonic pressure. The mind cannot accept what the ears

are telling it - that a full symphony orchestra, in all its power and majesty, has just appeared in the listening room. Therefore the brain goes into the shock of denial and paralysis results.

As to bouncy, the plucked strings that begin the same track Mars do exactly that - you'd swear the strings were on trampolines. Still the ET 8A's don't deal in mere crude sledgehammer slam, there is a quickness to these speakers (although admittedly not the quickness of an electrostat like the Martin-Logan CLS or Audiostatic). t'is beef combined with finesse.

My left brain is telling me, these paired ET 8A's lack the last word in transparency. There is a certain wooliness about the trumpets. They shimmer about the edges instead of being sharply defined. I'm speaking not of a shimmer of image, but of tone. The tone of the trumpets don't quite focus and gel. My right brain asks, "Who cares?" in the face of such luscious musicality and tells the left brain to pipe down and stop being so anal. The ability to deliver an honest 25Hz helps tremendously in conveying the feeling of a symphony orchestra in full flight. Let no mini-monitor maven fool you into thinking you don't really need the frequencies below 40Hz. Those 15 cycles between 40 and 25Hz may not seem like much but without it, the bass, tuba, and bass trombone will be emasculated. Only when you've heard this quality of bass will you understand what HP means by the bass being the foundation of the orchestra. Without it, you'll never fully experience the sense of Total Impending Doom conveyed by the upwelling of German brass.

As well, the Poor Man's IRS V is a very relaxed and natural sounding speaker, capable of providing hours of fatigue free musical enjoyment. It is, frankly, highly addictive and should probably sport a Surgeon General's Warning. I come from that school of audiophilism that believes the mark of a great system is not that it bops you over the head and calls attention to itself, but that it should let the music unfold naturally and effortlessly. Liquidity is a big part of that and the Poor Man's IRS V delivers in spades. It is one of the most liquid of speakers, with never a hint of dryness except on extremely dry recordings. My amps are the Manley Lab 440's which have an output impedance of 5 ohms. This makes for a mismatch with the LFT 8A which has a nominal impedance of 10 ohms. By wiring each pair of LFT 8A's in parallel, I halve the nominal impedance, achieving a much better match with my amps. So, good as a single pair of LFT 8A's sound, this improvement in impedance matching undoubtedly contributes mightily to the smoother, more relaxed sound obtained from two pairs of LFT 8A's. Therefore if you own a single pair of LFT 8A's and have a similar impedance mismatch with your amp, you might want to seriously consider getting a second pair of LFT 8A's. (When I propounded this theory to Frankland, he issued a stern

nolle prosequi and demanded to know the impedance on the woofer. "Only the impedance on the bass matters," quoth he. Well who am I to argue with a writer for Stereopile - that infallible font of wisdom, truth and the American Way? Looking at the impedance chart in the speaker manual, it seems that the minimum impedance on the woofer is 10 ohms right around 75 Hz.) I had previously experimented with doubling up the LFT 8 (the older version of this speaker). I may say that with the LFT 8A, I experienced none of the problems of image smearing that occurred with the old LFT 8. The LFT 8A is more transparent and has tighter bass than its older incarnation and I believe this leads to the much improved imaging, although still not in the top drawer for these soundstaging artifacts. Alas, like their LFT 8 predecessors, the LFT 8A's cannot handle the Saturn track from the aforementioned Mehta's traversal of Holst's Planets Suite (104 db SPL). The low organ pedal must correspond to some resonance in the bass cabinet of the LFT 8A's because they start hopping about like

crazed rabbits in heat. However, this was the only one of my records on which I experienced any lack of power handling. (440 watts into each bass cabinet and 150 watts into each panel.)

This just goes to show that full orchestral music is the ultimate challenge for any system. Jazz and rock could not reveal the faults of this system which only became apparent when I turned to full orchestral music with all that means in correctly reproducing the twenty or so core instruments of the orchestra the whole of which can go from a whisper to a roar in a split second. The Poor Man's IRS V does a better job than most, but I don't want you to go away thinking it does a perfect job. As alluded to above, it is not the last word in transparency. The tonal qualities, while very good, also fall short of perfection. Nevertheless, the overall sound picture is overwhelmingly correct, especially in being able to convey the weight of an entire orchestra in full flight. Conversely, of course, the inability of rock and jazz to smoke out the shortcomings of this speaker system means that it is superb for

this type of music. Let's listen to some and you'll see what I mean, starting with one of the best jazz albums ever made, some would say the best, Miles Davis' Kind of Blue.

Not least because on So What, Coltrane's playing is just beginning to break loose from the old mold. It is an eerie precursor to what is to come in the next decade as the Trane takes, ahem, giant steps and breaks completely free, culminating in that towering achievement, A Love Supreme. As Miles opened up his horn on this first cut, the normally sedate Iron Man rocketed out of his chair like a pheasant flushed from cover, pointed to stage right and exclaimed, "I can hear a real trumpet right there!" Anyone'd think he'd just spotted a Gullwing Mercedes for our Man of Fe is a devotee of German iron of a considerably more robust variety. Imagine his response if I'd had a master dub available instead of a well-worn commercial pre-record (albeit a 2 track). I admit to sharing the Iron Man's enthusiasm. In this case, the trumpet did gel. There was none of that fuzziness about the edges that I heard on Holst's Planets. You could peer right down into the bell of Miles' horn on this recording. I wish to also point out the shimmering delicacy of James Cobbs' cymbal work. A sound you'll not hear from any CD, I'll wager. On analog tape, the decay of the cymbals is captured down to the lowest level of detail. Also, Paul Chambers' rumbling bass. Those ominous chords that start So What never fail to send a shiver of anticipation up my spine.

One of my most memorable listening experiences was hearing the Floyd's Dark Side of the Moon over an IRS V system (panels powered by VTL 500's). The ground literally shook beneath my seat. Did I mention that the true glory of the IRS V is its twin bass towers (self-powered at 1,000 watts per side)? With the Poor Man's IRS V, no call to Caltech's seismology lab was necessary to check on whether a tremblor had rumbled through. Nevertheless it did manage to pressurize the room and inflict pressure on the chest. Gilmour's guitar sounds wonderfully chunky and Clare Torry's heavenly squawking is as silky as ever. The attraction of

doubling LFT 8A's is that a single pair of these speakers is so reasonably priced at $1,500 (soon to be $1,700) that the cost of doubling up is not prohibitive. Bear in mind though that you will have to factor in the cost of an additional pair of speaker cables to connect the two pairs of LFT 8A's. As well, a pair of Sound Anchor stands ($200/pair) and possible upgrade to Cardas chassis wire ($100/pair). (My original pair of LFT 8A's are Cardas wired, but due to a misunderstanding between the factory and myself, the second pair came standardly equipped with Monster. However, the sound is so glorious I am simply going to enjoy them for awhile before doing the Cardas modification.) In sum, if you like your music rich, full-bodied, and

dripping with calories, then the Poor Man's IRS V should seriously appeal to you.

Placement and Settings

I always play my speakers with the grills off, as should you, if you want to get the most out of your speakers. One of the cheapest tweaks available. I have my LFT 8A's on Sound Anchor stands. I had the front of the stands as close together as possible with a one inch gap in back so each pair formed an arc centered on my listening position. Recently, I have been doing my listening in the near field. i.e. about six feet from the speakers. The LFT 8A has optional settings allowing you to roll off the tweeter response. I ran mine flat. You may also experiment with damping the woofer enclosure. I tried placing a 25 pound lead ingot on my inner pair of LFT 8A's. The result was tighter bass and more transparency but also a loss of dynamics. I preferred the more dynamic sound and took the ingots off.

Room: irregular shape with approx dimensions 11 by 29 by 8.5 feet

Tape: Studer B67 transport, Manley Lab head and electronics

Pre: MFA Luminescence B1C

Amps: Bi-amped Manley Lab 440's

Speakers: Stacked Eminent Technology LFT 8A's

Interconnect: NBS King Serpent II

Speaker cable: NBS Siggie

Power cable: NBS Pro

Room treatment: BassTraps and RoomTunes

Isolation: UltraResolution Cornerstone, Brassfield plates

Update

Two major changes to the system.

Firstly, the tweeters have been upgraded to incorporate new and better magnet technology. The result is a smoother top end. The speaker now has the Bravo designation as in LFT 8B.

Secondly, two pairs of Hsu VTF-2 MK4's have been added. These are self-powered subs with a downward firing twelve inch driver and a 250 watt amp. So to be clear, two subs per side. These subs come with adjustable Q which I have on the lowest setting. They are crossed over at 50 Hz using the internal crossover with the volume set to twelve o' clock. The EQ switch is on the EQ2 setting. Both ports have been stuffed with the factory supplied stuffing.

Make that four major changes to the system.

Thirdly, the preamp is now the Manley Lab Wave which is no longer made. Actually, neither are the Manley Lab 440's leading some to dub this is the System That TIme Forgot. The MFA Luminescence B1C now serves as a phono preamp with the line output feeding into the Wave. The gain is tremendous.

Fourthly and perhaps most majorly, the room is now thirty five foot long by twenty five foot wide by nine feet high. Behind the speakers is a stone fireplace which reinforces the bass. (The best bass you can get would be in a concrete room. i.e. basement. The solid walls reflect back sound waves especially in the bass whereas drywall flexes and absorbs bass energy.) The fireplace also acts as a bass trap.

The wooden floor is heavily reinforced underneath, a legacy of an older time when builders were more profligate in their use of lumber. The turntables sit in what is effectively a separate room that used to be a patio with a concrete slab floor. The concrete has been covered with hardwood flooring, but the concrete is still there giving a solid base to the turntables.

Make that five major changes.

Interconnects and speaker cables have been upgraded to the seriously scarily named NBS Black Project II.

The result? The midrange of a Quad. The transparency of an electrostat. The dynamics of a horn. The sub-basement of an IRS V. Musical perfection for seven thousand United States Dollars? Yeah, it kinda is. Five thousand for two pair of Eminent Technology LFT8B's and two thousand for four Hsu VTF-2 MK4's. Admittedly more than you'd find between the cushions of your couch, but still. There are turntables that cost more than that. Much more ya know what I mean?

The one area where the LFT8B's fell short was in the sub-basement. The four eight inch drivers are good, but they're not the ultimate. The Hsu's round out the system nicely providing solid deep bass. One VTF-2 MK4 is good. Four is not so much louder as smoother. On Pictures at an Exhibition conducted by Fritz Reiner, the horse cart in Bydlo has weight and authority. Now the LFT8B's don't have to work as hard. On Bach Cantatas conducted by the great Karl Richter, the voices are ethereal.

Some subs are the devil to integrate with the rest of the system. The Hsu's just work. First place I plonked 'em down. Right out of the starting gate. No fuss, no muss.

My god, have two decades really passed? Tempus truly fugits.

-- ray

#Music