JBL 250Ti loudspeaker
When high fidelity took off during the early '50s, consumer loudspeaker systems were nothing more than cheaper, scaled-down versions of those professional systems, with much the same sonic flavor but even rougher highs. Then, in 1956, Edgar Villchur patented a new kind of speaker system designed specifically for consumer use.
Recognizing the fact that, in the home, bass extension was more important than efficiency, Villchur's "acoustic suspension" system achieved tremendous LF extension by (among other things) reducing mid- and upper-range sensitivity to match the system's bass sensitivity. By comparison with professional speakers, Villchur's AR-1 had a muted, almost withdrawn middle and upper range, which was far more pleasant to listen to in small rooms. It also launched high fidelity loudspeaker design on a tangent from "pro" sound, and independent evolution in those divergent directions has made the two increasingly different since then. While professional systems grew ever more efficient and forward, so-called audiophile speakers became more laid-back, polite. (Our Bill Sommerwerck dubbed this kind of sound "Boston bland," in honor of its place of origin.) The greater the schism, the more the audiophile community sneered at the "brashness" of professional speaker systems (footnote 2).
But that brashness has proven to be exactly what's needed for music normally heard at very high levels, such as hard rock. The result has been the evolution of two distinctly different kinds of "audiophile" speaker systems: highly efficient, up-front systems for rock enthusiasts, and the laid-back, "polite" systems with exaggerated depth and spaciousness favored by many classical listeners and most audio perfectionists.
One of the leading manufacturers of professional speakers during the '40s was a firm called Altec Lansing. The Lansing part of the name belonged to a young engineer named James B., who parted company with Altec to form his own firm, JBL. Through the years, JBL has always tried for high efficiency and a forward, gutsy sound in their consumer line, thus earning the undying scorn of all audio perfectionists, who consider "JBL" synonymous with sonic trash. This never bothered JBL as long as "high end" was a mental aberration afflicting only a miniscule part of the population. The masses preferred JBL's kind of sound.
But two developments in the past three years have prompted JBL to reconsider their public image. First, the masses discovered the snob appeal of the High End, and learned from the purists that liking the sound of JBL speakers waswell, it just wasn't done! And second, JBL recognized that digital recordings, whose lack of surface noise is an invitation to play them at high volume, put their own products at a decided advantage over those of most audiophile manufacturers. JBLs could play loudly without burning out; most audiophile loudspeakers can't. The Ti Series of loudspeakers is JBL's bid for a new imagerespectability.
The Ti in the 250Ti's model designation stands for titanium; some techniques JBL developed for working with this tricky metal made their new tweeters possible. Titanium has an extremely high mass-to-stiffness ratio. A very thin sheet of it has enough stiffness to behave very much like the ideal piston radiator, with its entire surface area moving in unison. But its stiffness also makes it very brittle, and likely to split when subjected to the kind of forming processes necessary to produce an effective radiating surface. JBL claims to have found a solution, and has even found a way of embossing a pattern of diamond-shaped ribs into the surface of the tweeter dome to increase its stiffness. The result is the new tweeter which shows up on the high end of all their new speaker systems, the 440Ti.
The cone drivers in the 250Ti are described in JBL's literature as "evolutionary rather than revolutionary," which is to say, they're the latest improved versions of earlier designs. But it's obvious that JBL has done their homework.
For example, this is the first time JBL has used polypropylene as a cone material for their midrange drivers, even though most high-end speaker manufacturers have favored it for some years. But JBL's is not the usual polyprope material; it's "doped" with an additive that increases its stiffness and reduces breakup. (One of the recognized shortcomings of polypropylene is that it is too flexible for its own good; its popularity stems mainly from its high internal damping, which minimizes colorations due to resonance.)
These are also the first speakers from JBL whose large crossover capacitors are bypassed by small ones, reducing the effects of dielectric absorption. This is strict perfectionism, but JBL ascertained to their own satisfaction that bypassing did, in fact, improve the sound. The other characteristics of the 250Tithe very high power-handing ability, the long-throw woofer (5/8" displacement within 10% linearity!), and the rigid enclosure constructionare pretty much old hat; they've been earmarks of JBL products for many years.
I have never much cared for most aspects of the traditional JBL sound: boomy midbass, shallow soundstage, vague imaging, lack of deep bass or really high highs, and (often) piercingly shrill middle highs. But I have always admired their midrange performance. Whether it was their professional or consumer lines, JBL's speakers always had a punchiness and detailed immediacy, an ability to make a voice or a solo instrument sound right in the room, that has not been equalled by any audiophile speakers I know of. "Wouldn't it be great," I thought, "if JBL has retained that middle-range performance, and just augmented it with state-of-the-art performance in those other areas?" I should have known better!
JBL did their homework, all right. In their bid for the perfectionist audiophile market (and who else would pay $3400/pair for loudspeakers?), JBL has produced nothing more than yet another high-priced "Boston bland" behemoth. Every vestige of the middle-range immediacy, aliveness, and incredible detailing that characterized their previous speakers is gone. Instead, what we have are outstanding lows, superb highs, excellent soundstaging, very good imaging, and a total inability to make anything sound real. It's another instance of the baby going down the drain with the bath water.
Perhaps I'm being too hard on the 250Ti. I acknowledge that it is capable of producing prodigiously high listening levels without a trace of strain, and that its highs are simply gorgeous!silky smooth, open, completely effortless, and free from steeliness, even at the highest listening levels any sane person would tolerate (footnote 3). I acknowledge its remarkably smooth low end (usable to around 35Hz), and its ability to float a wide, deep soundstage around the instruments in simply-miked recordings.
But I also admit that my unusually brusque dismissal of JBL's not-inconsiderable design efforts on behalf of this system stems more from frustrated expectations than from anything else. I expected a system that would combine the old JBL systems' best attributes with those of today's state-of-the-art audiophile systems. I did not expect a total sellout to the audiophile taste for unctuous blahh!
I am, however, constantly reminded by everyone here that my stubborn insistence that reproduced music should sound alive is not shared by everyonenor, perhaps, by most audiophiles. After all, it wasn't the terminally deaf that JBL surveyed prior to designing this system, but the people who apply perfectionist standards to reproduced sound. So, for those perfectionists among our readers who don't give a sow's teat about aliveness, here is an impassive description of how the 250Ti's sound when driven by the kind of amp they like best: a top-notch solid-state amp like the Electron Kinetics Eagle 2.
I got the most natural sound over-all with the midrange drivers at their maximum setting and the tweeters strapped for 1dB of attenuation. The highs, as I said, are just superbbetter in smoothness and freedom from steeliness than those of many electrostatic systems, and in perfect balance (in my listening room) with that 1dB of attenuation.
In general, the sound of the system is warm, a little laid-back, and a shade heavy and loose through the midbass. Bass detail is good but not excellent, having only moderately good delineation of pitch. The speakers' sound varies markedly according to the vertical angle of your ears relative to the midrange drivers, and is most neutral with the ears almost exactly on the axis of the lower-midrange driver. Below that, the sound becomes even more laid-back; above, a pronounced dip develops in the upper middle range. The 250Ti throws a very wide, deep soundstage, with stable but not very specific imaging. Mono sources produce a vague ear pressure suggesting substantial random-phase content, and center bunching is not very tight.
Overall, this is a very pleasant-sounding system that can produce some very impressive sounds, but it lacks the feeling of life that makes the difference between excellent reproduction and literally accurate reproduction. For $3400/pair, I expected more.J. Gordon Holt