Test Report: Polk Audio LSiM Speaker System Page 2
The 702F/X surrounds are neither bipole nor dipole but conventional forward-radiating speakers with an unusual, dual-face layout. I was repeatedly impressed by just how effective they were at both envelopment and discrete effects, smooth and non-localized to a degree that I had thought only dipoles capable.
As to level, the Polk system played far louder than I’d ever ask via my 150-watts-per-channel power amp without the least sign of strain or change. All three Polk models are of comparatively high sensitivity (at least as far as their maker’s specs go), and I could in fact play movie sound many decibels beyond “reference level” with no hint of stress — way, way louder than any sane home theaterphile would ever demand.
Note that at this point I haven’t even powered up the subwoofers yet. Connecting these to my processor’s subwoofer outputs and setting the front towers as “small” (hah!) with a crossover of 80 Hz had the expected result: tight, powerful, full-range sound. But with such wide-range main fronts, what’s the point? Instead, I returned the fronts to “large,” leaving center and surround crossovers at 60 Hz as before and allowing the subs to function purely as LFE-channel adjuncts, reproducing only the bass that sound designers judged to belong exclusively to a subwoofer channel.
Honestly, the net result wasn’t all that different — most of the time. The system sounded slightly leaner or perhaps “tighter” on more subtle deep-bass passages such as the sliding tomb door from the opening of Stargate. However, big-budget bass like the pod-emergence sequence from War of the Worlds went right over the freaking top, yielding a seismic, foundation-fracturing moment that was, frankly, somewhat alarming.
Do you need a sub (or two) with these biggest of Polks? Probably not — unless you’re a bit bass-hungry, that is. At any rate, Polk’s new flagship suite’s as-tested system price is well into “esoteric speaker” territory. Fortunately, the LSiM Series array I auditioned is a reference contender that should happily stand comparison with low-production- volume, high-end designs of similar heft and price, and even substantially higher. Just be sure you have a nice, big room, and solid foundations.