MartinLogan BalancedForce 212 subwoofer
Tubby thumpers need not apply
And when a speaker drops in with itty-bitty bass
It puts a frown upon my face
I get bummed . . .
Sir BassaLot, first audiophile rapper, 1992
Some folks put a pair of bookshelf speakers on stands in their room and are happy as clams. I imagine that they imagine the missing bass and never give it another thought. Not me, and perhaps not you. Some of us want to hear it and feel it, just as we would real instruments. We want sex in the room.
My quest for realistic bass began a quarter of a century agoI bought my first subwoofer, a Velodyne ULD-15, in 1989. The ULD-15 featured an outboard amplifier and crossover, and servo-control design to tighten everything up. What fun it was. With the right musicfor example, the Doors' "Waiting for the Sun" or Genesis's "Squonk"the Velodyne added a physical dimension that simply went MIA from most full-range or bookshelf speakers. It cranked up my listening adrenaline.
When, a few years later, I traded up my smallish speakers for a pair of MartinLogan Quests, I let the Velodyne go, thinking that the 'Logans' 12" woofers would be fine (also, I needed the cash). But nothough the bass was adequate, the physical impact was largely gone, and along with it, some of that excitement.
The Quests were eventually replaced with my current speakers, a pair of MartinLogan Prodigys, but this time I planned to add a couple subs when budget permitted. A few years later, the money saved, I bought a pair of MartinLogan Descent i powered subs. I was back in the bass business.
Then, in January of this year, I spotted ML's two new BalancedForce designs at the annual Consumer Electronics Show. Later, John Atkinson e-mailed to ask if I'd be interested in reviewing one of them. Well, why not? Should be easy, no? Maybe ML had improved on the Descents.
MartinLogan had originally wanted to submit for review the smaller of its two new BalancedForce models, the 210 ($2995 each), with dual 10" drive-units. But after explaining that I already had two Descent i's in the system and a fairly large room (23' deep by 32' wide by 11' high), they agreed that two of the larger BalancedForce 212s ($3995 each), each with a pair of 12" cones, would be in order.
In a two-channel system, a pair of subs has three advantages over a singleton: they smooth out standing waves considerably, help keep intact directional cues and the soundstage, and make possible more dynamic headroom with less distortion, as each sub must handle only one channel. After years of experimentation, I've settled on what's called a flanking subwoofer configuration: each sub is positioned to the outside and slightly behind a Prodigy.
Some claim that the range of frequencies a subwoofer is asked to reproduce is too low to affect soundstaging. But I've found that, even when the sub's low-pass filter is set to 6080Hz, the sound is still directional enough that, when I close my eyes, my ears can detect the physical location of each box (if not the actual soundwaves they produce, which are interacting with the room). In one blind test, I have someone randomly turn on only one of the two subs and play some music, and I try to guess which sub is on. Music with lively bass makes this easymy head and body, if not my ears, can tell which sub is active every single time.
If you have a multichannel home-theater system, multiple subs daisy-chained together (this arrangement is sometimes called dual mono) can make sensefilm soundtracks are mixed with mono bass for the ".1" channel. In my system, however, I run the audio straight to the left and right channels of my amps and subs, splitting each channel's signal at the preamp (or DAC with volume control) output and sending it full-range to both. The subs' crossovers therefore need to limit the subs' upper-frequency response so that the subs' outputs blend properly with that of the main speakers, which I prefer to run full range with no added crossovers in the signal path. More about MartinLogan's unique way of managing this in a bit.
Arriving and Unpacking
MartinLogan e-mailed to say they needed to send the BalancedForce 212s by semi truck. This sounded a bit scaryand exciting. I live a couple miles up a twisting road so steep that several cars' brakes have failed on the way down. A few years ago we lost a garbage truck and, unfortunately, its driver. And at the end of our dead-end street there's little room to turn around.
So I asked for a short semi, if possible, to make it easier on the driver. ML also told me that "delivery" doesn't usually include schlepping subs into the house (though that can be arranged). Instead, they place the hefty package at the driveway. Luckily for me, it rained on delivery day. The driver graciously pulled out his heavy-duty hand truck, and we carefully wheeled the more than 320 lbs of boxes, on two wooden pallets, into the garage, where they sat until I could get some help.
This is not a job for one person. I considered which members of our local audio club look as if they lift weights in their spare time. A couple e-mails and a few days later, Dan, an ex-correctional officer and body builder, and Craig, in his trademark butch haircut and combat boots, showed up. After manhandling the boxes into the listening room, we opened them and started to unpack the BF212s.
MartinLogan's Descent subs had pairs of handles, but they were in awkward spots and tough to get your fingers around. Realizing this, ML has omitted handles from the BalancedForce models, but does include handholds under the top edges and on the bottombut even with two strong men, the combination of size, shape, and a weight of 140 lbs made this process tricky. We screwed in the included spikes, placed the BF212s in the same spots the Descent i's had occupied, and set the controls in roughly the same places.
Viewed from the top, the BalancedForce 212 is slightly trapezoidal: it tapers toward the front, while its two 12" woofers are mounted on opposite sides of the sealed cabinet, inset at angles so that they are perfectly parallel to each other. The BF212 weighs 140 lbs and is roughly 22+" square (measured at the center of each side), while the BF210 weighs 96 lbs and is roughly 19" square.
About those woofers: MartinLogan says that they fire back to backin what ML calls a BalancedForce configuration, operating in exact opposition "to nullify distortion causing cabinet vibrations and deliver pure bass energy." And, in fact, the cabinets kept quite still as the cones madly moved prodigious amounts of air. The BalancedForce concept first appeared in 2007, and was also used in the Descent models. I've always been a fan of this design, compared to subs that rock back each time their single woofer hits hard.
The front of the BF212 has a high-gloss black finish; the top comes in black, white, Walnut, or Dark Cherry (custom finishes are also available). The woofers on each side are covered with black cloth on a frame that snaps magnetically into place and never rattled in use. The base is made of cast-aluminum, and is ribbed for strength, and a secure grip when the sub is moved around. Inset in the base are screw holes for four feet, of pointy metal or rounded rubber.
Can't Hardly Wait
We hadn't even used ML's Perfect Bass Kit calibration rig yetlike kids with newly opened birthday presents, we wanted to begin playing with them right away.
But before moving the Descents, we'd listened to a series of tracks so that everyone could get a sense of the system's sound with them in place. Now, with the BalancedForce 212s up and running, Craig asked to hear his favorite bass test, Dead Can Dance's "Song of the Stars," which we'd listened to an hour earlier. We all smiled, noting an immediate improvement. Dan said there was less bloom but additional physical sensation, and Craig thought that the new subs "locked in" with the Prodigyseven though we hadn't yet installed the Custom EQ Filter settings via USB (more about those later).