For a very long time my audiophile friends and I had a “nose-in-the-air” attitude toward subwoofers. In our minds, subs were meant for clubs, thunderous home theaters, and drivers who liked to annoy neighbors and passers-by with loud, thumping music coming from their cars. Subwoofers, for all intents and purposes, had no place in a dedicated high-end, two-channel audio systems. Awhile back, I’d experimented with several (single) subwoofers in my listening room, but each time I found that they produced nothing more than low-end filler—bass lines that were boomy and bloated, rather than taut and accurate.
Then I received two MartinLogan Balanced Force 210 subwoofers for audition, along with ML’s Perfect Bass Kit (PBK) for dial-in, and decided to give subs another go. Not only did these two subwoofers radically change my thinking, they’ve also become essential tools for achieving the kind of taut, controlled low end that would be impossible with most stand-alone speakers.
Setting up a subwoofer—much less two of them—is a long and involved process: To achieve optimal results you should expect to spend a minimum of ten hours, spread over a week or two, tweaking and listening. ML’s Perfect Bass Kit, sold separately ($100), helps immensely, but there’s no substitute for patient and careful tuning of your dual-subwoofer setup before employing PBK.
The classic method for discovering the optimal location for your subwoofer is to place the sub in your listening position, preferably in your chair, and then crawl around the room listening for the spots where the bass sounds best. While this method can be pretty accurate, it’s not very practical. What happens if the best locations are too far from your preamp, or in the middle of the room, or in some other unfeasible spot? Set-up challenges are further exacerbated when you use two subwoofers. I’m fortunate to have a very large listening space—33′ x 10′ x 27′. If you don’t have this kind of room and can only stick your subwoofers in corners, proceed with caution, as placing subwoofers there will reinforce room modes, and potentially cause your system to sound boomy.
I found the best placement for the Balanced Force 210s by using a kind of “balanced ratio” in between my speakers. Measuring from the tweeter, my speakers are set six feet from the rear wall, twelve feet apart, and toed-in 25 degrees. Measuring from the tweeter to the center of each subwoofer, I set each Balanced Force 210 three feet inside the main speakers and three feet behind each one. This means that the Balanced Force 210s are three feet from the rear walls, and roughly six feet apart.
I tested the Balanced Force 210s first with standard single-ended outputs and no bass management, then using PBK to measure the subwoofers’ outputs and optimize EQ, and finally with a preamp (the Classé CP-800) with bass-management capabilities. If you want to connect two Balanced Force 210s from a preamp or an integrated with subwoofer/auxiliary outputs, make sure the preamp has both left- and right-channel outputs—otherwise you will be running two mono subs. If you have only one subwoofer output, you can still “daisy chain” the two Balanced Force subs, and you can still use PBK to program one subwoofer, which will, in turn, control the second one. But far and away the best method for two subs is to have a preamp capable of dual-subwoofer bass management. The Classé CP-800 allows for this, permitting the use of two XLR outputs to run the Balanced Force 210s in a left-channel and right-channel setup.
The Perfect Bass Kit comprises a microphone, stand, two USB cables, and software that allows you to measure your MartinLogan subwoofers and automatically calibrate them to achieve the best sound in your room. Connect one USB cable from the Balanced Force 210 to your computer, and then connect the other USB cable from the computer to the microphone. Next, set the microphone at your listening position, then use the PBK software to run measurements in up to ten different positions around your room. The PBK software plays a series of test tones as you go through this process, and in the end automatically uploads the “correct” EQ into your subs.
One of the PBK software’s few pitfalls is that it’s a Windows-only program. This means that all of you Mac users will be out of luck, unless you use Boot Camp or Parallels to run Windows on your Mac. I had to borrow a PC in order to run PBK.
Another downside is that you will need a laptop or multiple USB extensions to complete your measurements. While the supplied USB cables are 12 feet long, they aren’t quite long enough to safely move the microphone around the room without potentially yanking a stationary computer off its rack. Invest in a ten-foot USB extender (about $6), or a USB-over-Ethernet extender (about $15), if you’re worried about the degradation that occurs with longer USB cable lengths.
The measurement process takes about ten minutes, and is fairly effective at performing final tweaks for you, but, as I said at the start, it is no substitute for proper subwoofer setup. Don’t expect to plop the subs down anywhere in the room and have PBK resolve all issues—correct placement is the first, and most important, step.
Even after all of this, you will still need to experiment with subwoofer output levels to find the ideal balance between too little and too much bass. However, once you’ve jumped through the hoops, things really take off.
How Dual Subs Sound
The ML Balanced Force 210 subwoofers are extremely effective at reproducing low end. I’m not saying that “these are really great” in a flippant way, or because I like subwoofers. As I stated earlier, I haven’t been a fan of subs in the past, but the Balanced Force 210s have changed all that.
In my large room, low-end extension has been an issue, and listening to great bass-centric albums from artists like Jaco Pastorius, Ron Carter, Charles Mingus, or Victor Wooten has always been a little unsatisfying—especially when it comes to electric bass. The Balanced Force 210s fixed that problem, and I can now listen to something like Victor Wooten’s Soul Circus without cranking my system’s volume to super-loud levels to achieve proper low-end response.
Listening to Jaco Pastorius’ eponymous debut album [180g, Epic Records] was a whole new experience with the 210s. Jaco Pastorius was the LP that put the electric bass front and center, and is considered by many to be the greatest bass album of all time. But without subwoofers or a really incredible, über-expensive floorstander to reproduce those super-fast, low-end notes, songs like “Come On, Come Over” and “Continuum” never sound complete. With properly set-up Balanced Force 210s, Pastorius’ bass finally came through in its full glory, each note taut and punchy. Most importantly, low-end imaging was dead-on precise—actual notes rather than some diffuse undertone floating ghost-like through the room.
Victor Wooten, one of the great modern electric bassists, can really test the limits of your system with his playing, especially on songs like “Bass Tribute” from Soul Circus [CD, Vanguard]. “Bass Tribute” features multiple electric basses, as well as an upright bass, and separating all of those low-end notes is difficult for even the best floorstanders. But with a pair of good subwoofers, these songs transform your listening room into a recording studio full of tall Ampegs and Fenders. Again, the Balanced Force 210s have an incredible ability to properly locate electric basses and upright basses within the soundstage, and to do so without sacrificing speed and articulation.
Many hardcore audiophiles deem pipe organ the ultimate test of a system’s ability to reproduce low bass. Of course, it’s impossible to reproduce a gigantic pipe organ in your home (as anyone who has heard a pipe organ concert can tell you), but you can bring your system to a whole new level of realism by properly setting up dual subwoofers. My go-to test record for organ music is, naturally, Karl Richter playing Bach’s Toccata and Fugue in D Minor from Bach’s Organ Works [LP, Deutsche Grammophon]. I’ve heard the Toccata and Fugue in D Minor played in several cathedrals throughout Germany, and the power and force of the organ is overwhelming—again, virtually impossible to reproduce at home. But the Balanced Force 210s get you eighty-percent there, which is pretty incredible for subwoofers a tiny fraction of the size of an actual pipe organ.
I can’t claim that the MartinLogan Balance Force 210s are the end-alls in low-end reproduction, or that they will fool you into thinking there is an actual standup or electric bass sitting in your living room. What I can say is that they have brought me much closer to the real thing and made me a believer in subwoofing. Now that the 210s are in my listening room, my music—and not just music where bass is prominent—has taken on a new life. They have made a far greater difference in my stereo than any other component I can remember in a very long time. If you have a large room or really feel the need to hear low bass, the Balanced Force 210s are essential tools to getting the most out of your music. Just make sure you have the space—and the patience—to fully appreciate these big boys.
SPECS & PRICING
Frequency response: 20–120Hz +/-3dB
Low-pass filter: 30–80Hz
Phase: 0, 90, 180, 270
Woofers: Two 10″ sealed, high-excursion aluminum cones
Amplification: 850W Class D
Inputs: RCA, XLR, speaker level, 3.5mm trigger
Outputs: RCA/XLR multi-out
Power consumption: 125 watts, 15 watts standby
Weight: 96 lbs. each
Dimensions: 19″ x 19″ x 19.5″
Price: $2995 each
2101 Delaware St.
Lawrence, KS 66046
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