When I first heard Outlaw Audio's LFM-1 subwoofers at the 2004 Hi-Fi Show in New York, I was impressed by their extension. A good sub, like a good woman, is felt but not heard (ouch, my wife just slapped me... thereby proving my point). With measurable output down to 20 Hz, let me tell you right now, the LFM1 lets you feeeel the bass. But I'm getting ahead of myself. Let's walk through the review process from the beginning.
In my roughly 16 X 18 foot listening room, I decided I would try two of the LFM-1s. With two (or more) subs, it's possible to minimize room placement issues because subs placed in different parts of the room can have different frequency modes. Bass frequencies that are cancelled out with a single subwoofer in a particular location may be emphasized with a second sub in another location, allowing you to get relatively flat low frequency response in multiple listening locations with some tweaking. Plus, for $579 each (or 2 for $999), a pair of LFM-1s is as affordable as some comparable single subwoofers offered by the competition.
The flip side of the "supplementary bass" benefit is the drawback of subwoofer interaction. Any frequency anomalies of a single sub will be doubled when you have two identical models, and placement of two subs is actually trickier than one, because now the subwoofers interact not only with the main speakers but also with each other. Small changes in placement can impact the relative phase of each subwoofer, and unless you have a continuously adjustable phase control (which the LFM-1 does not have), you may end up spending a whole lot of time trying to find the best positions for your subs. More on that later.
Belying their affordable price, the LFM-1s have an exceptionally high degree of fit and finish. Even the packing material screams "high quality" with a soft cloth sack protecting each subwoofer inside two sturdy layers of foam and cardboard. The subwoofer itself is available in any color you want, as long as you want black. The satin black wood veneer is enhanced by an integral smoked Plexiglas top, which allows the subwoofer to function as a passable end table or plant stand without fear of spills or condensation.
The rear controls are pretty standard fare for a powered sub these days -- power (on/off/auto-on), phase (0 or 180 degrees), level control and crossover frequency controls (continuously variable from 40Hz to 180Hz, or bypass). Connections support both speaker level and line level inputs. And as for its power, the internal BASH amp is rated at a whopping 325 Watts RMS (1300 Watts peak). I can tell you in all my punishing listening tests, I never heard these subs even begin to strain, so I don't have any reason to doubt the veracity of this claim.
The Scatter Effect
No, I'm not talking about my neighbors scattering when I cranked up Lord of the Rings, Return of the King on these bad boys, shaking the walls and floor, I'm talking about what Outlaw calls "S2: the scattered subwoofer system" -- using two or more LFM-1 subwoofers instead of one. I have heard many multi-subwoofer systems that have exhibited smooth bass response so I thought I'd give it a go with the LFM-1s. At the 2004 Hi-Fi show, the Outlaws apparently had three subwoofers working together for a smooth extended low end in a large listening area. Well after several weeks of trying, a white paper or two of research, multiple arrangements of the furniture, the subwoofers, and my scattered brains, I finally gave up.
After much experimentation, I was able to find good locations for each individual subwoofer in different parts of the room, adjusting the phase, crossover and levels so that they blended with well with my Martin-Logan Aerius main speakers individually. But any attempt to bring both subs into the system at the same time led to phase interactions between the two that were not readily addressable. Switching either sub into opposite phase did not solve the problem, the net effect of which was a major lack of bass in the 40Hz to 80Hz range but a whole lot of bass in the 20 Hz to 40Hz range -- enough low bass to spontaneously turn on my son's motion activated stuffed animals, and make me feel a tad short of breath from the pressure against my chest.
If you've got a whole lot of flexibility in placement (and a whole lot of time and patience for set-up and calibration), then you may have better luck than I, but the rest of my listening tests were conducted with a single LFM-1. Mine was placed along the left wall of my listening room about half way between the front and back wall. This was where I was able to measure (and hear) the flattest frequency response. There was still some bass energy missing in the 50Hz to 60Hz range, but this is most likely an artifact of my room and listening position, not the sub itself.
Ah yes, to arrive at this final conclusion about proper placement, I sent my wife and young son into exile at her sister's house and made extensive use of the Avia Guide to Home Theater DVD, specifically the subwoofer calibration section which includes descending bass warble tones from 200Hz down to 20 Hz. I used my trusty Radio Shack SPL meter to measure these bass series and stopped when I found the location that had the flattest response.
By the way, as a warning, if you're going to use low bass test tones and an SPL meter to measure the response, I would highly recommend wearing earplugs. I know it seems counterintuitive to not use your ears when setting up speakers, but the LFM-1 can put out gobs and gobs of very low frequency bass, which you can't necessarily hear, but it can still lead to premature listener fatigue and even damage your hearing if the test tone levels are too high for too long. Of course, you certainly will want to use your ears to make final tweaks to the levels to blend the sub with your main speakers. I also placed a couple of "Room Tunes" (large sound absorptive panels) in the two front corners, helping to tame the room modes and standing waves.
To determine the best crossover settings, I decided not to rely on the manufacturer's stated frequency response of my main, center and rear speakers but I used these same bass warble tones to measure the lower limits of all five speakers. To do this, I set all speakers to "large" in my processor's bass management, turned off the subwoofer output on the sub temporarily and simply wrote down the –3dB points for each speaker when playing the bass warble tones. I ended up with crossover settings of 60Hz for the front, 80Hz for the center and 120Hz for the surrounds. Because I use different speakers in front, center and rear, I thought it best to use the processor's bass management and I set the LFM-1's crossover to "bypass" mode. I experimented both ways, and reached the same conclusion from listening as from logic (handy how that is). Then I settled down for some serious listening.
One of my current favorite bass torture tests is the "Battle of Peleanor Fields" scene from Lord of the Rings: Return of the King (Extended Edition) -- where the enormous Olyphaunts charge in to squash what's left of mankind (unsuccessfully I might add, sorry if I spoil it for you). And it's all in glorious DTS ES sound. This scene has sent many a lesser subwoofer into overload or distortion, but the LFM-1 handled it without complaint, putting out prodigious amounts of extremely low bass without a hint of squishiness or muddiness. It performed equally well with 18-pound cannonball blasts in Master and Commander: The Far Side of the World capturing the attack and power of the blasts without losing definition. Moving along to the Diva scene in The Fifth Element (special edition with DTS soundtrack), the Outlaw sub provided a solid foundation for the bass drum, punctuated with the counterpoint of crisp powerful gunshots and karate chops. And when Mr. Incredible takes on the evil robot in The Incredibles, the rumble in the jungle (and in the lava-ridden cave) is suitably deep and powerful without being overbearing.
In music listening, I spent quite a bit of time (usually a good sign) with old and new favorites on DVD-Audio and SACD including Roxy Music's Avalon SACD, Fleetwood Mac's Rumours (DVD-Audio), Gus Black's Uncivilized Love (DVD-Audio), Norah Jones' Come Away with Me (SACD) and The Eagles' Hotel California (DVD-Audio). Avalon is a phenomenal 5.1 channel remix of this classic make-out album from the early 80s. With the LFM-1, the mix was full and rich, with excellent low-end extension in the bass guitar and drums. Similarly on Come Away with Me, the stand-up bass was deep and full without any loss of definition. I'd say the only recording where the LFM-1 did not shine was the Gus Black DVD-Audio disc, where the bass seemed to lag just slightly behind the Martin-Logan electrostatic main speakers. But this is a tricky recording. My two channel music selections included the MFSL copy of Rush 2112, plus various classical pieces including Wagner's "Orchestral Music" (with Zubin Mehta conducting the New York Philharmonic). The Rush recording sounded excellent in pure stereo mode (Martin-Logans with help from the LFM-1) and equally good in Dolby PLII surround. Apparently the LFM-1 doesn't play favorites -- music or movies -- it's all good. The Wagner tracks exhibited the same power and definition as the rock and pop cuts, with a nice attack to tympani and bass drum and a fairly seamless blend between bass and high frequencies.
I also tried the LFM-1 with standard dynamic speakers, something they're more likely to be paired with in the real world. I moved my NHT SuperOnes up from the home theater system into the main system and this pairing proved even more successful than the Martin-Logans. Even the problematic Gus Black track sounded good on the LFM-1s when mated with the SuperOnes. The LFM-1 is an excellent choice to supplement a system of high quality small-to-medium satellite speakers, as is typical these days in the average home theater system.
All in all, as you may have guessed, I thoroughly enjoyed my time with the LFM-1 subwoofer. I was not successful in getting the best performance out of a dual subwoofer system, but in a different room, with different placement options, you very well could be. In any case, a single-sub LFM-1 system did not leave me wanting more in my particular listening room. For $579, it's a no-brainer. Go buy one now.
Type: Self-powered subwoofer
Driver Type: Down firing, 12" long-throw woofer
Amplifier Power Rating: 325WRMS; 1300W peak
Frequency Response: 25Hz to 180Hz (+/- 2dB)
Crossover Type: Linkwitz-Reilly 4th Order Low Pass Network
Crossover Frequency: 40Hz to 180Hz and Bypass
Phase: 0 to 180 degrees
SPL: 115dB (subject to placement and room gain)
Dimensions: 21.75 x 15 x 22 (HxWxD in inches)
Weight: 58 lbs.
Price: $579 each ($999 for a pair) plus shipping
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