December 2014

World Premiere!
Soundfield Audio Monitor 2 Active Loudspeakers
Highly engineered two-piece powered stand-mounted speakers.
Review By A. Colin Flood

 AJ is a tinker. AJ is an engineer. He always sits off-center, near the middle front, always with his notebook computer in front of him. Throughout several demonstrations of his latest prototype, he fiddles with this setting and angle, or that setting and angle. AJ always has a prototype he is tweaking. He streams one percussive sample of music and EQ from his notebook to his DAC to a solid-state receiver. AJ frequently asks for opinions, but then answers them with an engineer's view of various issues. He moves from side to side, concerned with the size of the sweet spot, while a half-dozen middle tweaking audiophiles are content enough to sit, talk and sometimes listen. Ammar Jadusingh (AJ) is powerful looking man; short cropped hair, quietly muscular and very direct in his opinions. AJ pronounces his last name as "Jadu (as spelled) sing (the h is silent)," but without a hint of an Indian accent. It is Indian (as in the subcontinent) from his father's side, while his mother was English.

Fascination with Electronics
"I got into speaker design in my teens," AJ says, after his older brother built a speaker (with Radio Shack drivers) and his uncle was audiophile (with a Rogers/Dynaco/Thorens system) circa late 70s. AJ majored in Electrical Engineering in college. He built his own floor standers and giant subwoofer for his dorm room (late 80s). He became serious about audio in the mid-90s with the advent of easy internet access and dial-up modems! His knowledge base expanded to create more complex DIY designs. "I slowly started convincing myself I could do better than store designs (brick n' mortars, like Sound Advice), at least at less cost on my audiophile cravings budget at the time. By 1999, I had created my first active, variable sound field speaker. It consisted of a heavily modified BlueroomMinipod, the standard tweeter removed and a Vifa XT ring radiator implanted. A rear firing dome was grafted to the enclosure. The passive XO was removed, he says, "the speaker was tri-amped with a Rane active analog crossover, The rear driver amp had a remote controlled volume, that allowed the soundstage to be enlarged or shrunk. It was the precursor to what Soundfield is today."

AJ started marketing his loudspeakers with the Audio Expo of North America consumer audio at Jacksonville since it was only a few hours' drive from Tampa. I know AJ from the Suncoast Audiophile Society on Meetup, but I first saw his loudspeakers at AXPONA. He is always a font of generously given and valuable engineering information. The first and last loudspeakers of his I ever heard are his (as of yet still un-announced) signature "1812" flagships at AXPONA. They are still prototypes. The last iteration of the 1812s I saw recently were big, black, square boxes as AJ fiddles with drivers, cabinet designs, crossover, equalization, settings and angles. The 1812s currently have one barely moving, open baffle 18" driver per side in the middle, with boxed 12" sub-woofer on the bottom and a boxed horn-like coaxial driver on top. AJ says the final 1812 design will have a ribbon super-tweeter and rear drivers. I loved the 1812's then and now for their amazing clarity, dynamics, power and huge soundstage. When AJ said he had a smaller monitor was in production, I jumped at the chance to hear them.

Competitive Price
At 20" high yet a mere 10" wide, the Monitor 2 Active (M2A) powered woofer loudspeakers appear taller and thinner than typical bookshelf loudspeakers. They have a big black mouth above a silver moon in a butter yellow cabinet. The M2As sit upon their own matching butter stands. The wood is real Natural Cherry veneer, so they are a soft yellow tint, not fake pinkish cherry one. Another fellow tweaking audiophile in his woodshop handcrafts the M2As. The craftsman says "real natural cherry starts out a much lighter wood... and it takes time to darken as it is exposed to light. The length of time to go from this light color to the darker color above varies with the amount of light in the room and can take anywhere from a few months to a number of years." He expects most units will darken within 6 to 12 months.

In fact, the M2As have to use their own matching stands. Inside their stands are the plate amplifiers for the woofers. The M2As are two-way bookshelf loudspeaker with three drivers. There is a super-tweeter, crossed over at 14 kHz plus an optional rear firing 1" dome driver with shaped response for larger soundstage and improved ambiance. There is the front side 8" aluminum woofer, operating in the sealed cabinet. Strangely, the woofer crosses over right in the middle of the hypercritical range, 1 kHz, but I did not hear any mid-range notch or noise. AJ adds 150 Watt Class AB amplifiers into the matching custom butter stands. The amplifiers actively power the woofers, but not the other drivers. This leaves the relatively large, 9.5" x 6.5" planar magnetic horn-loaded driver to handle middle and upper portion of the hypercritical range of human appreciation, from 1 to 14 kHz.

Thus, the frequency response for these disarming simply looking babies is quite respectfully wide for bookshelf loudspeakers, 65 Hz to 23 kHz. It is also very nicely flat, within an important 3dB. Even better, within the hypercritical range (100-13,000 Hz), the M2As are very impressive, flat within 2dB. Wait, as the late night infomercial for Soundfield goes... there's more! Sensitivity for these butter babies is a very high 101dB/W/m. Equally impressive, while impedance is the typical 8 Ohm, but it is relatively constant (flat), dipping down to only 7.2 Ohms, meaning that the upper drivers are easily driven by impedance challenged low power/tube amplifiers. Finally, the M2As are only $2200 for the passive/active pair as reviewed, $1600 for available fully passive (no woofer amplifier) version. AJ says he is considering a version where the woofer amplifier is mounted on the rear, precluding the need to use his butter stands.

The big question for me was, with the woofer plate amplifier in the stands, and then the listener must use those matching Soundfield stands as if the M2As are two-part towers. Fair enough, bookshelf loudspeakers sound like crap unless they properly mounted away from the front and side walls on stands anyway. However, my question about the two-part M2As quickly becomes, "if you must include stands, why not just make the M2As into one-piece tower loudspeakers?"

Powered Stand Mount
 "I would say the single most important thing for a designer is," AJ responded quickly, "did the finished loudspeaker meet the design goal? For a commercial speaker, that could be as simple as "Will it sell? I certainly hope it does, as that was the specific design intent. In the case of the M2A, I guess the question there is, does it meet the goal of being a speaker that sounds good with low power, low (or no) negative feedback amplifiers, in a wide variety of rooms, while taking up the floor space of a modestly sized stand mount?"

The new buzzword is stand mount, which is more approximate than bookshelf loudspeakers. I do not know of true bookshelf loudspeakers that actually sound better in a bookshelf. Do you? All small loudspeakers sound best properly mounted at the ideal height and ways from the front and sidewalls. In this case, the stand mounts for the M2A are powered. The M2A woofer plate amplifier is in the stand mount. It handles the woofer up to 1 kHz, which is the crossover frequency to horn. It is not user adjustable like a sub-woofer, because AJ says that would allow change frequencies in the lower mid to horn transition (greater than 800 Hz), which is undesirable. "So the amplifier is "hidden" in the stand, with no possibility of user maladjustment."

As with everything AJ does, the cable from loudspeaker to amplifier is not quite normal, but it is well thought out. The cable is also unique. It is a Speakon connector cord, mostly used in professional audio systems for connecting loudspeakers to amplifiers. The male connector is a large round pin, with an interlocking button. "It is foolproof. No chance of reversing polarity, or shorts, like you have with dual bananas." The Speakon connector is a very solid connection. It cannot connect in any other way to any other component in a home theater music and movie reproduction system, except another Speakon connector.

Therefore, the M2As are an active version, which must be purchased together as a "system." There is a passive version of the M2, but like every passive speaker, the maximum sensitivity is tied to the woofer, something this active version circumvents. The passive is a more typical efficiency, 88dB/W/m, as an outboard amplifier has to drive everything versus the very high efficiency of 101dB/W/m for the active version, where the plate amplifier drives the woofer. AJ also mentions that there is also no impedance "hump" as with a passive crossover. The impedance of the M2A is near ruler flat - perfect for low or no feedback tube amplifiers, which is what he aimed the M2As squarely towards achieving. There is an option for a deeper "subwoofer" type bass driver, at additional cost. He says the output of the standard woofer is never lacking and most AXPONA "show attendees who heard them agreed the bass output/depth made a sub unnecessary." The idea, AJ says, perhaps pandering to my distinct Big Ole Horn loudspeakers tastes is "to get a taste of Klipschorn sound with two watts, with far more room friendly decor."

Fit & Finish
All cuts for the M2As are done on a computer numerical control wood cutting machine for tight tolerance. The support brackets are installed in strategic locations to give a rock solid rigidity to the cabinet, which improves minimum negative impact on sound reproduction. The wood smith, also a tweaking audiophile in my local Meetup, says he uses a high strength adhesive for all joints. AJ considers sealed, higher QMS (less "hi-fi" mechanical damping, more well behaved off axis, etc.) drivers, which narrows the wide field of choices significantly. Then a combination of experience and computer modeling takes care of the rest. He both designs and builds his own crossovers. Delivery depends upon the model and finish. As a small builder, AJ says practically anything goes regarding finish options, but that adds time. Generally, it is four weeks for "standard" model/finish (veneer), with real woods and boutique parts/drivers, delivery is more like eight weeks plus.

In addition to the signature 1812s, AJ is also working on a VSFT-3 model for the next AXPONA. It will slot between the 1812 and VSFT-2 (which you heard at Mike Ks). Similar concept as the M2A but with dual amps for the subwoofers, one open baffle dipole, the other sealed. Finally, he adds a separately driven (remote controlled mini-amp) rear "indirect" radiator. This is an evolved and fleshed out realization of his "Variable" Sound Field (tower) concept. Like his previous models, this would again be active 12" open baffle (dipole) and 10" sealed subwoofers, seven inch ScanSpeak mid-bass woofer, 9.5" x 6.5" Planar Magnetic horn loaded mid-tweeter, and one inch ribbon super-tweeter. He is also planning / working on a replacement for his M1 - Bookshelf coaxial/powered sub.

Being a local company, AJ did not ship the M2As to me. I met AJ each time to pick-up and drop them off. When I review electronic equipment, double boxing is meaningless to me, but I do like to see at least two-three inches on Styrofoam on all sides for "back of the truck" bounce protection, plus a moisture barrier inside. I have seen dented boxes, in hundreds of shipments though; I have not received any damaged equipment. AJ ships with 2" low-density polyethylene foam packing in a double-walled box. He uses a clear plastic bag for moisture barrier. AJ ships everything via Pilot Freight. The speakers are on pallet, which he says largely negates the need for super-duty packing. The truck driver should take the loudspeakers off the pallet on arrival and bring them into the home.

High Value
Please note I am not compensated, reimbursed or affiliated with any audio/visual company in any form or fashion except for online stereo equipment review magazine publishers. I have no ulterior motives, hidden agenda or professional bias, except to decide for myself what I like. When auditioning equipment for Enjoy the Music.com, I like to press it hard, push the top end, feel how it goes through the curves, hear the scream, see the tracks. I know many tweaking audiophiles are trying to recreate the 3D sonic holograph of the sexy singer performing in their own cozy living room, up close and personal, sensuous and intimate, 70dB, like a throat-warming sip of strong booze. I am certainly one also. But I also like the bone shaking 90dB bang of rock n' roll that vibrates the chair, tingles your butt, makes your feet jingle so you just have to get up and dance, carefully not to spill a drop, but pounding, live band loud. Yet the most powerful tube amplifier I used the M2As with was the charming white Glow Audio Two, an integrated amplifier with EL84 tubes, providing about 15 Watts. Despite AJ's intent, these tubes were not enough juice however to make the M2As come alive.

Crowded Field
At the $2000 price point, there are several excellent choices for loudspeakers. In "The Best I've Ever Heard Loudspeaker Round-Up," I lauded the "open and airy... even balance throughout the mid-range" of single drivers loudspeakers, like the Omega line. AJ's planar driver and powered woofer on the M2As certainly provide the light treble cream and beefy bass missing from the Omega loudspeakers I heard. Yet several excellent loudspeaker $2000 offerings are no longer made. I loved the punchy Classic Audio Reproductions Cinema horns, the deep Newtronics Skates* leaning transmission and smooth Supravox Carla single driver towers, but these wonderful values are no longer available new.

Ron May's loudspeakers are still online. His Carnegie Acoustics CST-1 Leaning Transmission Towers are slim, phase-aligned, backwards-leaning towers with a planer magnetic tweeter and 5.25" VipaCore woofers. The CST-1s are "incredibly flat 2dB frequency response, within 20 Hz to 20 kHz, in a slim $1999 tower!". Also in that competitive $2000 range are many used Big Ole Horn loudspeakers, such as my Klipsch classic corner horns, LaScalas and Belles. Big Ole Horn loudspeakers are excellent choices for dynamic, clear sound with tube amplifiers and solid-state sub-woofers.

More Booty to Hold
It is "all about that base" Meghan Trainor sings, "boys like a little more booty to hold at night." The same is true for loudspeakers. Boys, and music, like a little bass to hold at night. "No trouble." Loudspeakers like May's CST-1s and AJ's M2As do nothing seriously wrong - they get most of the frequency spectrum right, especially the all-important base end. The M2As are amazing capable for the money. I think AJ should bump their price up another grand and offer more customizing options. Since he never stops tweaking their settings and set-up, maybe he should also offer a personal service like Jim Smith does. The author of the wonderful audiophile book, Get Better Sound, provides a "custom voicing service," an on-site evaluation and tuning session for tweaking audiophiles seeking to maximize their home theater music and movie reproduction systems.

Compared to typical name brand passive cone loudspeakers costing as much as $7000, the M2As are a solid bargain. Because of their value, I easily award the M2As four Blue Notes in the Value category. In all other Enjoy the Music.com categories, the M2A are a solidly average (three Blue Notes) across the board. I found no serious deficiencies in their sound, efficiency, looks, construction or specifications. They join a thinning market as one of the most competitive and compelling loudspeakers available. I hope we see more of this company.

Specifications
Type: Two-way passive bookshelf loudspeaker with super-tweeter and rear firing spatial driver
Frequency Response: 65 Hz to 23,000 (+/-3dB) 
Tweeter: 0.5" dome super tweeter plus 1" dome rear firing driver with shaped response
Midrange Driver: 9.5" x 6.5" Planar magnetic, horn loaded
Woofer Driver: 8" aluminum cone
Cabinet: Sealed or rear ported cabinet 
Nominal Impedance: 8 Ohms, 7.2 Ohm minimum 
Sensitivity: 89dB/W/m 
Crossover Frequencies: 1 kHz and 14 kHz 
Recommended Amplifier Power: 10 to 200 Watts RMS 
Active Version Adds:
  150 Watt RMS Class AB woofer amplifier built into matching custom stand. 
  Sensitivity 101dB/W/m
  Impedance: 8 Ohm constant (flat) Impedance
Dimensions: 20" x 10" x 10" (HxWxD) 
Weight: 39 lbs. each
Available in a wide variety of finishes, cherry shown.
Price: $1600 per pair passive or $2200 per pair active (as reviewed)

Company Information
Soundfield Audio
425 W Burger St.
Tampa FL 33604

Voice: (813) 215-6101
E-mail: soundfieldaudio.net@gmail.com
Website: www.SoundfieldAudio.net