This Article Was Originally Published On: July 1st, 2014 #Issue 14.

We first discussed Mike Arnopol and Big E Loudspeakers back in BGM #12, when Chris Fitzgerald took a look at the MAS-45 in his column, In the Doghouse. Chris is an exceptional double bass player and professor at the University of Louisville, and his column is dedicated to all things related to playing (and amplifying) the double bass. As Chris explained, the MAS-45 is an exceptional double bass enclosure, and it should come as no surprise that the MAS-45 is listed on the Michael Arnopol Soundworks webpage under the category, “Double Bass Loudspeakers.”

This time around, we journey over to the “Electric Bass Loudspeakers” side of Mike’s catalog and take at look at the big dog of the line, the MAS-210Flex. But before we dig into the details of this astounding box, let’s take a step back and get to know Mike Arnopol and Big E Loudspeakers a bit better.

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The Man Behind the MAS

Mike Arnopol has played upright and electric bass professionally for the past 35 years. He has played and recorded with many top jazz artists, but is most known for his work with jazz vocalist Patricia Barber (for over 25 years). Mike is on most of her CD’s and has traveled the world with Patricia, headlining at venues like Carnegie Hall and the Kennedy Center, as well as many European jazz festivals. Her recordings have been mastered for conventional release (Blue Note Records), as well as for the audiophile market, winning many audiophile awards.

His speaker-building adventure began at age 16, when he built his first loudspeaker (Altec Lansing Voice of the Theater). He built an Electro-Voice 15″ folded-horn design when he was 17, and then reverse-engineered an Acoustic 360 and built one when he was 18. He went on to building audiophile designs, including a transmission line sub and a copy of the BBC’s LS3/5A. Mike has always played cabinets that he has designed and built himself. In the ’80s, he had a waiting list of local players who wanted his cabs. Although he has no formal training, Mike was building reflex cabinets with removable plates with different ports for different tuning. Also in the ’80s, he used a bi-amped speaker with a 15″ a reflex box, and a separate small cab with the first pro audio 6″ midrange, made by Audax. In the ’90s, he was too busy touring to make cabs. About ten years ago, he entered into an endorsement deal with Euphonic Audio, which lasted for several years. Once he retired from touring with Patricia, he renewed his interest in building bass enclosures.

Ultimate Ears

Mike is also an active member of the community. After reading on TalkBass about someone who had built a composite bass cabinet, he decided to give it a try. He wanted to replace his 1×10 enclosure, but couldn’t find a driver he liked. Mike explains, “I found a wonderful 8″ driver that actually moved as much air as the 10″, but with a MUCH better sound. I built a cab that weighed 10 pounds and could compete with any single 10. A friend of mine tried it and made a post on TalkBass about it. All of a sudden, I had a dozen guys that wanted one. I had just retired from touring and thought, ‘why not?’ Dave Green then approached me regarding a collaboration, and my little cab became the ‘Crazy 8.’ I then was making composite cabs for both Dave and Duke LeJeune. I was getting very ill from my exposure to the epoxy and fiberglass dust and was ramping-down production.”

Leland Crooks (of Speaker Hardware) was actually the man responsible for introducing Mike to the Big E guys. Leland was making the trip from Kansas to Mike’s house with his son to learn about composite cabinet making. Along the way, Leland and his son stopped by Piper City, Illinois, to visit with the Big E guys, who gave him one of their 12″ subs to take with him. When he arrived at the Arnopol household, Leland was excited to tell Mike about these wild cabs. “I thought he was nuts,” says Mike. “He showed me the sub. I tapped on the cone and heard this huge bass drum sound coming out. ‘What the hell?’ I said. ‘This cab has no damping!’ I knew something was up and made a trip down to Piper City, where they showed me their 48 prototype. I was floored. No matter where I moved with my 20′ cord, things sounded essentially the same. And these four 8’s were going as loud as an 8×10! I immediately got on board as their builder of the bass cabinet line. Michael Arnopol Speakerworks was born.”

The Big E Guys

Okay, so let’s learn a bit more about these “Big E guys.” Thomas Ewers and Stephen Regier had been collaborating on technology development long before Big E Loudspeakers was formed. Their first big challenge came in the medical technology field. A major international medical equipment manufacturer was seeking assistance in the development of a PC-based life support system. If successful, the platform would be adapted for use in dialysis machines, ventilators, patient monitors, and anesthesia delivery for medically fragile patients. The team was successful, after some big names in the industry failed. Today, these machines are preserving and enhancing lives, worldwide.


Flex Bass Cab
Flex Bass Cab

Several years after the medical equipment project, Tom and Steve were collaborating again, this time in the music industry. They teamed up to record, produce, and publish music from local artists. As their artists started receiving attention, it was time to go on tour, but the budget was limited. Steve had been involved in sound engineering since the mid 1970’s and Tom had demonstrated his uncanny ability for exhaustive research on any subject presented. The pair turned their abilities to the issue at hand: touring on a budget. They landed in the DIY arena, constructing an entire touring rig of folded-horn loudspeakers in Steve’s garage. As a reward to Tom, they built a set of small line array loudspeakers for Tom’s home theater. After listening to the small line array, Steve (a.k.a. “Dr. PsYchoBoom”) remarked, “How do I get that sound in there?” motioning toward his newly created PA. At that point, it was “game on” for the partners.

The first product of their collective efforts was a column line array loudspeaker named the 612. Testing of the 612 was quite successful, and later the same year, JBL released the CBT 70 series column line array loudspeaker. Larger column line arrays started to appear in the DIY market, as well. Tom and Steve knew, then, that they were not only onto something, their ideas about what a PA could be were becoming more mainstream. They then took their creations to a nationally recognized musician and concert producer, Chuck Gomez. Chuck was quite impressed and added suggestions for making their products more commercially viable.

Over the course of the ensuing year of touring and demos, they met a Chicago DJ who wanted a series of subwoofer scoops like the EV MTL series. Instead, they offered to develop a loudspeaker of equivalent or greater performance. The 218SLS cross-fired-in-a-scoop reflex subwoofer was developed for this client, and installed in a popular Chicago-area night club. The club was popular, but had a reputation of loud, offensive sound. Not only did Tom and Steve install the new 218SLS units, they re-aligned and reprogrammed the entire loudspeaker and signal processing system. The debut was to a packed house, with a special guest touring DJ. The client was not sure if the new system was loud enough by his standards until he was shown the SPL level to be in the mid-120dB’s, behind the bar, 90 degrees off-axis, at the far side of the club – a sizable increase from the original system. The new PA was an instant success for the club, resulting in their online reviews becoming enthusiastically positive. Steve and Tom’s theorems of loud, but not harsh, PA were beginning to prove themselves in the real world. It was at this time that the duo was introduced to concepts that led to development of MVW technology. Big E Loudspeakers was formed, with its name derived from Tom’s Naval moniker – given to him by MM1(SW) Ranada while serving in 1AMR aboard USS Independence CV62 (Freedom’s Flagship). DIY plans for the 612 and 218SLS are available free at

Flex Bass CabSetting the Stage

 My initial face-to-face meeting with Mike Arnopol was also the result of a road trip. Mike had just been to New York in order to visit with his daughter (and provide her with some hands-on fatherly help, courtesy of his wood-working skills). His return trip to Chicago took him straight across Ohio on the Turnpike, which happens to run right past my home town of Fremont. Mike just happened to have a couple of cabs with him: the MAS-85 and the MAS-110Flex. Mike and I spent what seemed like a day and a half (but was probably about an hour and a half) playing through these cabs using a variety of basses (both electric and double bass) and a variety of heads. The magical midrange presentation of the MAS-85 still haunts me, and it is an amazing cab in its own right. But it was the 110Flex that occupied most of our time. The combination of tight, growly lows and smooth, but present, mids and highs was very compelling (particularly with my Reeves C225). At the end of the day, I said to Mike, “This 110Flex is really great, but I keep asking myself what a 210Flex would be like.” After a soft chuckle, Mike began his reply with, “It’s funny you should mention that …”

Not too long after, the MAS-210Flex arrived (in a pretty big box). After unpacking and standing back a bit to take it all in, the first visual impression is that of a thinner, wider box with a pair of mids and a pair of tweets, sitting on top of a wider, vertically oriented 2×10. The MAS-210Flex presents this as a combined enclosure, but Mike now offers this rig in a modular setup, by pairing the mid/tweet section and one 10″ driver in one enclosure, called the MAS-210Mod, with an MAS-110 subwoofer. The modular approach will set you back an additional $325, but does have the advantage of increased portability, as well as the option of using just the MAS-210Mod, when you don’t need to “bring the boom.”

Product Details

The MAS-210Flex comes equipped with some serious hardware. This starts with the two Eminence Kappalite 3010LF drivers. These drivers take full advantage of their lightweight, super powerful neodymium-based motors. They go low (38Hz Fs) and can handle a lot of power (450 watts RMS, each). We’ve been raving over enclosures using their big brothers, the 3012LF and 3015LF, and it’s a real pleasure to see what these “super 10’s” can do. Moving on to the midrange drivers, we have two 6.5” Faital Pro W6N8-120’s, arranged in a “cross-fire” configuration. We’ve seen these fantastic drivers in other high-end enclosures, and they are a most-welcome addition. The tweeters are Ciare 1.26ND TW, another high-quality Italian import. The two Ciare tweets are aligned vertically, and placed in between the two Faital mids. Clearly, no corners were cut where it comes to driver selection.

Flanking the two 10″ drivers, on either side of the front baffle, we find what look like wide, vertical slot ports. Similar, smaller ports are also present to the right and the left of the cross-firing midrange drivers. Looks can be deceiving, though, and there is more going on here than simple shelf porting. Big E Loudspeakers and MAS refer to this design as the Manipulated Vortex Waveguide™ (MVW) alignment. At first blush, it seems to share some common traits with transmission line designs – which are surrounded by a fair bit of mystery, myth, and misconception, themselves. Rather than obtaining the necessary engineering degrees to attempt to adequately describe this technology to you – and preferring not to blindly guess at what’s going on – I asked Steve and Tom to describe this technology in their own words. They did this and more, even providing us with an exclusive first look at a diagram of how the MVW loudspeaker alignment works. Check out the article, The MVW Story, immediately following this review.

At the upper left on the front of the cabinet, we find an (initially intimidating) arrangement of switches, including a big red arming switch. The four switches (three 2-way switches and one 3-way switch) provide 24 different potential settings, which can be a real head-scratcher, at first. Fortunately, markings are provided indicating the “default settings,” which make a great starting point. The top (3-way) switch is the Tweeter control switch. This switch allows you to select one, two, or no tweeters (the default setting is one). At the bottom of the panel, we find the Voicing control switch. This controls the signal phase relation between the mid/high section and the woofer section (the default setting is in-phase). The two middle switches are designed to work together. The switch on the right (labeled “SW2”) does most of the heavy lifting, as it engages the “Bright” setting when set to the “up” position, which increases the sensitivity of the mid/high section, relative to the “Neutral” setting (SW2 switch “down”). The switch on the left is labeled “SW1,” and is only accessed by lifting the red plastic cover. This allows you to select the “Dark” setting, thereby engaging the “PXB circuit,” which decreases the sensitivity of the mid/high section (relative to the Neutral setting) and is also designed to add gentle compression and warmth when the cab is pushed hard (700+ watts).

The back panel is a much more simple and straightforward affair, with a recessed metal plate housing two Speakon™ jacks. The cab is designed for tilt-back rolling, facilitated by two built-in corner casters and a top-mounted strap handle. Removing the rear panel from the mid/high section, however, shows that the MAS-210Flex has a lot going on beneath the seemingly calm surface of the back of the enclosure. The cab also has two side handles, which enable a single individual to effectively lift the cab. However, I wouldn’t recommend trying to carry it very far, unless you have a buddy to grab the other handle. Despite its relatively large size, the weight (just under 80 lbs) is pretty reasonable. Using the side handles, it was fairly easy to lift the 210Flex and load it into the rear of my hatchback. When negotiating narrow hallways (or even stairways), using one side handle and the top strap handle is fairly effective. Of course, when the situation allows, the MAS-210Flex is a breeze to roll, using its built-in casters.

Flex Bass CabPut to the Test

I’ve been playing this cab for some time, now. I’ve compared it to many other cabs, and I’ve used it with a variety of basses and amps. It’s been to band practice sessions. It’s been to gigs. After all of this, the thoughts which come to mind most often when I think of how best to describe its performance are: 1.) “it does pretty much everything you could ask it to do, and does it well,” and 2.) “there are a few things it does really, really well.” All of the things that I liked about the 110Flex (tight, growly lows and smooth, but present, mids and highs) were there, but the depth, breadth, and overall “size” of the low end had been definitely kicked up a notch or two.

If you are shooting for a specific tone or response from your bass enclosure, you may seek out and obtain an enclosure (or two) that fit this specific need or set of needs. However, if you play in multiple bands, play varied styles of music, or play with a variety of instruments, you likely need a bass cab that is flexible enough to cover a lot of ground. To this end, it’s nice to have an enclosure which can handle a wide frequency range, with a decent degree of balance from top to bottom. The MAS-210Flex definitely has you covered, here. Let’s talk about the low end, first. The 210Flex goes very deep, but unlike some cabs I have tried which produce a low fundamental, but yet somehow come across as thin in the lows, the 210Flex remains very full all the way down. The overall low-end response is a touch on the warm side, but very articulate. Word of warning, though; all of that low-end energy can really excite other objects in the room. The use of a high-pass filter may be necessary if you find yourself shaking stuff in the room a bit too much. That Voicing switch is pretty cool. As I mentioned, it places the woofer section either in-phase or out-of-phase, relative to the mid/high section. The default setting is in-phase, but I spent most of my time playing it in the out-of-phase setting. This setting seems to boost bass response from about 50Hz through 600Hz, but also reduced the response from 600Hz to about 1kHz. The default setting is perhaps a bit more pure/pristine, but when I powered the 210Flex with most heads, I liked the added low mids when setting the Voicing switch to the left. With at least one bass head (my Reeves C225), though, I definitely preferred the default (in-phase) setting. Once again, it’s nice to have options.

Those Faital Pro W6N8-120 mids are very potent, with a stated frequency response range of 100Hz to 10kHz, making them great choices for bass enclosures. The cross-firing configuration, combined with the MVW design, allow the MAS-210Flex to fill a room much more uniformly throughout the mids (compared to “conventional enclosures”). Rather than risk the potential tone/performance-stealing impacts of a rotary attenuator for the mids, Mike and the Big E guys have opted for a series of switching options (which rely upon high-performance capacitors, inductors, and other wiring configuration tweaks) to control the midrange performance. The right middle switch, which allows you to select between Bright and Neutral (default) settings, is a very powerful control. The Bright setting adds a lot of upper midrange through lower treble. I preferred the response in the Neutral position, but I can see where the Bright setting would be very useful if you were going after a more aggressive tone, or if you needed help cutting through a given mix in a given room. The tonal impacts of engaging the Bright setting definitely varied in relation to where the Voicing control is set, so be sure to experiment a bit and see which combination of switches works best for you. The left middle switch, under the “arming” cover, can engage the Dark setting. This is a very subtle difference, and it takes a small bit off of the middle mids. Once again, I preferred the default (off) setting, but it did help smooth things out a bit when the Bright switch was also engaged.

The MAS-210Flex is capable of very smooth, yet extended highs. It is truly one of the most beautiful cabs I have heard when it comes to high-end presentation. Oftentimes, cabs with a “smooth” top end get this by being a tad shy in the treble range. In its default (one tweeter) setting, the 210Flex is not at all shy in this range, but there is no hint of harshness or brittleness. The 3-way Tweeter switch lets you bring the second tweeter into play, or take them both out of the equation. With both tweeters engaged (the far left setting), the cab gains a bit more sparkle and presence, and a little more edge to the attack of the note. There is still a good bit of high end extension (up to about 6-7kHz) with both tweeters turned off.

Okay, so we have the frequency range piece of the puzzle solved. How about overall output and power handling? Can it deliver the goods from an SPL perspective? Boy, howdy, can it! The 900-watt power handling tempted me to hit the 210Flex hard, and whenever I did, it hit back! Not only does it seem more than capable of handling 800 to 900-watt (solid state) heads, but it will pummel you for being foolhardy enough to stand in the same room when you try it. Not that it doesn’t sound good at lower volumes (it certainly does), but this is a cab that really likes to be pushed hard. In addition, unlike some vented enclosures, the 210Flex really shines when pushed with tube amps, as well.

Broad frequency range? Check. Ability to dial in a range of tones? Check. Does it get loud enough? Check. Hmm … What else? Oh, yeah; does it fill a stage, or can you only hear it when you stand in the “sweet spot?” One of the obvious goals of the Big E Loudspeaker designs is excellent off-axis response. The Manipulated Vortex Waveguide alignment – also referred to (by Big E Loudspeakers) as a “Frequency Independent Virtual Compression Labyrinth Horn” – claims to produce a “de-correlated reverberant field.” The Big E Loudspeakers webpage claims the following specific benefits over more conventional designs:

  • Increased loudspeaker sensitivity
  • Greater perceived clarity
  • Enhanced spacial immersion and imaging
  • Enhanced dynamic response
  • Reduction of adverse environmental interactions

My personal observations – over the course of playing the cab in multiple rooms, with multiple bands, using a range of basses and amps – would seem to jive with these claims. I definitely noticed that the bigger the room, the more obviously these traits stood out. However, even in very small rooms, the excellent off-axis response was very apparent. There is absolutely no need to be concerned about standing in the “sweet spot” with this cab.

Comparatively Speaking

The MAS-210Flex certainly seems to have a lot going for it, but like all bass gear, the best way to evaluate performance is to actually use it. Much as Mike and I found when playing through the MAS-85 and MAS-110Flex, the 210Flex sounded at least competent with pretty much everything I used, but it definitely had some amp pairings which were more favorable than others. The TecAmp Puma 900 is an exceptionally good match, which comes as no surprise, as Mike is very familiar with this particular amp. The smooth, full and solid Markbass F500 was another favorite combination. For whatever reason, though, my Glockenklang Bass Art Classic (normally a favorite of mine) didn’t make for as impressive of a pairing. On the tube amp side of the equation, I previously mentioned that my Reeves proved to be an excellent match, as did an old Trace Elliot VA400. Since not many cabs are wide enough to look “right” sitting beneath it, I had to try my old Ampeg V-4B with the 210Flex, and it was a nice pairing, with very present, growly mids, and plenty of low-end meat.

I compared the MAS-210Flex to a variety of enclosures, but it’s hard to find an apples to apples comparison. I did find two such comparisons worth mentioning, though. A pair of Bergantino AE210’s is about the same size as the MAS-210Flex (as are many 4×10’s). Compared to my 2xAE210 stack, the Flex (set to its default settings) seems to go deeper, but the AE210’s are more full in the low mids. The 210Flex is more smooth and clear in the upper mids and highs, while the Bergantino cabs are more present and articulate through the meat of the midrange. Overall, I felt that the MAS cab was “prettier,” while the Bergs were “punchier.” The other comparison was to the Mesa/Boogie 4×10 Traditional Powerhouse™ cab. I had been using this cab at one of my bands’ practice room, and when I brought the MAS-210Flex to practice, it was a simple thing to try them out, head to head, in a band setting. While the 210Flex is by no means a thin-sounding cabinet, the Boogie had a lot more going on the middle of the low end up through the lower-to-middle mids. The Flex, on the other hand, was much more articulate and present in the upper midrange.

At my last gig, I paired the MAS-210Flex with a Mesa/Boogie Strategy tube head. I knew going into it that this was one of the most “acoustically challenged” venues that I play, with a low, flat ceiling addition (where the band sets up) opening into a larger, arched-roof Quonset hut-style room. Normally, the lows to low mids are boomy and out of control in the addition, while the mix is thin as heck in the main room. Out of the gate, the 210Flex’s tight, controlled lows and midrange clarity helped the situation a great deal, but it was the Strategy’s graphic EQ which really saved the day (serious cut at about 80Hz helped a lot). Even when “hamstringed” by a drastic cut in the meat of the lows, this rig sounded big and powerful. I wasn’t able to let this rig “run free,” though, and kept a hand on the reigns. Clearly, both the amp and the cab would have loved to have been played even louder. But this level of control served the mix well. In fact, one of my bass-playing friends in the audience commented how my bass tone is “always big and full, but still tight.” Mission accomplished.

The Bottom Line

Sometimes, it’s easy to get caught up in “the next great thing,” but the products fail to live up to the hype. Sometimes, ideas that look great on paper, fall on their face in “the real world.” Sometimes, laying on the techno-babble too thick leads to a product that is all tricks and no treat. Any concerns that my review of the MAS-210Flex would fall down one of these rabbit holes were quickly and decidedly put to rest once I was able to spend some “quality time” with this cab. As I remarked above, it does just about everything well, and it does a number of things exceptionally well. You can cover a huge range of gigs with this cab. Yes, it’d be nice to get all that performance in a more easily transported package, but Mike Arnopol has you covered, there, with the MAS-210Mod & MAS-110 modular system. Thomas Ewers and Stephen Regier make some strong claims when describing the benefits of their Big E Loudspeakers and the Manipulated Vortex Waveguide alignment. After hearing this technology in action (and in the context of multiple cab designs, no less), they certainly seem to be onto something good. Whether you play double bass, electric bass or both, Big E Loudspeakers and Michael Arnopol Soundworks have a design for your application. I suggest that you plan a little road trip of your own and find a way to audition these cabs. Trust me, it’ll be worth the gas money.


Features: 5
Tonal Flexibility:5
Ease of Use: 3.5
Tone: 4.5

In-hand Score 4.35average


This cab can do it all, from a sonic perspective. The off-axis (and all around the room) response is very balanced and even. It is full and articulate, and generally smooth, though it can get more aggressive with certain settings.