Review: Bose Professional AMM Series
Solidly built, passive, two-way co-axial point source speakers (and sub) that let their performance do the talking.
Review:/ Mark Woods
Bose is known for its R&D-led lateral thinking, and Bose Professional live sound products have provided some notable examples over the years. For those who were there, the 800 Series from the early 1980s (onwards) was a fitting introduction to the quirky side of Bose – 8 x 4-inch drivers controlled by a processor was certainly different to other live speakers of the time. The Bose L1 from 2003 introduced the portable line array ‘stick’ system (and remains the ‘yardstick’ for many in that category). The Bose F1 Flexible Array from 2015 is a hybrid active two-way point source speaker that controls the vertical coverage by angling the top and bottom sections of the cabinet — again, something out of the ordinary.
The most unconventional systems have been the smaller portable speakers. Bose large-scale ShowMatch and ArenaMatch array systems arguably present as comparatively conventional designs backed by Bose ingenuity. Somewhere in between the smaller portable systems and the bigger PA systems is the new Bose AMM Series multi-purpose speaker range.
The range consists of only three models — the AMM108 and AMM112 full-range speakers and the accompanying AMS115 sub — but between them can cover all the common audio tasks: FOH, foldback or fill. Designed to be portable or installed, with voicing consistent with Bose ArenaMatch array systems and the ArenaMatch Utility range of two-way speakers, the idea is to create convenient, scalable, mix ’n’ match options for any size production requirement.
Bose may well be known for its distinctive designs but AMM presents as classic, almost old-school — passive, two-way coaxial point source speakers in a chunky wedge-shaped Baltic pine cabinet (without a hint of Bose branding on the front). Finished in an unpretentious polyurethane coating without any plastic styling embellishments or tricks. Simple and focused. Bose sees these products residing in professional settings where keeping a low profile is still seen as an advantage.
The classic theme continues with the sound. Bose recommends using AMM with the model-specific presets in the Bose ControlSpace DSP, included in Bose PowerMatch/Powershare amps or in stand-alone Bose processors, but they can be used without and, if you choose to do so, they’re quite entertaining.
Compared to the massaged output of processor-controlled powered speakers the unprocessed sound is refreshingly raw and responsive. The coaxial design delivers inherently coherent results while the drivers provide high-power handling and efficient units. Used as bare speakers in a box, the frequency response is not exactly linear and they do need a bit of EQ — there are a couple of spikes around 1.6kHz and 4kHz that could cut cheese if left unattended — but once tamed they develop a lot of sound with a clear, in-your-face delivery. The processor does it for you and adds protection too but it’s good to be given the choice.
Product Title H4
Sub Title H5
Passive design won’t suit many
It’s ‘back to the future’ for Bose Professional with this no-nonsense range of passive, coax loudspeakers. Not a ‘category buster’ but extremely competent in a wide range of portable and installed live sound duties. A cut above.
these are genuine high-power, multi-purpose speakers based on classic point source design in no-frills, practical cabinets
The AMM108 is the smaller model, almost cube shaped, and only a foot square in the old money. The 1.7-inch compression driver is mounted in front of an eight-inch woofer using a shared magnet design that helps maintain phase between the drivers, and reduces intermodulation distortion. The 110° x 60° dispersion is shaped by the Bose Beamwidth Matching Waveguide, it looks like something out of ‘Predator’ but its purpose is to align the high and low beam widths through the (passive) crossover region. Weight is 13kg, power handling is quoted as 150W long-term/2400W peak at 94dB sensitivity for a calculated max SPL of 116dB (121dB peak).
The AMM108’s output belies its footprint. The first time I used it was as an in-fill for the front section of the audience and it had plenty of volume with outstanding clarity and intelligibility at all levels. Some EQ was needed, it had a chunky Lab-clone amp driving it and proved an ideal speaker for the in-fill application — small enough to preserve sight lines but also able to handle high level peaks without distortion, if required.
As a foldback wedge the AMM108 is instantly likeable. It looks somewhere between cute and tiny on an empty stage but when the band is set up and they’ve got pedals and other paraphernalia strewn across the stage, it looks just right — the other traditional wedges look unnecessarily bulky. Throw angle is the usual 35° and the outstanding coherence delivered by the coaxial design makes vocals super present with high resistance to feedback. The bands were impressed.
The AMM112 is the larger full-range speaker and it’s a step up in every way. The 12-inch woofer and three-inch compression driver need a 50% larger cabinet than the AMM108 and it’s near twice the weight at 22kg. Power handling increases to 300W long term/2800W peak at 96dB sensitivity for max 121dB (131dB peak). The speaker can be switched to run passively through the internal crossover or bi-amped via an external crossover.
The first time I used the AMM112 was as a floor wedge with Ash Grunwald. Straight out of the box, a quick tune and, like the AMM108, the response was crisp and bright across the high-mids with no sense of being near the limit at average/high stage levels. The benefits of the coaxial design are evident working close to the speaker: traditional ‘horn on top of woofer’ designs exhibit noticeable phase changes between the components when the performers move around in front of the speaker, especially general purpose two-way speakers laid on their side. Coaxial speakers sound on-axis across the working area. Ash liked it, used it, and “it sounded awesome” was his comment after the show.
Completing the range is the AMS115 compact sub. It’s a direct radiating, ported design with a 15-inch long-throw neodymium driver in an enclosure measuring 470 x 470 x 500mm and weighing in at a manageable 28kg. Frequency response is quoted at 40Hz–100Hz (-3dB) with power handling at 500W long term/2800W peak for 123dB/130dB SPL. It takes a bit more thought to get going. It seemed low in level compared to the full-range speakers at first but once pumped a bit it was a good match with impressive power handling and a fast, accurate response. An AMM115 sub with an AMM108 on top makes a great full-range system. I enjoyed using this combination as a delay system half way down the Castlemaine Town Hall for the 2022 Spring Ball.
The AMM Series speakers can be used as portable systems but they’re beyond ‘throw-in-the-back-seat powered speakers’ type of portable. They’re the next step up in quality and price, and while they’re efficiently sized, they need at least amps and some processing. I’d suggest they’re better suited to professional production suppliers or installations where the AMM quality and scalability can be most valuable. Passive speakers often have advantages in these applications. Foldback is neater with passive speakers. Half a dozen of either of the AMM full-range speakers and one on top of an AMM115 sub for drumfill would make a powerful, flexible and coordinated foldback system (add more to scale up and throw in infill, if required).
Installations are made easy with a range of mounting options including 6 x M10 threaded inserts, a U-bracket and a suspension kit plus 4 x M8-threaded inserts for a pan-and-tilt bracket. The 110° x 60° dispersion can easily be changed to 60° x 110° by rotating the cabinet. For portable applications, both the AMM108 and AMM112 have pole mount sockets tucked away besides the handles. The Sub1 Adjustable Speaker Pole screws securely into the M20 threaded pole mount on the top of AMM115 sub. That’s a big improvement over the usual floppy pole sockets. The top half is like a regular speaker stand with adjustable heights and a locking pin, and that’s better than a fixed-length pole.
Overall these are genuine high-power, multi-purpose speakers based on classic point source design in no-frills, practical cabinets. Bose Professional seems to be aiming for a larger space in the pro audio world, the AMM Series will give them some street cred.