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John McJunkin on Sunburst Gear M3BR8 & M3R8

Rechargeable speakers deliver on portability, wireless technology integration, and good fidelity.

Most of the time we take it for granted that electrical power will be there. Nearly everywhere audio gear is used, we connect a three-prong plug to the wall socket, knowing we’ll get power. A generator is usually employed if there is no permanent power, and that is usually sufficient. However, sometimes, a generator simply will not do.

For example: a young lady wishes to be wed on the lush lawn just east of a golf resort’s 14th hole—several hundred yards from the nearest AC. A run of extension cords won’t do, and the bride wants zero noise or exhaust smell during her wedding, so a battery-powered system is used. Massive SPL isn’t necessary, but we will need to reach the guests in the 11th row, and we’ll need reasonable bandwidth—more than a honky bullhorn.

Sunburst Gear has introduced a system that meets these needs: the matched M3BR8 and M3R8 battery-powered speakers, and I am very impressed with them. 

I was struck with the heft of the M3BR8 and M3R8 as I unboxed them—the mass is owed to a handful of factors: batteries, magnets, and solid MDF construction chief among them. These magnetically-shielded speakers feel very solidly built, and their weight (M3BR8 – 23lbs., M3R8 – 22lbs.) is explained by these factors. They feature a 35mm receptacle at bottom for pole-mounting, and they’re wrapped in a textured covering in a way that I would describe as retro. In fact, the titanium-esque metal areas of the enclosure with controls and I/O have a modern labeling aesthetic, but the large metal knobs lend a retro flavor, as well. It’s a hip-looking design, both sexy and functional, with a minimalist carry handle of burnished metal across the top like a lunch pail.

On the rear panel of both models, from left to right, are two input “strips,” the first for channel 1, with a gain knob, ¼-in. TRS input jack, and XLR mic input. The second offers a trim knob, and two ¼-in. TRS jacks for a stereo input. To the right of the inputs is a ¼-in. TRS output jack, which passes along audio to an extension speaker. A pushbutton above this jack, used in conjunction with a pan knob, sends only the right channel so stereo can be accomplished. Below the channel strips are a power switch and a DC power inlet that powers and charges the speaker. Over to the right is a four-segment LED charge-level gauge. A red LED at the bottom indicates a low charge, and the three green LEDs stacked above it measure the level of charge up to maximum. A ludicrously over-bright blue LED to indicate charging is found below the gauge. (Sunburst Gear have already addressed the blinding LED issue and future speakers will feature tamer blue LEDs.)

Atop the enclosures of both models are most of the system’s controls. Looking at the panel as you would read text—left to right and top to bottom—there is first a master output knob labeled “speaker volume,” followed by a triangle of LEDs, indicating signal peak (lower left – red), signal presence (lower right – green), and power (top – again, the preposterously over-bright blue). Next are three cobalt-blue EQ knobs that boost or cut lows, mids, and highs by 15dB. Moving to the next line down, there is a ⅛-in. aux input jack and to its left, a knob determining level. Further right, another iteration of the red and green signal peak and presence LEDs, followed by level and pan knobs for channel 1. The M3BR8’s top panel also features Bluetooth indicator LEDs (one red, one extremely bright blue) and controls: buttons labeled back, next, mode, vol-, and vol+. To the right of this strip are a USB-B port and 2.4GHz Bluetooth antenna that can be folded down parallel with the top of the enclosure.

There are several analog ways to get signal into the speaker, but a truly standout feature of this system is the additional ability to introduce a signal either via USB or Bluetooth. Both protocols will be lauded by professionals who need to play back recordings. Our golf resort bride’s guests would very clearly hear Wagner’s bridal chorus, Mendelssohn’s wedding march, and the voices of the officiant, groom, and bride herself. A small, battery-powered receiver (think ENG) could be attached to an M3BR8 and used to grab RF from a mic (or two or three). A technician could fire musical cues at predetermined times from a Bluetooth-equipped mobile device carried in his or her pocket (or a USB-connected laptop would work too).

And if the bride wishes for the reception to be held on the lush lawn off the 14th hole as well, music for dining and a microphone for toasts and announcements are already in place. Only one cable of any kind would be necessary—that which feeds signal from the Bluetooth-equipped speaker to the extension speaker. It could be rigged wirelessly. There is no plan to facilitate channel-per-speaker Bluetooth due to audio quality degradation. I appreciate that Sunburst Gear has chosen to elevate quality over quantity in this case.

The post-dinner party with dance music loud enough for a small group could probably even be accomplished with just the addition of a battery-powered subwoofer to lighten the load on our M3BR8 / M3R8. There is no subwoofer currently under development, but it is under consideration. By the way, Bluetooth operation can accelerate battery depletion in mobile devices, but the M3BR8 actually has a USB-A port for charging the iPad from which the DJ may be spinning the hits, for instance.

Both speaker models are powered by shielded lead-acid batteries, which can be charged with household current by the included AC power supply or with automotive power by the included cigarette-lighter adapter. Both sources power the speakers directly if the batteries have no charge. Sunburst Gear publishes a play time duration of 15 hours on a full charge, which I discovered to be essentially true with one caveat—higher SPLs and cranked-up bass can both reduce that figure by an appreciable amount. Louder and lower both require the movement of more air, which in turn requires more energy, which in turn eats batteries more quickly. For more moderate applications, however, the play time is substantially longer than the charge time—indeed about 15 hours of playback based on a charge that took somewhat less than four hours.

So how do they sound? As an audio engineer who works in both studio and field, I’ve grown accustomed to the virtually universal rule that studio monitors, properly corrected for the acoustically-controlled environments in which they’re used, always sound vastly better than the speakers we use to disperse high SPLs to large groups of people in the field. Sunburst Gear has not developed the exception to that rule. But I will concede that these portable, battery-powered speakers are more closely related to studio monitors than they are to live-sound speakers. The porting in the enclosure helps the little 5 ¼-in. driver deliver low end that I would describe as surprisingly impressive. The high end is the tiniest bit brittle to my ear, but not brash or annoying. There’s an attenuation in the high mids—probably associated with the crossover frequency, but it’s definitely no deal-breaker. The three bands of equalization are helpful, but if more precision is necessary, you can set the EQ to zero and feed your own spectrally-sculpted and dynamically controlled signal to the speakers. They produce surprising SPL for speakers their size, and they only produce audible distortion under the circumstances that cause virtually all speakers to produce audible distortion.

The Sunburst Gear M3R8 and its Bluetooth-equipped sibling, the M3BR8, are truly innovative products, combining portability, easy integration with wireless technology, and capacity to deliver very good fidelity at meaningful SPLs. In order to accomplish this remarkable combination, compromises are necessary. But the exceptional achievement by the people at Sunburst Gear is that the compromises have been substantially minimized. The famous “good/cheap/fast – pick any two” Euler diagram used by project managers (and smart expectation managers) makes us all suspicious—we act as if exceptionally high-quality products are only produced by smoke and mirrors or violations of the laws of physics, and are hence not real and soon to be exposed. Yes, getting a full 15 hours of playback will require you to turn down the volume—especially the bass. And getting high SPL playback will reduce playback time—even more so if the bass is pumping. But you probably won’t need 15 hours of pumping bass. And in consideration of the other truly useful attributes the speakers offer, adjectives like “amazing” and “marvelous” begin to fill my mind. These speakers truly are amazing and marvelous.


Company:Sunburst Gear

Product: Sunburst Gear M3BR8 & M3R8 Rechargeable Speakers 

Pros: Impressive fidelity, portability, solid SPL, Bluetooth and USB inputs 

Cons: Could use the help of a subwoofer 

Applications: Small PA applications in locations with no AC power available  

Price: $349 (M3BR8); $279 (M3R8)


Drivers: LF – 5 1/4in.; HF – 1in. 

Amplifier: Class D Bi-AMP 

Nominal Input Level (1kHz): CH1: -60dBu; CH2/3: -20dBu; AUX in: -10dBu 

Nominal Output Level (1kHz): Right channel link out: -10dBu 

Power Supply: DC 12V  

Current Draw: 2000 mA 

Dimensions: 9’’x 9’’x14.5’’ 

Weight: M3BR8: 23lbs.; M3R8: 22lbs.

John McJunkin is the founding manager of Avalon Podcasting, LLC, and produces video for a variety of clients. He has consulted in the development of studios and installations and provides high quality podcast and voice production services.

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