Some years ago, when I was first exposed to the concept of incorporating power amplifiers into loudspeaker enclosures, I scoffed at the idea. What could be more hostile to a circuit board (with all the solder joints and attached components) than to be placed inside an enclosure that was producing copious amounts of low-frequency energy?
In the ensuing years, loudspeaker manufacturing trends have continued to move in the direction of incorporating power amplifiers (and, in some cases, speaker processing) into cabinet design and, as best I can tell, my previous apprehensions have been nullified by years of reliable operation.
Having produced excellent passive loudspeakers for many years, Bag End has begun to produce active speakers, too. Notable among those products, the P-Crystal R is a full range/mid-high box that incorporates a powerful amplifier and pro-grade components into a robust enclosure.
The P-Crystal’s cabinet is a trapezoidal affair that measures 39.5 inches high by 14.5 inches wide by 17 inches deep. The box is a two-way vented enclosure, housing two 12-inch woofers (top and bottom) and a 1.4-inch exit compression driver with a 3-inch titanium diaphragm (center). It also has a substantial onboard power amp mounted in the rear. All these components, combined with a stout 13-ply birch shell, yield a hefty weight of 115 pounds. The cabinet features a Rotex finish and has protective end caps that shield the top and bottom from surface damage. It is also outfitted with quick-release rigging points, handles, and a stand adapter (but it better be one sturdy stand).
The P-Crystal has a somewhat focused dispersion area with 55° of horizontal and 40° of vertical coverage, making it suitable for longer throw applications. The cabinet features a claimed frequency response of 80 Hz-18 kHz (+/-3 dB), a maximum acoustic output of 130 dB SPL, and an internal crossover that is centered at 1.9 kHz and utilizes Bag End’s proprietary Time-Align process, claimed to improve overall clarity.
The onboard amp is Bag End’s proprietary Minima One power amp. It features a switch mode design and, with minimal heat generation, has no cooling fan. By nature, the amp is professed to be very efficient (as switch mode amps are) and can operate on a wide range of incoming AC voltages (88-270 volts). It has a claimed output of 1,000 watts when presented with a 4-ohm load, and the amp is responsible for only 6 pounds of the overall cabinet weight. The amp module has an XLR input, an XLR thru, a Neutrik PowerCon AC input, a high-pass filter (6 dB down @ 8, 50, or 95 Hz), a mute switch, an input sensitivity control, and a modest three LED display to indicate power, limiting, and fault.
My first impression of the P-Crystal was not a sonic one. Rather, it was the strain of trying to lift the cabinet while it was still in the box. It is seriously dense for its modest size. My other initial impression was an admiration for its obvious prograde construction. The cabinet is attractive and robust with a sturdy grille and a nice, durable finish. While the end caps seem functional, they do generate a distinct look with upper and lower plateaus.
Given the P Crystal’s lack of low-frequency capacity (rated down to 80 Hz), I made sure to use the cabinets in situations where subwoofer augmentation was appropriate. The first instance where I used the cabinets was providing a small concert PA for legendary folk music performer, Pete Seeger. We spaced the P-Crystals about 35 feet apart (atop small subs) and placed a center fill between them (as well as other distributed cabinets around the venue). Pete performed with two other musicians who played guitars (acoustic and electric) and sang. In addition to singing, Pete played a 12-string guitar and his signature banjo. During setup, I played some familiar music through the system and found that the P-Crystals responded best when using a crossover point situated at 90 Hz (Linkwitz-Riley, 24 dB). As I walked the room during the sound check, I was struck by the Bag End’s excellent vocal clarity. On the stringed instruments too, the P-Crystals offered up fantastic images. The guitars sounded clean and open and intermingled nicely with the vocals. With house and zone EQs set flat, there was a stark difference between my moderately expensive center fill cabinet, so much so that I felt compelled to immediately go back to the EQ for the center fill and try to tweak it to match the clarity of the two Bag End cabs.
Later, to test the cabinets with some louder music, I brought the Bag Ends to a dance band performance. The band featured three lead singers, a three-piece horn section and a full rhythm section driving the band. The crowd of about 150 was in a coverage area that was about 40 feet wide and 65 feet deep. The P-Crystal’s horn dispersion was well suited to the hall, and the speakers yielded plenty of midrange punch and a very sweet top end in the semi-reverberant environment. Again, the boxes delivered excellent vocal clarity despite the congested mix that featured blaring horns, a cracking snare and a big dose of kick and bass. In the midst of one of the band’s most up-tempo tunes, I went over to assess the cabinet’s level of thermal stress. While not exactly scientific, I found that they were barely warm to the touch — impressive considering the output level at that point in the performance (over 100 dB SPL at one meter, according to my iPhone’s decibel meter). The cabinets had no trouble covering to a depth of about 50 feet from the stage, although there was a defined center sweet spot within each cabinet’s throw depending on horizontal positioning within the listening area (not unexpected with an enclosure that is geared to throw longer).
The Bag End P-Crystal R is truly a pro-grade powered loudspeaker and, at $3,480 street, its price reflects that. It delivers superb sonic images with a wonderful complement of drivers and a robust amplifier. The cabinet is rugged and attractive. The fact that the box has rigging points and can be horizontally arrayed makes it ripe for upscale installs. The P-Crystal’s efficient amp and superb sonics make it a great candidate for live sound work but, with such a hefty weight, it can be a modest challenge to transport and lift up onto a sub or a pole.
Andrew Roberts is a live-sound and recording engineer based in the Washington, DC area.