December 2007 Issue
Road Tests

BBE DS24 Speaker Processor

The BBE DS24 speaker processor intrigued me because of its low cost (around $299.95 street) and its professional looks and performance. The BBE name is famous for its Sonic Maximizer processors, a hotly contested piece of gear that some engineers dismiss as a crutch and others swear by as a gig saver. Now BBE is putting its substantial experience behind universally accepted gear, including equalization and DSP speaker processing that may have even the skeptics taking a good hard look….


 

The DS24 starts out with an eye-catching red-brushed aluminum front panel with the LCD, switches, rotary encoder and LED bargraphs, making it obvious that the product is a speaker processor from its look and feel. The backlit two-row monochrome LCD with adjoining six editing switches (back, next, menu, enter, gain and quit), plus the rotary encoder for parameter adjustment, provides plenty of menu-surfing capability. The two signal inputs and four signal outputs get a seven-LED bargraph treatment (-30, -24, -12, -6, -3, Limit, Clip) with the output having mute switches below the bargraphs. A conventional curvette rocker on/off power rounds out the front-panel interfaces.

The back panel maintains the “all business” feature set, but with black paint and white legends. Prominently featured are the two XLR-F balanced audio inputs and four XLR-M balanced audio outputs for handling the typical ins and outs expected of this basic speaker processor design. A nine-pin D-sub serial port connector (RS-232) is also provided for standard personal computer interfacing with the included SYSOMAX software for graphical control of the processor’s parameters. After the RS-232 interface, the obligatory (and welcome) IEC inlet is evidence that the DS24 will have the power supply and signal headroom like other professional speaker processors.

The Gear
The BBE DS24 uses quality 24-bit analog to digital to analog converters working at 48k samples per second with low-latency conversions. With this knowledge, the 0.01% THD and 110 dB dynamic range are easily met. The downside of the DS24 design is that the maximum signal levels handled are 7.6 volts peak to peak (~14.6 dBu). While 14.6 dBu is plenty enough snort for most power amplifiers, it is not the usual +22 to +28 dBu advertised by many other professional speaker processor manufacturers.

The DS24 includes most of the essential speaker processor elements needed to get the job done. These processing elements are: gain adjustment on the inputs and outputs; polarity flipping; pass and crossover filters for Bessel (12/18/24/48 dB), Butterworth (6/12/18/24/48 dB) and Linkwitz-Riley (24/48dB); parametric eqs; output delays; and a flexible limiter. A couple of limitations caught my eye in checking out the DS24. First was the 0 –7-millisecond output delay element in 0.5 millisecond increments. To me, this means there is about a six-inch distance correction for each increment of delay — quite a bit less resolution than I would like when phase matching the voice coil displacement in speaker cabinets. A better compromise would have been 0.1 millisecond increments (resolution), but over just a couple of milliseconds of range. Also, the DS24 could have enjoyed a much longer delay range, up to a second, for setting up delay speakers in a large venue scenario.

The second niggle I ran into is the 31 ISO frequency choices on the encoder when setting up the parametric filters. When jogging the encoder fast, I noticed better resolution, but it was thwarted when the speed was reduced to home in to an exact frequency. Here is an instance where a better feature could have been designed for no extra recurring cost. Also, the encoder detenting had in-between settings that concerned me. This may have been a case of good design intent and cost cutting at production.

The Gigs
The important part of the BBE DS24 is its performance once set it up the way I want it. In both the shop critical listening and out at the clubs, the DS24 performed very nicely and compared well to much more expensive speaker processors. The metering was easy to read and useful, and the audio quality was clean and without noticeable artifacts.

In weighing the technical issues and the outstanding aural performance, it really depends on your sense of frugalness versus your technical scruples. On the negative side, you are battling issues like dBV scaling, encoder resolution, delay resolution and limited parametric frequency settings. On the positive side, you are getting a ton more flexibility than a standard analog crossover, with pristine audio added in for a bargain price. I would offer the proposition that cost-conscious sound engineers would jump at the BBE DS24 from the value standpoint, while fussy and less frugal engineers would take a pass to fuller-featured speaker processors.  

What it is: Economy speaker processor.
Who it’s for: Budget-minded soundco’s needing solutions for bi-amping, tri-amping.
Pros: Nice looks, great price, quality audio processing.
Cons: Limited delay and parametric selections, encoder detenting.
How much: $429.00.


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