Redefining PA System Control
By DJ Madeline
I have always been curious about the DriveRack PA+ and dbx's claim that it's everything I need between my mixer and my amps. They call it a complete speaker management system with a crossover, compressor, limiter, pink noise generator, and subharmonic synth, plus three separate Wizards including Auto EQ, Automatic Feedback Suppression (AFS), and system setup with popular amp and speaker presets. It sounded too good to be true and seemed like a bit too much to spend on my smaller system. Still, when Musician's Friend asked if I wanted to give it a go, I jumped at the chance to test the hype.
Well, it's not hype. This thing is a dream come true. Besides eliminating the need for extra gear, it was a snap to set up and sounded great. It sweetened the highs, tightened the bass, and all frequencies were perfectly balanced--never too much of one or the other.
The life-saving setup
My DJ buddies and I were surprised such a feature-packed unit was only one rackspace when we took it out of the box. After rounding up some XLR cables, we hooked up two outputs from a mixer and went out to two JBL MP225s through a Crown CE2000 amp and to a JBL MP418SP powered sub. Once the DriveRack was hooked up, we could do everything from the intuitive buttons on the front panel.
The DriveRack PA+ has presets for JBL and Crown (among other popular brands)--which is exactly what I have and is one of the reasons I've looked into getting the unit. All we had to do was press the Wizard button and it walked us through a series of system selections, where we dialed in our amp and speaker presets.
The amazing Auto EQ
Now it was time to test the vaunted Auto EQ Wizard, which feels out the performance space using the pink noise generator and the optional Real Time Analyzer (RTA) reference mic to automatically EQ the room. The Wizard walks you through equalization for the room with a flat frequency response or a choice of preset curves (we liked Response A).
The guys at dbx recommended dividing the audience area into thirds and placing the RTA mic between the first and second thirds. Also, they said it should be slightly off-center to avoid standing waves. We connected the mic, adjusted the pink noise level to our program level, and let the DriveRack PA+ do its thing. I can see why this is such a talked-about feature--it's quick, easy, and works wonders on a room.
The room sounded worlds better but we were getting a bit too much bass. I suspected the MP225's large bass output was to blame, so I decided to manually EQ the bass bands. dbx recommended using the high-pass filter to adjust only the high frequencies with the Auto EQ so it could work its magic. Then I included the low frequencies in the mix, threw a record on the Technics 1200s, and manually EQed the bass bands to perfection. The bass still sounded a bit growly, so we simply turned down the 36-56kHz subharmonic synthesizer level. Now we had it-smooth, deeply extended bass.
Putting AFS to the test
We couldn't wait to see how well the Automatic Feedback Suppression (AFS) Wizard did its job--pinpointing the exact frequencies causing feedback and automatically reducing them. We selected how many filters out of 12 we wanted to be Fixed (six) and permanently assigned them to a known feedback-causing frequency, leaving the remaining six Live filters to dynamically detect and remove feedback frequencies as the show went on.
We decided to really test the DriveRack PA+ by trying to get feedback using a Shure KSM27 mic. The AFS performed surprisingly well. We also turned up the mixer gain way past our program level and found it was silent--no hum--until it was almost all the way to the top! The hiss reduction alone is cause enough to treasure the DriveRack.
Another thing I love about the unit is the versatility it offers. You can get a great sound with minimal live sound knowledge using the Wizard sections. At the same time, it offers experts the ability to go in and fine-tune each of the settings to perfection. The six XLR outputs can be configured to handle a variety of system sizes and configurations. With the DriveRack PA's 25 factory and 25 user presets, when you finish a particular setup, you can save your settings and easily dial them in next time.
Worth every penny
DriveRack PA+ might seem a bit expensive for a beginner's sound system, but I would recommend it even to a small band buying their very first system. It'll actually save you money by including features you would have to buy as additional equipment along the way, such as limiters, dedicated EQs, and compressors.
I'm certainly kicking myself for not getting a DriveRack sooner. It's going to replace a whole lot of my gear. If you already have a system, the DriveRack will make your life easier, plus it will take your sound up a notch with the subharmonic synth, pink noise generator, and feedback suppressor.
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