There is nothing magical or strange about powered speakers—the amplifier has simply been relocated from a box that was in-between your console and speaker right into the speaker cabinet itself. The sound coming out will still reflect the signal coming into the speaker. It’s the same as it ever was.[box] Note: This article is the result of a recent discussion in the Pro DJ/MC Senior’s Tour* (facebook) regarding the pros and cons of signal processing. While processors (such as compressor/limiters and aural exciters) typically reside in a processor rack between the mixer and loudspeaker, there were several comments suggesting that, with powered speakers, no processing is necessary. Stu Chisolm decided to run with this and (with his permission) we reprint his comments here.[/box]
That said, most powered speakers have incorporated Digital Signal Processors (DSPs) that process the signal to match the speaker’s dynamics. Remember the Bose and EV passive speakers that came with an external processor back in the day? (I have some ancient EV S-200s that have a switch that selects between “with EQ” and “without EQ”) If your active speakers have a built-in DSP, then you ARE running a processed signal.
Start with a basic system calibration.
This is best done outdoors using a spectrum analyzer, pink noise generator and calibrated mic. This will allow you to actually SEE what your system is doing. All components must be ON, but set to neutral. (Aural exciters/Sonic maximizers set to “bypass” and EQs flattened at 0.) Then, with the pink noise running, (CAREFUL! TOO LOUD can KILL a speaker!) bring up the volume on ONE SIDE ONLY and adjust it to FLAT. When properly done, your sound spectrum should be a flat line. Repeat with the opposite channel. At this point, your system is acoustically neutral; you’ve eliminated any sonic artifacts introduced by your cabinets, cables, processing chain, etc. While sonically neutral, though, it will sound horrible at this point, since our ears are NOT acoustically neutral!
This is the starting point for “sweetening” the sound. Humans tend to suck at hearing the extreme ends of the sound spectrum, which is why you see equalizers set in the classic “V” or “smile” pattern. Short of having test discs/files, I just pick a piece of music that I know very well that has extreme low and high end content (mine are the old “Age of Love” techno track, along with Holst “The Planets” classical piece) and tweak until it sounds perfect. Unless you’ve got hearing damage, your ears are usually the best judges of sound you own. Mine do, sadly, so my tweaks are hawked by keeping a wary eye on the spectrum analyzer. Next, punch-in your other processors. Adjust as necessary until you’re 100% satisfied. At this point, your system is optimized. But wait… there’s more!
Every room “colors” your music.
The construction of the walls, floors, the floor covering (carpet, tile, wood, etc.), wall treatments, the type of cieling, the furniture (and chair/table coverings) and on and on ALL impact your sound. For us old schoolers, if your system has two EQs (one in the rack and one on the board or software) use THIS to tweak your sound for each room. Rather than run the whole pink noise profile in each room like I used to do, requiring me to arrive 45 minutes earlier, I instead run the analyzer and get my overall setting to look like it did when I optimized the system. What you see on the analyzer should also match what your ears hear. On those rare occasions when the two conflict, let your ears trump your eyes. Of course, when people arrive, it will throw the whole scheme off, but again, you’ve gotten as close to perfection as you’re likely to achieve.
One thing that has been a game changer since it was introduced is the The DriveRack PX Powered Speaker Optimizer from dbx. It has all of your processing in one unit: EQs; compressors; noise gates; limiters and on and on. Further, if you do decide to pink noise calibrate each and every room you frequent, you can then store the settings. If you change nothing, then your system can be instantly optimized to the room you’re playing at the touch of a button (It also contains auto-calibration software.) dbx has updated the unit as technology has progressed and does have a unit made especially for powered speakers. By the way, it’s inexpensive, especially when compared to the cost of having a whole rack full of gear. You can save a ton of money and weight. (And no, I don’t work for them or make a buck from ’em.)
Also See: Loudspeakers: Powered Or Unpowered by Jamie Rio[box type=”bio”] About Stu Chisholm: Stu is a 30 year veteran Mobile Entertainer, still actively entertaining throughout southeast Michigan. He is a well-known speaker and presenter at DJ Trade shows throughout North America and a regular contributor to Mobile Beat Magazine. His book, The Complete Disc Jockey details over a dozen different money-making opportunities for DJs. Stu’s career as a mobile entertainer began in 1979. Over the past 35 years he has worked in broadcasting, nightclubs, underground raves, skating rinks, and done commercial voice-over work and Webcasting. In The Complete Disc Jockey, Stu discusses techniques and gear, shares business, marketing and promotional ideas and talks about how to develop your own unique personality and performance.[/box]