The orange curve shows the originally measured room responses and indicates an audible bass boost around 70 and 150 Hz. The white curve shows ARC''s corrected output.
As a self-taught acoustical architect and designer, I've never been a fan of EQ for tuning studios, largely because the response of a room can change drastically over very small distances, and EQ alone doesn't take into account time-related issues such as modal ringing at bass frequencies and phase response. I prefer to fix the problem by treating the room with substantial amounts of acoustic materials. Granted, not many home studios have the budget or space to line walls and ceilings with two feet of bass traps and diffusion materials. Now IK Multimedia has partnered with Audyssey Laboratories to introduce ARC (Advanced Room Correction) System, which boldly claims to address frequency, as well as positional and timing problems as well.
ARC System consists of a calibrated measurement microphone, stand-alone measurement software powered by the Audyssey MultEQ room correction algorithm for capturing sound information and calculating proper room correction and a multiplatform plug-in that applies the correction. Installation was a snap, and the step-by-step measurement wizard executes brilliantly. Basically, once you've mounted the calibration microphone vertically (using the included mic-stand clamp) at ear level when in seated mix position, the measurement software instructs you to select the input on your audio interface and the outputs that are going out to your speakers. The interface must have a phantom-powered input (preferably noncoloring and not through a tube preamp), some sort of manual output level control and be capable of working at 48 kHz.
Following a short calibration process to set reference levels, the measurement wizard instructs you to place the microphone in the “main” position — the sweet spot where you normally mix. ARC performs a quick series of full-frequency spectrum sweeps the left to right speaker. That's measurement number one of a minimum of 12 you must take at multiple placements within the listening zone, so the measurement software averages a good overall picture. While the program allows as many as 32 measurements for optimum accuracy, I took 18 within my listening space, placing numbered pieces of masking tape on the floor ahead of time. Measurements have to be done in a specific symmetrical pattern, so you must read the excellent manual thoroughly for successful results.
After 20 minutes of measurements, I had the program calculate the response and save it as a preset, giving it a unique name and also assigning a representational picture of the speakers (Mackie HR-824s). It's cool that you can repeat the process again for other sets of speakers or for other listening positions within the room (such as a client couch) and save them as additional measurement sets. You can even perform tests that take into account multiple sweet spots within the room at the same time.
With analysis complete, open your DAW and put the Correction plug-in in the last slot of the stereo master bus. With graphs for both left and right speakers, an orange curve represents the original measured room response; green shows the ideal “target” curve; and white shows the corrected output calculated by MultEQ. You can select from four target curves, including a perfectly flat response and a few high frequency — rolloff curves that compensate for excessively bright rooms. Hit the Correction On button, and you're off. Remember to remove the plug-in from the master bus prior to rendering the song.
HEAR THE DIFFERENCE
I tested ARC in a carpeted room with acoustic-panel treated walls, several corner bass traps, an 11-foot floor-ceiling plate and a fair amount of gear and furniture.
With MultEQ correction turned on, it was as though I'd thrown on a pair of my best headphones. Stereo imagery snapped right into place; mids became clearer and highs were far less fatiguing over long sessions. With ARC squashing those bass peaks, the room lost much of its artificial boom. Tracks I'd finished in my professionally treated mix studio translated much better into the edit suite, and vice versa. Indeed, the room was now much flatter. Also, I could lean several feet to the side or back and enjoy a larger sweet spot than before.
Many bedroom producers may balk at the street price of around $600, but IK is offering a price of $499 if you own another IK product. It's a smart investment for your music — one you can use to correct any room in the future. You also get a great calibration mic. Ultimately, ARC lives up to its promise of producing a sound you can trust, so you can achieve a clearer mix.
ARC > $699
Pros: Impressive frequency and time correction creates vastly more accurate and larger sweet spot for mixing. Addresses multiple listening locations with savable presets for different speakers. Simple to execute.
Cons: Doesn't work with surround monitoring systems.
Mac: G4/866 MHz or Intel/1.5 GHz; 512 MB RAM; OS X 10.4.4 or later; RTAS, VST or Audio Units host
PC: Pentium/1 GHz; 512 MB RAM; Windows XP/Vista; RTAS or VST host