Sonarworks: Reference 3 speaker & headphone calibration software

It goes without saying that our studio monitors, be they speakers or headphones, influence the sound of our productions more than any other processor, instrument, or device. Recently, the technologies of speaker system design and advanced materials have allowed manufacturers to produce accurate monitors at every price-point. Once our speakers have been chosen and the room has been acoustically treated, we listen, adjust, tune, equalize, re-treat, and repeat until our mixes translate (reasonably) well to other playback environments. For most of us, however, there are practical limitations to the type of monitors we use and the amount of room treatment we can employ. Even in world-class rooms with the most esoteric systems, providing the most accurate playback requires lots of expertise and time spent adjusting speaker placement, acoustic treatments, and possibly room EQ. Sonarworks, a new company from Latvia, has developed a product to simplify the process of bringing our playback system to the highest level of accurate playback. Reference 3 allows novice and seasoned users to calibrate their speakers and headphones. 

Sonarworks Reference 3 software consists of three components: speaker and room calibration software; speaker correction plug-in; and headphone correction plug-in. Additionally, the full kit includes a Sonarworks calibrated measurement mic. The software walks the user through room analysis and then generates a unique plug-in preset which provides correction for the specific monitors as measured in the room. The headphone plug-in will correct the response of many commonly used professional headphones. Headphones with individually measured response curves may be purchased directly from Sonarworks. Each headphone comes with a unique plug-in preset which matches that exact headphone. Alternatively, an "average" curve, derived from many sets of a particular model of headphone, may be applied to match your existing headphone. 

In use, the Reference 3 software (Windows and Mac OS) walks the user through the steps of setting up the reference mic, choosing appropriate monitor levels, and measuring the room response at 24 positions around the main listening area. The software produces bursts of clicks, which are used to calculate the mic's exact position in the room, along with short frequency sweeps, which measure the perceived acoustic power, or apparent frequency response of the speaker in that room. After completing the measurement steps, which takes 5 to 10 minutes, the software generates a user-named plug-in preset. The Reference 3 plug-in running in your DAW uses this preset to correct the frequency response of your speakers. Multiple plug-in presets may be generated, for different monitor sets or listening positions. The plug-in itself, which is available for AU, VST, RTAS, and AAX Native hosts, lives on the master monitor fader in the DAW. This may be a bit confusing at first — you don't want to bounce your mix through the Reference 3 plug-in; you just want to listen through it to hear your corrected room response. Each DAW provides a different method for routing master and monitor faders, so you'll have to determine the best way to instantiate the plug-in for your system. Alternatively, the plug-in may simply be bypassed during the final bounce to avoid printing the mix with your room EQ. I found a simple routing setup in Pro Tools to insert the Reference 3 plug-in on my monitor output while my mix bus (bounce path) remains unaffected by the plug-in. Unfortunately, other sources besides your DAW, like an MP3 player or iTunes, will not be heard through the room correction software — that would require an external processor (running Sonarworks) between your monitor controller and speakers (hint-hint, Sonarworks!), or routing your playback device through your DAW. 

Sonarworks Reference 3 software separates itself from other speaker calibration software in a few different ways. First, Sonarworks provides linear-phase equalization, which minimizes the phase distortion and artifacts that traditional equalizers produce. Second, Sonarworks provides up to 16,000 EQ points for precise correction. Third, the software lets the user adjust or "voice" the EQ preset to tailor settings for a desired response. This voicing may simply turn up the bass (or treble) because you enjoy it, or you can apply stock presets which allow your measured speakers to emulate the frequency response of some other typical studio monitors. This, to a large degree, lets you hear what your mix may sound like on other common speakers. These same principles apply to the headphone plug-in, except that users aren't able to measure their own headphones — Sonarworks can do this for you, or you can choose a typical response curve for your specific model of headphone. 

I have spent many hours tuning my room with real-time analyzers and room analysis software, adjusting my crossovers, subwoofer level, speaker positioning, and acoustic treatment until I was most satisfied with my monitor system. I typically try to avoid room equalizers, except for gently tweaking soffit-mounted main speakers in well-tuned rooms. After installing Sonarworks Reference 3, I can honestly say that my room sounds noticeably more accurate. I hear better stereo separation and imaging, smoother overall frequency response (especially at the subwoofer crossover point), and even some additional perceived height information. My long-time clients have commented on how well my recent mixes have translated to their playback systems, which bolsters my confidence during mixing and mastering. I believe it is important to fix acoustic and electronic issues in the room and playback system first; and then adding Sonarworks Reference 3 provides a very noticeable improvement in an already well-balanced system. I have applied Reference 3 to more than five different rooms, including low, mid, and high- priced monitor systems, and every room's accuracy benefitted from the software. After several weeks of using the plug-in on my own mixes and masters, I can't find any noticeable artifacts or limitations that I have previously found in other software-based room correction. 

As with any plug-in, latency is possible, and Sonarworks provides three modes of accuracy versus latency. The lowest latency setting produces a monitoring delay of around 1 ms, while the most accurate setting produces about 60 ms of delay. Obviously, for tracking and programming, the lowest latency setting is essential, but for mixing and mastering, the greater latency is not a problem. I found all three latency/accuracy settings provided similar improvement to the sound of my monitors, though each of the three settings produces its own extremely subtle tradeoff between frequency and phase-response accuracy. 

The Reference 3 plug-in provides many useful features, like graphs of the before and after frequency responses, the correction curve, as well as more esoteric information like dynamic range limits and phase-response graphs for those who desire to view such information. This effective plug-in may be used in a very simple plug-and-play way, or you can delve under the hood for finer tweaking, experimentation, and useful feedback about your system. A professional room tuning can cost hundreds up to thousands of dollars, while this simple-to-use tool from Sonarworks brings a high level of accuracy to your room for much less. I highly recommend this software as a finishing touch in any room.