When producing, mixing, or mastering, how frequently do you go out to your car and check your mix? Do you listen on three different headphones and a few different Bluetooth speakers? My answer to this question has changed over the years, and today the simple answer is that I don't feel the need to check my mixes anywhere outside of my studio. That is due to the fact that I trust that what I hear in my room will sound very similar on most other playback systems. I am fortunate to record in some of the best studios in the world, but I am more fortunate that when I mix and master projects I almost always work in my own studio. I know exactly what my room sounds like. I have the gear and plug-ins that I rely on and am intimately familiar with. When I used to record and mix in different rooms every day, I was much more insecure about my mixes translating well – I relied on car checks and a trusted mastering engineer to polish and verify my mixes. Over the years, I have tuned my room to sound great to my ears, and also to provide a sound that translates well to what others will hear on their systems. An important part of dialing in my monitoring has been implementing Sonarworks Reference 4 software for correcting the last bit of EQ imbalances in my speaker/room setup.

Since 2012 Sonarworks has been improving the sound in studios by providing software-based correction of the frequency response of speakers and headphones. Over the last seven years, the folks at Sonarworks have analyzed the real-world frequency response of speakers in thousands of rooms and hundreds different models of headphones, making Sonarworks perhaps the most experienced monitor testing company in the world. The result of all this testing is the development of Sonarworks Reference 4, a refined software product that essentially flattens the frequency response of monitors and headphones so that the sound we hear can be trusted and consistent.

Reference 4 starts by measuring the speakers' frequency response through a calibrated measurement mic, and then the software creates a plug-in preset that effectively equalizes the sound from the monitors for a flat frequency response. The Reference 4 Measure software walks the user through the measurement procedure with onscreen as well as audible instructions. The whole process takes about fifteen minutes. You can use your usual audio interface and mic preamp for this procedure. Headphones can only be measured in a lab so Sonarworks has created profiles for hundreds of different headphone brands and models, which are included in the software download. Alternatively, you can purchase individually measured headphones (from among more than 20 brands) with their own profile directly from the Sonarworks store. To apply the Reference 4 EQ to monitors or headphones, the Reference 4 plug-in is inserted on the master or monitor fader of a DAW. Alternatively, the Sonarworks Systemwide app can run without a DAW on the built-in audio output of Windows or Mac computers so that iTunes or any other audio source played from your computer plays through the room correction EQ.

The Sonarworks DAW plug-in interface provides a variety of user controls, including latency versus accuracy settings, strength of correction, user or preset house EQ adjustments, along with headroom adjustments and mono/stereo monitoring modes. While these settings provide a considerable amount of control over the plug-in, the default settings will serve most users very well, and, as time goes by, the user can experiment with the various plug-in settings. The main caution in using a room correction DAW plug-in is that you must understand how to bounce or print the final mix without the Sonarworks plug-in processing the mix – it should only process what plays to the monitors, not the bounce path. There are various simple ways to avoid printing a mix through the plug-in and lots of information is available about how to achieve that.

The second use of the software is as the Systemwide app, which provides room or headphone correction that affects any audio that plays through the built-in audio outputs of the computer. The Systemwide app launches at startup, and the app's controls can be accessed from the menu bar on your computer. Systemwide detects when the Reference 4 plug-in is active in a DAW session and prompts you to bypass the Systemwide app so that the audio does not play through two instances of the plug-in. Systemwide provides a similar user interface to the DAW plug-in and both monitor and headphone profiles can be loaded and customized.

I have been using Sonarworks software in my mixing and mastering studio for over five years and for the last two years with my laptop system. Sonarworks has refined and streamlined the measurement procedure over previous versions of the software, and I find that with Sonarworks running I have more confidence that my mixes and masters will translate well to other playback systems. I would always recommend that the listening environment and monitors be properly tuned, and set up before relying on any type of corrective room EQ – even then you'll find that Reference 4 provides a noticeable improvement in stereo imaging, soundfield depth, and enhanced clarity in the mid and bass frequencies. Sonarworks will optimize the performance of full range monitor systems, and on smaller nearfield systems Reference 4 adds noticeable clarity with a slightly more extended low frequency response.

On the headphone side, I had never been comfortable mixing or mastering on headphones until Sonarworks headphone calibration came along and now use Reference 4 and Systemwide on my laptop with my Beyerdynamic headphones, giving me the confidence to work on mixes and masters on my laptop – even when using the built-in headphone jack. I use the Reference 4 plug-in when I work in Pro Tools or Presonus Studio One and the Systemwide app when listening to streaming services or my iTunes library.

Speaker and headphone calibration is becoming more common, and, among the many companies that have created correction systems, Sonarworks provides the most sophisticated and easy-to-use applications around.

Tape Op is a bi-monthly magazine devoted to the art of record making.

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