This article originally appeared in the February 2021 issue of Pro Sound News. Innovations is a monthly column in which different pro audio manufacturers are invited to discuss the thought process behind creating their products of note.
Mixing on headphones has become increasingly common in recent years. Producers and engineers, even at higher levels of the profession, do not always have regular access to a high-end professional mix room—a situation only exacerbated in the COVID-19 era. Given the monitoring conditions of an acoustically untreated or under-treated room, it is often tempting to resort to headphones during the mixing process in order to hear details which might get lost otherwise. In addition, many audio pros need to mix or check their mixes on the go, while away from their own familiar monitoring environment.
All this often makes headphone monitoring a necessity.
But headphones—no matter how good or expensive—are notoriously unreliable when it comes to critical mix decisions. Mix depth, precise panning, stereo image decisions, reverb amount and placement, and, in particular, low-end frequency response are all difficult to get right on headphones. Decisions made over headphones, with the audio ‘injected’ directly into one’s ears, often translate unpredictably when the same mix is heard back through monitors, over real distance in a physical environment.
In recent years, pro-audio manufacturers have turned to spatial audio technologies to deliver truer-to-life, three-dimensional acoustic response over headphones. Waves Audio has spearheaded this development with its proprietary Waves Nx technology, which restores the missing three-dimensional acoustic information provided by loudspeakers in a room. The Nx algorithm is designed to achieve this on any headphone model, without changing the color of the user’s favorite headphones.
Four years ago, Waves released its first Nx-powered pro-audio product, the well-received Nx Virtual Mix Room plug-in for professional headphone monitoring. The plug-in uses channel crosstalk, inter-aural delays (ITD), filters and gains (ILD) for each ear, early reflections and head motion tracking to construct the “virtual acoustics” of an ideal imagined room.
The next challenge was to combine the Waves Nx 3D audio algorithm with the precision-measured impulse responses of an actual high-end control room. The first outcome of this effort was the Waves Abbey Road Studio 3 plugin, released in 2019, which emulated the legendary UK studio’s Studio 3 control room.
Now, Waves has applied the same painstaking 360° acoustic image capture process to the famous Ocean Way Nashville control rooms. Ocean Way Nashville was chosen because it is widely regarded as an audiophile sound engineer’s dream—designed from the ground up by Ocean Way founder Allen Sides to meet his vision of the ultimate recording, mixing and monitoring environment.
The studio’s control rooms in particular were designed to provide an accurate acoustic response that translates seamlessly to other listening conditions. Ocean Way Nashville’s spacious control rooms combine unusually large ‘sweet spots,’ resulting from the rooms’ construction specs, with the Allen Sides-designed Ocean Way Audio HR1 and HR5 monitors, built for even dispersion across the room.
Development of the Waves Nx Ocean Way Nashville plug-in was closely supervised and approved by Allen Sides himself, to deliver—over any set of headphones—faithful representations of the room’s finely tuned acoustics, as experienced through the Ocean Way near-field and far-field monitors. Users inserting the plug-in on a stereo bus can monitor through the emulated soffit-mounted Ocean Way Audio HR1 main monitor system, or through the free-standing HR5 reference monitors. Both monitor systems are known for their wide bandwidth and dynamic range, ultra-low distortion, and particularly wide and even dispersion.
The Nx Ocean Way plug-in also allows users to control the exact blend of room ambience into the monitor mix. Sides himself was particularly enthusiastic about this ability; on his request, Waves engineers opened up the ambience blend to up to 160% of measured performance. While 100% is the default setting and useful in most monitoring scenarios, Allen simply loved the sound of the room turned up for his own monitoring pleasure and urged Waves to include this option.
As developers of immersive audio solutions know, our experience of the stereo field over spatial audio technologies can be affected by the user’s precise head size and shape. To complete the realistic spatial experience, the Waves plug-in allows users to customize the plug-in to their precise head circumference and ear-to-ear distance measurements, for a better, personalized Head-Related Transfer Function (HRTF) approximation.
Head tracking, using a webcam or the separate Waves Nx Head Tracker Bluetooth device, is optional but recommended. While the plug-in improves the reliability of headphone monitoring even without head tracking, the spatial cues provided by tracking the listener’s natural head movements enhance the immersive experience, especially over long mixing sessions.
Recent listening sessions at Ocean Way Nashville, with top Nashville engineers who are intimately familiar with the original control rooms and monitors, bore out the plug-in’s accuracy, with many hearing in it the “Allen Sides fingerprint.”
Waves Audio • www.waves.com