360 Waves

WAVES 360° WAVES WAVES SURROUND TOOLS KK PROFFITT takes time to explore this enormous range of surround tools for anybody who wants to do it, and do it well. T he new Waves 360°Surround Tools provide the missing links necessary to create a sophisticated, accurate, and robust environment for mixing multi-channel audio on the Pro Tools platform. While other options exist for multi-channel panning, reverberation, dynamics processing, calibration, and bass management, none of them is as well developed or tightly integrated for Pro Tools as the new toolkit from Waves. The Waves 360° toolkit comprises nine modules: the M360° Surround Manager, M360° Surround Mixdown, the LFE360° Low-Pass Filter, the S360° Panner, the S360° Imager, the R360° Surround Reverb, the C360° SurroundComp, the L360° UltraMaximizer, and the IDR360° Bit Requantizer. While any of them may be used alone in a Pro Tools session, several of them may be used together in order to properly align speaker angles among the relevant modules. Setting Up For Surround... The M360° When Pro Tools 5.1 was released, those of us who had been familiar with the constraints of building studios for surround mixing sent up a collective groan whenever we were faced with surround demos that 46 AUDIO MEDIA had been mixed with five channels of ‘treble material’ and the sixth being overwhelmed by bass, bass drum, and explosions. Some of us had built our own hardware bass management systems and we operated in calibrated rooms, so playing back early efforts by some Pro Tools aficionados was often disconcerting, if not downright painful. Gradually, after many assaults and flames by Internet surround evangelists, rank and file audio engineers began to acknowledge that mixing surround involved more than simply putting speakers in a circle. While the debate amongst designers concerning ‘full-range’ versus ‘Sub/Sat’ (satellites plus subwoofer) speaker systems continues to rage, it is appropriate to mention that most home theaters (the target of much surround audio product) as well as many mid-sized studios employ a system with satellites and subwoofers. This kind of system demands bass management and proper calibration to ensure good translation from audio source to audio playback. The M360° Surround Manager comes to the rescue of studios that have no external bass management for the Pro Tools environment and provides a wealth of other features for surround ➤ audio production. MARCH 2003 ➤ It has been stated many times (but it is worth repeating) that the LFE (low-frequency effects) is a channel, while the Subwoofer is a speaker. With the M360°, the LFE channel audio (boosted by 10dB) is combined with the subwoofer signal (a low-pass split from the five full-range audio channels) into the subwoofer feed for playback only. When you layback (not playback) audio for encoding or transfer, the LFE channel (sans offset) is printed, while the Subwoofer feed created by the Bass Management portion of the playback system should never be printed to the master. M360°has two components: M360° Manager and M360° Mixdown. M360° Manager should be inserted on the master surround output (limited to 5.0 or 5.1 channels). It allows for calibration of the studio monitoring system, setting up monitoring with a Sub/Sat playback system, and previewing standard 5.1 target playback processing. M360° Mixdown should be instantiated after M360° Manager for previewing or applying Mixdown options. Once again, in most cases, you’ll need to bypass M360° Manager when printing your final mix. M360° allows you to set the speaker angles of the plug equal to those in your studio (L/R and Ls/Rs). Even if your monitoring setup does not conform to the standard ±30° for Left and Right speakers, and ±110° for Ls/Rs, matching the speaker angles of the plug to those in your studio will provide better translation for your mix and will allow you to work more accurately with the S360° Panner/Imager. A useful function, send angles, pokes the M360° angle values into those of the Panners and Imagers. Before you print a mix, if you have customized these angle values, it’s important to reset angles to the default and to send angles again in order to zero angle values in the Panners and Imagers. Like any good bass manager, M360° provides gain, delay, crossover, sub send and polarity controls on every full-range channel. Crossover frequency is selectable, as are low-pass and high-pass filter slopes. If you want to mix the LFE channel back into the full-range channels for future downmixes (where the LFE will be eliminated), you can use the ‘Get LFE’ controls. There are separate gains for LFE and subwoofer levels. LFE gain adjusts the level of the LFE input after the overall input gain. LFE adjust provides ±10dB gain offset for the LFE channel. The Waves 360° toolkit manual includes a brief section on calibration that gives a simplified calibration routine. It leaves out some important information, however, and the user would benefit from outside reading of more thorough texts, such as Thomlinson Holman’s excellent book, 5.1 Surround Sound, Up and Running. Although the 48 Waves 360° Surround Tools require Pro Tools TDM Mix version 5.1.3 and higher, or Pro Tools TDM HD version 5.3.1 and higher, Mix users should be aware that the pink noise that is suggested for calibration from the signal generator in version 5.1.3 is not accurate. According to Digidesign, the pink noise is corrected in version 6.0 for Mix. If Mix users prefer to stay with version 5.1.3, they should consider an alternative test signal souurce with the proper bandwidth-limited pink noise necessary for accurate calibration (another point not mentioned in the manual). Bandwidth-limited pink noise is especially important for calibrating satellite speakers in order to avoid low-frequency errors due to standing waves and high-end from the listener. The M360° Circle Display shows the final imaging, rotation, and width as well as speaker angles. The letters L,C, R, Ls, and Rs show the standard ITU speaker placement, while four beams radiating from the center show the user-adjusted angles. When Rotation is selected, it varies from -180° to +180° and the angle determines the direction of the panned phantom image. Rotation may be pair-wise (two speakers at a time) or triple-wise (three at a time). The M360° Mixdown module enables the user to fold 5.1 channels into a variety of output formats. It’s also useful for previewing downmix scenarios resulting from decoding for smaller, or modestly priced surround environments. The mixdown matrices do not Monitor calibration, set-up and target preview miscalibration due to slight movements of the test microphone. Finally, the large room level suggested is 85 dB SPL. Many would argue, however, that using -20 dBFS bandwidth-limited pink noise should properly yield 83dB SPL. For more detailed information, check out www.digido.com and read the second part of the Level Practices article. After the system has been calibrated, M360° can be used to set target adjustments to mimic consumer playback systems and evaluate possible conflicts. Surround offsets may be varied from -6dB to +6dB in 3dB increments. Center level can be ±3dB, ±4.5dB or ±6dB. You can also select +Aligned to simulate a situation where the front speakers are in a straight line, rather than equidistant AUDIO MEDIA MARCH 2003 fold the LFE into the downmix, so there’s a Mix LFE control to redirect the LFE to the mixdown channels. The Waves LFE360° module should be instantiated above the M360° plug. It’s a steep low-pass filter that will affect only the LFE channel. You can, for instance, set the cutoff for the LFE at the Dolbyrecommended 120Hz while leaving M360° to emulate a THX set-up for the sub-woofer with an 80Hz split. M360° provides an extraordinary flexibility for setting up surround environments. While neither the concepts nor the features are simple, it’s worthwhile for the user to experiment with various setups to become familiar with possible effects in target situations. The S360° Panner|Imager... The Waves S360° Panner is a surround panning and imaging tool for 5 or 5.1 channels. It’s an alternative to X/Y panners, offering better control of Phantom images, better localization, and an enhanced sweet spot. You can set Rotation and Width for mono, stereo, 5.0-channel or 5.1-channel sources. The S360° Imager, enhances the Panner by adding Room Model Early Reflections for distance panning, and Shuffling for low-frequency width. It’s a good idea to start with the Panner and swap it for an Imager if you need it later because the Panner uses less DSP. All Panner components support 192kHz, but some of the Imager components are limited to 96kHz. You can set Width Ratio to change the width of the image. Since divergence is related to rotation, widening an image will spread it sideways from its centre or collapse it toward a mono image. There’s an LFE send that sends a sum of the input audio to the LFE channel. Center can vary from 0 to 100 percent, depending on whether a phantom or discrete image, or something in between, is desired. A splined-circle energy scope gives a graphic panning display of the information indicated by the meters. The Front Stage control (available for stereo and multi-channel components) widens the front stage by multiplying the directional image width by a specified ratio. Front/Rear Stage (multichannel components only) widens both front and rear stages in the same manner. The Focus control (stereo and multichannel components) is useful for light ambience extraction. It takes each speaker pair and extracts the MS component, with a value of 0 being only M and a value of 4 being only S. The S360° coexists peacefully with other panners in a session, so if you want to vary panning effects track by track, it’s easy to mix and match panners from different manufacturers. Tailor LFE cut-off for your target several parameters specific to surround audio production. Rear offset creates an offset between the pre-delay for front and back channels, so that the rear channels have a slightly longer pre-delay. There’s a control for the level of input from the LFE to the reverb and a low-pass for the LFE output. You can lower the reverb output from the center channel or remove it completely. Front/Rear balances the reverb between the front and back sound stages. quadraphonic phantom images), and Center|Front LR|Rear with LFE bypassed. The L360° UltraMaximizer... The L360° is a surround peak limiter and level maximizer for five or 5.1 channels. Using technology inherited from the L1 and L2 UltraMaximizers, it provides look-ahead brickwall peak limiting with 48-bit double precision processing and it incorporates Waves ARC. Like the C360°, the L360° has five link modes with up to three sidechains. The two main controls are threshold and ceiling, with a range from 0 to -48dB. C360° and L360° both support sample rates up to 96kHz. The C360° SurroundComp... The Waves C360° is a soft-knee compressor for 5 or 5.1 channels. While the controls and functions of the C360° are similar to the L360° (the companion limiter), the sound of the C360° is different. It starts to The IDR360° Bit Requantizer... IDR (Increased Digital Resolution) provides dither and noise shaping used primarily when the wordlength of the source needs to be reduced. If you choose noise shaping without dither, quantization error noise will be shifted to a less audible range. When both dither and noise shaping are de-selected, the IDR plug rounds (instead of truncating) the audio to the desired bit depth. Conclusion I wish I could have had these plug-ins a few years ago. They make comparing various target environments nearly instantaneous. Although my studio has a hardware bass management system, I find myself using various features in the toolkit on a daily basis. The Waves 360° Surround Tools enhance Pro Tools so that serious audio engineers may now do real work in surround. ❏ The R360° Surround Reverb... Surround dynamics The R360° generates reverb tails only. This makes it the perfect companion for the S360° Imager’s early reflections. Based on the same technology used in Waves’ wellknown Renaissance Reverb, the R360° generates reverb tails that are pitchpreserving and fully decorrelated among all channels. R360° has a compact component for running in true 96kHz mode, while saving DSP when working in 44.1kHz or 48kHz mode. The full component is required for MIX systems and the compact component will not work on MIX systems. In addition to common reverb controls such as pre-delay, reverb time, wet/dry mix, damping and filters, R360° adds attenuate the signal before it reaches threshold and increases attenuation as the level reaches and overshoots threshold. It can also function as a limiter with a specified ceiling. It’s a look-ahead compressor with 64 samples of delay. Like other similar Waves plugs, the C360° uses Waves ARC (Auto Release Control) and peak reference compression with automatic gain make-up. The C360° preserves cross-channel balance and phantom imaging with linked dynamics processing. It has five link modes with up to three separate sidechains. Modes include All Linked, 5 Linked|Sub, Front|Rear|Sub (useful for film with ambience and effects in the rear sound stage), Center|Quad|Sub (fully preserves AUDIO MEDIA MARCH 2003 .................................. INFORMATION $ ❍ A ❍ Waves 360° Surround Tools $2400 Waves, 306 West Depot Avenue Suite 100, Knoxville, TN 37917 T 865 546 6115 F 865 546 8445 E sales@waves.com w www.waves.com ❍ ❍ ❍ ❍ 49