NOVEMBER 18, 2020

Cranking Up the Hardware Horsepower: Taming Recording Latency with DSP Acceleration

using a DSP accelerator

When recording latency isn’t a problem, it probably doesn’t cross your mind. But when it is an issue, you can’t think of anything else. Latency can become a massive distraction during recording and easily affect the good vibes of a session.

Recording latency—neatly summarized by Ledger Note as a time delay between the production of a sound and its playback or recording—is usually rooted in one of two causes. The first is a lack of synchronization between the timing of hardware-monitored audio and the accompanying software-produced audio. The other is an inconsistency between the timing of an audio recording and its appearance on the DAW multitrack. Some compressors and limiters depend on a technique called lookahead, which has the effect of stalling the incoming stream of audio; a delay might stem from buffering audio data between DSPs or plugins being used in the project.

Plugins are a common choice for enhancing or individualizing performers’ monitoring experience, so it’s not hard to see how a delay could impact a vocal or instrumental take. Want to bet that a saxophonist or guitarist about to begin a soaring solo won’t notice a delay? If they do and get flustered, it risks spoiling what could have been a great take.

With a bit of careful thought and an integrated solution, engineers can reduce latency to an absolute minimum—ensuring that nothing stands in the way of a musician achieving a great performance.

Ditch Workarounds for Integrated Solutions

There have been plenty of attempts to tackle recording latency over the years. These workarounds have included direct input monitoring, an expansion of RAM on the host system, and recording/tracking without plugins on the recording track. These steps can make it easier for the artist to stay in time, but they have their limitations—including curbing performers’ options for how they receive their preferred playback. Meanwhile, a host system expansion can be expensive and require downtime.

In this context, the recent trend toward processing plugins via a DSP accelerator in the hardware makes sense. If you want to apply treatments or effects, these combined solutions remove the need to route audio to different systems or platforms. Without this jump, it’s possible to reduce latency to virtually zero and, from there, create a bespoke cue mix for the artist to perform to.

Deploying that crucial hardware horsepower with virtually no audible latency, a DSP accelerator gives engineers the closest equivalent to an analog session recording direct to tape.

Confront Recording Latency with DSP-Accelerated Hardware

The benefits of DSP acceleration are easiest to understand from the performer’s perspective. If a track’s slow fade calls for an eloquent solo, a star session guitarist might come in and work with the producer on a suitable part. Usually, there will only be an hour or two to capture the solo—ideally not slowed down by the engineer having to comp multiple takes. DSP acceleration allows the engineer to fine-tune a cue mix and deliver it without latency, ensuring there’s no delay to take the performer out of the moment. The chances of getting that perfect take are going to rise by quite a bit.

Timing is also critical in another sense. Recording budgets are generally much lower than they were even 10 or 15 years ago, especially for newer acts. When sessions do take place in commercial facilities, chances are they’re scheduled within a highly compressed time frame without much room for error. Even if you’re working in a project or home studio, time is money. A rock-solid solution saves engineers from losing valuable time tampering with workflows.

For guaranteed results and ease of use, an integrated DSP acceleration solution will be the best approach for most projects. Latency is a beast, but it’s one that can be tamed.

  • David Davies headshot

    David Davies is a journalist, editor, and copywriter specializing in audio and broadcast technology, music production, and professional AV.

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