In Summary

Offering creative clipping and limiting effects, Submission Audio’s latest offering sets out to deliver hard-edged sounds without the red lights. Here we take a look at Flatline 2 to see if there really is an intelligent way to hit the top.

Going Deeper

Clip, Limit, Or Both?

With the art of mixing bringing together a wide range of styles, some mix engineers are not averse to lopping the tops off their master for creative effect. This can do some of the things that listeners can respond well to, such as increased loudness and/or extra harmonic texture for harder-edged sounds. Some electronic styles embrace the bright digital red lights that would signal Full Scale ruin for others. Although limiting can stop clipping in the DAW, it’s still possible to clip audio inside an audio plugin as an effect with controlled results.

Although both clipping and limiting can change the waveshape in a way that can introduce distortion, the two are different. On a transient rich material, hard clipping can be easier to use without adding audible distortion. On longer steady-state musical sounds, limiting can be more appropriate and less likely to introduce distortion than the use of clipping.

Submission Audio Flatline 2

Promising the edge and density that ‘flat-topped’ audio can deliver, Flatline 2 is a purpose-made audio mastering maximiser that offers three modes for limiting and clipping, including a Hybrid mode for fine control of the processor’s time constants. At its output, a LUFS-calibrated loudness readout confirms Flatline 2’s function as a creative medium between your DAW and the final destination.

Flatline 2’s Hybrid mode addresses the problem of clipping distortion on steady state sounds. Using the Envelope controls, users can regulate how much of the signal transients go to the clipper, and how quickly the remainder of the signal is fed into the limiter when using Hybrid mode.

In the video we strap Flatline 2 across our master for controlled clipping and limiting effects into its loudness metering. Using its Hybrid mode, we show a varying amount of gain reduction, as well as the use of the Colour control for seamless morphing between classic hard knee maximised effects as well as softer treatments. We also show how its ceiling peak readout lines up exactly at the DAW output. 

Tough At The Top?

While many engineers will have employed the soft clipping effects of tape or even the limiters built into some famous and infamous digital boxes, red lights for most are still bad. That said, certain styles can actually benefit from hitting the top and stopping there. For anyone who thinks deliberately clipping audio is universally bad, it could be argued that doing it inside an audio plugin is ethically justified just like the CGI artist who blows up a planet inside their computer! Check out our article What Are Clipper Plugins And Why Use Them?

Submission Audio On Flatline 2

[Flatline 2’s] intelligent Hybrid algorithm handles the entire maximization process, allowing for extreme punch and transient retention at extremely loud levels, all without audible distortion.

The intelligent Hybrid algorithm combines the 'best' aspects of both clipping and limiting, while mitigating the disadvantages of both. The transients are clipped in order to ensure maximum punch retention during mastering, while the steady-state portions of the signal are limited, in order to minimize audible distortion. The clipper uses a euphonic waveshaping algorithm to always sound pleasant, whether it be clipping a full mix, or individual mix elements (such as drum shells). The limiter is based on the classic 'brickwall' design to act as a 'no-pass' filter to transients. The way the sidechain is coded can make it sound 'wider' than other plugin limiters of this type. The limiter is great to use on anything from drums through to bass, vocals, synths, or any mix elements which require that final degree of absolute transient control.

Flatline 2 Key Features:

• Multi-Mode Audio Mastering Maximizer: Clip, Limit & Hybrid.

• Clipping: Variable soft saturation for a 2000’s 'radio' mastering sound.

• Limiting: Brickwall limiter with adjustable release for 90s-style transient control.

• Hybrid: The punch of clipping with the distortion resistance of limiting. Features envelope control, tailored charge times, multi-stage release, lookahead, and channel linking for both transient and sustain portions of the signal.

• Metering: Comprehensive LUFS (Integrated, Short-Term, Momentary, Range) with targets for major platforms like Spotify, Apple Music, YouTube, and more.

• Extras: Oversampling to 64x, DC Offset Filter, Multi-bitrate Dither, Delta Monitoring.

• Developed for “home producing musicians, studio owners and mastering professionals”.

• Preset collection from top producers and mastering engineers.