Every plugin limiter on this list is unique and provides its own set of interesting features. I pitted limiters against each other from brands like A.O.M., FabFilter, IK Multimedia, iZotope, Nugen, Softube, Sonnox, Sonible, Tokyo Dawn Labs, Universal Audio, and Waves but there were just three that rose to the top. Each of the following limiters have proven to be the "best" in one way or another, slamming the competition.
Best Limiter for Maximum Loudness - Sonnox Oxford Limiter
I allowed the Sonnox Oxford Limiter to fly under my radar for far too long due to its somewhat limited set of features. Although, out of all the limiters I've tested, this is the one that has allowed me to achieve the greatest perceived loudness with the least amount of effort and distortion. For mastering extremely loud EDM tracks, the Oxford Limiter is my top recommendation thanks to its Enhance feature.
The GUI is broken down into an Input section, Pre-Process section, and Output section. Within the Input section, you can adjust the threshold level and input gain. There's also an input meter that allows you to visualize the level of your input signal.
Next, the signal runs through the Pre-Process section where you can adjust the attack, release, knee value, and toggle Auto Gain on and off. The Auto Gain function compensates for wide input level variations by using a long-term time constant that underlies the peak timing, reducing short-term gain modulation.
Afterwards, the signal passes through the Output module where you can adjust the Enhance slider's value. The Enhance function is a unique feature that allows you to further boost the loudness of your music once it's been limited. It works by adding harmonic content to your signal to enhance perceived loudness. With Safe Mode engaged, and using an Enhance value between 0-100% (the slider goes up to 125%), you should be able to achieve insane loudness without much distortion.
There are some additional features worth noting like a true peak meter, true peak compressor, peak hold function, and various dither options. This is a relatively straightforward limiter. It doesn't include all of the bells and whistles that the other limiters on this list come with but it's phenomenal when it comes to loudness maximization.
I recommend following up the Oxford Limiter up with an LUFS meter like the one built into iZotope's Insight 2 or ADPTR AUDIO's Metric AB which has quickly become one of my favorite metering plugins. If LUFS levels are a foreign concept to you, make sure to watch the following video to learn what they are, why they're important, and which target LUFS level is recommended for streaming services.
Best Sub-Mix Limiter - Brainworx bx_limiter True Peak
Brainworx's bx_limiter True Peak is one of the most musical-sounding true peak limiters available. The limiter's CLASSIC mode delivers a safe and controlled sound, while its MODERN mode takes a faster and louder approach that's well suited for harsh transients.
Using this limiter, you can expect a tight overall sound, punchy transients, solid low-end, and a stable stereo image. It has a variety of controls that make it an excellent bus limiter.
The bx_limiter True Peak provides a ceiling control that you can use to set the threshold level at which gain reduction will occur; this allows you to avoid completely rebalancing bus levels after taming transients.
There's also an XL saturation knob that you can use to sweeten up individual tracks, instrument buses, or your master track. Most mixes can benefit from a little bit of saturation; it will help thicken up your music, tame harshness, and increase perceived loudness.
Limiting an audio signal can affect its tonal balance. Using the Tone Control section, you can low-cut tracks up to 120 Hz, high-cut tracks down to 15,000 Hz, or rebalance the overall tonality of your mix with the Foundation knob that acts like a tilt filter. Try turning down the Foundation knob and boosting the input gain if your goal is extreme loudness — low-end frequencies can impede loudness potential.
The bx_limiter True Peak has a Limiter Mix knob that allows you to adjust the blend between the unprocessed signal and processed signal. You can apply parallel limiting to sub-mixes (instrument busses and vocal busses) to decrease dynamic range without killing transients. For mastering purposes, I recommend keeping the Limiter Mix knob set to 100% so that there's no risk of clipping.
In typical Brainworx fashion, there are multiple controls that allow you to solo the left channel, right channel, mid channel, and side channel. There's also a switch that lets you swap the left and right channel, providing you with an alternative perspective on your mix.
Best All-Round Limiter - FabFilter Pro-L 2
There's a lot of hype surrounding FabFilter's Pro-L 2, and for good reason. It delivers a robust set of processing and metering features that make it an excellent all-round limiter. If you can only afford one limiter on this list, get the FabFilter Pro-L 2.
Basic features include an adjustable Gain slider, lookahead time, attack time, and release time. With over eight limiting algorithms to choose from, the Pro-L 2 feels like eight limiters in one. This plugin delivers linear-phase oversampling, dithering and noise shaping, surround support (up to Dolby Atmos 7.1.2), and intelligent channel linking.
There's an optional DC offset filter, external sidechain triggering for stem mastering, a Unity Gain option that lets you accurately hear the affects of limiting, and an "Audition Limiting" option that you can use to listen to the difference between the input and output signal.
The Pro-L2's meters are comprehensive and easy to work with. There's extensive loudness metering with support for the EBU R128, ITU-R BS.1770-4 and ATSC A/85 standards.
The main display has four display modes that include Slow Down, Fast, Slow, and Infinite. I like Fast mode, in which level data originates on the right side of the display and scrolls to the left. You can use the display to identify the most aggressive peaks in your audio material over time.
Rather than relying on limiter presets, watch the following video to perfectly dial in the Pro-L 2's settings every time. The settings in the "Advanced" tab aren't as scary as you might think. In fact, those are the main settings you should be changing to hit recommended loudness targets while avoiding distortion!
