CEDAR Adaptive Limiter 2

NIGEL JOPSON tries a natural-sounding maximiser with an unusual algorithm

For years CEDAR Audio has been the gold standard for software and hardware products for audio restoration, dialogue noise suppression, speech enhancement and mastering. Previously only available as part of their CEDAR Studio packages, CEDAR has made the Adaptive Limiter available as a separate plug-in for both Mac and PC platforms — available via its dealers and directly from CEDAR’s website for £360/$440/€432 and licensed via iLok.

Spectral & Temporal

Adaptive Limiter has an unusual feature: an algorithm that calculates a continuingly varying EQ profile which “constrains the amplitude of the output while retaining the integrity of the input signal”. This is controlled via the green Spectral knob, and the LF and HF purple Temporal knobs. Turning the Spectral knob all the way up, with the Temporal knobs low, the attenuation is allowed to vary considerably across the spectrum, but varies slowly in time. The difference between the peak and minimum attenuations at any frequency will be small. CEDAR say “this is similar to the action of a multi-band limiter with a slow release”.

With all three knobs turned up, the attenuation profile varies considerably across the spectrum and can change quickly in time. The difference between the peak attenuation and the minimum attenuation at any frequency will be greater than if the temporal knob was turned down. I found these higher settings to be useful on instruments in a multitrack — the perceived loudness is definitely maximised — but sometimes with a change in tonality. Obviously not the sort of processing to use heavily on a vocal, for instance, but useful on a bass or keyboard part that needs lifting in the mix.

If you crank up the Temporal LF and HF knobs but keep the Spectral green knob low, then the limiter starts to behave a bit like a frequency-conscious limiter. Control interactions are hard to rationalise because the concept is a bit unusual, but the cyan and turquoise moving frequency plot soon guides you in the correct operational direction.

I’ve found myself dealing with a mixed bag of sound over recent years. Audio for video with crowd noise and gunshots, musician’s home recordings — galloping horses. I have a supply of platinum bundles and several ‘true peak’ limiter plug-ins, but sadly many limiters cannot guarantee an output which will not illuminate someone’s clip lights somewhere down the line. On a 90 minute audio-for-video mix it’s infuriating. There really ought to be some sort of international body to certify so-called true peak limiters for ‘no overs’! We can discuss the finer points of inter-sample peaks (and we have, in Resolution V18.3 — Understanding the Loudness Penalty) but sometimes audio wranglers just need a tool to do the job. In this respect CEDAR delivers. If you set the ceiling control to -0.02 or -0.25 …then nothing in excess will pass, whatever occurs program wise, and whichever metering is used to check later. Thank you! The ability to add 16-bit or 24-bit dither also makes Adaptive Limiter a flexible final plug-in for use in a non-DAW host.

Multitrack mixing

I had been expecting the CEDAR Adaptive Limiter to be very effective as a mastering tool — which it is — but I’d not anticipated quite how powerful it would be at treating individual instruments in a multi-track mix. This plug-in had the ability to bring up a rather limply-played Fender Rhodes so that every chord bulged with energy and sparkly tine sounds — and maintained a consistent level to sit back in the mix. Music engineers should bear in mind that this is the sort of plug-in CEDAR anticipated being used to elevate complete mumbling or thin vintage recordings to audibility!

I selected a few instances of normal music production limiters — McDSP, sonible, Waves and Sonnox — and set them all up so as to ‘bring up’ the musicality of each track in a multitrack. I then bypassed them all and set up an instance of CEDAR Adaptive Limiter to do the same job on the same tracks. I took a break and then A-B compared the setups. Wow. The CEDAR is a powerful tool, and especially so when tailored to specific instruments, as the temptation is to be a little more radical in control setting than on a full program mix. CEDAR’s Adaptive Limiter is certainly a more useful addition to the music arsenal than I’d anticipated; it’s an order of magnitude more capable of ‘fattening’ a sound than something like the Sonnox Inflator. It’s the type of tool which a music engineer has to make a rule to be sparing with, because it can make quite radical dynamic transformation.

The question readers may ask is: do we need another limiter or maximiser plug-in? The Adaptive Limiter’s UI-look harks back to Pro Tools 6, and the price reflects CEDAR’s high end niche. Here’s my answer: do you mix audio for video, where you’re faced with unpredictable sound, plus a long mix program which you can’t always plough-through in real time? You need it. Do you mix music? Then ask yourself if you’re actually happy with your current peak limiter… or do you sometimes scream: “Bring back my TC Electronic System 6000!” If the latter, you know what to do…

The CEDAR Adaptive Limiter 2 brings some unusual but easy to use temporal features to limiting, with a truly professional approach to limiting peak output. It is capable of radical dynamic enhancement, making many so-called ‘maximisers’ sound a bit feeble.

VERDICT

PROS A remarkable ability to maximise audio without changing character — beyond the bounds of what seems possible

CONS UI looks a bit basic! (but of course does the job)