The transfer curve in the dynamics section differs from the 45‑degree line of most compressor plug‑ins, but it shows the same information, and lets you adjust the threshold and ratio simply by dragging at different points on the line.
We take a tour of Avid’s surprisingly deep Channel Strip plug‑in.
Pro Tools Intro has broadened the potential appeal of Pro Tools to a whole new audience. Its predecessor Pro Tools First was free, but despite this, it struggled to get traction with the new users it was designed to engage. Fundamentally, this was because it came with too many limitations to its core functionality. Less restrictive options were available to the new user, so many went with other choices.
The feature set of Intro is just about right, given that you can’t expect Avid to create a free offering which is too close to the accessibly priced Pro Tools Artist. However, when looking at the bundle of plug‑ins it ships with, I can’t help thinking that with all of the effort which is being made to make third‑party plug‑ins easier and quicker to use, one important plug‑in in particular isn’t the friendliest of propositions for novices. And if you want to use Pro Tools Intro to its fullest potential, this plug‑in is too important to pass over. I’m talking about the Avid Channel Strip.
AAX To Grind
Pro Tools Intro ships with what looks like a fairly generous selection of AAX plug‑ins. Ignoring the utility plug‑ins like Trim, Time Adjuster and Click II, and some of the creative effects like SansAmp, Mod Delay and Pitch II, what we’re left with is EQ and dynamics processors, many of which duplicate parts of the Avid Channel Strip. However, while I have no issue with the venerable EQ III, I wouldn’t really recommend the Dynamics III compressor/limiter, especially to a new user. It’s rather prone to distortion and as such is rather unforgiving. There is the BF76, but again I’d never recommend an 1176 plug‑in to someone with little experience. Fixed threshold and backwards attack and release controls are all fine once you know, but I wouldn’t think of it as anyone’s ideal first compressor.
The Avid Channel Strip is derived from a Euphonix design, and in terms of facilities and sound, is truly excellent. But I have to say, it’s not friendly to the new user. It has a busy UI with some design features that are easy to miss and others that are easy to misunderstand. Considering you’re likely to be spending a lot of time in this plug‑in, it’s worth getting to know well. Here are some tips to help you learn to love this powerful but deep plug‑in.
Hide & Seek
Firstly there’s that UI. Avid Channel Strip was first introduced with Pro Tools 10, and many of the stock plug‑ins got updated UIs at the same time. A new dark grey house style was used throughout, and Channel Strip and Revibe II were housed in tall, narrow windows. Part of the point of these plug‑ins was that they were configurable, with the ability to fold away sections which aren’t needed, but I very rarely see this done. I’d recommend it — particularly if, like me, you prefer to use the 7‑Band EQ III instead of the Channel Strip EQ. If I’m not using the Channel Strip EQ, I hide it.
To hide either the EQ or middle section with the knobs for the dynamics section, click the little disclosure triangle at the top left. The Dynamics Transfer curve can’t be hidden. You can set up compression and expansion without using the knobs, but they need to be accessed to set up the side‑chain.
Ahead Of The Curve
A transfer curve is a graph of how the output of a compressor/limiter or expander/gate relates to its input. While how it sounds is more important than how it looks, these curves can be very helpful in understanding the current state of the processor. However the transfer curve doesn’t tell you anything about the attack and release settings.
The potentially confusing thing about the Channel Strip’s transfer curve is that instead of plotting input level against output level, like the Dyn III plug‑ins (and pretty much everything else out there), Channel Strip and its Avid Pro Series siblings plot input level against gain reduction. It’s no more difficult to understand, but it is different. Whereas no processing in a Dyn III plug‑in is represented as a 45‑degree line rising left to right, in Channel Strip it is a horizontal line across the top of the graph.
To set up the compressor or expander, grab with the mouse at the appropriate point on the curve and you’ll see the cursor change. To set the threshold, grab the orange threshold line; to change the ratio, grab the curve above the threshold. You’ll find the other parameters by mousing around. You can’t access the attack, release or make‑up gain in this way though. This immediate, hands‑on control of the transfer curve is one of the things which set this plug‑in apart from the competition when it launched.
Above the transfer curve is the easily missed side‑chain level meter. This shows the level of the signal which the detector is receiving. In standard use this is the same as the audio being processed, but if you’re using it with an external side‑chain then it will show the level of the kick drum or whatever source you have set up to control the compressor. The instantaneous level is shown on the transfer curve by a red dot that moves up and down, depicting the current level of the audio relative to the threshold. ‘Overshoots’, which happen when the level change of the audio is too fast for the current attack and release times, cause the dot to leave the curve. As this is where a lot of the interesting sounds reside, this can be a useful thing to keep an eye on when learning compression.
The band solo mode in Channel Strip is brilliant for finding the frequency you’re after.
Other Tricks
The input meter to the left of the compressor transfer graph can also show gain reduction, as here.Other things about the dynamics section that are useful to know include the option to change the detector mode between peak and average. Peak is great for fast, ‘grabby’ compression, while average is much more forgiving and suits gentler levelling tasks.
To the right of the transfer curve is the rather tiny gain‑reduction meter. Few people know that by clicking the tiny disclosure triangle to the right of the input meter label, this can also be turned into a gain‑reduction meter, which not only is much bigger, but also has very different ballistics. It’s much slower, based on some kind of average, though comparing it to Pro Compressor it doesn’t quite match the latter’s AVG or RMS modes. If you’re going to use a gain‑reduction meter to help guide your compression decisions, this one probably reflects what you perceive more closely than the normal meter.
Channel Strip EQ
Unlike the Dyn III plug‑ins that preceded Channel Strip, I would recommend EQ III, which is still my default choice for EQ in Pro Tools. However, many of the features I like EQ III for are also available in the Channel Strip EQ.
The EQ section can likewise be manipulated by dragging the graph.The UI is controllable from the tabbed system of knobs at the bottom of the EQ section, but it is much more efficiently driven from the curve itself. New users might be disappointed by the lack of a real‑time analyser, but I’ve always felt that these can be misleading. Far better to use your ears, and the band solo mode in Channel Strip is brilliant for finding the frequency you’re after. Hold Ctrl+Shift (Start+Shift on PC) and grab a control point, and you’ll temporarily hear that band in isolation.
Adjusting Q can be done by holding Ctrl, or Start on a PC, and dragging, but if you position the cursor in the coloured area under the control point (or over if you are cutting) it changes to an up/down arrow with which you can adjust Q.
Holding Shift on its own is useful as it constrains either the frequency (allowing you to adjust gain while staying on the same frequency) or the gain (while keeping the frequency adjustable). People often revert to using the knobs to achieve this sort of control, but you don’t really have to if you know this keystroke. Another nice trick here is to Opt+Shift‑click on a control point. This inverts the gain of that band.
What really matters with a plug‑in is how it sounds, but the UI is about usability as much as it is about appearance. Channel Strip can feel a little crowded, but if you take control of and understand what you’re seeing the results absolutely stand up.
