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Pro Tools Plug-ins & Rewire • Gated Effects • Bouncing

Pro Tools Tips & Techniques
Published April 2004
By Simon Price

Consolidating and exporting a selection can be quicker than bouncing, and bypasses the mixer.Consolidating and exporting a selection can be quicker than bouncing, and bypasses the mixer.

Public service time in Pro Tools Notes this month as we respond to user queries on recording via plug-ins and Rewire, creating gated effects, and bouncing.

Pro Tools is the subject of plenty of requests for help on the SOS Forum, so I've devoted this month's column to answering some of them.

Question posted by user 'Pete404': I set up one MIDI track and one audio track, route the MIDI to Reason and set the Rewire plug-in on the audio mixer channel to Reason . When I record my MIDI sequence into Pro Tools , I can hear the Reason sound and it registers on the audio meters. The problem is, when I arm the audio channel to record and start the recording process, I can still hear Reason sounding, but no audio registers on the audio channel meter, and when the recording process is finished, I'm left with a chunk of audio track with just silence recorded.

A: What Pete has encountered here is a side-effect of the fact that, in Pro Tools, Rewire inputs are connected via plug-ins rather than the usual track input selectors. Pro Tools always records the signal coming into a track's main input section, before it goes through any plug-ins or other inserts. Normally this is a good thing, because when you're recording instruments or vocals you can monitor through plug-ins but still record the source dry. When you play back the recording you leave your plug-ins in the track and can alter or remove them at a later stage. Sometimes, though, you might want to record with the plug-in effect, and to do this you need to use two tracks (see screen shot, below left). The first track picks up the input signal and has the plug-ins inserted. You then send the output of this track to the second track via an internal buss, and record to the second track. The situation is exactly the same when recording Rewire inputs. Because the input is coming in at the plug-in (insert) stage, putting the track into Record will not capture anything. If you need to record a Rewire input, say to free up some CPU power or to have the audio available for editing, you'll need to buss to another track. For this reason PT LE has an advantage over TDM: being able to use aux inputs for its Rewire inputs, it doesn't waste any audio tracks.

Bouncing Bits

Question posted by user 'Schuey': I'm working at distance with someone using LE for the first time. I just need them to bounce a vocal and send it over to me. From recollection, you just highlight the selection in the arrange window and then bounce to disk. Only the selected material will be bounced. The vocalist is adamant that it bounces the entire mix. So how do you bounce just a small section of a mix or just part of a track?

A: In Pro Tools, the Bounce to Disk function works on a 'What you hear is what you get' basis. A bounce records the signal at the chosen stereo outputs exactly as the mixer is currently set up, including mutes and solos, so (as forum user 'Dr Bob' pointed out) if you want to bounce only the vocal, you should solo that track before bouncing. The selection you highlight in the Edit window just sets the time range that will be recorded. If you make no selection, the entire song will be bounced. An alternative to using Bounce to Disk is to use the Export Selected as File(s) command. This can be quicker on TDM systems, where a bounce is performed in real time. The main difference is that this bypasses the mixer, so it's the simplest option when you don't want the audio to go through any effects. Select the region you want to export and choose Consolidate Selection from the Edit menu. This joins everything up into one chunk. Give the selection a useful name by double-clicking with the Grabber. Finally, select Export Selected as File(s) from the Audio Region List sub-menu and choose your location and file format.

Help With Stuttering

Question posted by 'Daddy J': I'm trying to figure out how to achieve the stuttering, chopped, gated type of effect used in quite a few dance and commercial rock productions.

A: Traditionally this effect has been achieved using gates, but there are also other possibilities in Pro Tools. On the SOS Forum 'Jim EM' suggests using volume automation, a quick and simple solution with Pro Tools ' drawing tool options. In the screen shot below I've laid out three steps across three tracks.

Step 1: Home in the section you want to stutter, and switch to Volume automation view for that track. Use the Grabber to make break-points in the graph at either end of the audio in question to keep the rest of the track's volume undisturbed.

Step 2: Click and hold on the Pencil tool (inset) and choose the Square shape. Set your edit grid to half the note length that you want each stutter to be — for instance, if you want to chop out 1/16ths, set the grid to 1/32 notes. Now click and drag across your audio to draw in the automation. You'll need to drag the pencil to the top or bottom of the track if you want to completely mute the audio between stutters.

Step 3: Highlight the section with the Selector, then use the Trim tool to bring down the top half of the automation to match the volume of the rest of the track.

Of course you're not limited to using this effect on volume automation, you could do this for panning, sends or plug-in parameters to create other interesting choppy effects.

The traditional gating method for effects like this is still relevant as it lets you use the rhythm of another track (often a hi-hat) to control a rhythmic effect in another track, and have greater creative scope for tweaking the results. This trick employs the 'key input' available on some plug-ins. What happens is that audio peaks in the key track trigger events in a plug-in on the effected track, such as opening a gate or firing a filter envelope.

One way to create rhythmic 'gated' effects is to use the automation shape drawing tools.One way to create rhythmic 'gated' effects is to use the automation shape drawing tools.

The screen shot above shows an example configuration. A gate plug-in is inserted on the 'Vox' track, with the 'External Key' switched on and the key input channel set to buss 1. The 'Hats' track has a send going to buss 1. Audio from the 'Vox' track will now be heard only when the key input from 'Hats' exceeds the Threshold level set in the plug-in. If this level is set close to the peaks from the key track you will get a stuttering effect that follows the hi-hats. The Attack, Hold and Decay sliders will adjust the volume envelope of each 'hit', allowing for a much wider range of effects than a simple on/off chopping of the audio. Finally, if you don't actually want to hear the trigger track some or all of the time, switch the send to 'post fader' so that you can adjust the level or mute the track without affecting the key signal.

Quick Tips

  • Automation data can be nudged forward or back (with the keypad's '+' and '-' keys) independently of the underlying audio. However, if you nudge or otherwise move the audio, the automation will go with it.
  • The volume automation created for the example in the main text can be copied and layered onto other parameters such as pan, or even plug-in parameters, for unexpected results. Copy a selection, then switch to view the destination parameter. You then need to use the 'Special Automation Paste' command (Ctrl+Apple+V for Mac, Ctrl+Start+V for Windows) to force Pro Tools to paste.
  • In OS X, it's not a good idea to include a '/' (forward slash) in the name of a folder or hard drive. If you do, Pro Tools can sometimes get very confused, fail to find audio in these locations, and sit with the spinning wheel icon, scratching its head.
Published April 2004