Using Bus Effects


Let's continue working with the lead vocal channel by applying some reverb. You could insert a reverb effects processor into the channel as you did with the EQ and dynamics plug-ins, and adjust the plug-in mix between the direct and processed signal to achieve satisfactory results. However, a much more efficient approach is to set up the reverb plug-in as a bus effect that can receive a signal from any channel.

With the reverb setup as a bus effect, controlled amounts of signal from individual tracks can be sent to the bus via the Sends on their respective channels. The audio signals are then processed with the effect and mixed with the stereo output.

This carries the additional advantage of saving considerable CPU power because a single instantiation of the effect processor is inserted, instead of the same plug-in being inserted on every channel that needs processing.

Let's start by accessing the busses with the dedicated Global view mixer you set up earlier.

1.

Click the Global button.

All 16 busses available to the song are displayed.

2.

On Bus 4, click-hold the top Insert slot and choose Stereo > Logic > Reverb > Space Designer.

The Space Designer plug-in window opens.

Space Designer is a convolution reverb that utilizes a special audio recording of a real acoustic space (or an effect processor) to apply reverb by means of a real-time process. Think of it as a reverb "sampler" that imposes its sonic signature upon a track.

Space Designer comes with a wealth of these acoustic space recordings, called impulse responses (IR), upon which it bases its processing. IR files, as well as any processing parameters, are stored in the effect settings.

3.

Click the Settings menu (the small triangle below the Bypass button) and choose 01 Vocal Reverbs > Long Vocal Reverbs > 3.8s_Vocal Plate Clear.

NOTE

If you have created custom presets of your own, Logic will list the installed factory presets in a folder named Factory. If you do not see the 01 Vocal Reverbs folder, look in the Factory folder, and then continue along the file path specified above.

The IR takes a moment to load. After loading, you can see the visual representation of the IR, which, in this case, was sampled from an electronic reverb processor's plate algorithm.

4.

Click the A button located at the bottom of the IR waveform display.

This button allows you to zoom in on the attack area of the IR's waveform display. The magnification helps you see how the signal will be affected by the reverb sample.

NOTE

If you look closely at the zoomed IR waveform, you'll notice that the reverberation signal occurs immediately (it starts at the far left).

Space Designer offers additional processing of the IR signal via an extensive array of editing parameters. These parameters range from settings found on traditional reverb units to control settings specific to working with volume and filter envelopes.

When using reverb on vocal tracks, it is often desirable to complement the sound with an amount of pre-delay to separate the original signal from the reverb tail.

5.

Drag up the pre-delay number (located just below the IR waveform display) to a value of 61ms.

NOTE

Making an adjustment on any parameter that affects the IR (such as pre-delay) requires a moment for the plug-in to reload the IR and recalculate the convolution. This limits automation and causes a short delay in playback through the plug-in while it completes the process.

Now that you've completed some basic adjustments to the Space Designer reverb, you can send the lead vocal signal to the bus effect for processing. You do this by assigning the channel Send to the bus and controlling the amount of signal sent by means of the Send level.

6.

Close the Space Designer window.

7.

Click the Global button.

The screen toggles back to the Track view, and all tracks used in the arrangement are displayed.

8.

Click-hold the topmost Send slot on the Vox_lead channel, and choose Bus > Bus 4.

Once a Send destination has been assigned, the corresponding Send knob appears next to the slot. By adjusting the Send knob, you can choose the amount of signal sent to the chosen destination (in this case, Bus 4).

9.

Play the song.

10.

While listening to the lead vocal track, drag up the Send knob, setting a value of 14.9dB.

NOTE

When you solo a track assigned to a bus, Logic automatically keeps the effects return channels (bus channels) open. This automatic mute suppression allows you to hear the soloed track with the bussed effects applied. The same applies when you solo an effect return signal. The channels fed into the effect are muted, but their effect Sends remain open, ensuring that the effect continues to receive a signal.

11.

Stop the song.

12.

Click the Solo button on the Vox_lead channel to unsolo the channel.

13.

Disable Cycle.

MORE INFO

The distributed audio processing feature in Logic Pro 7 allows you to expand the processing capacity of your Logic Pro system by offloading calculations for software instrument and DSP effects to additional Macintosh computers that are connected by Gigabit Ethernet. This is effective when you need additional processing horsepower for CPU-intensive software synthesizers or plug-ins such as Sculpture or Space Designer. For more information on how to set up a distributed audio processing system, refer to page 382 in the Logic Pro 7 Reference Manual.




Apple Pro Training Series Advanced Logic Pro 7
Apple Pro Training Series: Advanced Logic Pro 7
ISBN: 0321256077
EAN: 2147483647
Year: 2004
Pages: 166
Authors: David Dvorin

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