Basics: Five Questions about Effects Placement

By Craig Anderton

There are plenty of places in SONAR where you can process the audio signal, but you need to know how to choose the right one.

What’s an “insert” effect? Don’t you always “insert” an effect? You indeed “insert” effects, but there’s a specific effect type usually called an Insert effect that inserts into an individual mixer channel. In SONAR, this inserts into a channel’s FX Bin or the ProChannel (Fig. 1).

Fig. 1: The FX bin for two channels have insert effects, as does the ProChannel for the Vocals channel.

Insert effects affect only the channel into which they are inserted. Typical insert effects include dynamics processors, distortion, EQ (because of EQ’s importance, it’s a permanent ProChannel insert effect), flanging, and other effects that apply to a specific sound in a specific channel.

Then what’s a “send” effect? Also called an “aux” or “bus” effect by various manufacturers to make sure beginners are as confused as possible, these effects insert into a send bus’s FX Bin or ProChannel. Therefore, it processes all the individual track signals feeding the bus.

The signals riding on the aux bus originate from the send controls on individual channels. For example, suppose you want to add reverb (a common bus effect) to the instruments on channels 1, 3, and 4 (Fig. 2). You insert a send in each channel, then use their send controls to send some of the channel signal (the amount depends on the send control knob) to the send bus.

Fig. 2: Three channels are sending a portion of their signal to a bus, which has a reverb effect inserted.

The pre/post switch for the send bus chooses whether the signal going to the bus comes from before the channel fader (this means the signal level feeding the send bus is constant, regardless of the channel fader level), or after the fader (pulling down the fader also reduces the amount going to the bus).

Bus effects are generally edited to produce a processed (wet) sound only, because channel faders send the dry signal to the main output bus. The dry signals blend with the processed sound returning from the bus to obtain the desired balance.

What’s a “master” effect? This inserts in the master stereo (or surround) bus. Therefore, it affects all audio—every track and every bus. The most common master effects are EQ and dynamics, and they insert into the master bus’s FX Bin or ProChannel.

If a send effect processes several different tracks at the same time, why not just insert those effects on each track? Every instance of an effect requires some CPU power. Reverbs often take a lot of CPU power, so feeding different tracks to a common reverb send effect saves CPU power. However, another advantage is that in this case, a common reverb providing something like a “hall” sound is more realistic as it emulates the effect of all those tracks being in a common hall. If each had its own hall effect, the overall result would likely not be as realistic.

What are “series” and “parallel” effects? These refer to effects routings. With series effects, one effect’s output feeds the input of the next effect in the series of effects. All ProChannel effects are in series, and all FX Chains contain a series connection of effects.

Parallel effects require splitting a signal into two paths. Each path goes through its own effect (or series combination of effects) and is then summed together (Fig. 3).

Fig. 3: TH2 can split the signal into two paths, and you can insert processors in each path. They’re summed back together to provide the output.

There are two main ways of creating parallel effects in SONAR. Some effects have the capability built-in, like Overloud’s TH2. It splits the signal internally into two paths and mixes them back together again. The PC4K S-Type Bus Compressor and PC76 U-Type Compressor ProChannel modules have two parallel paths, one processed and one dry, so you can set a balance of the two. Another option is to send a track’s signal to two send buses, each with its own effect, then send them into a master bus (or other bus) to mix them together.