Three ways to group tracks
- Bus (audio subgroup): several tracks are routed into a common track, which receives their sum. Plugins (group compression, EQ, saturation) can be inserted on the bus and a single fader controls the whole group. Examples: drum bus, vocal bus, instrumental bus.
- Send (aux): a copy of the signal, adjustable per track, goes to a return track with an effect at 100% wet (reverb, delay, parallel compression). The original track continues to its bus.
- VCA: a control fader that receives no audio: it moves the faders of the assigned tracks together while keeping their relationships. Born on consoles with Voltage Controlled Amplifiers, it now exists in almost every DAW (in FL Studio through fader “links” to a controller or through the automation of a group; in Pro Tools, Cubase, Logic and Studio One as a VCA track).
Practical differences between bus and VCA
| Aspect | Bus | VCA |
|---|---|---|
| Passes audio | Yes | No |
| Group plugins | Yes | No |
| Post-fader sends | Stay unchanged when you lower the bus (the reverb does not go down) | Go down with the tracks (the reverb follows) |
| Group compression | The compressor on the bus reacts to the input level | No effect on the group compressor |
| Typical use | Glue, character, group control | Level automation of a group together with its effects |
If you lower a vocal bus by 3 dB, the post-fader sends of the individual vocals to the reverb stay the same: proportionally the vocal becomes “wetter”. With a VCA the vocal and its sends go down together and the dry/wet ratio is preserved.
Recommended session structure
- Tracks → group buses: Drums, Percussion, Bass (808 + bass), Harmony (piano, guitars, pads), Lead/synths, Lead vocal, Backing, FX.
- Group buses → (optional) instrumental bus (everything except vocals) and vocal bus.
- Buses → mix bus / master.
- Sends for shared effects: 1–2 reverbs (short and long), 1–2 delays (1/4 and dotted 1/8), parallel drum compression, possibly parallel saturation.
- VCA or group control for: all the drums including returns, all the vocals, everything except the lead vocal (for vocal/backing balance).
In FL Studio
- Routing: select the source track, then on the destination track click the arrow at the bottom (Route to this track only) or right-click “Route to this track only”. Disable the source's send to the master when it goes to a bus.
- Sends: you adjust the send level from the send arrow; with right-click → “Sidechain to this track” the source is only a control signal.
- Pre/post fader: by default sends are post-fader; for a pre-fader send use an intermediate track or the “Fruity Send” tool in the track's chain.
- Fader groups (VCA function): link the faders of the tracks to a single control with “Link to controller” and a common controller (Fruity Formula Controller, Fruity Peak Controller or a MIDI fader); moving or automating that control moves all the tracks in the group.
- Details in “Routing in FL Studio”.
Typical processors on buses
| Bus | Processors | Values |
|---|---|---|
| Drums | Glue compressor, saturation, EQ | 2–4 dB GR, ratio 2–4:1, attack 10–30 ms |
| Bass (808 + bass) | EQ, saturation, light limiter | 1–2 dB of limiting |
| Harmony | EQ (cut at 2–4 kHz for the vocal), light compression | 1–2 dB GR |
| Vocals (lead + backing) | Light compression, group de-esser | 1–3 dB GR |
| Instrumental | Dynamic EQ with sidechain from the vocal | −1/−3 dB at 2–4 kHz |
| Mix bus | Glue, wide EQ, possibly saturation | 1–3 dB GR |
Common mistakes
- Sending the same track to both the bus and the master: the track sounds doubled and the phase changes with the bus plugins.
- Heavy compression on every bus and then on the master: the mix loses dynamics at every stage.
- Lowering a bus to reduce a section and forgetting that post-fader sends stay the same.
- Too many bus levels: harder to tell where a problem is, and more latency from plugins.
- Reverbs inserted on every track instead of on a send: more CPU and inconsistent spaces.
Starting settings
| Parameter | Value | Why |
|---|---|---|
| Main groups | Drums, Bass, Harmony, Lead, Vocals, FX | Simple balance control. |
| Shared sends | 1–2 reverbs, 1–2 delays | Consistent space and less CPU. |
| Glue on the drum bus | 2–4 dB GR | Drum cohesion. |
| Bus level | Peak −10/−6 dBFS | Headroom on the mix bus. |
| Mix bus before the master | Peak −6/−3 dBFS | Room for mastering. |
Frequencies to watch
| Range | What to do |
|---|---|
| Below 100 Hz | Bass bus: control 808 and bass together, mono, limited peaks. |
| 2–4 kHz | Harmony and instrumental buses: room for the vocal with static or dynamic EQ. |
| Above 8 kHz | Vocal bus: group de-essing if the sibilance of lead and backing adds up. |
Example chain
| Step | Tool | Settings | Why |
|---|---|---|---|
| Tracks | FL Studio mixer | Trim and track processors | Sound of each element. |
| Group buses | Dedicated mixer tracks | Glue, EQ, saturation | Group cohesion. |
| Sends | Return tracks | Reverb, delay, parallel | Space and density. |
| VCA / fader group | Link to controller / multiple selection | Group automation | Balance of the sections together with their effects. |
| Mix bus | Master or “Mix” track before the master | Light glue | Premix ready for mastering. |
How to check the result
- Peak of each exported bus between −10 and −6 dBFS; mix bus between −6 and −3 dBFS before mastering.
- Exported buses (stems) summed: they must rebuild the mix (null test against the full mix, residual below −60 dB).
- Bass bus correlation +0.9/+1; drum bus +0.5/+0.9.
- Short-term loudness of the vocal bus relative to the instrumental bus consistent with the genre (in pop the vocal solo is about 1–3 LU below the instrumental solo).