A
Andrew Camp
Description:
Add a host-level
Frequency Crossover
module that splits any audio source into multiple bands (e.g., Low/Mid/High, up to 5), routes each band to its own bus/FX chain, and then
phase-aligned
recombines them—or leaves them discrete for multibus workflows.
Problem:
Creating multiband processing in Loopy Pro currently requires awkward stacks of filters, manual routing, and ad-hoc phase compensation. That’s slow to set up, error-prone (level/phase holes at crossover points), and hard to manage live—especially when you need band mutes/solos, quick slope changes, or precise latency alignment.
Proposed Solution:
  • Crossover Module (Insert or Send Splitter):
- Up to
5 bands
with draggable crossover points (Hz) and
filter types/slopes
: Linkwitz–Riley, Butterworth, Bessel;
6–48 dB/oct
.
-
Processing modes:
-
Zero-Latency
— minimum-phase IIR,
no added latency
(no look-ahead), ideal for live monitoring and tight feel.
-
Minimum-Phase
— classic IIR with negligible latency, musical phase response.
-
Linear-Phase
— FIR with latency shown; perfect summing and no phase shift across bands.
-
Phase-safe summing
with automatic
latency compensation
and per-band gain trim; global auto-gain to preserve loudness.
-
Per-band routing:
send each band to a
Bus
,
Channel
, or
Return FX
; optional internal
Band Slots
for inline FX.
-
Solo/Mute/Bypass
per band;
Band Link
(adjust symmetric crossovers together);
Oversampling
option for HF integrity.
-
Metering:
per-band peak/RMS/LU with correlation; global
summed meter
to verify null-safe recombine.
  • Workflow & UX:
- One-click templates:
3-Band (LR24)
,
4-Band Mastering
,
Low-Split (Sub)
,
Top-Shimmer
.
-
Snapshot
A/B for crossover points & levels; copy/paste settings across instances.
-
Drag-to-assign:
drop a bus or AU onto a band slot to route instantly.
  • Actions & Variables:
- Actions:
Add Crossover
,
Set Band Count
,
Set Crossover Hz (band n)
,
Set Slope/Type
,
Solo/Mute Band
,
Route Band to Bus …
,
Toggle Linear-Phase
,
Toggle Zero-Latency
,
Recall Snapshot A/B
.
- Variables:
xover.bandCount
,
xover.band[n].hz
,
xover.band[n].slope
,
xover.band[n].gainDb
,
xover.latencyMs
,
xover.isLinear
, **
xover.isZeroLatency
**,
xover.sumDeltaDb
.
  • Safety & Performance:
-
Zero-Latency mode
guarantees
0 ms added latency
by avoiding look-ahead; linear-phase displays and compensates its latency.
-
CPU guard
and latency readout; linear-phase warns when project quantize/count-in might need offset.
-
Auto-polarity checks
; soft clip/limit at recombine to prevent overs.
- Fully
undoable
; presets per project/page.
Benefits:
  • Fast, reliable
    multiband
    setups with correct
    phase
    and predictable gain.
  • Zero-latency option for
    tight live performance
    , plus linear-phase for transparent studio work.
  • Cleaner routing: lows to subs, mids to comps, highs to shimmer—without manual filter spaghetti.
  • Reusable, readable templates that are easy to tweak under show conditions.
Examples:
  • Tri-band live mix (Zero-Latency):
    Lows (<120 Hz) →
    Sub Bus
    (Outputs 3–4), Mids (120–3.5 kHz) → glue comp, Highs (>3.5 kHz) → shimmer verb; LR24; summed meter shows −0.1 dB delta.
  • Parallel distortion:
    High band (>2 kHz) to a fuzz AU; mids to clean delay;
    Linear-Phase
    with 48 dB/oct to keep crossover invisible on a studio bounce.
  • Kick/bass management:
    Low band (<90 Hz) routed to a sidechain-controlled limiter on the bass bus; mids/highs remain unaffected for clarity—
    Zero-Latency
    keeps playing feel intact.
This summary was automatically generated by GPT-5 Thinking on 2025-10-08.
Original Post:
I want the ability to route audio to separate paths based on frequency points. Ex. I play guitar and want all notes below 100 hz to go to channel with octave down fx, everything above to main guitar channel.