Simone Lovera
The pad arrives as a stereo file, occupies a stereo track, and feeds two channels of every plugin in its chain. Fold it to mono and play it against itself: nothing changes, because the left and right channels are identical. It was never stereo. It was mono wearing a wider file.
The three things a stereo file can be
A stereo file holds two channels, and that is all the format promises. What the channels contain is one of three situations. True stereo: left and right genuinely differ, and the width is real information. Fake stereo: the two channels are identical, so the file is mono in a stereo container. Hard panned: the content sits entirely on one side, usually because a stereo bounce captured a mono source panned off center.
Files arrive this way for boring reasons. Bounce templates print everything as stereo regardless of content. Export presets default to interleaved. And some deliveries carry the opposite problem: one stereo source split into two mono files named .L and .R, which need putting back together before anything else about them makes sense.
Why fake stereo is a tax
Every fake stereo file doubles something for no return. Two channels on the track, two channels through every insert, twice the voices for content that is mono by any honest measure, in a session that now reads wider than it is. One file costs little; a forty stem folder where half the files are fake stereo costs real resources and real clarity, and the session lies about its own size.
The manual cure is worse than quiet acceptance, which is why most rooms quietly accept it. Finding the fakes means auditioning each suspicious file, folding it, listening for the difference and deciding, one file at a time, with a deadline running. Nobody audits a stem folder by ear, so the tax ships with the session.
What fMusic decides
On import, fMusic resolves stereo content before anything else depends on it. Pairs of mono files named .L and .R are first merged back into one stereo file, unless you set them to stay as two mono tracks. Then every stereo file's actual content is classified by reading the audio, not the file name: fake stereo, hard panned or true stereo. Each fake stereo or hard panned file then follows the rule you set in Settings for its case: folded to mono, split into two mono files, or left as it is, applied identically on every import. True stereo is never touched.
The resolution runs at the very start of the per file pipeline, deliberately, because everything downstream depends on each file's final channel form: how many tracks exist, how lanes are built, what gets routed where. Deciding late would mean building the session twice.
The badge is the feature
Classification that acts silently asks for faith. Every file fMusic converted carries a badge in the routing screen saying what was done to it: → Mono (L+R), → Mono (L), → Mono (R) or → Split, with the verdict behind it, mono content or hard panned, one hover away. A file without a badge arrives exactly as it was delivered. You see what the tool decided before Pro Tools is touched, and can verify any call you doubt. The visualizer sits right there for the listening half of that check, and the same rules power Add Track… in the editor, so a file added late is resolved exactly like the batch it joins.
The previous fMusic badged its conversions too, but applied one fixed treatment per case; in the rebuild the treatment is yours to set, part of the larger pattern mapped in what changed from fMusic. A visible decision is the difference between automation you tolerate and automation you trust, because a badge can be challenged and a silent fold cannot.
Your rules, not a guess
The classification is a fact about the file; what happens next is policy, and the policy is yours. Which cases fold and which stay is set once in Settings, like the rest of the import pipeline, and read by every import afterwards. A room that wants every fake stereo file folded and hard panned material left alone writes that down once. Alongside gain staging in fMusic Suite, which lands levels the same way on every session, the stereo rules are the other half of material arriving in a known state rather than an inherited one.
Stereo verdicts are part of both tiers: the detection, the rules and the badges work the same in fMusic Studio and fMusic Suite, with the split between the tiers mapped in fMusic Studio vs Suite.
What it does not do
The verdict is about channel content, not musical intent. True stereo means the channels differ; it does not certify that the width is good, and fake stereo means the channels match, not that the producer was wrong to print it wide. That is exactly why the action is a rule you set rather than a judgment the tool makes. And the verdicts stop at channel identity: phase relationships, width tricks and anything subtler than whether two channels match are still your ears' job.
Frequently asked questions
What is a fake stereo file?
A stereo file whose left and right channels are identical: mono content in a stereo container. It doubles track width and processing for no audible return, which is why detecting it matters.
How does fMusic handle .L and .R files?
Pairs of mono files named .L and .R are merged back into one stereo file before classification (a setting you can turn off), so split deliveries are put back together first and then judged like any other file.
Does fMusic fold every stereo file to mono?
No. Fake stereo and hard panned files each follow the rule you set for their case in Settings: fold to mono, split into two mono files, or leave as is. True stereo is never touched. The rules apply identically on every import.
Where do I see what fMusic decided?
In the routing screen. Every file fMusic converted carries a badge saying what was done, → Mono (L+R), → Mono (L), → Mono (R) or → Split, and hovering it shows the verdict behind it. Files without a badge were left as they arrived. The badges stay visible, so any call can be checked before the session is built.
Is stereo detection a Suite feature?
No. Stereo content resolution, the rules and the badges are in both fMusic Studio and fMusic Suite.
Can I check a verdict before it reaches Pro Tools?
Yes. The badges sit in the routing screen and the material can be auditioned in the visualizer, so a doubtful verdict is a listen away from confirmed, before anything is written. If you disagree with a call, change the rule for that case in Settings and import again.
fMusic classifies every stereo file by what its channels actually contain, folds it per your rules, and badges every file it converted so you can check the call. The import pipeline is at forte-ai.com/fmusic.
