Specula for Recording: narration with a room check and punch-ins on macOS

Why the room comes first

ACX wants a noise floor less than −60 dB RMS, and the floor is set in the room, before the first word.

Level dialogue buys a few dB on a floor that just misses. Hiss, a fridge, a fan or traffic in the room cannot be leveled out of a narration. The room check reads that floor while the input is armed and nothing is recording, measured as the finished file's noise floor will be: the mono mix of the last five seconds, the 90th percentile of its 100 ms blocks. It reads Quiet enough for ACX or Too loud for ACX, and an input that delivers digital silence, such as a microphone without permission, reads No input signal instead of passing.

MetersEach input channel's level and peak, the momentary loudness and the true peak, on Specula's own BS.1770 meter.

RoomThe room's floor over the last five seconds against ACX's −60 dB RMS limit, paused while a take records.

TakesEvery take kept for seven days, to add to Compare, save as a file or move to the Trash.

PunchA punch at the playhead keeps the file's length, and speech is detected again inside it.

From input to take

Arm the input, check the room, choose where the take goes, record.

1 · Arm the input

⌘7, or Record in the top bar, arms the input, with a file open or none: Record is how a file starts. The sidebar's Input part picks the device, the layout (mono, stereo or 5.1) and the source channels on a multichannel interface. The canvas shows each input channel's level and peak, the momentary loudness and the true peak. Without microphone access it says so and names the switch in System Settings › Privacy & Security › Microphone.

2 · Check the room

While the input is armed, the Room check asks for five quiet seconds, then gives the room's floor against ACX's limit, and keeps reading it until a take starts.

3 · Choose where the take goes

Take goes to, in the task bar: New file opens the take as its own file; Append puts it on the end of the open file; Insert at playhead puts it in at the playhead and moves the rest of the file later; Punch in replaces the selection, or records over the audio from the playhead and keeps the file's length. Every join gets an equal-power crossfade of the Splice length set beside it.

4 · Record

The record button in the top bar's transport starts and stops a take (Record › Start Recording), and the take draws on the canvas as it records; Esc never ends one. A take that lands in the file is one step in the Edit task's history, so Undo takes it back out. A punch keeps the file's chapters and corrected speech regions, and speech is detected again inside the punched stretch, also after Undo and Redo.

5 · Keep the takes

Every take is written as it records and listed in the sidebar's Takes for seven days, with how long it is kept. To Compare puts a take beside the file in Compare, Save As… writes it as 32-bit float WAV, AIFF or CAF, and Move to Trash removes it. The Record menu acts on the selected take as well.

After the take

A recorded file goes through the same checks as any other. Under Deliver to Audiobook the delivery card judges it against ACX, the Chapters task measures it chapter by chapter, the Speech task corrects the speech regions its dialogue loudness and noise floor are measured with, and Level dialogue ducks a floor that just misses. Audiobook / ACX → Podcast →

Before the first chapter

The Record task checks the room against ACX's floor, keeps every take for a week, and punches a correction in without moving the rest of the file.

Read the Record guide → Back to Specula