Octant Documentation

Overview

Octant is a free VST3 and AU loudness and true peak meter for delivering audio to spec. You set a delivery target, then instead of a wall of numbers you get a plain verdict: how far under or over that target you are, your actual integrated loudness, and a peak hold that flags OVER once a true peak crosses the ceiling. It measures to the ITU-R BS.1770-4 and EBU R128 standards. Load it on your master bus in any VST3 or AU host: Ableton Live, Bitwig, FL Studio, Reason, Logic, Cubase, Studio One, Reaper, and more. Everything is unlocked from the first launch: there is no account, no license key, and no nag.

Installing

• Download the installer .dmg from the Octant page.
• Open the .dmg and run the installer, following the prompts.
• The installer places both the VST3 and AU into your system plugin folders.
• Open your DAW and rescan plugins if it does not pick up the new install automatically.
• Load Octant on your master bus, so it hears the full mix.

Choosing a target

Pick where the audio is going from the target selector and Octant loads that platform's loudness target and true peak ceiling. The built-in presets are Spotify (-14 LUFS), Apple Music (-16), YouTube, Amazon, EBU R128 (-23), ATSC A/85 (-24), Podcast, and Netflix (approximate).

Two more choices sit alongside the presets:

• Custom is where Octant opens by default: a plain 0 dBFS reference at a 0 dBTP ceiling that you dial in with three sliders for target LUFS, ceiling (dBTP), and tolerance. Octant judges against those exactly as it would a preset, so you can meter to a house spec or a client delivery sheet that is not on the list.

Reading the verdict

The verdict is split into three, so you can see at a glance both whether the loudness lands and whether anything clipped:

• Under / over. How far the integrated loudness sits from the target, with its direction, so you know exactly which way to move.
• Integrated loudness. The actual measured integrated loudness (LUFS) of the pass, the number the target is compared against.
• Peak hold. The highest true peak seen so far, which flips to OVER once it crosses the target's ceiling. See below.

Above the three cells, a large headline shows the target ceiling for the selected target (for example 0.0 dBTP), so the number you are aiming under is always in view. It is not a pass or fail light, and not a second copy of the loudness reading.

PEAK HOLD

PEAK HOLD keeps the single highest true peak (dBTP) of the pass and holds it on screen rather than letting it flick past. The moment that held peak crosses the target's true peak ceiling it flags OVER, so one clipped transient in a long pass cannot slip by while you were looking somewhere else. Clear it with RESET (below) when you want to start a fresh measurement.

The meter and history graph

The on-screen bar meter shows momentary, short term, and true peak side by side, each with a peak-hold mark, and draws the target band right on the scale so you can see the signal sitting inside or outside spec in real time.

Below it, a scrolling loudness history graph plots the pass over time, so you can see where the mix drifted loud or quiet across a whole song or program instead of only knowing the final number.

Clip indicator, RESET, and AUTO RESET

The clip indicator latches the moment a true peak crosses your ceiling and stays lit until you click it to clear, so a single clip buried in a long pass is still there waiting when you look back.

Clearing the measurement itself is up to you. Press RESET to clear the integrated loudness, the peak hold, and the history graph and start a fresh pass. Turn on AUTO RESET and Octant clears them for you automatically whenever playback starts from the top, so every take is measured clean. Leave AUTO RESET off to free-run and reset by hand whenever you choose.

Second-screen window

Octant has a detachable, always-on-top meter window that shows everything the plugin window does: the verdict, the readouts, the bar meter, and the history graph. Float it on a second display and keep it visible over your DAW while you work, big enough to read from across the room. A STEREO / MONO readout tells you what is actually feeding the meter, so you can confirm you are metering the full stereo bus and not a collapsed or single channel.

System requirements

• OS: macOS 11 (Big Sur) or later.
• Chips: Apple Silicon and Intel (a single universal build).
• Formats: VST3 and Audio Unit (AU).
• Hosts: any VST3 or AU host, including Ableton Live, Bitwig, FL Studio, Reason, Logic, Cubase, Studio One, and Reaper.
• A Windows build is not available yet.

Troubleshooting

Octant is not appearing in my DAW. Rescan plugins in your DAW's plugin manager, then fully restart the DAW (not just close and reopen the project window).

The meter is not moving. Confirm Octant is on a bus that is actually passing audio, ideally the master bus, and that the track is playing. As a meter it reports what it hears and passes the signal through unchanged.

The readout says MONO when I expected stereo. Octant is being fed a single channel. Check that it is inserted on the stereo master bus rather than a mono channel or a summed send.

My verdict never lands on target. Make sure the selected target matches where the audio is really going, or switch to Custom and enter the exact target, ceiling, and tolerance from your delivery sheet.