UDP Audio Meter

The UDP Audiometer was born from a straightforward frustration: existing audio measurement tools were too limited, too expensive, too complex, or too slow for practical real-time monitoring over a network.

Development began as an app to display the data from an old hardware 8 channel audio meter that I love, but wanted the meter data in my Computer screen.

Using serial RS232 I got the meter to output a binary data stream to render the UI in my app.

Serial connection and newer M-series Macs don't get along very well, so I used an ESP32 board as a Serial to Ethernet bridge, and got a UDP data stream which the meter app was able to use.

Then I hit the latency wall. Serial connection was just too slow, even after I increased the baud rate to the maximum the meter could handle without errors and while it worked to reduce latency, the higher rate was too much for the CPU in the meter app to work correctly. (Real-time metering can be quite CPU-intensive.)

So I did some data filtering and some other rate adjustment tricks on the app, and got the CPU under control and the latency to sit around (~35ms).

I would have been done, except that after using the app for a while, I started to really hate this "latency" and also found the meter hardware to be quite limiting, especially now that I have the computer to display the data, I wanted to display Loudness information, I wanted phase relationship with side wall channels (ie: L to LS, or RS to RBS) I wanted an FFT analyzer to find problematic frequencies, etc... so I decided it was time to build a plugin and skip the hardware meter altogether.

My plan was to make it easier for the DAW to get me this info, so I decided to use a remote client for display, I had the connection backbone figured out, so I moved the meter app to iOS (iPad) and let the plugin just stream the data, like the old hardware unit.

Getting up and running takes under two minutes.

Download the installer, add the plugin to an AUX or Master track in your session and select the Network interface that is in the same LAN as your meter app.

Install the companion iOS app from the App Store. Alternatively, open the meter app on the same system.

The connection should be automatic and meter data streaming will begin.

The Offline Analyzer is designed for post-production workflows where you need to measure loudness across a queue of stems or deliverables quickly and accurately. It processes files at many times real-time speed, using all available CPU cores in parallel so large batches complete in a fraction of the time it would take to play them back.

All enabled metrics are measured in a single read of the file. EBU R128, ATSC A/85, True Peak, and Leq are fed the same audio block per iteration — no additional file reads are needed regardless of how many metrics are active.

Results are cached per file. If you analyse a queue with EBU R128 enabled, then later enable Leq, only the Leq pass runs on the already-measured files. Previously computed values are preserved.

Multi-mono sessions — where each channel lives in a separate mono file with a suffix (L, R, C, LFE, Ls, Rs, etc.) — are detected and grouped automatically. The files are opened simultaneously and read in lockstep into a single interleaved buffer, so the engine receives a proper multichannel stream.

Results can be exported as a tab-delimited text file compatible with Excel, Numbers, or any QC spreadsheet workflow.