RTL Utility is a tool for measuring the Round Trip Latency of your DAW and audio interface. The utility has been developed for the Low Latency Performance test at dawbench.com.

Balanced jack
Loopback patching is required

When your DAW sends data to your audio interface for playback, it doesn’t send a continuous stream of data one bit at a time. What it does is fill up a section of RAM called a buffer and sends that in one message when it is ready. Before sending the next message it has to fill the buffer again. This wait time introduces a latency, or delay, between something happening in your DAW and when you actually hear it.

When you are recording, the audio interface buffers and sends data to your DAW in a similar fashion. This introduces latency into your recordings.

If you send a signal from your DAW, out through the audio interface and back in via a loopback patch, then there will be a round trip latency which is the sum of the output and input delays. This is the RTL.


Windows only (tested OK on WinXP, Win7x64)

Current version: v0.4.1 (still in beta)

Download zip file

Download documentation