ETC: The “Radar” of Room Acoustics
If an RTA is a snapshot of your sound, the Energy Time Curve (ETC) is its radar. Found in Smaart’s Impulse Response mode, the ETC tracks the energy of a sound as it travels through a room over time.
The first and largest spike represents the direct path—the sound travelling straight from the speaker to the microphone. Every spike that follows is a reflection.
By measuring the time delay in milliseconds between the direct spike and a reflection, you can calculate exactly how far the sound has travelled before hitting a surface. For example, a prominent spike 25 ms after the direct sound corresponds to a reflection that has travelled roughly 8.5 metres further than the direct path (1 ms ≈ 34 cm).
This makes it possible to identify whether the reflection comes from a back wall, a balcony rail, or a side-stage monitor desk. Do not EQ the “dip” in the frequency response caused by that reflection; it is better to fix the reflection physically whenever you can.
Smaart is excellent on its own, but most users find they get much more out of it after some structured training. That’s where our seminars come in. At TZ Audio we run practical seminars, both online and in-venue. We offer seminar-only or full “all you need packages” including software & hardware. It’s simply the fastest way to become comfortable and confident with the measuring a sound system.
If you’re in Norway, Sweden, Denmark or Iceland – or elsewhere – we offer is online seminars and traveling to Norway is a valid option too of course. We’re here if you have any questions about the software or upcoming seminars.
Thanks for reading!