Just recorded beautiful resonant thunder, strong peaks @ 1kHz 2kHz, consistent throughout whole storm, any idea what could be causing this? <a class="auto-link" href="https://soundcloud.com/barnabywalters/2016-07-13-1khz-2khz-resonant-thunder">Listen: <a href="https://soundcloud.com/barnabywalters/2016-07-13-1khz-2khz-resonant-thunder">https://soundcloud.com/barnabywalters/2016-07-13-1khz-2khz-resonant-thunder</a>
