I knew it changed but I didn't think the speed of sound changed that much....

It will probably be in 0.2ms increments so most people are happy. That way I am currently doing things will allow a maximum of about 26ms (about 8-9 metres using my value for speed of sound). The distance given will be based on a fixed speed of sound probably - the delay in milliseconds value will be the accurate number.

Don't worry about the UI - I have that basically done already - just like temperature setting under Hijack. In fact it's just another Hijack menu.

I'm not using any of Richard's voladj stuff -it's basically all my code.