Behavior of combining Loopback timing reference and Offset

[neodog]

Does using a Loopback timing reference automatically compensate for the timing differences observed bout output and ref in a measurement?

If so, what is the effect of having both the loopback and the offset?

I got the above by using a loopback reference, and then using "Estimate IR" to update the standing offset for future measurements. Do the authorities fight with each other in establishing t=0, or does the loopback reference always win?

 

[John Mulcahy]

t=0 is offset from the loopback by the offset time.

 

[neodog]

I see. So even if you use a loopback timing reference, you pretty much always have to use "Estimate IR delay" on the result, unless you are 100% sure nothing moved since the last time the offset was updated?

But if "Estimate IR delay" is required, do I actually get a benefit from using a loopback reference at all? Won't I get the same accuracy if I just use "set t=0 on IR peak"?

 

[John Mulcahy]

I don't understand the questions. The loopback provides a timing reference. The timing offset allows additional fixed delays, such as time of flight from source to microphone, to be removed. If you don't care about the timing reference, don't use it.