Loosing Time information when Exporting IR

[heleneb35]

Hi,
I've been using REW to make IR measurements of several speakers of an array. I used the acoustic time reference option so that I could compare the time delays between my different speakers' measurements. Once I've done the measurements, I could visualize and estimate the IR delays according to the reference output. However, when I export the impulse responses, I loose the time information. All the impulse responses are aligned at 1 second. How to export the IR with their actual delays with respect to the acoustic timing reference?
I've seen in the REW Beta Releases that the following feature was added: "Ensure peak in an exported impulse response is at 1 second if the export has only one channel". That's exactly what is happening to me. However, how could I bypass this feature?
Thank you very much for your help.

 

[John Mulcahy]

The difficulty is that there is no concept of absolute time in a WAV file, and delays can be positive or negative relative to the reference. There is a suggestion for preserving relative timing in the help though:

The peak of the exported response occurs 1 second after the start unless the IR window has been applied, in which case the export starts at the first windowed sample and the peak location depends on the IR window settings. That can be used to preserve relative timing for exported impulse responses that have been captured with a timing reference: define IR windows for the responses that have the same window ref time and the same left window width - use rectangular windows if the data should not be altered by the window. The exported IR for each impulse will then start at the start of the left window, which will be at the same absolute time for each, so their relative timing will be preserved.

 

[heleneb35]

It's working! Thank you so much.