.GLL File

The gll file extension seems to be mainly associated with EASE SpeakerLab application that is used to simulate electro and room acoustics.

The gll compiled text file describes geometric and acoustic properties of a loudspeaker system, cluster, and array or of a similar system.

How to open:

Use EASE SpeakerLab to open *.gll compiled text files.

How to convert:

There doesn't seem to exist a way to convert or export *.gll files to anything else.