Acoustic treatment for side glass doors / please, need ideas.

Understood, thanks for the tip Erik

can you listen with the doors open?

do this in steps:

Phase 1 - heavy curtains over the closed doors

Phase 2 - get & read the Master Handbook of Acoustics; do the calculations for high vs. md vs. low freq. regions for your room
- then do further tmts

Mathematics to the rescue! Hurray! 😬

In my listening room I have 8' sliding door on left side, 3' x 6' window directly behind equipment and 4' x 6'8" doors on right. My first approach was the Marigo Window treatment on all. That took a noticeable bite out of the muddiness/bounce I was hearing.  I then put vertical fabric blinds on the doors and fabric venetian blinds on the windows behind the gear which helped dampen the LFs and lessen the glass bounce. The real improvement however came with finally adding ASC Thermal tube traps in each corner. The traps cleaned up remaining ugly acoustics in the room - not just those caused by the amount of glass. Plus by rotating them (top & bottom) independently, I can fine tune them to the music I'm playing (e.g. digital v analog).  I took it step by step assessing each one along the way.  That's my experience, FWIW.  Good luck   

Thanks for your comments but honestly can't understand how tube traps can deal with the first reflections from both sides, would you please elaborate?