We are just about finished painting the theatre and are ready to order the carpet. We are getting a commercial nylon cut pile type. My carpet guy isn't able to offer an opinion one way or another on whether we should go with a fiber pad or the standard bonded rubber pad under the carpet for best sound in the theatre. This will be tacked on a concrete floor and continues on the 7" riser where the seating goes. Any recommendations? Many thanks in advance for any help. I hope to order this week.