Advise appreciated on my Acoustical plan

[SMM]

This is my (getting close to final as the builder starts next week) layout. Any/all advise would be greatl appreciated. The room will be approx. 20' 6" long x 12' 6" wide with an 86" finished ceiling height (acoustical ceiling).

It's been suggested to fill the riser and stage with fiberglass insulation, and to add lots more fiberglass insulation to the floor joists above the drop ceiling. The room has no windows and two doors. The surrounds will be on-wall dipoles and the rears will be in-walls. I'm planning to wire for two subs but for budget reasons will start with one and see how it goes. Thks!

 

[Ethan Winer]

> Any/all advise would be greatl appreciated. <

It looks to me like your front row seating is dangerously close to the center of the room, front to back. That's where the low frequency response is worst (least bass). If you could move back a bit that will really help a lot. Ideally you'd sit so your ears are 7 to 8 feet in front of the rear wall behind you. If that's not possible, at least aim to be as far behind the center line as you can.

> It's been suggested to fill the riser and stage with fiberglass insulation <

Yes, all hollow cavities should be damped so they won't resonate.

--Ethan

 

[SMM]

seating positions

I moved the riser out as it was suggested to get the rear row at least 1' off the rear wall...this moved my front row to approx 1' behind the center line of the room. Which of these two suggestions is more beneficial?

 

[Ethan Winer]

> I moved the riser out as it was suggested to get the rear row at least 1' off the rear wall...this moved my front row to approx 1' behind the center line of the room. Which of these two suggestions is more beneficial? <

It's true that a seat right up against a wall is a bad location because that's where the peaks and nulls are worst. But whether you're right against the wall or a foot in front of it, either way the sound will be terrible.

The best solution is to treat that wall with rigid fiberglass four inches thick, covered with fabric, or equivalent commercial panels. You don't need to cover the entire wall - just the part behind people's heads, and maybe an extra foot beyond that in all directions for good measure. Then you can move the back row against the wall, and slide the front row back a foot, and both rows will be greatly improved.

--Ethan