[john4618]

I’ve been reading and reading about room treatments and here’s what I’m going to do to start:

1.  Put one 12” diameter by 3 foot high bass trap behind each of my front Klipsch RF-7’s.  (The traps will be DIY per Jon Risch and Adam Salisbury plans.)

2.  Put one 12” diameter by 3 foot high bass trap in each rear wall corner.

3.  Centered on front wall, put one 1” x 2’ x 4’ sheet of Knauf 3.0 PCF FSK Insulation Board mounted directly to wall. (covered with burlap or Guilford acoustical cloth)

4.  Centered on rear wall, put one 1” x 2’ x 4’ sheet of Knauf 3.0 PCF FSK Insulation Board mounted directly to wall.

5.  At Klipsch RC-7 reflection point on ceiling, put one 1” x 2’ x 4’ sheet of Knauf 3.0 PCF FSK Insulation Board mounted directly to wall.

6.  My room is L-shaped so I have no left side front wall, but at the RF-7 reflection point on the right side front wall, put one 1” x 2’ x 4’ sheet of Knauf 3.0 PCF FSK Insulation Board

Am I on the right track to start - and then experiment from this point on ???  

Critical Question:  Is the 1” thick x 2’ x 4’ Knauf 3.0 PCF FSK Insulation Board the correct board to get ???  The coefficients are:  125=.21, 250=.63, 500=.84, 1000=.93, 2000=.51, 4000=.22.  Where I live it is impossible to buy any kind/brand of rigid fiberglass insulation board, but I found a Knauf dealer that will ship it to me so I want to be absolutely sure that I order the proper board.

Any help and guidance is appreciated.

[Ethan Winer]

John,

> Put one 12” diameter by 3 foot high bass trap behind each of my front Klipsch RF-7’s <

I suggest using 2x4 foot Knauf panels in all locations. For bass traps in the room corners they should be three or four inches thick, and run all the way from the floor to the ceiling. A 12" trap three feet high will help a little, but you'll get a lot more benefit from larger panels that cover all the corners completely.

For the first reflection points you can put them flat on the wall, but I'd use two inches thick instead of only one. The difference is the thicker panels absorb to a lower frequency.

For more advice on room treatment see the Acoustics FAQ, second in the list on my Articles page:

www.ethanwiner.com/articles.html

--Ethan

[john4618]

Thanks Ethan – from everything I read you are correct -- but since these panels are going into my living room I can’t use huge thick panels everywhere.

Another possible option is hiring Rives Audio.  They claim to be able to get your room acoustically near-perfect without huge panels and such in the room (it will still look like a living room, not a sound studio with huge panels everywhere) – but this is at a price of $900 for their designing and engineering plans, and then I would do the actual work in the living room myself – has anyone used Rives design services ???  Is it worth the $900 cost ???

[Ethan Winer]

John,

Rives is a great company and I'm sure they'll give you excellent advice. But physics is physics, and there's no way to get adequate bass trapping without using large "panels." It's possible to build bass trapping into the room so it's hidden. But then the room becomes smaller because you need to build new fabric false walls inside the existing walls to hide the panels.

There's no free lunch with acoustic treatment. You need to cover a certain amount of surface area to achieve a given amount of absorption.

--Ethan