Operation Fix Listening Environment

[hainter]

Howdy

I am currently undertaking a small project to fix the mixing situation in my bedroom. I have a small bedroom (see layout and pictures). I would like this to be a sort of journal so that everyone can learn from this experience. This is by no means close to some of the stuff i have seen on here, but i figure maybe there are a lot of people in the same situation I'm in and they could benefit from this.

I have a big problem with my mixes not being transferable. When i take my mixes to another system, they are always very bass heavy. Upon careful listening of the system, i have also noticed stereo problems, as well as what seems like beat frequencies at the listening position. I can only assume that this is some sort of frequency/cancellation problem at the mixing position.


I have a few goals for this project:

1. Fix and even out the bass response of this room.
2. Improve the stereo imaging of the mixing position
3. Improve the work flow for in room tracking.
4. Fix a small 'flutter' problem with the room (deaden the room slightly).
5. Improve the tracking of this room (I track vocals and acoustic guitar in here).
5. Do all of this in the most unobtrusive way possible(i'm only renting and would like to be able to take the panels with me when i go).
6. Make mixing and listening more enjoyable.

Budget

I would like to keep the budget under $500. I found a place that will sell Owens Corning semi rigid fiberglass at a pretty resonable price. I will post the company and pricing information later in the week. A quick estimate of this project put my budget at $300. This includes fiberglass, burlap, and wood.


Acoustic Panels

For the panels, I will use 2" thick fiberglass. I'll make a few with thin frames (2" frames) for higher frequencies and a few with thicker frames (8" or wider) to leave an air gap for mid to low frequencies. I'm thinking maybe combinations of 2x4 and 2x8 panels of both thicknesses. I'm not sure where I will place these panels until I get the room laid out.

Bass Traps

The bass traps will consist of 2x4 sheets of 2" thick fiberglass (4" thick total). These will be wedged into the corners to create the bass traps.
I have two full corners (carpet to ceiling) that i can put bass traps in. I also have about 2 feet above the windows and 4 feet below the windows for bass traps. The 2 corners at the front of the room have obstructions (closet and door) except for maybe 2 feet above the door. All of the ceiling corners are open except for where the closet is. (see pictures)

I think the best idea is to fill the two full corners with bass traps from floor to ceiling, as well as the area above the door and above the windows. Possible some of the ceiling corners will also have bass traps. One of the few construction details I'm sketchy on is how to attach the fiberglass into the corners/ceiling corners. I would appreciate suggestions for this.

I am also open to suggestions for panel placement/ configuration.



Room Layout

So, my proposed idea is to re-organize the room for the purpose of balancing the listening position. By moving around the room, it will also give me a better work flow.
This in conjunction with the acoustic panels/bass traps will allow me to have the best sounding/most productive listening position.

As far as the room set up goes, I have come up with two plans. (see pictures)



I have a couple of topics I'm hoping for some feedback on...

1. is my bed acting like a bass trap and could this be causing problems? i tried to search for any info on this but have not been able to find any.
2. is there anything special i could do with the closet to help my situation out? like maybe fill some of it with fiberglass. just a thought.
3. I'm curious as to how many corners need to be filled with bass traps to be effective.



Thanks in advance for any input.

Joe


PICTURES (all dimensions in inches)

 

[hainter]

Part 2.



Well, after thinking about it for a few days I have decided on the following room layout and panel placement. Let me know what you think.

In the two floor to ceiling corners that I have i'm going to place 2x8 bass traps with 2" 705FRK on the outside and regular 705 on the inside. Above the windows and above the door I'm going to use a 2x4 sheet of 705 2" in each place.

The rest of the room will use 703 2x4 panels.

On the walls I'm going to place 6 panels of various thicknesses. 2 with 2" fiberglass, 2 with 2" fiberglass and a 4" air gap, and 2 with 2" fiberglass and a 6" air gap.

on the ceiling i'm going to put 2 panels with 2" fiberglass and a 4" airgap.

See the drawing for a better description.

This totals out to 4 pieces of 2" 705FRK, 6 pieces of 2" 705, and 8 pieces of 703.


The local place I found that stocks the owens corning is called CWCI Insulation of L.A. and they quoted me the following prices:

703 1" - .71/sq ft
703 2" - 1.41/sq ft
705 1" - 1.26/sq ft
705 2" - 2.57/sq ft
705 FRK - 4.24/sq ft

This totals out to be $349 for the fiberglass.

Construction

For the bass traps I would like to just figure out a way to glue burlap onto the actual fiberglass. I think this can be done but if anyone has any tips please let me know. I will construct these in 2 - 4" thick panels and then lay them in the corners or use finish nails.

For the bass trap wall panels I want to use 1" thick pieces of wood at whatever width i need to build frames and secure the fiberglass inside of these and then hang them on the walls.


Let me know if you have any suggestions/comments.

Thanks!

Joe



Picture

 

[hainter]

Quick Update

I bought all the materials for the project. The insulation place would only sell me 2" 703 in a box of 12 and 2" 705 in a box of 5 so I bought one box of each. I also bought all the burlap I needed after staging a sit-in at wal-mart for about 40 minutes. I also bought some 3m spray adhesive 77. There is also a number 90, but since 90 is 13 higher than 77, I think this is too strong for burlap.

So, after gluing some of my roommates fingers together, we have finished all the of the corner traps. I will post pictures and descriptions later.

I also managed to do a quick response plot of the current listening position. I used matlab to make a huge wave file that steps from 20hz to 250hz in 5 second increments. After I did this I discovered that Ethan Winer (www.realtraps.com Thanks Ethan) already has some files specifically for this purpose and I ended up following his method to get a quick relative response plot. (see picture) I also noticed that if I moved my head around the room the response seemed to change quite a bit.