Layout and trap placement.

[GloryisSilent]

I have a small room that is my only space for recording/music, and I work predominantly alone on my own music.


In the room would be:
4x12 + head
4x10 + head
10 space guitar stand (full)
3 keyboards
2 monitors
5 piece drumset (2 floor toms, 1 rack)
Very small desk (3'x2') with macbook pro, interface and external HDD

The room is 20'x13'x8.5'

There's some unique issues with the room as well in that it has 3 doorways, only the left doorway has a door, and 2 windows.

I am not sure where to put bass traps either. Due to the asymmetry of the room, I'm at a loss for a good layout that would be most efficient. Every opposing wall space is blocked by something!

I attached a layout of the room bare. It is to scale except for the door sizes, which are slightly larger (32" doorways)


Any ideas would be very helpful. I've been struggling with this for weeks now

[Ethan Winer]

See this:

RealTraps - How To Set Up a Room

As for treatment, here's my standard reply which applies to your room too:

Room treatment is a deep subject, and a complete answer requires far more than will fit into a single reply here. So here's the short version. All rooms need:

* Broadband (not tuned) bass traps straddling as many corners as you can manage, including the wall-ceiling corners. More bass traps on the rear wall behind helps even further. You simply cannot have too much bass trapping. Real bass trapping, that is - thin foam and thin fiberglass don't work to a low enough frequency.

* Mid/high frequency absorption at the first reflection points on the side walls and ceiling.

* Some additional amount of mid/high absorption and/or diffusion on any large areas of bare parallel surfaces, such as opposing walls or the ceiling if the floor is reflective. Diffusion on the rear wall behind you is also useful in larger rooms.

For the complete story see my Acoustics FAQ.

There's a lot of additional non-sales technical information on my company's site - articles, videos, test tones and other downloads - linked under my name below.

--Ethan

[GloryisSilent]

Thanks for the info ethan...

but my situation makes it very difficult for me to follow those guidelines. I'm trying to be creative here and effective at the same time but...

[Ethan Winer]

Originally Posted by GloryisSilent

my situation makes it very difficult for me to follow those guidelines.

Why do you think that? This is a standard rectangle room having 12 corners. Where you have a door or window in a corner you can still put bass traps on the walls near the corner and get similar results to straddling the corner. You can also put traps right on the doors. This is shown in the top photo below. Two traps adjacent near a corner works similar to one trap straddling the corner. Another option is to put treatment on stands as shown in the lower two photos below. Traps in wall-floor corners also work well, as seen in the bottom photo.

--Ethan

[GloryisSilent]

Originally Posted by Ethan Winer

Why do you think that? This is a standard rectangle room having 12 corners. Where you have a door or window in a corner you can still put bass traps on the walls near the corner and get similar results to straddling the corner. You can also put traps right on the doors. This is shown in the top photo below. Two traps adjacent near a corner works similar to one trap straddling the corner. Another option is to put treatment on stands as shown in the lower two photos below. Traps in wall-floor corners also work well, as seen in the bottom photo.

--Ethan

No it's not

I only have 1 vertical corner where I can put a bass trap. I may have not been clear, but only one of the doorways actually has a door. The other 2 are simply doorways with no door.

The north wall's (left in the drawing) top horizontal corner is nearly completely blocked by a window, and door.

There are only 2 places in the room where I can symmetrically put bass traps or 2" panels. It is more like 1, because one of the spaces is directly behind the only door in the room, which would crush the panel due the very shallow inward door swing!


Does that make my trouble more clear? I can asymmetrically place panels rather easily, but I suspect that would destroy stereo imaging.


Thank you very much for your replies.

[Ethan Winer]

Originally Posted by GloryisSilent

only one of the doorways actually has a door. The other 2 are simply doorways with no door.

Your drawing shows three doors.

Openings are good, and are similar to having bass traps there.

There are only 2 places in the room where I can symmetrically put bass traps or 2" panels.

Maybe you should post some photos because I don't see the fatal problems you describe. If you put bass traps in the front and rear wall-ceiling corners, that could be symmetrical, no?

--Ethan

[GloryisSilent]

Originally Posted by Ethan Winer

Your drawing shows three doors.

Openings are good, and are similar to having bass traps there.



Maybe you should post some photos because I don't see the fatal problems you describe. If you put bass traps in the front and rear wall-ceiling corners, that could be symmetrical, no?

--Ethan

Posting pictures would be difficult for me as I don't have a camera right now.

I'll see what I can do...

The windows extend to the ceiling, and near to the floor. So where there's a window in the drawing, assume that entire portion of the wall is off limits. Doorways also extend to the ceiling. It is a very strange house. The walls are solid block as well.

I do not have the luxury of blocking off doorways unfortunately.

Thank you again for your help

[GloryisSilent]

Here is a copy of the frequency response graph done with fuzz-measure.

The waterfall graph doesn't work correctly (despite reading the instructions).

This is without any treatment.





Just so I don't forget, output at -10, preamp at +12

[GloryisSilent]

Ok, I figured out the layout.. room sounds rather great... EXCEPT

there is a fairly obvious flutter echo now.

I guess that means diffusion is needed ?

[Glenn Kuras]

Originally Posted by GloryisSilent

Ok, I figured out the layout.. room sounds rather great... EXCEPT

there is a fairly obvious flutter echo now.

I guess that means diffusion is needed ?

That would be the ticket.

[GloryisSilent]

Originally Posted by Glenn Kuras

That would be the ticket.

Any cheap diffusion ideas?

[gullfo]

some opened drapes hung on the walls will kill off the flutter echo if you stagger them on opposite walls. then you can adjust some of the high frequency levels in the room.

another option - polys - made from 2'x6' sheets of 1/8" plywood bent to be 5.5" deep. a few of those in the room should help as well as add some additional low freq trapping.

[GloryisSilent]

I placed traps on the ceiling 'down the room'. 4 in center of the ceiling evenly spaced. Shorted dimension of the traps aligning the longest dimension of the room.


I have them incrementally aligned in height, starting at mix position going towards the back, each one is 4" closer to the ceiling than the one before. I tried even spacing and it did help.. but not as much as this configuration. The stereo imaging at mix position has HUGELY improved. There's no more 'mush' in the center.

The obvious flutter echo is well gone now. All that's left is my inability to measure anything below 50hz accurately. Hopefully when my new sub and monitors arrive I can get a clearer picture...

So far rom 55hz-20khz, I'm +/-3db now. I'd consider that pretty damn flat. The nasty dipy at ~70hz is gone yay!

Thanks for the help so far.