some questions.. odd shaped, odd frequencies?

[saltysea]

Hello,

Firstly, thanks for looking, all advice most welcome!

I built the space described in the sketches below in one week a few years ago.
I literally had 2 hours to make a decision on the shape and materials (on account of a willing step father builder who there and then wanted to help me make an enclosure to work in).
I had a 2,000 sqft concrete shell in which I needed a little concentrated space.. I'd seen this shape mentioned as an ideal control room so did the best I did in the time I had to chalk out a shape on the floor and we set to building it!
I realised later that the shape was just an interior one.. the construction would usually house bass traps etc..
no matter I thought.. I have a room and it sounded pretty good when I filled it with lots of shelves of old vinyl, some thick foam that I had hanging around placed either side of my ear space .. also on back wall and above my head.

Things were pretty good except I couldn't work out why my Dynaudio BM15a suddenly had the weirdest bass response! (almost none it seemed)
(I also have a genelec 1029a + 1091 set up which has proved very useful)

when I built the space I was primarily using the space to write and record.. now I primarily mix for post-production and I really need to tackle the rooms idiosyncrasies.

As you can see from the existing sketch.. I currently have (double) doors coming in through one of the back side walls (where I'm thinking I should really have bass traps). I'm thinking to change entrance as shown on proposed sketch to extend the space slightly (VO booth/ desk with some natural light) and have a 2 stage entrance.

Question there is.. will I then compromise the back wall by having a door in it.. if I need diffusion/ bass trap there will I have enough space for that plus door? I probably have enough space for a 1.2 metre wide trap centred on back wall plus a smallish door top one side.

I followed the test advice from the Real Traps website.. I enclose the results.. looks pretty scary to me .. should I be scared??!!

This is a long post.. my apologies. once again thanks for any advice that you can give me.

all best
dennis wheatley

lost in a moment on Vimeo

[Weasel9992]

Okay...well, you've got at least a couple of things working against you. First, 2.4m is really small; the non parallel walls are only serving to make the room smaller than it needs to be. Second, I'm inferring from your post that you don't have any bass trapping...? That's a big problem in a small room. That huge 50Hz thing is probably directly related to the rear of the room (4m=10', which corresponds with a 56Hz mode). The height is a mystery, but that's undoubtedly adding to the problems.

No matter what you do you'll need bass trapping, and a ton of it, on the back wall, the front wall, the ceiling over the mix position and the walls to either side....6" traps on the front and back and 4" traps everywhere else. Skip diffusion entirely at this point. It's fine to put that door on the back wall as long as you can mount a trap or two to it.

Frank

[saltysea]

Thanks for that Frank!

sorry.. i thought the height was on one of the sketches..

it's 2.75m high .. concrete ceiling (just one piece of 4" foam above head) , concrete floor (carpet tiled).

Big question.. Do you think the room can eventually be tamed if I install all of the bass trapping??

when you say 6" traps.. would that equate to your "Monster Traps"
and 4" traps = your 244 trap?

all best
dennis

[Weasel9992]

Originally Posted by saltysea

it's 2.75m high .. concrete ceiling (just one piece of 4" foam above head) , concrete floor (carpet tiled).

I thought it was probably close to that. Thanks for the info.

Originally Posted by saltysea

Big question.. Do you think the room can eventually be tamed if I install all of the bass trapping??

Yes. Read this report. This was my room, which was as bad as yours...a little worse, actually. It took some doing, but it's not +/-4dB or so throughout most of the spectrum with some exceptions here and there. Definitely very usable.

Originally Posted by saltysea

when you say 6" traps.. would that equate to your "Monster Traps"
and 4" traps = your 244 trap?

Yes, exactly, or you can DIY them if you'd rather.

Frank

[Ethan Winer]

Originally Posted by saltysea

I followed the test advice from the Real Traps website.. I enclose the results.. looks pretty scary to me .. should I be scared??!!

Concerned maybe.

This is typical for a small untreated room. You need as much bass trapping as you can possible manage. The more bass traps you have, the closer you'll get to flat. It's that simple.

--Ethan