Control room bass trap help

[FirstLoveStudio]

I need advice regarding bass traps in my control room - slightly complicated dimensions.

The room is 12' by 10' - Height is complicated as it has a bricked, vaulted ceiling arches 6' across and 2' deep - the lowest point is 9' high. Two of the walls are solid brick, but 2 are just thin partition walls. The control room is part of a larger space with brick walls and the same ceiling - about 40' by 40'.

My mix position have very little 150hz - the back of the room has loads.

Of course I need bass traps but should I try moving my mix position first?

Also, should I be viewing my room as in the middle of the smaller partitioned space, or will the bass pass through the partitions, and thus I should be viewing myself as in the corner of the larger space? If that makes any sense!

[Weasel9992]

Originally Posted by FirstLoveStudio

I need advice regarding bass traps in my control room - slightly complicated dimensions.

The room is 12' by 10' - Height is complicated as it has a bricked, vaulted ceiling arches 6' across and 2' deep - the lowest point is 9' high. Two of the walls are solid brick, but 2 are just thin partition walls. The control room is part of a larger space with brick walls and the same ceiling - about 40' by 40'.

My mix position have very little 150hz - the back of the room has loads.

Given your dimensions that's entirely predictable.

Originally Posted by FirstLoveStudio

Of course I need bass traps but should I try moving my mix position first?

Yes. Try placing your head at 38% of the length of the room first. If you can, take measurements and adjust your positioning from there.

Originally Posted by FirstLoveStudio

Also, should I be viewing my room as in the middle of the smaller partitioned space, or will the bass pass through the partitions, and thus I should be viewing myself as in the corner of the larger space? If that makes any sense!

Can you tell me more about the partition walls? Are they real stud walls, or really just office partition kind of things or what? The exact makeup will determine what passes through vs. what is reflected, but whatever the case you'll probably benefit from the usual bass trapping wisdom...unless the walls are thin as a sheet or something, in which case they might as well not be there at all from a low end standpoint.

Frank

[Ethan Winer]

Originally Posted by FirstLoveStudio

Of course I need bass traps but should I try moving my mix position first?

Yes and Yes. Frank is correct with the 38 percent "rule," but the only way to know for sure where's the best place for yourself and your speakers is to measure the LF response at high resolution using software like ETF, Fuzzmeasure, or Room EQ Wizard. And of course you need as many good bass traps as you can possibly manage.

--Ethan

[FirstLoveStudio]

Originally Posted by Weasel9992

Given your dimensions that's entirely predictable.



Yes. Try placing your head at 38% of the length of the room first. If you can, take measurements and adjust your positioning from there.



Can you tell me more about the partition walls? Are they real stud walls, or really just office partition kind of things or what? The exact makeup will determine what passes through vs. what is reflected, but whatever the case you'll probably benefit from the usual bass trapping wisdom...unless the walls are thin as a sheet or something, in which case they might as well not be there at all from a low end standpoint.

Frank

Thanks a lot guys. I will take some measurements.

The partitions are 2 pieces of plaster board with nothing in between (apart fron the studwork of course).

Am I right to have one of the solid wall behind my speakers, or may it happen to work out better facing the partitions?

Can I get foam style corner traps to absorb below 150hz? Should I be looking at some membrane absorbers?

I was wondering whether large rolls of loft insulation - still in their packs could be piled up in corners? Would the plastic obstruct the bass absoption? I've got space in one corner for these...

[Weasel9992]

Originally Posted by FirstLoveStudio

The partitions are 2 pieces of plaster board with nothing in between (apart fron the studwork of course).

Treat it as a hard boundary.

Originally Posted by FirstLoveStudio

Am I right to have one of the solid wall behind my speakers, or may it happen to work out better facing the partitions?

Face the short wall, firing down the longest dimension in the room.

Originally Posted by FirstLoveStudio

Can I get foam style corner traps to absorb below 150hz? Should I be looking at some membrane absorbers?

Membrane style absorbers made from mineral wool or rigid fiberglass are what you want.

Originally Posted by FirstLoveStudio

I was wondering whether large rolls of loft insulation - still in their packs could be piled up in corners? Would the plastic obstruct the bass absoption? I've got space in one corner for these...

Yes.

Frank

[Lynx™]

I can't seem to get my room right. I have huge variations in the low end everywhere I go in the room. It's all dry wall: 13.9(L) x 10.10(w) x 7(h), with a vocal booth that appears to be helping to messing things up...maybe I need to break it down? I also used Ethan Winer's 300Hz and below sine wave test to do the bass response analysis, then added six 2' x 4' x 4" 705 bass traps in the corners, along with auralex LENRDs behind all at top and bottom corners - and did the test again. To my surprise, there was very little change both in listening and looking at the response on paper. I have attached the rom structure and both test results. Can someone help here? Thanks very much!

[Weasel9992]

Originally Posted by Lynx™

I can't seem to get my room right. I have huge variations in the low end everywhere I go in the room. It's all dry wall: 13.9(L) x 10.10(w) x 7(h), with a vocal booth that appears to be helping to messing things up...maybe I need to break it down? I also used Ethan Winer's 300Hz and below sine wave test to do the bass response analysis, then added six 2' x 4' x 4" 705 bass traps in the corners, along with auralex LENRDs behind all at top and bottom corners - and did the test again. To my surprise, there was very little change both in listening and looking at the response on paper. I have attached the rom structure and both test results. Can someone help here? Thanks very much!

First thing...probably would be a better idea to start a new thread in the future. It's a little confusing to start a whole new issue on an old thread.

Second, you'll need higher resolution measurements to make any real decisions. Have you tried Room EQ Wizard?

Frank

[Ethan Winer]

Originally Posted by Lynx™

I also used Ethan Winer's 300Hz and below sine wave test to do the bass response analysis, then added six 2' x 4' x 4" 705 bass traps in the corners

A photo of your setup might help. Six traps is not enough, but it should have made more improvement. I agree with Frank about getting REW, though 1 Hz sine waves provides plenty of resolution. The real advantage of REW is it lets you assess the change in ringing as well as raw LF response.

--Ethan

[Glenn Kuras]

Good advise from the other guys but just to add move your mix spot back a few feet and see if that changes things for the better. It looks like you are right up against the wall.

Glenn

[Lynx™]

Thanks very much all.
The reaon the mix position is there, is because the bass response seemed to have smoothed out a bit (on paper) when i moved everything forward and closed the "triangle" in from about 5 1/2ft to 4ft 2 inches. I then started adding traps from there but the room has very audible bass variations. I've attached some pics of the room. I've never used Room EQ Wizard, but will check it out. I'm also using a small element omni (RTA 420) that I got with a mackie quad EQ which includes an RTA and an SPL meter. I am trying not to use the EQ so that the sweet spot isn't the sixe of an ant. The tests were done pointing the mic from ear position to the monitors, but I'll re-do pointing up. I don't know how much the open or closed door matters, especially when mixing. The bottom line is that I can still hear the variations clearly as i move around. Any advice would be seriously considered.

Thanks.