Bass in the corners of my room. Now what?

R

rcktdg

New member
I have a fairly large recording/mix room. It's unusually shaped but not free of the typical problems. I feel pretty good about the way my mixes are progressing. As the mic cabinet is satisfied, my pre's are making me happy and my monitors are working for me I am beginning to think more about my room.

I walked around the room while playing a mix at a much higher volume than I would ever use to see what it sounded like in the corners specifically. I was not surprised to find a stronger bass response but was surprised at how strong it was. I had to be about 4 feet from the corner to really notice it but it was there for sure. One corner which is less the 90 degrees was much more pronounced than the rest.

With the exception of the corners most of the room sounded uniform. I know there are peaks and dips all over the place but how much of a problem is bass buildup in the corners if my closest corner is 17 feet from my mix position.

I am considering buying some 703 to mess with and see if it does anything obvious. I know there is more to it than just putting it here and there but it's a start.

Cheers, rd
 
RD,

> how much of a problem is bass buildup in the corners if my closest corner is 17 feet from my mix position. <

You don't care what's happening in the corners, but that build-up is evidence that the response is not right at the mix position.

--Ethan
 
Ethan Winer said:
RD,

... that build-up is evidence that the response is not right at the mix position.

--Ethan
Click to expand...

Okay. Would treating the corners flatten things out or just change the response? My tests were done at a much higher level than I ever use to mix. At about 85db the effect is barely noticable and that is about as loud as I get for doing any work. I guess I'm wondering when reflection becomes a factor when I am 4 feet from my monitors.

Don't get me wrong, I'm not denying that my room is not a perfect mix environment but where and what to treat is what I am trying to solve.

I am in the Los Angeles area and I was quite surprised to find in my initial search for 703 that it is hard to come by. Home Depot called Johns Manville and they referred me to another place that would only sell a truck load. When I asked HD about Owens Corning they said freight would kill me. I told them I need 200 sq ft, maybe a little more.

I find it a bit strange but I guess it's no surprise to many of you. I saw the link to the place in another thread but San Fransisco is quite a haul.

Cheers, RD
 
RD,

> Would treating the corners flatten things out or just change the response? <

Those are the same thing. Yes, bass traps help flatten the response.

> My tests were done at a much higher level than I ever use to mix. <

Acoustic problems are independant of level. The skewed response is the same whether you play music loud or soft.

> I guess I'm wondering when reflection becomes a factor when I am 4 feet from my monitors. <

Yes, reflections are always a problem.

> search for 703 that it is hard to come by <

Try this chain:

www.spi-co.com/servicecenterdirectory.mv

Also see the Acoustics FAQ, second in the list on my Articles page:

www.ethanwiner.com/articles.html

It explains a lot about these problems and how to solve them.

--Ethan
 
I'm getting a bit more scientific...

Last nite I downloaded the Sonar file from your site. After looking at the wavefile I recorded from my mix position I nearly had a heart attack. As 89 Hz nearly disappeared and then 116 Hz went through like a tornado I could only shake my head as I heard physics in slow motion. I spent the entire day thinking about how to deal with the peaks and troughs in my room.

I used an ECM 8000 in the mix postion to make the sample. I looked at the wave form in every way possible in Wavelab. I just couldn't believe it.

I started wondering if I could find any place in my room that had these frequencies at a more normal level. It defied me. I started moving around the room and found peaks and valleys all over the place.

I guess my mixes are inversely reflective of the sonic fingerprint I can see in that file. Ugh.

I've got a big room. It's gonna cost me if I can ever find some rigid fiberglass. I was thinking of starting with 400 sq ft.

Thanks for the help and the great site.
Cheers.
 
I'm kind of embarassed. I just watched the videos on your site and discovered that my improvised tests were very similar to those you presented. I also saw that my peaks and valleys aren't as plentiful as the room you tested. There might be some hope!

Cheers,
 
RD,

> I also saw that my peaks and valleys aren't as plentiful as the room you tested. There might be some hope! <

Yeah, at 16 x 10 x 7-1/2 feet that room is pretty small. If you have a larger room you're already way ahead. But peaks and deep nulls exist in all rooms, even large ones and even when there are plenty of bass traps. The point is to reduce them as much as possible.

--Ethan
 
Will the locations of the nulls and peaks be reletive to the location of the monitors or is it an actual physical profile? I don't have an easy way to test this out. It strikes me as a billiards game where the point of origin will determine the locations.

Should I get 2" or 4"?

Cheers, RD
 
RD,

> Will the locations of the nulls and peaks be reletive to the location of the monitors or is it an actual physical profile? <

The locations depends on a lot of different factors: What frequency, where you are in the room, where the speakers are, how far you and the speakers are from the room boundaries, and so forth.

> I don't have an easy way to test this out. <

Sure you do. Play some static sine waves and walk around the room. Play 50 Hz, then 60 Hz, and so forth up to maybe 300 or 400 Hz.

> Should I get 2" or 4"? <

For bass trapping 4" is much better.

--Ethan
 
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