building a room according to best Room ratios

[bastawa]

i'm curious if they build control room which shape is not rectangular. do they apply room ratios somehow? some of those control rooms seemed to have width and length almost the same or very close to 1:1. or they only focus on creating RFZ?

[Rod Gervais]

You cannot use room ratios to analyze spaces that are significantly outside of those ratios due to things like cathedral ceilings and splayed walls.

But those rooms can still be analyzed for modal activity with either some very sophisticated formulas or (much more easily) through the use of specialized 3D modeling software.

Rod

[jhbrandt]

Originally Posted by AwwDeOhh

.... Think of Room Ratios in this way: If you have good modal spacing (by result of having a good ratio), you can focus most of your treatment efforts on controlling decay times and directing reflections and such. If you have a bad ratio (and thus poor modal spacing) you're going to spend most of your treatment efforts on "fixing" a problem that need not be there in the first place, with proper design.

+1

You've got it in a nutshell.

Cheers,
John

[ScottB601]

JH Brandt says: My preferred ratio is the Sepmeyer 1 : 1.6 : 2.33... but I don't stick to it religiously and neither should you.

I am designing my studio from the ground up - right now it's bare ground and I have as much room as I need. I have Gervais' book and one other one but I wanted to ask a quick question.

How far out of spec according to the Sepmeyer ratio you like is considered acceptable? My problem is all of the ratios, Louden, Sepmeyer, Volkman, even phi, all give me rooms that are either too short or too high on the front wall. I want approximately a front wall that is 8 to 10 feet high, but I also want a room that is no less than 30 feet long. Any way to do that?

Thanks in advance.

[DanDan]

Mode Wiz will run all the permutations for you, and apply up to four qualifying filters. e.g. Bolt's area and so on.

Note these calculators assume fully hard boundaries.

DD

[jhbrandt]

Originally Posted by DanDan

Note these calculators assume fully hard boundaries.

+1 (Emphasis Added) ie; solid concrete walls/boundaries.

You will also find room mode calculators on my publications page - I like mine are better, but Mode Wiz is easier to understand.... I think.

Anyway, since most partitions will have a 'pass-band' or Invisible Alpha 'ala Andre Vare... you should calculate their resonance.. use my Reflections Boundaries Mass EXCEL calculator. The point where these walls will be effective barriers is approximately = {square root of 2 times the resonant frequency of the partition}

NOTE: you can have a 'treatment' ceiling (which consists of trapping - which is usually absolutely necessary) that is 8 to 10' high.. but the wave boundary can and should be much higher. Between 11' and 13' is optimal for an accurate control room. - We're not really talking 'home studio' here, but many folks are building very professional rooms these days AT HOME.

So, like Dan recommended; play with the calculator a bit to make the ideal fit into reality.. I do this for each and every client and I sometimes spend several HOURS at it... honestly. But building from the ground up, I have a few room sizes that work extremely well which I have used over and over. AND THEY ARE NOT ON THE RATIOS LIST.

Cheers,
John

[avare]

Originally Posted by ScottB601

My problem is all of the ratios, Louden, Sepmeyer, Volkman, even phi, all give me rooms that are either too short or too high on the front wall. I want approximately a front wall that is 8 to 10 feet high, but I also want a room that is no less than 30 feet long. Any way to do that?

Thanks in advance.

Look at Cox's best and second best room ratio spreadsheets.

http://www.acoustics.salford.ac.uk/a...oom_ratios.xls
http://www.acoustics.salford.ac.uk/a...econd_best.xls

Have fun!

Well proportioned,
Andre