Has anyone heard of Bolt's ratio
It is a ratio of room dimentions to minimize room modes
it was created in 1946?
Where can i see a diagram?
Bolt's Ratio
Originally posted at johnlsayers.com, topic 6036.
Google is your friend :D
[url=http://forum.studiotips.com/viewtopic.php?p=5570]Article on Studio Tips re room ratios
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Eric's post is a fantastic resource. To emphasis something in his post that is often overlooked, the "good" ratios are volume dependent! They vary with the size of the room.
An additional reference, that is quite heavy on the math, is BBC RD 1993-08.
[edit] In case the BBC just whetted you appetite, Room Dimensions and Volume should provide you with more pleasure! :D
Dimensionally:
Andre
And how do you apply these ratios to non-rectangular rooms? For example, here's John's sample for a "large" control room. Should an optimized ratio be used where I drew the red line, that is, before realizing the angled surfaces of the bass traps, sliding doors, etc.?
Great question! I have wondered the same. My non expert conclusion is that it ultimately boils down to room pressure, so open cavities do contribute to the modal response, but closed off walls or doors do not. So in the diagram you posted I'd say (in my non-expert opinion) the volume of the room would include the soffits and bass traps, but the angled sliding glass doors do reduce the volume of the room. Could be wrong. Please correct me if I am.And how do you apply these ratios to non-rectangular rooms? For example, here's John's sample for a "large" control room. Should an optimized ratio be used where I drew the red line, that is, before realizing the angled surfaces of the bass traps, sliding doors, etc.?
For angled walls, the usual approach is to use the average of the dimension. Something usually overlooked by people working on room dimansions and ratios is that all the theory is just that. In real life, things get, well, strange.BBC RD 1992-09 is a great resource as it shows theoretical vs actual results for several rooms. Table 1 is a great start with theoretical vs. actual room mode frequencies.s. All the room mode ratios are based on these frequencies. :D It also has examples of rooms with asymmetrical features, and discussions on the actual modes. A great exercise is reality :D If after absorbing the above report you get the feeiling that room med prediction and room mode ratios are educated stabs in the dark, congratulations! You have groked one of the major points of small room acoustic design! May all your room modes be even in frequency spacing and liner in peak amplitude: Andrehow do you apply these ratios to non-rectangular rooms?