[Archived phorum post from squ1.com v2 by craines]

No you don't have to do this manually.
Basically what you need to do is....
once you have calculated your Acoustic Response, spraying say 40,000 points, switch Tabs to the Reverberation Times tab (to the left of Acoustic Responce in the Graphical Results window).
It will probably then ask to calc. Inter-zonal Adjascencies -- click OK to this dialog box. Make sure there is a volume in the the Zone dei\finition on the left (if not hit the Recalc. button for this -- this is actually a minor bug it should be done automatically), and then finally hit Recalculate again. You should now get a Statistical RT graph using 3 different algorithms, which you switch between or show all of if you like.

Hope this helps.

Regards,
Caroline

Caroline Raines
Square One research Pty Ltd

[Archived phorum post from squ1.com v2 by Nancy]

I have done that but what I am trying to do is compare the statistical reverberation graph with a more accurate reverberation graph generated from the geometry rather than from statistics. The two graphs are not in the same format. Switching to the statistical tab gives me statistical results.

[Archived phorum post from squ1.com v2 by Andrew]

Hi Nancy,

Sorry for the delay in replying...

To compare the statistical RT graph with that generated using the estimated RT:

1. Choose the Acoustic Response Tab in the Graphical Results dialog.

2. In the Calculation Method, choose Estimated Reverberation.

3. Click Recalculate and watch the number of rays sprayed in the top left corner of the graphical display. Obviously the more rays you spray the more accurate the result, so you may want to let it run for at least a couple of minutes. You may want to play with the time and level settings to ensure you get smooth linear decays for each frequency.

4. When you are tired of waiting, click the Cancel button.

5. To display the RT graph, choose the Show Derived Curve button. This will display a graph exactly the same as the Statistical RT. You can then switch between the Reverb Times and Acoustic Response tabs to visually compare the two.

NOTE: If you use the Existing Rays/Particles calculation, you cannot generate a valid RT graph as it is not possible to tell whether you sprayed rays only over only a small part of the model. The Estimated Reverberation calculation, on the other hand, sprays random rays in all directions so you _can_ generate such a graph.

Hope that helps...

Regards,
Andrew

Dr. Andrew Marsh
Square One research Pty Ltd

[Archived phorum post from squ1.com v2 by Ben Hall]

Hi all,

In response to this quote from Andrew:

"NOTE: If you use the Existing Rays/Particles calculation, you cannot generate a valid RT graph as it is not possible to tell whether you sprayed rays only over only a small part of the model. The Estimated Reverberation calculation, on the other hand, sprays random rays in all directions so you _can_ generate such a graph."

It would be nice from a speaker placement point of view to be able to use exisiting rays to calculate the 'effective RT.' Meaning that when you point a directional speaker into the audience seating area, most of the energy is absorbed by the audience and the reverb time of the room is effectivly less. I know that this is not statistically correct, but in many cases this is closer to what happens in the room.
EG - I position a speaker with a *known* dispersion angle (which is also a bit of a myth - but that's another story) and spray rays within that defined angle - the RT will be calculated for sound coming out of that speaker onto the audience area.

I realise that this is playing with fire a bit, but it would be a nice addition. maybe version 7.x

Thanks again for the great software.

Ben.