CAD software for reverberation time

[keyser]

I'm looking for software that can do RT-simulations. CARA seems to do that, but I don't really feel like spending money on such an old program. Does anyone know of a (preferably free-ware) alternative?

 

[keyser]

I just bumped into this one: Reverberation Time Calculator

It seems usable!

 

[keyser]

And some more:

OWA - Service/Downloads - Reverberation time calculation
Reverberation Time Calculation
threedB.com | Reverberation Time (RT60) Calculator

Unfortunately they all indicate higher RT than I'm measuring in my room, although the last one seems to get pretty close.

 

[Speedskater]

I believe that the current thinking is that reverberation time is only useful in rather large rooms. I have an old copy of CARA and it was a lot of work to model a room and then there was the question of whether it was a good model.

 

[a_tewinkel]

I think reverberation time can be useful in small rooms as a rough indication to see if its acoustics are okay since it's related to the amount of absorption (which is very relevant), but it is indeed wrong to state that there is a diffuse field in small rooms.

 

[Pano]

The more you put into CARA, the better the results. It's very powerful. Before my room was filled up with too much junk to model, it did a great job with reverb times. The results were very close to my measurements of a bare room, then room with treatment. I've done more than one room and it's been very close.

I do understand that not everyone will want to pay for CARA or take the time to model the room.