CARA - anyone use it?

More screenshots from cara

From a real example

Sound colouration map

http://farm3.static.flickr.com/2033/2163122801_061d32236b_b.jpg

Sound Pressure Amplitude map
http://farm3.static.flickr.com/2400/2163122393_a09c513de0_b.jpg


Sound Pressure Level Chart
http://farm3.static.flickr.com/2075/2163921666_b3c73a275b_b.jpg



Plan of new hifi layout
http://farm3.static.flickr.com/2163/2163921056_c2c72e74a4_o.jpg


3d model of new layout
http://farm3.static.flickr.com/2226/2163121135_a8931ae5e6_b.jpg



Lastly a sound level meter reading of real responce in room 10 -300 hz in I hz steps

http://farm3.static.flickr.com/2200/2176208916_a0e94f2f62_o.jpg


Now i need to interpret these

Andy
 
Last edited by a moderator:
Hi Andy

It looks like you need to look at your speaker numbers on CARA - you've got them floating in space.
 
bottleneck said:
Hi Andy


It looks like you need to look at your speaker numbers on CARA - you've got them floating in space.
Click to expand...

Whilst my example is real it is Work In Progress

I havent drawn the legs in yet - It seems CARA is suggesting 47cm stands as apposed to my current 35cm ones.
I am experiencing snags zooming in close up (I cannot zoom above 1:1 so drawing small legs is a RPITA.

I had another play adding little details this morning - so Will update 3d piccies at some point.
Andy
 
Hi,

Does CARA have the ability to model the effect of diffusors? QRD specifically. They only mention absorption and reflection on the website.

I was planning to learn Cat Acoustic, but I have just not got round to it. Thought I would get CARA to play with for now.
 
Don't think it supports diffusers. I'll check again when I get home tonight
 
Hi

You do have the ability to change the 'characteristic' of a wall, or part of a wall.

It may not have ''fibreglass absorber'' for example, but if you know the properties of the item you could probably enter it manually.

NB
Simon - I'm getting on great with your bass absorbers. They are great.

In combination with acoustic panels on the wall, my room is greatly improved.

Of course, it could never be as good as a 'very good room' is automatically, but it's a lot better than it previously was, and that is all that counts.

Thanks again.
 
With an absorption or reflective panel you can enter the level of absorption or reflection but this is harder to do with diffusors.

I don't think there are enough parameters in Cara to be able to define a diffusor.


Bottleneck - you don't happen to need another pair of Simon's bass traps by any chance?
 
Hi,

Thanks for the replies. Kenan, if you could double check that when home I would appreciate it.

Diffusors are neither absorber or reflector so it can't be simulated like that. Once might be able to make the profile of a diffusors from small pieces of reflective wall correctly arranged but CARA probably doesn't use enough ray tracing lines to calculate the true effect.

If it can't simulate QRD diffusors it is no use to me :(

Chris, very happy to hear the Confidence are helping. Kenan has a pair too, but his wife is a strict mistress!
 
It does, actually, that will work, but you'll bump-up the iterations high to get an accurate picture and that will slow simulations up ( a step of 1 from the standard '5' makes a difference of a whole order of magnitude in time taken.)

I'll give it a go later...
 
Okay had a look at Cara just now. From what I can work out it will be practically impossible to simulate the effects of a diffusor.

From what I understand a diffusor will reflect mostof the sound but in a fairly random way in different directions.

Can't see how you would simulate that in Cara - you can create a panel of consisting of lots of smaller panels with different absorptive qualities but I think the simulation will assume that they all reflect sound waves in the same direction rather than the randomness caused by differing slopes in a diffusor.

Felix if you have found a way to do this then please enlighten me
 
Kenan,

A QRD diffusor works by having different depth 'wells'. The difference in time for each part of the sound to reflect from these create phase differences and this is what steers the sound in to a wide dispersion pattern. So if CARA can simulate accurately enough to notice the tiny differences i nthe depth of the QRD wells and it accounts for phase (well, it must) then it will work.

However, I am planning on QRDs with wells only 2.5cm wide, and a 23 prime seed. Very complex to simulate.
 

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