Styrodur / XPS QRD fins?

[ThomasT]

Hi,

just wondering.

All(?) 1D-QRD diffusors (e.g. GIK verifusor) made of foam have no fins between the wells.
Would it be possible to have fins like the wooden equivalents? Or is Styrodur too light for 0.5-1cm thick fins?

I asked some month before about 1D-QRD with fins and finless. The opinion was, that finless 1D-QRD are not as good in diffusion. (but the difference with fins vs. finless for 2D-QRD should not be so significant).

To be more practical:
This in mind I wondering if the verifusor (or a similar product) is a good a) for diffusor panels directly behind e.g. acoustic guitar player. b) for general room threatment on my remaining still naked studio walls.

Thanks Thomas

[Jens Eklund]

Originally Posted by ThomasT

Hi,

just wondering.

All(?) 1D-QRD diffusors (e.g. GIK verifusor) made of foam have no fins between the wells.
Would it be possible to have fins like the wooden equivalents? Or is Styrodur too light for 0.5-1cm thick fins?

I asked some month before about 1D-QRD with fins and finless. The opinion was, that finless 1D-QRD are not as good in diffusion. (but the difference with fins vs. finless for 2D-QRD should not be so significant).

To be more practical:
This in mind I wondering if the verifusor (or a similar product) is a good a) for diffusor panels directly behind e.g. acoustic guitar player. b) for general room threatment on my remaining still naked studio walls.

Thanks Thomas

A QRD relies on the fins so simply removing them is not a good idea unless you modify it using shape optimization but then it is not a QRD any more.

Although QRDs are not bad, they have several limitations and by using the latest BEM modelling techniques, one can find shapes that performs better, both in terms of diffusion but also absorption (the lack of it) by exploring finless shapes thus avoiding resonant and viscous losses due to wells.

The Optiffuser is an example of a shape optimised stepped (finless) diffuser using BEM-simulation:
Diffusors: opinions about EPS polystyrene?

[ThomasT]

Seems I had to work the predicting capitel in Cox & D'Antonio ...

[Jens Eklund]

Originally Posted by ThomasT

Seems I had to work the predicting capitel in Cox & D'Antonio ...

Especially page 321 - 329 (if 2nd edition).