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Big ACDA limits and diminishing returns?
Posts: 8
December 3, 2021 - 8:05 am


Hi, I can’t find any answers to this question so if anyone can point me in the direction or if new, does anyone know…?

I have a very small garage room that I am building out. It has an almost unusable void at one end which is 8ft x 4ft x 3ft (2.4m x 1.2m x 0.9m). So, would placing my speakers at that end with an ACDA that fills the void space be worth the cost and effort or are there limits to what actually works depth-wise? And would the layout be just multiples of the standard 12″ or 16″ designs?

Note: I have found about +15dBa in that area but can only find10″-12″ free space in the sides around that area.

Posts: 549
December 5, 2021 - 2:55 pm

This room volume is not workable for any usage.

Posts: 8
December 9, 2021 - 4:42 pm


Dennis Foley said
This room volume is not workable for any usage.Β Β 

Which is a shame, so it looks like I’m relegated to headphones and a Subpac to mix and master music on then πŸ€¦πŸ»β€β™‚οΈ

Posts: 8
December 9, 2021 - 4:48 pm


Just to be clear, Dennis, the room volume is 3.8m x 2.4m x 2.5m, it is only the void space which is 2.4m x 1.2m. I don’t think I mentioned that. I was asking about the ACDA being 8ft x 4ft x 3ft to fill the void space creating a wall to nearly half the room height and the full width (8ft) of the room. Still the same thoughts?

Posts: 549
December 10, 2021 - 4:35 am

Low frequency energy is all about pressure management. Since the walls are producing the pressure, we must use the walls to absorb the excess pressure. You must treat at least two walls to mange axial modal pressure. The two walls you select for treatment are the two that exhibit the largest and lowest frequency issues.

Posts: 8
December 10, 2021 - 7:08 am


OK wicked, thanks for that. I think I’ve understood what you’ve been saying in all your videos as my plan was what you are suggesting. One quick question: when we absorb energy around the energy source, should that mitigate much of the further reflections on the opposite walls in the direction of energy projection, thus reducing overall modal issues? My point being, treating the two biggest low frequency wall problems; will that have an exponential reduction in overall problems on other surfaces or is it really a case of slicing away equal parts of the overall issue?

Posts: 549
December 12, 2021 - 7:27 am

Reducing pressure issues reduces problems but does not eliminate them. The end user must decide what degree of resolution they desire to achieve for their sonic stratedgy. As a general rule, the more surface area coverage you have to manage lower frequency issues the better.

Posts: 8
December 12, 2021 - 7:37 pm



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