I bought 10 rolls of loft insulation roll and stacked them in the corners of my studio. Here's the results.
Tired of navigating information online I thought I'd try an experiment - I bought 10 bags of Knauf EKO roll here in the UK and measured the changes along the way. Currently they're stacked in the 5 corners (yes - one slightly annoying wall in this room) and still in their bags whilst I decide on wether to keep the material and pursue this further.
The insulation, whilst in their bags, is approx 400mm deep - I've got it stacked floor to ceiling.
My room is approx. 9m x 6m x 2.4m (L x W x H).
SPL graph has 6bB smoothing.
There's an incredibly long decay time here from 50 hz and down - plus the usual confusion around the 120-150hz range.
The results of this test have been interesting for me.
The biggest improvement has been the reduction of the 39 hz reverb time (-300ms). Along with some around 50hz (-100ms) 70hz (-100ms).
Whilst there's a long way to go - you can clearly see on the spectrogram that the lowend clarity is being improved. It's gone from "What the hell is going on down there?" to "Ok I have an issue at 39hz, 50hz etc" and the change is clearly audible in the room. It's an improvement to my ears.
In terms of improving decay time - I feel confident enough to proceed with this; I intend to open up the bags and build in some framing for 600mm*600mm traps in the corners and potentially do the same with the wall ceiling corners around the room.
A question for the more informed...
The part that is confusing me is the spl/frequency plot. Whilst there's some smoothing of the response going on - it doesn't strike me as "better'... but different.
The most confusing part is 95hz - this measurement has gone from "about right" to 5dB down. Is it possible I'm battling an additive and subtractive issue at the same time? I've fixed one but not the other?
This experience has been incredibly rewarding and informative - I feel confident in tracking down issues to which axis they are on... and can also tell where issues lie beyond this room and into adjoining rooms/loft space.
Hopefully some of this helps someone else's research along the way and if anyone wants to chip in with analysing the data or provide any tips with this - it would be much welcomed!
Posted Mar 8, 2026, 1:24 PM UTC