I love the bass trap that Hugh and Paul described in this SOS article

I was in my 30s back then, Nelly Furtado was hot in the charts and I was blissfully unaware of what bass traps were. Good times.

The trap sounds still very sound to me (see what I did there!), but having to make it now, would there be any design improvements that the Dynamic Duo would have come with?

There are many ways of building that kind of trap, some rather easier than others, but the concept remains sound and the barrier-mat certainly does improve the trap's effectiveness. In fact, I'm just about to install a trio of corner bass traps with barrier-mats in my own studio...

Just make sure that the mat hangs freely without touching anything in front or behind, or to the sides or at the bottom... but make sure the gaps around its edges are as small as you can make them -- a few millimetres at most.

H

Hugh Robjohns wrote:There are many ways of building that kind of trap, some rather easier than others, but the concept remains sound and the barrier-mat certainly does improve the trap's effectiveness. In fact, I'm just about to install a trio of corner bass traps with barrier-mats in my own studio...

Just make sure that the mat hangs freely without touching anything in front or behind, or to the sides or at the bottom... but make sure the gaps around its edges are as small as you can make them -- a few millimetres at most.

H

Excellent, thanks for the tip. Great stuff when a contribution from 13 years ago is still valid!

Physics rarely changes.... :-)

True that, but materials do... I'm on the lookout for some felt carpet which doesn't smell like wet dogs! :D

The BBC ended up using simple hardboard.
http://downloads.bbc.co.uk/rd/pubs/reports/1992-10.pdf
DD

DanDan wrote:The BBC ended up using simple hardboard.
http://downloads.bbc.co.uk/rd/pubs/reports/1992-10.pdf
DD

They did, but only because the R&D boffins were focused on building a dedicated standard-sized modular bass ansorber... And as the report explains, a loaded vinyl membrane didn't work well when fixed as the front of a standard-sized modular absorber panel. Hardboard proved to be a better option in that specific form of construction.

In other forms of construction, a large, free-hanging limp-mass membrane is a very effective solution.

Hugh Robjohns wrote:

DanDan wrote:The BBC ended up using simple hardboard.
http://downloads.bbc.co.uk/rd/pubs/reports/1992-10.pdf
DD

They did, but only because the R&D boffins were focused on building a dedicated standard-sized modular bass ansorber... And as the report explains, a loaded vinyl membrane didn't work well when fixed as the front of a standard-sized modular absorber panel. Hardboard proved to be a better option in that specific form of construction.

In other forms of construction, a large, free-hanging limp-mass membrane is a very effective solution.

I’ve read a couple of those BBC reports (very interesting) and I was wondering if anyone has built their own units to the spec in the reports? If so what were the results? I’m looking to convert a spare room and I’m trying to get some treatment planned beforehand.

Hugh Robjohns wrote:There are many ways of building that kind of trap, some rather easier than others, but the concept remains sound and the barrier-mat certainly does improve the trap's effectiveness. In fact, I'm just about to install a trio of corner bass traps with barrier-mats in my own studio...

Just make sure that the mat hangs freely without touching anything in front or behind, or to the sides or at the bottom... but make sure the gaps around its edges are as small as you can make them -- a few millimetres at most.

H

I read your 'Making A Small Room Sound Good' SOS article (June 2020) and I'm planning to build some corner bass traps similar to your own design (though without the fibreglass panels which seem impossible to find in the UK, so will probably use some carpet felt like yourself and Paul made in the DIY vocal booth). My question is where do you find barrier mat that will cover 2.4m from ceiling to floor? And is it necessary for it to go all the way from ceiling to floor? Also, in the SOS book (and in this thread), reinforced fabric backing is recommended to prevent the mat deforming, but where can this be bought? Thanks.