Resonant adjustable trap system



The issue

Every listening environment in the universe (except outdoors), has bass overhang due to room resonance.
The overhang masks mid detail and very low bass, as well as causing tiny timing errors due to air pressure modulation.
And, (in some ways, even worse), large, musical timing errors resulting in a performance :- “A million miles from what the artist intended”.

Resonance & standing waves

Imagine your bath at home, with a decent amount of water in it.
Flap your hand around in the water right at one end, to make a “wave”.
Watch with stunned amazement, as the “wave” reaches the far end of the bath, crashes with the end of the bath, then starts heading back towards you.  Given a large enough wave to start with, the wave will get back to your end of the bath, crash with that end, and start off in the direction of the far end again. Exactly what happens in a room to sound waves.
In a room, this happens kind of automatically at certain frequencies. It’s all to do with the size of the room.
Without getting into boring maths, if your room is 17 feet long the first and lowest note of one of these “automatic” waves (that us acoustician’s call “standing waves”) is about 33 Hz.
That’s a pretty womb trembling low frequency, and just one of many low frequencies at which, the room will resonate with the slightest sniff of audio input from your speakers.
The sound wave, just like in the bath, bangs up and down the rooms length and will do so for some time unless it’s actively stopped.

* Typically, with say pop music, you could still be hearing a standing wave frequency excited by a bass drum, some 2 or 3 bass drum beats later !.

* Controlling low frequency overhang vastly improves the listening experience, increasing intelligibility, detail recovery, dynamics, musical emotionality, low frequency extension and more  …




The Solution

Oddly, restoring a sloppy, ill defined mess of a bass  back to something tight and dynamic that actually starts and stops at the correct time, is just as simple as the problem wave itself …

Rather elegantly ironic too – the problem is born of resonance, so we’ll kill it with resonance.
If you take any “vessel” or “cavity” it will, just like a room, resonate. It becomes a bass traps.
Take a pipe or tube, with one end open and the other closed and it will resonate at a frequency dependent on it’s size. If you imagine blowing across the top of a milk bottle, you’ll get a note. Well, the flute players among us will, the rest of us might struggle a bit !. The note however is the resonant frequency of the bottle. Now put some water in the bottle, and you have effectively changed it’s dimensions (size!). Blow across the top now, and you’ll have a different note. A different resonant frequency.

This technology has been used to absorb bass overhang since 700 BC in ancient Greek theaters !
We’ve simply re-packaged what was generally bronze or earthenware “echea” in ancient Greece, and all the many types of bass trap since into :-

The most cost effective, lightest weight, most positionally flexible, smallest and only tunable bass trap on the planet.



Serving every kind of environment, from recording studios to concert halls, offices, public spaces, churches and much much more …

In 21 years of soaking up unwanted “waste bass” RaTs have removed over 5 minutes of bass decay time !


Users Include


* What hi-fi magazine
* Tag Mclaren audio
* Mercedes GP / Honda F1
* Partners BDDH
* Cadogan Hall / RPO
* Marks & Spencer
* Royal Northern college of Music
* Leeds college of music
* Serious sound studio
* De-Lane-Lea sound centre
* Eton college
* Chris Rea.
* Level 42.
* Alan Darby.
* Gary Kemp.
* Felix Dennis
* Sir Richard Branson
* Grahams Hi-Fi
* Oxford Audio Consultants
* Phase3 Hi – Fi

And they report …

I’m having to listen to my entire record collection again – the difference is amazing ! : –  UK audiophile

I do love classical music and, in that regard, I find this venue perfect as the sound quality is one of the best in London : –  Cadogan hall concert goer

You were right, the acoustic treatment exposed an electronics problem : –  UK Hi-Fi manufacturer


See the Physical mounting options & tuning information