Fitting RaTs

Where to mount RaTs bass traps


RaTs mounting

While “some standards” exist, the method of mounting is almost bespoke.  This allows for the absolute maximum flexibility : wall and ceiling surface fixing, an under floor / floor riser fix, and, even fitted to an adjacent room or space !!!
The “rules” for physical placement are very simple.
Tube OPEN ends must :- Point into a corner
The resonator tubes have, effectively, an “Open” end, and a “Closed” end.  There’s no actual difference in the ends of the resonator tube itself – the ends being designated “Open” or “Closed” at the time of installation.

Call this end the OPEN end & it will be the end that “points into a corner” of the room

Fitting RaTs

Call this end the CLOSED end – it’s the end the tune bungs MUST be inserted …

Room corners & orientation

All these are possible and valid “room corners”
wall / wall corner. 
wall / ceiling corner.
wall / floor corner.
wall / wall / ceiling corner
wall / wall / floor corner.

And, all these are possible and valid mounting orientations
horizontal on wall
vertical on wall
north/south on ceiling
north/south on floor
east/west on ceiling
east/west on floor

Either end can be the CLOSED end – so long as you know which ….  then you can point the OPEN end into the room corner, and insert the tune bung from the CLOSED end, and everything will be the right way round and in the correct orientation.

Pointing into a room corner

In this diagram, the OPEN ends of tubes in various positions are shown with red dots. 
All these ends are “pointing into a corner” and all positions are valid.

The diagram doesn’t show every single position for clarity sake – you may easily find other mounting positions that follow the simple rule -

The tube OPEN end must point into a corner of the room

Fitting RaTs



Don’t waste your time with calculations, spread sheets or reverberation time measurements !


Just Listen


* Calculation / spreadsheets can only tell you what the resonant  frequencies are, based on room size, and NOT what the real aural effect will be, of the complex additions and subtractions of all a room’s resonances.
* Reverberation measurements should show the same results as a listening test.  But, a listening test will have it’s absolutely correct results in, before any form of reverberation analysis kit has even booted up.

Simply play this test tone track

See the listening test procedure video

Screen shot 2014-10-21 at 15.51.47



Play the test tone set, and make a note of the tone number, for any tone that is significantly loud.

Loud tones will easily stand out from the rest !!

Refer those loud tone numbers to the graph below …

Fitting RaTs

The Graph shows

The 2 vertical scales:

* The bung setting depth for RaTs bass absorbers

* The frequency (just for your information)

The horizontal scale (along the bottom)

* The tome numbers identified during the test tone set listening test


Set the tune bungs into the tube/s, (in MM) according to the “RaTs bung setting” corresponding to the desired tone number
For example: 
If you heard a very loud tone at, say, tone number 8, the tune bung must be set in the tube @ 42 mm, from the tube’s closed end. 
HintRemember the difference between “open” & “closed” tube ends from the previous section


Sit back and enjoy your tight firm bottom, & all the extra detail and dynamics that come with it