Vari Bass

Bass frequency resonance is one of the most difficult acoustic issues to solve in any room. Until now, the most effective options have generally involved using bass traps that are specifically designed, or customized to fit the room.
However, these solutions can often be expensive and invariably involve complex measuring procedures. There's also little scope for flexibility if changes are made to the listening space, such as moving furniture or gear.
Vari Bass is designed for use in any professional recording space, home studio, or hi-fi room. Made from wood and high-density acoustic foam, the bass trap can be tuned between 50 Hz and 100 Hz by simply rotating its wooden top (which has a series of resonant pots) until the problem disappears. A scale is included to show the exact frequencies on which Vari Bass is acting. The unit's stand-alone structure enables it to be repositioned as required and used in different rooms.
Advised Units per Room Area

• If room size is 7 to 11 m2 – use 4 Units (2 Boxes)
• If room size is 11 to 16 m2 – use 6 Units (3 Boxes)
• If room size is 16 to 22 m2 – use 8 Units (4 Boxes)

For rooms more than 22 m2, modes formation should be measured and analyzed.
Vary Bass should be placed where the soundpressure is maximum.
Applications
Listening Rooms, Home Theaters, Recording and Broadcast Studios, Post Production Studios, Performance Spaces, Rehearsal Rooms, Conference and Teleconference Rooms, Public Spaces, Auditoriums, etc.
When using two Vari Bass units in a corner, it's very convenient to mount them with a Stacker (sold separately).

https://www.vicoustic.com/product/vari-bass