Bass Trap Pro Audio Acoustic Treatments
A bass trap is an acoustic energy absorber designed to damp sound in order to gain a low frequency by lowering low frequency resonances in rooms such as recording studios.
Bass traps are usually built of a form of insulation material and work by using friction to turn sound energy into heat. They are usually placed in the corners of the room for maximum efficiency.
Types of bass trap
There are two basic forms of bass trap:
- Porous absorbers – tend to be smaller in size and easier to construct than resonant absorbers. They are less expensive and needn’t be tuned to resonate, but their ability to lower frequency resonances is limited. Porous absorbers are generally made from mineral wool, open cell foam or fibreglass and paper or foil facing to reflect the frequencies. A bass trap contains a core absorbent damp material, a frame and a covering
- Resonant absorbers – there are panel absorbers and Helmholtz resonators. A resonant absorber will need to be mechanically tuned in line with the frequencies to be absorbed. They usually have a narrower spectrum than porous absorbers, although this can be adjusted. Construction of resonant absorbers varies, often with a membrane absorber on a springy sheet of wood and another membrane using a sheet of thin material that is stretched over the corners and edges.
Why use a bass trap?
- Bass traps are used for low frequency control which can lead to distorted acoustics and interference
- Bass traps can absorb lower frequencies because they are thicker. They are best placed in every corner of the room, as this is the area where bass builds up the most, at angles of 45° in order to eliminate the 90° angle of the walls.
Building a bass trap
It is possible to build your own bass trap:
- Create a back frame for the bass trap using wood, add posts on each side of the frame in order to add the front frame later
- Tack a barrier on the inside of the back frame
- Place rigid fibreglass onto the frame, trimming where the posts will be situated.
- Create a front frame and fasten to the posts on the back frame with strips of wood using glue and/or nails
- Cover the bass trap with fabric that won’t rip when it is stretched over the frame, and trim excess fabric
- Hang bass traps using angle brackets that a strong enough to hold the weight.