I’d like to make a DIY bass traps to reduce dips around 80hz ~ 100hz in my room. Pre-made bass traps I found are very expensive, or don’t actually absorb low frequency sound much.
I recently learned that helmholtz resonator could absorb lower frequency only. Is it that simple as making a wooden box with many holes on one of 6 sides and some absorbers in it?
- Make a thin wooden box with 600mm height, 600mm width, and 100mm thickness. The thickness of the front panel is 15mm.
- Drill holes to the one of 6 sides of the box.
- Seal the box with silicone tape.
- Put absorber materials with 600mm width, 600mm height, 90mm thickness in the box.
I calculated absorber dimensions with this calculator. I just changed the absorber thickness to 90mm from 100mm. But is the 100mm thickness enough?
Even if could make a resonator successfully, do I need to make 8 panels or so to make meaningful changes to the room mode (since each panel is small)?
http://www.acousticmodelling.com/helmholtz.php
Bass management is the hardest part of acoustics.
Depending on your equipment there could be spikes and nulls all over the place, so I’d look at multiple subs, room correction and listening position first.
If it’s a dedicated listening room and aesthetics aren’t an issue you could experiment with resonators. If memory serves correctly, resonators perform better when ‘floating’. Suspended by cables.
A few control rooms I’ve been in had huge resonators installed in a notched out section of ceiling. Without doing any calcs, the ones you specify sound small, particularly in thickness.
If you’re planning on installing behind the listening position they’re also going to affect the upper mids and highs.
If you’re committed then I suppose the best way to move forward would be to get some dense foam and experiment with positioning before building anything permanent.
I’m no expert, but I did a module in acoustics when I studied sound engineering.