Q - perf board in front of Superchuncks

I have been researching tuned perf board bass treatments & already have corner Superchunks in place. Q - Do perf board bass treatments need to go in tandem with the suggested, sealed back, boxes that come with the excel calculator, or can they be placed ''free standing", with, say, a 100 mm open backed frame, directly in front of the Superchunck? Cheers, Bob.

Perf panel devices are basically Helmholtz resonators (or rather, a large array of small Helmholtz resonators) so they do need to go over a sealed cavity. If the cavity behind the panel is not sealed, then you don't get the resonance. Sound moving through the perf panel still undergoes some minor acoustic effects, but there's no resonance going on behind, so you don't have the major benefit, which is the tuned trap. - Stuart -

Soundman2020 wrote:

Perf panel devices are basically Helmholtz resonators (or rather, a large array of small Helmholtz resonators) so they do need to go over a sealed cavity. If the cavity behind the panel is not sealed, then you don't get the resonance. Sound moving through the perf panel still undergoes some minor acoustic effects, but there's no resonance going on behind, so you don't have the major benefit, which is the tuned trap. - Stuart -

Ah! Thanks mate. On the wall they go! Cheers, Bob.