I'm making my own Skyline Diffusers using a pattern I got from the Internet, and the recommendations were to use a lighter type of wood, such as Pinus. The problem is it's still too heavy, once I'm going to hang it on my apartment. So I made some research and found some Styrofoam Acoustic Diffusers, and I'm wondering now if they would do the same job. Would they?
Diffusers are meant to reflect and scatter incoming sounds, not to absorb them.
Polystyrene is quite transparent to low frequencies, so the more rigid wood is the better material.
A more precise comparison could be made by looking at the acoustic reflection coefficients of both materials for the frequencies of interest.
No they would not . They make styrofoam pannels because those are 100 times much easy to produce compared to wood so is about making money. If you imagine an acoustic guitar body made of styrofoam is easy to figure that such instrument will sound dull, sloppy and without definition compared to a real wood guitar ..
Not true . Styrofom diffusers are snake oil esspecially the 10 cm thickness ones. Those that sale such crap they trick every custromer really bad. The guitar body made of polystyrene analogy is very good . In a guitar the strings resonate and the sound goes inside the guitar body which reflects inside the body . So it has more to do with reflection and not resonance . Of course that the whole guitar will resonate a little but is more about reflection .