Hanger traps behind flush-mount speaker soffits

See pictures below. I found the second one on this forum from a post by gullfo. I'm looking for broadband low-frequency absorption. Will this provide the absorption I want? ADVthanksANCE -Jack (still making sawdust in central Texas) PS: Sorry, Glenn - I do not know your last name, but thank you very much for your countless and informative posts here.