SlugButter
CarAudio.com VIP
It probably will actually make a difference in the Atrend box. If you have a properly braced, designed and constructed enclosure it probably won’t make a difference at all, but in a cheap prefab box like Atrend, I bet it would help it hold together better and you’d have less panel flex. if you do the math though, the cost of the enclosure plus deadener might not be the best investment. At that point you’re almost into it for enough dollars to just get a decent ported enclosure from the beginning.