exhaust resonator question

i'm really distraught here. i got custom catback with a new resonator and apexi n1 universal muffler 2 weeks ago. sounds really bad (tinny, buzzy, ricey, "wohhhhhhhhh!") at WOT and even if i give it more gas. driving normally sounds good deep, especially in 1st and downshifting. it's fine above 3000 rpms.

just wanted to know if it's anything to do with the exhaust resonator? and whether changing the resonator would help.

thanks in advance and sorry bout this...