My Refinery Metallica has stock backbox speakers and POLK sub. Sounds incredible. I think Hemi removed the resistor that is attached to the stock speakers.
My AC/Dc has Pinball pro backbox speakers and a polk sub. Sounds OK but not as clear and nearly not as loud as my Metallica. I still have the stock speakers so I may switch them back some day. Don't understand it but my next Stern I am keeping the stock back box speakers.