Instruction: Evaluate each product title in the given list, assess its relevance to the given query, and then arrange the products in descending order of relevance, with the most relevant product at the top of the ranked list.

Input:
Query: pa subwoofer amp with crossover
Product list:
A: Rockville New RBG12S Bass Gig 1400 Watt Active Powered PA Subwoofer DJ/Pro, 12 inch
B: Rockville RPA5 1000w Peak / 400w RMS (200 x 2) 2 Channel Power Amplifier Pro/DJ Amp
Answer: B,A