I've had my z-5500 for some time now, and while they are very good in video games, it seems to be lacking in mid-bass for music. The satellites are actually not very good because it's only single driver with no tweeter and it's very small. I'd like to consider replacing the front and back surrounds with polk audio monitor 40 ii bookshelf speakers. I believe they are compatible because they are both 8 ohm impedance and the z5500 has enough power as long as I don't increase the volume too much. Would I experience an improvement from this set up? I use these as PC in my bedroom so not quite a full blown HT system. Here are the specs of each... z5500: # Total FTC power: 505 watts RMS Sub-woofer: 188 watts RMS (into 8 ohms, @ 100Hz, @ 10% THD) Satellites: Left/Right: 62 watts RMS x 2 (into 8 ohms, @ 1khz, @ 10% THD) Center: 69 watts RMS (into 8 ohms, @ 1kHz, @ 10% THD) Rear Left & Right: 62 watts RMS x 2 (into 8 ohms, @ 1kHz, @ 10% THD) # Total Peak power: 1010 watts # Maximum SPL: >115 dB # Frequency response: 33 Hz — 20 kHz # Amplifier: Ultra-linear, high-capacity analog # Signal to noise ratio: >93.5 dB, typical 100 # Input impedance: 8,000 ohms polk audio 40 ii: Overall Frequency Response 47Hz - 25kHz Lower -3dB Limit 57Hz Upper -3dB Limit 24kHz Nominal Impedance 8 ohms Recommended Amplifier Power 20 - 125 w/channel Efficiency 89 dB Crossover 2.3kHz, second order high and low pass Inputs Dual (bi-amp) 5-way binding posts The crossover frequency for the sub is not adjustable and stuck at 150 Hz instead of the more standard 120Hz. I've read about people saying that there wouldn't be much of an improvement because of the amp in the subwoofer. Can somebody clarify on this?