Hi Koushik,
I am not questioning my buying decision, I have seen tower speakers with 5 drivers and a tweeter, my question is regarding that.
Most of the online manual / articles / forums speak of setting the front to small, the justification being, it will be easier of the amplifier to drive the sub and also that the sub is better suited to do the job.
Below is something I read...
I totally disagree with anyone who says you should always set the speakers to "large" regardless of their actual size/low-frequency responsewhich means I agree with Audyssey that you should set the speakers to "small" when using a subwoofer, even if the main speakers are full-range. Why? First of all, if the speakers are not full-range, there's no point in trying to make them reproduce low frequencies.
Even so-called full-range speakers rarely reach as low as true subwoofers. In your case, the Monitor 11 specifies a low-frequency extension (the frequency that measures -3dB from the nominal level in a typical room) at 30Hz, which is pretty low, but not as low as the PW-2100, which specifies a low-frequency extension of 23Hz. I was unable to find the CC-390 on the Paradigm website, but the CC-490's low-frequency extension is specified at 43Hz, and the Mini Monitor's low-frequency extension is 42Hz. The specified on-axis frequency response (2dB) of the Monitor 11 goes down to 42Hz, while the CC-490 goes down to 65Hz and the Mini Monitor goes down to 75Hz.
Then there's the issue of speaker locationthe best positions for low-frequency drivers in a room are often not the same as the best positions for the midrange and high-frequency drivers. Redirecting all the low frequencies in a soundtrack to one or more subwoofers lets you optimize the bass performance of the room by placing the sub(s) independently of the main speakers. And because low frequencies are not directionalthat is, you can't perceive the direction from which they emanatethey needn't come from the main speakers for the sake of imaging.
The THX specification for crossover frequency is 80Hz, so that's where I'd set the speakers and subwoofer lowpass. You might want to try different settings just to see if they sound betterin particular, setting it a bit lower for the front L/R than the center and surrounds might work in your case, since the Monitor 11 goes lower than the othersbut 80Hz is a good starting point.
To answer your last two questions, information below the crossover frequency is redirected from the main channels to the subwoofer. And the amp still sends full power to the speakers even though they are set to "small."