Dear Junwei,
Since I'm new to AVR (previously HTiB & HTPC), I just learn to listen via trial & error methods.

My components not match well? I hope to find out too!

The bass when viewing DVD are acceptable but not when listening to Audio CD.
When listenning to Audio CD, it lacks of treble and the bass is acceptable if set my SW manually to max, that is +12dB.

But there is no sharp and clean treble which I can obtain from my Car Audio System (something like tweeters) or even my HTPC obtain better result. I am puzzled too a few $$$k system compare to $1k system!

Also, I noticed my Denon Manual might not be new as there was some pencil writing and remark on some of the pages! (but I bought it brand new!)

Anyway, my answers :-

1) what's the dimension of your listening area? Room or Living room?
ANSWER : My squerish living room is too open actually. 20x28 feet, but with opening (no door) to Kitchen and to staircase of 1st floor (typical MY terrace house)
2) what's your roger SW model and size?
ANSWER :
Model                : Roger ASB 100.
Power amplifier :  100W RMS (8 ohms) .
Frequency Response : 30Hz-200Hz+/-3dB .
Crossover :  50Hz-150Hz (variable) .
Crossover Slope :  12dB per Octave .
Driver Unit :  254mm Long Throw .
Function    : Power (On, Auto, Off), Phase (0, 180 degree), Level Controller, Crossover Frequency, Controller .
Inputs        :  Hi Level (Speaker) In, Line (RCA) In .
Dimension (WxHxD) : 290 x 335 x 325 mm
Weight        :  12 kg (Net) 

Front Speaker : Usher V-601
2-way system :
tweeter 1" (9930-20NC), low-bass 7" (8935A)
Sensitivity  86.5dB @ 1 watt/1m
nominal impedance  6 ohms
frequency response  (-3 dB): 42 Hz ~ 20 kHz
power handling  70 watts 
crossover frequencies  2.22 kHz
weight  12.6 kgs (per speaker)
dimensions (wxdxh)  23.8cm x 29.2cm x 44.5cm
3) what subwoofer cable are you using?
ANSWER : I'm using the given RCA-RCA cable (Denon SW Out straight to Roger ASB) Actually, I'm not sure the best way to connect up my SW as there was more than the RCA interface. I will try to share it diagram later.
4) where is the subwoofer located?
ANSWER : SW located at about 2m away from the AVR and FL, FR.
5) front and rear speakers model.
Front = Usher V601
Centre = Mission
Surround = my previosu Panasonic, 6 Ohm type.
6) AVR level for each speakers.
ANSWER :
These are not Audessy value as I changed it manually or should I use the Audyssey?

FrontL = 8dB
FrontR =  10
Centre =  7
RearL = 8
RearR = 8
SW = 12
Thank you ina advanced to those who is willing to read and comments.

---

Added on October 15, 2009, 10:31 amJunwei,

Sorry, I failed (do not know how) to insert the image of the SW wiring diagram, so I can only provide the website link.

http://www.rogershifi.com/brochure/ASB100-ENG.pdf
Thanks.