Room EQ Wizard (REW)

Latest AVR model comes with built in speaker level system. You just need to hook up the supplied mic to the AVR and execute the speaker setup and done deal. Of course this is better than using our ears to tune the speakers level (i.e. to get the same sound level in between front, centre, surround & subwoofer). If you want more accurate result, you can do the manual setup using more accurate mic. For me, I'm using Radioshack Digital sound level meter (~US$50). Radioshack SPL meter is very popular amongst HT kaki, fairly accurate (upto 10kHz) and very affordable as compare to few hundred bucks professional mic.





Even with proper speaker level setup, you may find the subwoofer very boomy, the vocal kind of thin etc. etc. etc. Then, it could be your speaker/subwoofer placement not done properly or room acoustic problem. Then, what you going to do???? after spent thousand of bucks and yet did not get the full potential of your gears.

Errrr... you got couple of options. Either pay the professional to solve your problem or DIY.

For me, I would rather spend the professional fees on my gears. Kind of stingy huh... No lah, actually I would prefer DIY so that I can learn more. Hobby ma.

So, what do you need?
a) A computer, either desktop or laptor with line in/out soundcard.
b) REW software (Freeeeeeeeee!!!)
c) Some RCA cables and adapter
d) Tripod
e) SPL meter

This is how I setup the equipments in my tiny HT room :)


Computers with REW software. Cables here and there. Make sure the computers don't block the sound waves from the front speakers and subwoofer. SPL meter on the tripod @ your listening position.


Next, you need to calibrate the soundcard, checking level and calibrate the SPL reading. Sound complicated? Not actually, just follow the steps highlighted in the HELP file.

Example of the measurement done by REW.


Look how the speaker position affect the frequency response. Major dips and peaks should be avoided at all cost. Actually quite happy with the curve (RED color). The major dips after 10kHz is due to the SPL meter efficiency. If money is not a concern to you, get a more accurate mic/pre-amp and you can see how your speaker/room acoustic behave upto 20kHz.


Once I'm happy with the speaker location, I done another measurement on the left speaker. You can see the left and right speakers frequency response if quite similar (below chart).



Next measurement done on my 12" Velodyne CHT-12Q subwoofer. The frequency response curve (20Hz - 200Hz) at below is quite close to the target (cyan color). Also done the waterfall chart below. Quite good with minor ringing around 50Hz and 65Hz.




Below FR is the interaction of main front LR speakers and subwoofer. The Green FR only with main LR speakers whereas the Orange FR with both main LR speakers and subwoofer.


Waterfall chart for both main speakers and subwoofer.


So, with all the speakers/subwoofer & acoustic panels placements here and there, what is the outcome???? Well, I am very satisfy with the end result. You should try it yourself.