Optimizing Frequency Response
Now that you have situated your loudspeakers for maximum soundstage and imaging it is time to custom tailor the frequency response to achieve a well balanced sonic presentation to your ears. The benefit to user adjustability of both the tweeter and woofer response is three fold. The first being that you can tailor your systems frequency response to achieve flat neutral response without having to spend countless hours moving your speakers all over the room. The second is that you may not necessarily have to spend a fortune on room tuning devices or consultation. Third and finally the most important, you can adjust your loudspeakers response to compliment the characteristics of your existing electronics.
There are two ways to adjust frequency response to obtain optimum results. The first is with measurement equipment such as an SPL meter or Real Time Analyzer like the Phonic PAA3. The second is with your own ears. First step, no matter what process you are using, is to play only one speaker at a time. Trying to calibrate two speakers at the same time is far too difficult and being able to separately tune each speaker within separate environments will yield the best overall results. If using an SPL meter, you need to find a signal generator or disc with test tones. Be sure you understand the tendencies of your SPL meter since most meters have their own calibrated scale and varying meters will give you varying results. Begin graphing your speakers as they are, right out of the box. If this is not desirable, then begin again but turn off the tweeter so you can focus on bass to midrange first. Keep making adjustments until you feel you have balanced response then begin turning up the tweeter until you feel that you have reached your desired target. If using an RTA this process will be much faster as you can see the changes over real time without having to start and stop. You will need a pink noise generator or a test disc with pink noise. Once again, turn the tweeter off and focus on the bass and midrange only. Once this is dialed in then begin turning up the tweeter until you reach your desired graph. If you are only using your ears then begin by playing pink noise. Starting with the tweeter off and the bass off, begin adjusting the bass until you feel that the bass and midrange pink noise sound balanced with each other. Basically no frequency should be jumping out at you and everything should sound smooth and seamless. Now that this part is done, start turning up the tweeter level gradually filling up the top of the pink noise. Once again, the levels should be set so that no one frequency jumps out but rather sounds smooth and seamless as if all of the sound were coming from a single source. You could liken the sound when fully optimized as completely organic, such as a waterfall, sounding very natural with no excess rumble or aggressive glare or hiss. If the frequency response is not adjusted properly then the sound would have more of a digital sound or artificial sound, with elements that jump out at you and stick out from the rest, basically not very smooth or real.