A reference chart for you brother. As Jay-cee suggested, test tones might help you pick out the offensive frequencies. Here is a link. http://www.soundsolutionsaudio.com/forum/topic/42728-test-tones-sliding-tones-pink-noise-all-lossless-for-dl/ As we are all here to learn and help. I will give my logic on a few things. My logic on making cuts FIRST on the EQ before boosting, Is its best to remove the nasty shit first before adding more to the mess. sure you can start anywhere, but logically that's a good place to start if your unsure. My logic on phase vs T/A as Sean's answer was brief. Different frequency soundwaves are different lengths crest to crest. The only way to achieve absolute phase would be if the drivers are mounted together, on the same plane at the same distance. Which is almost impossible even in a studio let alone anywhere else. What we are trying to achieve by reversing polarity on only one speaker is to change the relative phase. In a car for example the passenger speaker is already multiple crests ahead of the drivers speaker by the time it reaches your ear. Some frequency's will still be in phase or close to it, while other frequencys are not. Due to the waves being different lengths they are going to be different degrees out of phase. When you reverse to polarity you are hoping to bring certain frequencys waves closer to an acceptable degree of phase. An out of phase wave may lead to an absence or even distortion at that particular frequency. Some will even prefer the distortion as it may sound louder to them, over the sterile sound. Subwoofers would be a great example, out of phase they may sound louder due to distortion, but the ear is not as sensitive to distortion in that range so they will enjoy the obnoxious boost. For YOUR purpose today we are hoping that the reverse brings the midbass to life by shifting the relative phase. T/A will shift all soundwaves, I believe it is called a phase shift. The other purpose for trying different phasing would be at the x-over points. As the tweeter and mid are playing the same freq at or near this point, you may get a suck out around the x-over point. The same thing is occurring with the relative phase. Sometimes reversing phase will only worsen the dip in the response and you just have to live with the better of the two. I do not have a degree in acoustics so may of used a term with other meanings or missed something. My experience is from being in friends studios and at live shows. Nothing worse than live music coming through in waves with half the harmonics missing. Not to be confused with the echo of to many sound sources. I call the latter the Wal-mart sound.