Full Active Time/Alignment Method

I start by measuring the distance to the drivers, just like in the passive TA post, and establish which driver will be my zero reference. Next, I input the distance differences (see the other post) in to the processor and/or do the conversion of distance to milliseconds and enter the millisecond value. The subs should be off at this point, just to make things less sonically confusing.

Grab the aforementioned reference song to audition, you remember, the one with acoustic instruments and a good defined center vocal. Play it and listen for the vocalist' image only. The goal of T/A is to make the arrival times of each speaker the same, thus the center image should be as clear and concisely placed as possible, being as high as possible, with all sibilances and lower notes seeming to come from the same location. If I hear the "S" sounds of the vocal coming from anyplace other than the center, or coming from both sides slightly, then I know the tweeters need fine tuning, possibly a phase flip or just ms adjustment. Picture the vocalist sounding as if they were standing on the center of your dash, but whenever she sings "S" sounds or other sibilances, she sounds like shes in front of you. We are experiencing whats called a "frequency-dependant" center image, caused by speakers being out of acoustic phase with each other. If the polarity switch doesnt help, I delay the tweet that sounds most dominant step by step until the sibilances move to where the vocalist is supposed to be. Then if necessary, do the other tweeter.
Next, focus on the bottom octaves of the voice, or switch to a good recording of , say a stand-up bass, on center stage, and listen to the low notes. I prefer Pat Barber or Dianna Krall tracks for this b/c the stand-up bass stays center stage just behind the vocalist. Focus on the low notes, when the musician works down the scale, does the bass instrument itself stay "focused", nice and high and definitely center stage, or do the low notes sound diffused, side-biased, or "drop height"? If they do, we must adjust the midbasses to align them properly with the mids. (see how a 3 way is more complex than a 2). It is definitely harder to localize lower notes, and if your midbasses dont play up to at least 250Hz, this may be impossible for most of you.

If the midbasses dont play very high, I use another technique...I turn off the mids and highs and defeat the midbass x/o so they play full range. Once you do this, adjust the T/A to get the best image focus on the bass, engage the x/o, and turn the mids and highs back on. Listen again, and fine tune if necessary. Phase shifts and reflections or standing waves will usually be the culprits IF a problem persists.

Now, to this point we have set the front stage arrival times the best we can using music, now it's time to bring the subs in (please refer to the other posts), and adjust them accordingly.

Next installment will be useful if you are unfamiliar with the music or uncertain of your listening skills OR simply just want to double-check your findings...to be continued!

YES mono pink noise is fabulous for setting TA because it is all frequencies at the same time, ALL of which should be focused dead center. Some people are sensitive to pink noise, and I know I get a little "ticky" after about 15 minutes of it...wanting to go sit on the rooftop of a daycare and, well, nevermind.
You can also use the "stereo" pink noise as a music alternative to the first post when doing left and right channels individually. THe goal there would be to make the sound come from the smallest, most focused SINGLE location possible, not a huge left sided glob of hiss
I think the IASCA Test and Set-up disc has mono pink on it as well.
YOu can also use test tones to check different speakers at the point AFTER WHICH passives and/or actives and slopes have been chosen by selecting certain frequencies for each pair of drivers. THis is very good because, if the x/o slope/alignment has introduced a phase shift and made things "muddy", you will hear it and you can select frequencies to help localize it.Lost yet?
Picture this---a test CD with various test tones recorded at constant level and ranging from subbass to high treble frequencies. After you have the system "dialed in" and you wanna check stuff out, check the subs first---play a 40Hz tone (softly, silly! No need to do 150dB here, you are focussing on WHERE THE SOUND IS COMING FROM), next pick a tone nearest your x/o freq between sub and midbass (if you have the sub-to-midbass x/o at 75Hz, pick the test tone nearest this frequncy). Then, do a tone that fits right in the middle of the freq range of your midbasses, then at the x/o point between midbass and mids, then in the middle of midrange, and so on. Record your finding in terms of actual sound source point location and compare.

NOTE: High freq test tones can damage yer hearing! Any constant tone above about 2K can be a painful experience, PLEASE turn down your volume accordingly. You will likely find that localizing the point source above 2K using a test tone is nearly impossible unless at real low volume. If you cant localize the treble, refer to another method of tweaking the tweets.
After you have compared your finding using the various frequency tones, you can use the info to determine if you have problems at a particular x/o point in the system or if a pair of drivers is still "out of whack" with the rest, or if a reflection or cabinet resonance is causing image smearing, etc. YOur findings can be used to > Change x/o pojnt, change x/o slope, fine-tune the millisecond delay of certain drivers, try polarity reversing again, try some EQ at the problem frequencies, etc etc. All of these things can have an affect. I have found that x/o filter order/slope selection is a big factor b/c of the phase shifting that occurs as a byproduct of the different filter designs....the topic of an entirely whole different can of worms!