Rock Band 3

Ok I think I have this down, with an on disc song and solo. I have checked it 4 times and I got it easily each time. I will describe exactly what I did.
Requires 2 mics

Song: The Look
Difficulty Setting: Medium
Section : Start of the 2nd verse "Fire in her eyes......"

This section has a two part harmony where they sing the same thing and has a 3rd part that is a talkie at the end of the phrase over lapping the other 2.

Method : I was using a Rock Band mic and a lips mic, I held the the RB mic close to my lips and the other one an inch lower around my chin and out away from me ever so slightly. SO when I sang the fire in her eyes part I nailed the 2 part one, and the talkie bit gets tagged on for the triple at the end of the phrase.

If you have trouble with the end bit just shout it, you should have the other 2 full before it comes.

Mic volume was set right down on both mic's

Note: this may be just a total fluke with my setup just thought I'd post it in case it helps someone else.

Edit: I did this on medium, but I can't see why you can't try it on easy too

You can do this solo with one microphone HOWEVER you do need to buy one DLC track

"You Should Be Dancing" by the Bee Gees features one phrase where all 3 vocal lines play at different times.

I DO NOT take credit for this video but the phrase in question appears around the 3 minute mark.

Update/Edit: Another DLC song released this week allows for a Triple Awesome with just one mic! "Fat Lip" by Sum 41 features a phrase where each vocal color parts are sung separately. New video attached (again I DO NOT take credit), phrase in question appears around 34 seconds into the video. The difference is in this song the phrase is entirely talkies so success is guaranteed first time.

Turn on no-fail, stick 3 mics in front of a fan, and play rock lobster, any difficulty. There are a bunch of harmony phrases that are all talkie - they are guaranteed triple awesomes every time.

If you're going for the 50 and 100 triple awesomes goals, there are also lots of phrases with 1 singing part plus talkies. If you play it on easy, you should also be able to get 20+ triple awesomes per play.

This can be done with ONE MIC, WITHOUT buying DLC, and with an ON-DISC SONG.

Play "Humanoid" by Tokio Hotel on easy, and towards the end of the song, there is one spot where each vocal phrase is separated (there's a small bit of overlap, but it won't matter).

Before going for the achievement, go into practice and try it a few times - it's in section Bridge 2B. The reason I recommend practice is because you only get one shot at it, and it's almost at the very end of the song.

I practiced it two or three times, got comfortable with it, played the song, and I got the achievement first try... again, with only one mic.

This achievement can be done on any difficulty, but only on Vocal Harmonies on songs with three parts. You only need to hit one Triple Awesome in the song for this achievement to pop, not all of them.

It is also very possible to do this solo. I personally did it on Easy Harmony Vocals on "The Static Age" from GD:RB, using two microphones. This song only has four triple harmonies, all in Chorus 4. The first triple harmony is as follows:

Blue.......I can't see a thing in the video
Orange..I can't see a thing in the video
Yellow......................................................Woah-oh

The blue and orange lines are so close together that all you need to do is wave your voice between them to fill both the bars, then when you say "Vid-e", raise your voice to hit the yellow "Woah", and you should be fine. I am in no way a skilled singer, and still managed to get this first try.