So we are comparing the vocalizer on the Pa3x to the Tyros 4, to the Audya

Has anyone compared all three?

I own the AUDYA 4 and AUDYA 5 and can honestly say I've never hooked up a mic to it,
let alone test its vocalizer features

A friend of mine just bought a Pa3x and raves about it, how you can play an MP3, sing , and it will harmonize based off the mp3 that is playing, he says it reads the chords and harmonizes accordingly

I know Korgs Harmonizer is based off, or is a TC Helicon

Is is miles ahead of Yamahas or Ketrons?

How do the 3 compare to each other? Which is best, seconds best? Etc.

I've had all three. Korg is best, Ketron next and Yamaha a distant third.

DUCK !!!

Listen to Don....big Ditto!

Any way to improve upon, let's say, Audya's Vocalizer?

Or is it all Hardware,
it is what it is....what it is , it is!!!

.

I was quite pleased with the Audya harmonizer. It did everything I wanted and sounded great. I still think the Korg has the edge though.
It may just be the setup I use most. They are both excellent. Stand-alone harmonizers as a rule have more options and easier access to comtrols on the fly, but I don't know that they sound any better.
I haven't had the Audya for several years and I went from PA3x to PA900 about nine months ago. I was pleased with all three.
The Yamaha harmonizer starting with Tyros 4 was improved over previous models and is now usable, but it is harder to set up, more prone to picking up external sounds and distorting, and not as natural sounding to my aging ears.

Anyone else?

I never tried ketron harmonizer, but I do have T5 and for number of years I owned t c - helicon harmonizers. From VoicePrizme plus to voicelive 2. Korg uses tchelicon in their pa keyboards and is much better than one on Yamaha.The best thing is to get separate unit and use it.Everything else doesn't come close.
I never tried voicelive 3.It has too many things that I don't need.Actually the way things go with tchelicon units is they are starting to become everything else but a harmony units.One thing that I don't like in T5 harmonizer is you can't make user scales. I could understand in a MOTL you cut features but not in TOTL keyboard.
You will not go wrong if you tweak ketron to your liking, or even if you get tchelicon unit on the side.They are the best out there, we'll if you exclude Eventide.

Keton's VH in my X1, Sd1+,XD9,SD5, MidJay, were all quirky and never performed properly.....
they are very temperamental. But, when they worked it sounded fine....programming & setting it up with song setups is the difficult part. KORG TC Helicon is a breeze to use and sounds fantastic...
Yamaha VH1 & VH2 still needs alot of help although at this time I have finally come up with settings after lots of extensive tweaking that makes VH2 usable to a point on my S950, Tyros4/5.