12.9" iPad Pro sounds terrible compared to my 4 Retina and Air.
I have been doing multi-track music production on the iPad 4 Retina and iPad Air for years. There are a ton of high quality synthesizer and recording apps out there and it's amazing how good they sound. I recently "upgraded" to the 12.9" iPad Pro. Now everything sounds downright awful, even through quality head phones. Previously recorded music that I made is now totally out of balance and often distorted. The Pro also sounds way off on many of the synthesizer apps, tonally, output levels, and distortion...not only rendering them useless, but destroying any previous multi-track recordings where recorded midi-notes play the synthesizers. About the only thing that sound relatively the same as before is GarageBand....(go figure!)
As for the built in speakers, they sound like crap...even when playing standard iTunes downloads, alot of music sounds just O.K. - I would not call it an improvement, but a downgrade. Having a "woofer" and a tweeter on each side is ridiculous on a speaker set this small. For the music that sounds just "O.K.", this results in subdued volumes, as the "woofers" attempt to produce the lower frequency range and the tweeters over react at the high range, leaving 'hole' in the mid range. On music with heavy cymbal hits and other like transients, the tweeters actually break-up, crackle and glitch, leaving one to reduce the volume even further to where the music can't be adequately heard more than a few feet away.....and tonally, out of balance, This can only be sometimes be partially corrected with the E.Q. Presets, which is not only annoying, but never had to be done on prior iPads.
EIther this iPad Pro is way out of calibration, or this thing is an overpriced hoax. As for the audio criticisms I have made here, ......I am a retired
electrical engineer with a great deal of audio design experience.