Tech Note: Iron Man on Blu-ray Disc

I recently received my copy of Iron Man on Blu-ray disc and made an interesting discovery. You may have read about this on forums already but I'm talking about it here for those that don't want to wade through the 3,000 post mega-threads on AVS. As you probably know, the Blu-ray release of Iron Man was recalled at the last minute due to an authoring error. Apparently, some reviewers had trouble with their pre-release copies. I found in my research that there is an old and new UPC code and the old one was covered by a decal when the disc was replaced by the manufacturer. Well, there is still a quirk with the replacement disc that I discovered when I viewed the film.

Iron Man includes an excellent Dolby TrueHD soundtrack. Unfortunately those of us who own certain model receivers (Onkyo 805 in my case) will note that the sound lacks the punch and dynamic range we've come to expect from lossless sound mixes. I watched the entire movie and felt underwhelmed by the sound even when I turned it up quite high. I remembered an early review I'd read which said the standard Dolby Digital track actually had more punch and the TrueHD track was enabling Dynamic Range Compression automatically. I played the movie again checking the Late Night mode on my receiver. Sure enough, it was set to Auto. Turning it to Off made a huge improvement. I watched the movie through two more times and was much more impressed. I also discovered that powering down the receiver resets the Late Night mode on all TrueHD tracks to Auto. I have to manually turn it off for every Blu-ray that has Dolby TrueHD. Auto doesn't always mean compressed but Off is a guarantee that there won't be any range compression. I had always wondered why some TrueHD movies required a higher volume level than DTS Master Audio. I believe I now know why. By the way, this only applies if you're bitstreaming the audio. Analog or PCM won't exhibit this behavior.

Advice: check the Late Night setting on your receiver every time you watch a TrueHD enabled movie. You don't have to worry about DTS because Late Night mode is only for Dolby codecs. This may also not be the case for all receivers and processors. I believe Onkyo and Yamaha use the same DSP chips so you Yamaha owners might want to check this out the next time you watch Iron Man.

Thanks for reading and enjoy the view!