Dolby TrueHD, DTS-MA, Uncompressed PCM...no big woop

[speakerman39]

I think the take home message is that all the Discrete Sound Codecs - DD, DD+, DTS, TrueHD, DTS-HR, DTS-MA, and LPCM - all sound great as long as the recording studio did a great job with the original source. Take a movie like "Day After Tomorrow", which is DTS-MA. The DTS-core sounds just as good as the DTS-MA.

But some of us just gotta have the latest greatest, don't we?

Yeah, we know who we are!

This sums up what I attempted to say quite nicely. Thanks for the information.

Cheers,

Phil

 

[fmw]

Anyways, when I first got my players, I did a bit of non-blind swapping between lossy and lossless on my HD-DVD player. My impressions are that the lossless tracks' best improvement was the dynamic range, slight as that might be. But, as fmw would point out to you, these remarks are not the most reliable by any means.

I'm hoping someone knows more about digital compression than I do. I'm thinking about this and wondering why digital compression should do what audio compression does. Reducing dynamic range is exactly what audio compressers do. But digital compression isn't the same thing at all. It's purpose is to remove data that the algorithm determines is not audible (or in the case of more severe compression not very audible.)

I would think that if you lost dynamic range from digital compression it is because the engineers did that on purpose for whatever reason. I don't think audio compression would be a natural byproduct of the process.

I don't know where to find it on the internet but some people have put together some interesting exercises. They take an original signal and a compressed one and sum them out so that you can hear only what was removed by the compression algorithm. It sounds something like a barely audible gentle breeze or whisper. It is gentle enough that it explains why people (including me) can't distinguish a Wav file from a 320 mp3 file in blind tests. Even though something like 3/4 of the data was removed, what was removed is extreeeeemly subtle and perhaps 50 or 60 db below the average signal level - way, way beyond what an audio compresser would do.

I guess my point is that the digital compression schemes are very effective if they aren't used too heavy handedly. Truthfully, I find them impressive. That's why I have converted my entire CD collection to 320 Mp3 and listen to the compressed music through a streamer instead of listening to the CD's themselves. For me there isn't a whit of difference in sound quality. I've conducted bias controlled listening tests to verify that.

Today's project, believe it or not, is to work with the compressers in my own project recording studio. I'm one of those people who can sing on pitch but I don't have a very good voice quality. You could use me as backup vocalist but the record companies aren't breaking down my door to sign me. So I have a tendency to process my own singing to try to help improve its sound. Any good recording engineer will tell you that you can't fix bad sound with effects and processing but, heck, it's my own voice and I'm not much of a recording engineer anyway. I have to do what I can, don't I?

 

[jostenmeat]

That's a very interesting post, fmw. I have to say my experiences with mp3 are extremely limited. While my friend recently recorded a disc and was shocked at the differences between recording with WAV and mp3, my best amateur recording I ever made was on a mini disc player, lol. Unfortunately, that disc died. Im pretty bad about keeping stuff for posterity's sake. Im even afraid I might have thrown out a string quartet I wrote based on Alban Berg's Lyric Suite. But, that disc did get me my first 5 digit scholarship offers. Well, I had a pianist friend who would help friends with anything from recorded discs as gifts, to transferring mp3 to wav files etc. The de-compression from mp3 to wav helped, but the fact that it was ever an mp3 already and irreversibly reduced its quality. It was pretty apparent when he was giving us a demonstration. He was also quite the concert pianist, and happens to hold the world record for fastest typed alphabet, lol. Again, I have to say I am very unfamiliar, and have no idea exactly how much compression was applied at any given time. I will agree that I bet I would be perfectly happy with lightly compressed recordings, for the most part anyways. I don't know how much you listen to classical music, but there aren't any other genres that have anywhere near the SQ, imo. Even my very best jazz recordings would only be middle of the road compared to my classical collection. Then again, my classical collection is way bigger than my jazz collection. I just bring this up because I wonder if having such compression applied to the best recordings would make it slightly more obvious. As that is what I like listening to, for better or worse, because I think I "ruined" a bunch of recordings by becoming an audiophile of sorts.

Nothing is worse than what you describe as audio compression. Oh, gawd I hate it. I hired someone to record a concert of mine, and he applied some because of my unfortunately less than ideal performance. It just sounded like I had absolutely zero soul. I, and others, remembered the live performance, and it just takes sooooo much away. Its like if we all spoke like robots. And that's even when the guy said that the compression was applied only moderately.

In any case, I am more than happy with my collection of both movie soundtracks and music recordings. Its the hardware that is a little harder to setup.