Axiom Home Page Forums General Discussion Home Theater Lets plan a theater space

That's not the first time someone called me crazy. I've really lost track at this stage in life.

This situation is where the term "quality" must be clearly defined and it is hard to do so since the sound mix of one format vs. another can vary even with the same material on the same disc. However, try to remain objective when you evaluate the sound not for what you prefer, but for what you can hear (technical vs. subjective).
Are the vocals sibilant on one mix but not another?
Is bass heavier on one mix vs the other?
Can you hear the raspy strum on guitar strings in both mixes?
etc.
AND, most importantly, are these artifacts reproduced consistently with other material on other discs in exactly the same way?
i.e does a DVD-audio mix always sound more bassy than its DD 5.1 counterpart on 10, 20, 30 different discs?
I think you will find that these types of 'quality' differences do not reproduce consistently for one format such that it could be labeled as 'lesser quality'.

Reproduce the sound quality differences then decide if one can be deemed a better quality than another, but don't assume that a 6.1 True HD DD mix somehow is higher quality than a DD 5.1 mix. The technical quality at which these mixes are produced already go beyond that which the human ear can detect from a mechanistic, engineering perspective.
We are not dogs or bats. Human hearing capability is much more limited.

All that being said, yes, i absolutely agree that a DD 5.1 mix will sound 'different' from a DVD-audio track on the exact same disc. I've tested this in the past with an A/B switch method and demonstrated this very difference with people who came to audition the Axioms. I have tried 3 different DVD-audio discs with their DD 5.1 tracks on the same discs and reproduced what i perceive as differences in the formats, but both are of equal (and very high) quality.

I preferred the sound of the dvd-audio mix but not because i thought it sounded more clear, or accurate, etc. I chose it because i found the soundstage was more up at the front vs. the DD 5.1 mix of the same material which moved the soundstage more overhead, a bit more immersive (the more "surround sound" type of sound).
To me, i described the differences in the mixes as follows:
DVD-A sounded like i was sitting in the first couple of rows of a concert.
DD 5.1 sounded like i was onstage somewhere in the middle of the band/orchestra.

I've also tested (long ago), DD 5.1 vs DTS on the same disc. This was not an instantaneous A/B test though and offhand i recall thinking that DTS really reduced the SPL for some reason so i ignored using it ever again.

Different does not equate to higher quality.
Some people may prefer one mix over another, sure, but that does not define it as a technical quality difference vs.a personal preference likely related to the variation during the sound mix process.

Agreed. I typically prefer the Bluray HD mixes of movie soundtracks when comparing them to their DVD counterparts. I dont know if I would be capable of listening to a DD5.1 track on a bluray when its HD counterpart is there waiting. I would feel dirty.

I believe the newer batmans and new daniel craig bond films on bluray include both the non and HD versions of the soundtrack. I believe oblivion does as well. Anyway, these are good examples of films which would have been mastered for HD sound and likely good candidates for a DD/DTS vs HD counterpart test. I mention these as they are fairly ubiquitous and anyone can run the test for themselves.

Homework assignment for everyone willing.

I predict in every case the HD track is prefered.

I would agree that a DVD could potentially sound even better than its Bluray version technically, but in my experience this has never been the case. I dont think DD5.1 or DTS tracks got the same "love" when the studio sound master folks make the decisions which determine the final experience. This may be less the case now with newer releases, since a DVD soundtrack is likely a lossy version of the HD counterpart, but when back catalog movies are released and remixed for HD sound on Bluray, the differences can be startling. Holy run on sentence.

Btw, a lower SPL between DTS vs DD5.1 tracks could be an artifact of a component misreading or omitting the dynamic range parameters within the soundtrack from what I understand. If one sounded louder than the other, it could also have meant that track had more dynamic compression applied by the processor or during the studio mix.

I like this exchange.

Chess, you're crazy!!!
Well, not really, I just felt like I was missing out.

I know I have a particular concert Bluray home that the HD format is actually way less enjoyable than the DD5.1. Damn it, I can't remember which one it is though. I recall the HD version really brought forward the sibilant aspect of the lead vocals.

From a technical standpoint, the HD version was probably doing it's job and being more accurate. However, the resulting accuracy created something that really bugged me.

In this case, you could have an interesting argument. Is it the responsibility of the producer/mixer to make it as accurate as possible, should they remove unwanted qualities, even if it is less accurate or do you just blame the source (artists/sound gear.)

In short, you are both right but sometimes accuracy does indeed come with a price.

Perhaps someone can try to explain how a DD 5.1 format is not "HD".

It's a crazy thought, i know.

Short answer:
DD5.1 is compressed.... DTS-Master Audio and Dolby TrueHD are not.

Ok, technically DTS-MA and Dolby TrueHD ARE compressed, but they are more like a .zip file. extract the data from that file and you get the full lossless (uncompressed) audio in perfect form. DD5.1 is compressed much like an .mp3 is compressed. It literally throws away a lot of data to save space. Now, the problem is that just like some .mp3 files, the level of compression can vary from one source to another.

In the movie sound industry, HD audio is reserved for uncompressed or lossless audio like DTS-MA and Dolby TrueHD, and DD5.1 is just considered a sub-par audio track that is missing a lot of information. It is still surround sound, but it is like saying that the DVD that the DD5.1 audio is on is HD when comparing the DVD to a blu-ray which is in HD.

Now, do I really care what you enjoy? Heck no. Play what you want and enjoy it. You are missing out on what you *could* hear, but you seem fine with what you *currently* hear and who am I to spend your money on something that you don't think that you need.

Indeed Nick you have described a technical difference between the formats but i was questioning more the subjective term "high definition" sound.

DD 5.1 is not unlike a mp3 at >500 kbps (DVD audio is rated for a similar bitrate although this is only one metric of quality among the formats). I doubt anyone has been able to tell the difference between the compression and non-compressed versions at such a high sampling rate.

Compression does not equate to a loss in audio quality if it can't be distinguished by the human ear anyway.
There is another similar discussion at the bluray forums which parallels this one.
http://forum.blu-ray.com/showthread.php?t=159982

Chess, if you have an oppo you may be able to use the multichannel analog outputs into your avr. You can then use the oppo for HD audio decoding and your avr will basically become just an amplifier.

You didnt mention which oppo you purchased, but if it is the 103 or higher, it has channel controls like distance and spl trim level built in. It may afford you more features than your onkyo currently offers in terms of system setup parameters. Not sure about the 83 or 93 though.

You can also use the HDMI out at the same time for video only. This means when your tv is replaced, you can bypass your avr for video and go straight to the tv from the oppo. The newer oppos also have video inputs for hdmi and can act as a switcher and scaler. I believe they will also strip the audio from inputs and output over analog to your amp as well.

Good ole oppo!

Understood...

I generally steer away from Dolby TrueHD whenever there is a DTS-MA track, and most of the blu-rays default to DTS-MA as *the* track of preference. Maybe that is why I hear such a big difference. The DTS mix on DVD was always more dynamic than the DD5.1, so when they put it into a lossless format on blu-ray, it still sounds light years better than DD5.1.

I will admit, since we are all being honest here, that I have never done an A/B comparison between a DD5.1 DVD track and the Dolby TrueHD track for the same movie on blu-ray.

You may have challenged me to give it a shot tonight.

One thing to keep in mind is that my gear and your gear are going to have different variables, heck, I have an acoustically treated room that may be the biggest variable in hearing a difference or not. If a room destroys upper frequencies or has nulls in the low end bass, that would suck up any real clarity or bass extension that would would get from a lossless audio track.

Then again, some people have better hearing than others. Even though my wife is younger than me, I hear a lot more detail than she does, but not as much as my teenage kids.

I will see if I still have a DVD of something that I also have on blu-ray, but if not, I will just manually switch between the two Dolby tracks from the same blu-ray and report back tonight. The trick will be to find a blu-ray with Dolby TrueHD on it since most studios went with DTS-MA as the default for blu-ray and DTS in general is more "dynamic" than Dolby, so that wouldn't be a good comparison.

Give Bose a chance. For $2000, they'll come up with a 20 mini cube system that will leave you wanting to rip the ears right off of your head.

Oil tank moved! What a difference it makes to the flow of the space. Starting to visualize the room size now. Going from previous room of 12x17 to 15x22 or so. Woohoo!

The offending column is the unpainted one. Hopefully engineering report later this week for removal and LVL install.

I have to stop the household habit of "just put it in the basement for now." Its starting to become a storage morgue down there.....