DTS vs DD

kberg

Some might say LOTR - FOTR, since it was mastered so hot, but not me.

The DTS version of LOTR-FOTR, and TTT still rules in my book.

Kpt_Krunch

Originally posted by gregure
DD has a higher volume output (switching to DTS lowers the volume for some reason), and has a greater bass impact.

I guess everyone's setup is a bit different - but I can concur with you gregure - DTS is by far the best sounding to me overall - speech, music, surround sound (rain falling, shell casings falling, waves hitting a boat, etc) all sound like you're right there with DTS. However, DD has much more LFE encoded in it. Some disks it is not as noticable. One I really notice it on is the Led Zepplin DVD, on DD the bass really booms, but the overall sound is muddied, Plants vocals especially seem to get washed out a bit, but switch to DTS and it is much more realistic. Don't get me wrong, the bass is still there, it just blends in better, and does not overwhelm the soundtrack.

So, overall, I listen to DTS when available, like most everyone else.

Does anyone have anything 'scientific' to add as to why there is more (or at least louder) bass with DD vs. DTS?

kuntasensei

It's really just because of the way the individual formats are encoded. It is NOT, as someone said earlier, because of the bitrate... because you're comparing apples to oranges. Does DTS have a higher bitrate? Yes... but that's because it's a totally different encoding scheme, not because it is inherently of greater quality. That would be like comparing a 192k MP3 to a 192k WMA file; bitrate is inconsequential because they are two totally different codecs.

What most people hear as the difference is due to the way each encoding scheme handles incoherent data. The way both DD and DTS are able to essentially compress data from the original sound master is by throwing out or combining data that the human ear can not really perceive all that well. DTS at full bitrate sounds better than full bitrate DD most of the time because DTS doesn't combine the highs until around 18kHz (whereas DD starts around 14kHz if I remember correctly). Because of this, DTS will often seem to have more detail. The same goes for half-bitrate DTS. Because the codec handles the compression differently, DTS can sound more detailed, depending on the system.

This same explanation goes for the differences in bass as well. DD tends to combine a wider range of bass frequencies for compression than the DTS codec does, resulting in the perception of "louder" bass... when actually, it's really just slightly muddier and less defined than the DTS track from the same master. DD may sound more "loud" to some, and on most consumer grade subwoofers that is probably a good thing. For those of us with subwoofers that troll down into the sub 20Hz region (SVS 20-39CS+ for me), the LFE on DTS tracks is usually preferable because it seems less muddy, allowing our subs to show off their accuracy AND clean output.

There is also the issue of dialogue normalization. Dolby Digital includes a feature in its bitstream that automatically adjusts overall level so that movie soundtracks will be somewhat consistent (i.e. not louder than another at the same volume setting). DTS does not implement dialnorm, so often you will have to turn a DTS track up considerably higher on the volume control than the equivalent DD track.

Also (and this is an obscure but real problem), some older receivers do not properly pad the LFE channel of DTS tracks, making them sound weaker than their DD equivalents by 10dB. By this, I mean that some receivers don't apply the default adjustment of the LFE channel's level per DTS specs. Some higher end receivers let you adjust the LFE padding for DTS so that you can really tweak, but most consumer receivers stick to the default. Unfortunately, there are a few out there that do not pad the LFE correctly for DTS and do not offer any way to adjust it. You could always raise the overall subwoofer level if you are afflicted with this problem, but this will also raise the level of the bass redirected from your other speakers via bass management. Luckily, as I said, this is a fairly obscure problem.

Shizelbs

Welcome to the forum kuntasensei. Thanks for taking us to school.

That was perhaps the most coherent, well thought-out, grammatically correct, well spelled and constructive post I have ever seen on this forum.

Shizelbs

I just had a good example of when dts is superior to DD. I watched Pirates of the Caribbean yesterday. I must have watched the first 70% of the movie in DD. As the movie was dragging on, I went to the case to find out how long the damned thing was. Thats when I saw that it had dts as well. Up to this point I was pretty unmoved by the THX sound. dts goes on, and BAM, the movie got a whole lot better just through better sound. The difference was night and day. More detail and finally some bass was present. On that note, I would like to recommend Pirates as a good demo for DD vs. dts.