Hey guys. This is a silly question but what is the actual difference between DTS and PLIIx?

DTS is a data-compression technology (like MP3 or Dolby Digital).

PLIIx is surround processing technology.

Ok. Thanks for answering here too . I was watching Assault on Precinct 13 which is supposed to have DTS but for some reason when I hit the DTS button on my Sherwood I get silence. I believe the Sherwood has a similar menu to the 990. Does anyone know what I need to do to hear the DTS tracks?

As Sanjay pointed out, DTS is an audio format similar to Dolby Digital. DVD's that have DTS tracks generally also have a Dolby Digital track that is the default, so you first need to go into the disc's audio or setup menu (whatever that particular movie calls it) and change the audio from Dolby Digital to DTS. It may prompt you to confirm that you really want DTS, since not all receivers support DTS (mainly older gear). Once that is done and you start the movie, the Sherwood should detect the presence of a DTS source and automatically switch to it with no effort on your part.

You have to select the DTS track on the DVD player.

Hey it worked. What a dweeby newby question. :p I have just always watched it in Dolby and never explored DTS. Okay so here I am watching Assault on Precinct 13 and I switched it over midway through to DTS. First thing I notice is its louder. I have it with the PLIIX. It sounds great. Why don't they all have DTS?

DTS is typically about 4dB louder than Dolby Digital, which is sometimes suggested as a reason that many people prefer DTS - the ears can equate "louder" sound to "better" sound.

The reason that many discs do not include DTS is "bit budget". A DVD has a finite amount of space, and DTS typically takes more space than Dolby Digital. At one time, studios would get around this by releasing separate Dolby Digital 5.1 and DTS 5.1 discs (with a legacy DD 2.0 track on the DTS disc to satisfy the DVD standard). That practice has largely ceased, and instead we see DTS 5.1 tracks coexisting on discs with DD 5.1 tracks. The combination of those two cuts into the space left for video (potentially requiring higher compression, which incurs a possible decrease in image quality) and extra features.

Besides being louder, are there any other real differences in sound quality? I have not been watching long enough here to really come to a conclusion but my instincts are that it is smoother? That could just be the 4dbs talking though.

Cliff, what do you have your sub set to in relation to your Dolby for DTS? I notice the sub output is a lot less. Thanks.

Do you mean the LFE level trim settings or the sub channel trim?

For sub channel trim I have the preamp set to 0dB and used the sub amp volume control to balance the subwoofer with the main speakers.

After setting the volume on the subwoofer I set the LFE level trim to -4dB for Dolby Digital and +10dB for DTS.

Yes. That is what I meant. Great minds think alike. That is just what I set mine to also.

As gonk noted, the "bit budget" for DTS is higher than for DD, to my understanding because it uses a "lossless" compression algorithm, while DD's is lossy, so to that point I suppose that there is a quality difference. I think that audiophiles in general see DTS as superior, and I personally notice that DD is a bit harsher in the higher frequencies. Sounds like your ears are noticing something similar.

No difference in quality has ever been demonstrated by any of the magazines, movie studios or music labels that have done careful tests between DD and DTS. Probably is. Louder, especially if it's a small difference in volume, is almost always heard as an improvement in sound quality. It's an old salesman trick. Both use lossy compression that discards data; the DTS codec is ineffecient compared to DD, which is why it requires so much more bandwidth.

Actually, both are lossy, but DTS claims a less lossy compression algorithm. Lossless compression (such as DVD-Audio's MLP) takes a lot of disc space.

My take after comparing a few films with both is that the difference is minimal. DTS is louder and perhaps a tad smoother. But that could be my imagination running away with me. It will take a lot more flicks to see which I prefer.

Yup, but Soundhound and I did a test one afternoon quite a while ago in his personal studio, calibrated for professional application. (He mixed commercial films there.)

We both could clearly hear a difference, even with careful level matching. The Dolby compression was audibly more lossy than the DTS, less smooth, with less clarity of detail (manifest primarily in a loss of acoustical ambiance in the music tracks.)

And do I have the temerity to place our informal testing over the testing of the magazines, movie studios and music labels?

Damn right, I do. :p

In the last analysis, it's nothing to lose sleep over. But a difference is there and it sounds related directly to the compression algorithms.

The difference that you SHOULD lose sleep over is the difference between the original audio stems of the soundtrack and the chewed-up, compressed versions of BOTH DD and DTS. The amount of sound that those compression schemes throw away is heart-breaking.

Speaking of, Soundhound has been MIA since the great balanced/unbalanced debate. That was like a month and a half ago. I hope all is well.

I can't really speak for Da Hound, but he is OK. Just very busy these days.

Thanks for the update Bob. Good to hear he has a lot on his table and its not something else. By the way, I agree with your assesment of DD vs DTS.

Right, and people routinely hear differences in cables, power cords, etc. Doesn't mean those differences actually exist.

Controlled tests between the codecs done by 5.1 Entertainment, Warner Home Video, Home Theater Mag, What Hi-Fi magazine, Home Cinema Choice magazine, etc., were all unable to reliably pick DD apart from DTS (let alone demonstrate a consistent listener preference).

Had somebody (anybody) been able to establish DTS's superiority over DD, it would not only have been news but been flaunted by DTS in all their marketing material. But in the decade that DTS has been out, they have never ever been able to point to a single controlled listening test that supports what you're claiming. That's a fact.

You can place your "informal testing" over the testing of the magazines, movie studios and music labels, but that doesn't establish a difference that formal testing has never been able to demonstrate.

Gee whiz, Sanjay, I'm sorry. I had no idea that I had somehow urinated in your cornflakes. Why the onslaught?

Am I not entitled to respect what my own ears tell me? I was a professional musician, conductor and music critic for nearly 20 years. I was with a professional sound engineer and composer for motion pictures. I don't think it's unreasonable that I placed value on what I heard, also confirmed in detail by the ears of someone I respect.

I agree with you that no one has ever proven a difference. Still, my admittedly "informal testing" indicated that there is a difference. That's all I'm saying.

Or reason to insult a forum colleague in public.

dts is less compression, but it also uses a different algorithm than dolby digital. one thing you will notice is that the center channel on dts tracks is louder in relation to the mains. that is my main gripe against dolby digital.

dts takes up about 300mb more per disc typically, so on longer movies, that extra space forces the video to be more compressed.

if dts is an option, take it.

I thought I noticed the center a little more.

That's all I'm saying.

But my posting that fact is a public "insult" to you? And my supporting that statement with specific details is an "onslought"?

Gee whiz, Bob, I'm sorry. I had no idea that I had somehow tread on you personally by posting something at variance with your anecdotal experience. Why the reaction? Am I not entitled to respect factual information (that even you agree with)?

You'll note that when you countered my earlier statement with your "admittedly informal testing", I didn't take it as an insult or onslought. Nor did I tell you that you didn't hear it. However, if you are going to claim "a difference is there", then I don't think it's unreasonable to inform readers of the fact that this "difference" has never been proven. Unless you feel it's OK for you to reply to my posts but not the other way 'round? Agreed, wholeheartedly. We're discussing a hobby here, not some cure for cancer. If facts I've posted don't jibe with your personal experience, then readers can decide for themselves which they want to believe. Happens all the time with cables, amps, etc. Discussion is healthy and productive. And an opposing viewpoint is not a personal attack, so please don't take it that way.

Best,
Sanjay

I don't think Bob was upset with the fact you have a dissenting opinion, Sanjay. It's the structure of your post. Without being face to face, or having the benefit of knowing your speech mannerisms, I see how it could read a little confrontational, rather than conversational.

We all just need to remember that it's easy to take things the wrong way when the only way we have to communicate is the written word. Sometimes what reads one way to the poster, comes across completely different to a reader.

i'll go dts over dd any day!i even own a dvd that sounds like poo-poo in dd,but beautiful in dts:iron maiden-rock in rio

Are you setting the dB levels for DD and DTS globally and adjust the levels for each disc or can you save the dB levels for DD and DTS seperately?

Also, why do you feel you need to increase the LFE dB for DTS by 14dB?

I have 3 seperate LFE settings. For DD (-10dB to 0dB), DTS (+/- 10dB) and MPEG (+/- 10dB).

The difference is really not 14dB between DD and DTS because the DD decoder boosts the LFE by +10dB where the DTS decoder does not. The difference is only 4dB and that settings is based on playing a DD DVD with the loudest sound and adjusting so as not to break my subwoofer.