Reference calibration for Dolby Digital and DTS?

[Lee-c]

Our system is calibrated for DD Reference Level, but I was wondering if anyone here knew if
DTS uses the same standards for what it considers Reference Level (105dB for regular channels,
115dB for subwoofer) for a movie. I usually listen to the DD track, as I know where I'm at
relative to Reference with that. Obviously some movies can run rather hot compared to Reference
with their DD tracks and I assume that is also true with the DTS tracks. But generally speaking,
is, say, -12 on the DD track for a recent action movie going to be the same as -12 on the DTS
track for the same movie? Or do they tend be quite a bit different in SPL levels? And if so,
how in the world are you supposed to know where you are relative to the established DD Reference
Level when listening to the DTS track? It's hard enough trying to keep track of the movies
that run hot on their DD tracks.

Thanks for any info.

 

[Johnny_M]

good question, on my system DTS is alot louder thand dolby digital. id like to know the answer to this myself.


Johnny

 

[Phil Iturralde]

If you have Sound&Vision HT Tuneup DVD (by AVIA), you can REF Calibrate using DD-5.1 or DTS-5.1.

Do both and you'll see what the difference is with your AV Receiver.

With my Yamaha RX-V1300, the only difference was the overall Volume Knob level (digital readout - DTS was lower vs. DD for the same 85 dB SPL) - all the speaker trim levels were identical.

Phil

 

[Lee-c]

Good idea, Phil.

I didn't know you could set reference for either DD or DTS ref. level
with Avia (which is what I use).

I don't suppose you recall off the top of your head what the dB difference was?

It would be convenient if we could assume an automatic 2dB SPL boost or something when playing
a DTS soundtrack.

Of course, that still leaves us with the very real problem of knowing how much do DTS tracks tend
to vary from reference. If they get run just as hot above their ref. level as DD soundtracks
sometimes do, then for a movie's DD track that runs +6 hot, that would be equivalent to +8 hot
when listening to the DTS track at the same master volume level (assuming DTS' ref. is 2dB hot
by default compared to DD). Or maybe DTS tracks don't get run as hot because their ref starting levels
are higher to begin with.

Thoughts on this, anyone?

 

[Nick Breckon]

On my setup, it's more than a simple overall volume boost. Offhand I can't remember, but there are some 1-2db changes between the L&R versus the center, and the fronts vs. the rears. On DVE, you simply hit the audio button on the DVD player and switch to DTS to calibrate.

 

[Phil Iturralde]

I think it was around 4 dB lower vs. DD-5.1/6.1 (test done last summer). I'll check it again tonight if I have a chance.

Phil

 

[Lee-c]

Ah, I see. I saw Avia and just assumed you meant the standard Avia disk that many who are into
this sort of thing use.

I don't have that one, just the Avia calibration disk.

Any dB differences you could report would be great. Since all the other settings on your receiver
are exactly the same, then the difference on the master volume dial needed to get to ref. level
should give us a very accurate idea of just how much louder DTS ref. is. Thanks!