soundtrack equalization (1 Viewer)

[Chris_Eff]

Does anyone know of an easy way, such as dvd credits, to determine if a movie sound track has been equalized for home theater already? Such as I noticed with LOTR EE in some of the credits. The reason I am asking is I have been reading that using THX re-eq (which I usually just leave on) on a pre-eq movie lessens the sound by double filtering.

Thanks for any help

 

[Dan Ramer]

Chris,
Have a look at the list on this Mi Casa page.
Mi Casa Multimedia is an audio production house that removes the X-Curve pre-emphasis from DVD audio. Recent New Line releases indicate that no re-equalization is required; this notice is found on the audio setup screen. Alternatively, selecting the New Line logo in the main menu screen typically displays disc credits; if Mi Casa is credited with the audio, you may assume that re-equalization is not necessary.
They may be out there, but I'm unaware of other audio subcontractors that re-equalize the audio prior to compression and authoring.
Dan

 

[Rick Blaine]

I believe the answer is Yes and No.

There is no eq applied to audio tracks that will dramatically change their quality.
I believe there is some minor eq added to surround channels in cases where the 5.1 track may be folded down to Pro-Logic or Stereo. That is in the case (which is most common) when an LT-RT is NOT included on the disc. There is also some minor base redirection done for the same reason.
If done properly this has no real effect on the quality of the 5.1 and hopefully improves the audio for people who do not have Home Theater 5.1 setups at home and will be listening through their stereo system or TV speakers.

There is NO eq done for THX in mastering. THX is purely a Home Theater setting.

Rick

 

[Dan Ramer]

Rick,

I believe Chris was referring to the high frequency pre-emphasis added to motion picture soundtracks and which should be removed for home theater playback. I’ve written about the issue of audio inconsistency and lack of proper labeling (one of DVD’s dirty little secrets) at DVDfile, so I’ll be brief here. Film soundtrack frequency response is rolled up at 3 dB per octave from 2 KHz onward. This is to compliment motion picture theaters’ electro-acoustic frequency response, designed to conform to the X-Curve. Small acoustic spaces with flat loudspeakers like your home theater don’t require such high frequency pre-emphasis. THX re-equalization in home theater electronics filters the audio to return the frequency response to a reasonable degree of flatness.

When you listen to film audio at home in which the pre-emphasis is intact and without X-Curve de-emphasis (THX re-equalization), the sound will be too hot - too much high frequency content. If you listen to a Mi Casa de-emphasized DVD with THX re-equalization enabled, the sound will be too dull - too little high frequency content. So it’s important to know how each DVD’s audio is prepared so you can correctly apply re-equalization and achieve proper sound.

Dan