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25 Hz filter on BD DTS tracks?

post #1 of 928
5/3/10 at 10:32am
Thread Starter 
A member in the PB13-Ultra thread brought up an interesting subject. He stated that studios are filtering audio below 25 Hz on new major bluray releases. If this is true I for one am really put out, as one of my primary motivations for upgrading to BD was lossless audio. Filtering out the deepest bass is in no way "lossless" by definition.

Movies mentioned to have this filter are some of the new release giants, such as Avatar and the BD of Lord of the Rings trilogy.

Does anyone here have more info on this? Just an evil rumor, a misunderstanding, or is this some lame attempt to short change the BD's we spend our hard earned cash on?

The first post on it in the PB13-Ultra thread can be found here.


***Update***After lengthy debate***Update***

Apparently the only film that has some kind of filtering is master and Commander. This thread has a couple of well done waterfalls comparing the LFE on M&C on both DVD and BD. The BD does appear to have less LFE but, again, this appears to be the only film with a difference between the DVD and BD, so it is not apparently a trend. Sorry if the threads title came off as sensationalist to anyone, I wasn't intending that, but merely asking a question after reading another post on the subject. As far as I am concerned the thread has served to answer that question rather definitively.
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post #2 of 928
5/3/10 at 11:07am
I am only aware of one instance of this phenomenon... Master and Commander. The DVD DTS version is leaps and bounds better in regards to LFE than the Bluray DTSMA version.

Are there other instances where the mixers intentionally neutered the LFE for Bluray?
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post #3 of 928
5/3/10 at 11:17am
It happened on Avatar(special HT mix) and from what little experience I have LOTR:ROTK. My DVD is much better with the LFE on that one. I hope it is a rumor because there are 3 movies that I know of that seem filtered. Maybe they are exceptions and not the rule.
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post #4 of 928
5/3/10 at 12:00pm
So far we have three major instances of this dead stop of LFE at 25hz.

Avatar, Master and Commander and LOTR.

If these three have this...more are bound to have it.

The only way we can tell is to watch them and listen, but to REALLY find out running a waterfall graph of the actual information encoded on the disc will confirm this.

This has been done on these discs and it is clear there is a filter at 25hz.

My question is WHY and how do we get around this?

Can we indeed watch the movie on Blu Ray and simply bitstream the DTS core and still achieve the REAL sound without the 25hz filter? I'll take a LOWER bitrate to have the sub 25hz LFE anyday!
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post #5 of 928
5/3/10 at 12:03pm


Just look at these. One is M&C on DVD with DTS...the other is on BluRay with DTS-MA.

(this is from a member named Bosso...he gets credit for doing the leg work of graphing these for us.)
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post #6 of 928
5/3/10 at 12:33pm
Quote:
Originally Posted by bgillyjcu View Post

So far we have three major instances of this dead stop of LFE at 25hz.

Avatar, Master and Commander and LOTR.

If these three have this...more are bound to have it.

The only way we can tell is to watch them and listen, but to REALLY find out running a waterfall graph of the actual information encoded on the disc will confirm this.

This has been done on these discs and it is clear there is a filter at 25hz.

My question is WHY and how do we get around this?

Can we indeed watch the movie on Blu Ray and simply bitstream the DTS core and still achieve the REAL sound without the 25hz filter? I'll take a LOWER bitrate to have the sub 25hz LFE anyday!

The only evidence I saw so far for filtering is M&C there is no doubt about that one. Avatar is not filtered, but can't comment on LOTR.
In any case you won't be able to get around it by using the lossy core.
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post #7 of 928
5/3/10 at 12:36pm
Can someone please do waterfall of M&C in DTS-MA.

Then BITSTREAM the Core DTS and waterfall that.

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post #8 of 928
5/3/10 at 12:56pm
How would BD producers benefit by dead stopping at 25hz? Why do it?
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post #9 of 928
5/3/10 at 1:03pm
Anyone have Transformers 2?
http://www.avsforum.com/avs-vb/showp...postcount=3594
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post #10 of 928
5/3/10 at 1:12pm
Quote:
Originally Posted by bgillyjcu View Post

Can someone please do waterfall of M&C in DTS-MA.

Then BITSTREAM the Core DTS and waterfall that.


Bosso's waterfall graph was from the lossy core.


http://www.avsforum.com/avs-vb/showp...&postcount=144
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post #11 of 928
5/3/10 at 2:16pm
DAMN....so mad I sold my old dvd.

I wish i could compare back to back.
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post #12 of 928
5/3/10 at 2:31pm
Quote:
Originally Posted by Mrkazador View Post

Anyone have Transformers 2?
http://www.avsforum.com/avs-vb/showp...postcount=3594

To be honest, even in the movie theaters, the bass for Transformers 2 felt dissapointing. Saw it at two different theaters. The opening scene when the big deceptacon emerged and threw allot of concrete drains about the place, I expected more bass there. When he went thru the overpass and Prime leaped on him grabbing around his neck.....more bass expected there. The highlight scene bass wise really for me was the Devastator assembly scene and the Fallen on the Pyramid. Any waterfalls for those scenes?
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post #13 of 928
5/3/10 at 2:50pm
Wonder what they will do to BD version of "Private Ryan"?
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post #14 of 928
5/3/10 at 4:39pm
20th Cent Fox made both Avatar and M&C. Think that has something to do with it?

I DO.

So I have sent two separate emails to them complaining about the blu-ray version.
You should too!!!

foxmovies@fox.com

If we flood them with complaints maybe something might happen!
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post #15 of 928
5/3/10 at 4:39pm
Quote:
Originally Posted by bsoko2 View Post

Wonder what they will do to BD version of "Private Ryan"?

I'm not getting rid of my DTS DVD version until I have PROOF that the blu-ray DTS-MA is just as good in the LFE department that is for sure!
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post #16 of 928
5/3/10 at 4:40pm
So am I correct in what I think is being said here? When some BR movies are played in full lossless mode that some of the audio seems to be lacking? But if the same movie is played with just the "core" audio, it sounds much better? If that is true, and I am already getting the "core" audio with my PS3 connected to my Halo C2, what possible benefit could there be for me to upgrade to a newer preamp that does the audio in lossless form. I am already happy with how my audio sounds now but I was wondering if it would sound better by getting the full audio. After reading this, I am not sure I want to risk giving up the sound I have. I know I can choose the Core if Lossless is flawed but I don't want to have to always check to see if it sounds good with lossless or not.
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post #17 of 928
5/3/10 at 4:46pm
Quote:
Originally Posted by bsoko2 View Post

Wonder what they will do to BD version of "Private Ryan"?

http://www.avsforum.com/avs-vb/showthread.php?t=1246425
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post #18 of 928
5/3/10 at 4:49pm
Subscribed
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post #19 of 928
5/3/10 at 4:51pm
Quote:
Originally Posted by MIkeDuke View Post

So am I correct in what I think is being said here? When some BR movies are played in full lossless mode that some of the audio seems to be lacking? But if the same movie is played with just the "core" audio, it sounds much better? If that is true, and I am already getting the "core" audio with my PS3 connected to my Halo C2, what possible benefit could there be for me to upgrade to a newer preamp that does the audio in lossless form. I am already happy with how my audio sounds now but I was wondering if it would sound better by getting the full audio. After reading this, I am not sure I want to risk giving up the sound I have. I know I can choose the Core if Lossless is flawed but I don't want to have to always check to see if it sounds good with lossless or not.


NO..the CORE on the blu-rays is still affected.

Only the ORIGINAL DTS version on DVD has the unfiltered version.
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post #20 of 928
5/3/10 at 4:53pm
Quote:
Originally Posted by cyberbri View Post

http://www.avsforum.com/avs-vb/showthread.php?t=1246425

Ralph does say "hose expecting the ultra low and gut punching low frequency effects that are found on many of today's big budget action films may be disappointed. That isn't to suggest that there is a lack of high quality bass because there is plenty to be found here. "

I remember my DVD DTS really rocking low and punching my gut....so I'll rent the BluRay and compare before I buy BLU and sell my DVD.
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post #21 of 928
5/3/10 at 5:08pm
Quote:
Originally Posted by MIkeDuke View Post

So am I correct in what I think is being said here? When some BR movies are played in full lossless mode that some of the audio seems to be lacking? But if the same movie is played with just the "core" audio, it sounds much better? If that is true, and I am already getting the "core" audio with my PS3 connected to my Halo C2, what possible benefit could there be for me to upgrade to a newer preamp that does the audio in lossless form. I am already happy with how my audio sounds now but I was wondering if it would sound better by getting the full audio. After reading this, I am not sure I want to risk giving up the sound I have. I know I can choose the Core if Lossless is flawed but I don't want to have to always check to see if it sounds good with lossless or not.


Don't buy into the hysteria. The core can't sound any better then the full lossless track. Anybody who claims that don't know jack about the codec.
The lossless DTS HD MA contains exactly what was fed into it, the core is roughly 1/3rd of that. If the BR has a different soundtrack then the DVD counterpart, then it was sourced from a different master[remixed].
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post #22 of 928
5/3/10 at 5:18pm
Quote:
Originally Posted by bgillyjcu View Post

Ralph does say "hose expecting the ultra low and gut punching low frequency effects that are found on many of today’s big budget action films may be disappointed. That isn’t to suggest that there is a lack of high quality bass because there is plenty to be found here. "

I remember my DVD DTS really rocking low and punching my gut....so I'll rent the BluRay and compare before I buy BLU and sell my DVD.

If you dig up old graphs of the DTS DVD, you'll see that SPR never had much below 30hz.
Same goes for Jurassic Park, another bass favorite from the 90's.


BTW Paramount use theatrical mixes on their HV releases. So no HT mix.
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post #23 of 928
5/3/10 at 5:52pm
thehun -- Or the source (remastered or not) was filtered to eliminate the real low frequency LFE. It almost sounds like somebody decided to apply a 25Hz filter to protect the "masses" from blowing out their woofers (or the subs in their "economy" HTIBs).

Nobody thought to put a warning label on the BDs instead. I have a Telarc CD of the 1812 Overture with just such a warning label (the real canons firing in the finale are awsome).

As I mentioned, in the Ultra 13 thread, my Laserdisc of the IMAX "The Dream is Alive" could rattle my windows & walls during the first shuttle lift-off. The DVD version appeared to be severely filtered too (my silent sub was a really big disappointment).

RE: your comment on Paramount BDs. Does that mean we need to set our AVR/Pre-Pro to "both" in order to hear what should be in the LFE channel? The theatrical mixes should have plenty of low frequency info (if it wasn't filtered).
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post #24 of 928
5/3/10 at 5:58pm
I've noticed that all my blu rays are louder in volume than my dvds. Maybe with all this amazing movie sound technology they now they are afraid of people damaging equipment because of spikes in bass/volume? Some sort of lawsuit thing maybe, i dunno. i'm just throwing that out there because it seems like the new movies have just such a nice and dense sound now that most likely COULD damage a theater noobs equipment that's not setup right. blah blah blah
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post #25 of 928
5/3/10 at 6:12pm
Quote:
Originally Posted by thehun View Post

Same goes for Jurassic Park, another bass favorite from the 90's.

I rented Jurassic Park a couple months ago just to check out the bass sequences(I was kinda young when it came out) and it was VERY underwhelming. I almost double checked to make sure my sub amp was even on.
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post #26 of 928
5/3/10 at 6:18pm
cmryan821 -- When I get home, next week, I will have to pull out my copy of Jurassic Park (DVD) and play it with my AVR set to "Sub-Plus" (= "both") and see if it is better that way.
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post #27 of 928
5/3/10 at 6:21pm
Gotta get the limited edition JP with the DTS track.

The DD sucks...the DTS track is pretty great (for a 90s flick).

And if you have the DTS version look up the old threads on here because there was a defective DTS version and we actually got NEW DVDs with the corrected version.


On another note, playing DD or DTS bitstreamed from my PS3 to my HT Receiver nets around 4db LOUDER volume overall compared to DTS-MA or TRUEHD being PCMed to my Reciever.

I simply crank the HD audio tracks 4db more because they are not employing the dialog norm that the old DD and DTS used to use. When I do this it measures exactly the same on the SPL meter in terms of overall master volume level.
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post #28 of 928
5/3/10 at 6:30pm
Quote:
Originally Posted by bgillyjcu View Post

Gotta get the limited edition JP with the DTS track.

The DD sucks...the DTS track is pretty great (for a 90s flick).

And if you have the DTS version look up the old threads on here because there was a defective DTS version and we actually got NEW DVDs with the corrected version.

That could explain it. I doubt netflix uses limited edition copies for its purposes. I remember something similar with The Haunting. The DD was absolutely worthless and I'm told the dts is much better.
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post #29 of 928
5/3/10 at 6:36pm
You are correct. The Haunting in DTS is amazing..in DD it was nothing special at all.

I had to go to the "ends of the earth" to find a DTS version of JP and then had to wait 3 months to get the corrected version, but Paramount did come through and mail me the corrected version! The T-Rex stomps are a treat and a half!

If you have a DTS version read the following:
On the back cover, at the bottom, the grid of disc specifications is outlined in red on the corrected version, not black as on the incorrect first pressing.
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post #30 of 928
5/3/10 at 6:38pm
Great thread here and also the initial post in the PB13 Ultra thread. I would have never even known about this pathetic "trend" otherwise.

This just saved me $2000 I was going to spend on upgrading to a PB13 Ultra. Now I can put that $2000 to MUCH better use.

I can't say I'm surprised that studio's are doing this.... par for the course to screw the consumer. It's what they're best at.

This type of **** justifies piracy.

Cheers!
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