# LFE channel audio filter on some new release movies???



## tonyvdb (Sep 5, 2007)

Ok, so I have now been reading and can attest to the fact (as I can tell) that it seems that some movies are now coming out with a filter on the LFE channel!

First out of the gate was the Hobbit with a 50Hz filter and now Star Trek into darkness with a 30Hz filter. What is up with that! Is anyone else upset about this like I am?


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## Mike0206 (Jul 14, 2013)

tonyvdb said:


> Ok, so I have now been reading and can attest to the fact (as I can tell) that it seems that some movies are now coming out with a filter on the LFE channel! First out of the gate was the Hobbit with a 50Hz filter and now Star Trek into darkness with a 30Hz filter. What is up with that! Is anyone else upset about this like I am?


 I am! I was really looking forward to the deep low frequencies Star Trek had the potential of putting out. Needless to say that movie lacked lfe big time to me. I hope they don't do pacific rim like that! It would be real disappointing if all of a sudden movies stop putting out subsonic frequencies. Even frequencies in the mid 20hz range add just that much more oomph to the soundtrack. If they start filtering everything at 30hz and above then I guess there would be no point in getting a sub that can put out sub 30hz frequencies. That would not be cool.


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## tonyvdb (Sep 5, 2007)

I can understand a 15Hz filter as anything below that really pushes a sub hard but 30Hz!


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## Mike Edwards (Mar 10, 2011)

yeah, it's VERY frustrating. especially for those of us with low tuned or sealed subs.. the 50hz filter is almost unexcusable in my opinion. a lot of older releases had the dreaded 50hz hpf on them.. the biggest offender being "master and commander" which had an unfiltered release on DVD then they destroyed it with a 50hz filter on the audio


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## PassingInterest (Mar 29, 2009)

There should be a *Warning--This movie has an RB rating for Ruined Bass* in big, bold letters on the packaging, so we know it's junk before we buy.

Are the manufacturers afraid that someone might blow up their little _girly _subs?
I would think that would be something to brag about on the packaging--*Little Girly subs beware of big manly bass signals on this disc.*


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## Tonto (Jun 30, 2007)

Money talks, just don't buy these movies & send an email to the company making them & explain why you did not. LFE is the reason HT works, lest they forget that!


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## asere (Dec 7, 2011)

LFE all the way! Without it we lose the magic!


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## PassingInterest (Mar 29, 2009)

So, how do we know which movies had the bass chopped out of it? Is there a database somewhere?

Also, is it _only _with Blu-Ray discs or do they deliberately ruin the DVDs also?

My wife likes the Despicable Me movie enough that she picked it up in Blu-Ray, even though we already had it on DVD. I was so disappointed to find the really cool bass gone on the Blu-Ray disc.

Our _expectation _is for improved audio and video with Blu-Ray, but this movie is more enjoyable in DVD with all the bass still in it.


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## Mike0206 (Jul 14, 2013)

PassingInterest said:


> So, how do we know which movies had the bass chopped out of it? Is there a database somewhere? Also, is it only with Blu-Ray discs or do they deliberately ruin the DVDs also? My wife likes the Despicable Me movie enough that she picked it up in Blu-Ray, even though we already had it on DVD. I was so disappointed to find the really cool bass gone on the Blu-Ray disc. Our expectation is for improved audio and video with Blu-Ray, but this movie is more enjoyable in DVD with all the bass still in it.


 I believe AVS forums has a listing of all the best movies with bass on it listed in 5 star, 4 star etc...They specify whether its blu ray or DVD and you'll notice quite a few movies on DVD made the list and the blu ray versions didnt. Master and Commander comes to mind. DVD was great blu ray got the life sucked out of it bass wise.


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## PassingInterest (Mar 29, 2009)

Okay, thanks for the tip, Mike.

Has a _reason _ever been offered for butchering the LFE track?
Any good speculation for it.


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## BD55 (Oct 18, 2011)

This seems so counter intuitive to me. I would think that a Blu-ray would have much better LFE than a DVD, not worse. I guess it really isn't a technology issue but how it's filtered on the disc. Just seems like a backwards step to me; shouldn't it be: DVD - older tech, fewer people with capable systems, step up to Blu-ray - newer tech and more capable systems... 

Or is it that more people are buying HTiBs and those little dinky satellites can't handle any LFE nor can the tiny sub? When I was younger, we had the huge three way towers for LR with 12" drivers.

In any case, I hope this isn't a new trend; I would like to have the PQ and AQ together instead of having DVDs to enjoy LFE and Blu-rays for PQ.


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## asere (Dec 7, 2011)

I don't think the dvd/bluray industry cares about htib or if you blow the satellites. If that's the case then listen at lower levels. To each their own is how they see it I think.


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## Mike Edwards (Mar 10, 2011)

exactly. what it is, is some audio tech decides to implement a filter or something during the re-encode from master to film and voila. we have this... it's happened on the DVD format as well before.


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## asere (Dec 7, 2011)

tonyvdb said:


> Ok, so I have now been reading and can attest to the fact (as I can tell) that it seems that some movies are now coming out with a filter on the LFE channel!
> 
> First out of the gate was the Hobbit with a 50Hz filter and now Star Trek into darkness with a 30Hz filter. What is up with that! Is anyone else upset about this like I am?


Where did you read this? Did it compare the audio from dvd to bluray?


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## tonyvdb (Sep 5, 2007)

AVS has a discussion about it and its also been talked about in several posts here as well.


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## Mike Edwards (Mar 10, 2011)

check out Data-bass.com as well, they have the waterfalls up


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## jdent02 (Jan 13, 2012)

Just out of curiosity is anybody comparing these 'neutered' bass tracks to the actual theatrical releases? I ask since there's a possibility the exact opposite is happening: they are no longer enhancing bass for home video. It's known that few (if any) theaters can reproduce bass effectively below about 30Hz. As a Hollywood sound mixer, why would you then waste available headroom in the LFE with bass infomation that nobody is going to hear? I read an interview with mixer Lora Hirschberg (The Dark Knight) and she admitted that when she mixes she doesnt' think about the home video environment at all.

That being said is there a possibility that these theatrical tracks are (or were) being tweaked for home video release by running them through some kind of bass expander in order to fill in the ultra low end of the spectrum that was never used in the theatrical track? DTS was rumored to do this when they authored their own tracks for Laser Disc and DVD (one of the reasons why they usually sounded 'better' than Dolby tracks). If you look at a spectrum graph of bass content it seems to back this up, as almost all of the subsonic material is duplicating bass information in the higher octaves.

I can use the first Hobbit movie as an example. I saw it in an IMAX theater and even there the bass was very underwhelming. By all accounts it is pretty weak on home video too. I saw Avatar (another rumored 'filter' victim) in the same theater and it was the same story: weak bass in the theater and on home video. I saw MI: Ghost Protocol in the same theater and it nearly shook my teeth out. It did the same thing on home video. So my point is that for the Hobbit and Avatar it doesn't seem like the bass was filtered at all for home video (and MI:GP certainly wasn't), and most likely the original theatrical mix just didn't have subsonic content to begin with.

Of course I could be wrong and maybe they are putting filters on home theater releases (wouldn't make any sense to do this). But ultimately without someone putting up spectrographs of an actual theatrical track vs. the home video version nobody will know for sure.


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