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  #21  
Old 10-19-2018, 08:57 PM
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Default Re: Avid LoRo Downmixer

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Originally Posted by KingTor View Post
My intent is to send audio above 120Hz to the sub. I'm not doing it irresponsibility (I don't get calls from Michael Bay), but I do use the effect of a sub playing full bandwidth with intention. It's not mixing 101, that's for sure, and should be done carefully, but I've been mixing 5.1 for 20 years now.

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DUDE!...
You are SO WRONG!
Do not send full bandwidth to the sub.
Where in the hell did you get that idea?
First off, any movie worth $5 or more will be QC's by the people who make the DCP. You will fail. It will need to be made again. The Studio/ Production company will be upset and you will have to fix it.
You will not get paid until you pass QC. This will mean your great idea will cost you, the Studio and everyone else involved money.
Stop while you're ahead... and please don't come up with crap ideas like that.
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  #22  
Old 10-19-2018, 08:58 PM
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Default Re: Avid LoRo Downmixer

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Originally Posted by KingTor View Post
Have you listened to full bandwidth sound through a subwoofer? I'm sure you have if you've seen any summer action movie (the first Thor movie did it a lot from what my ears told me), but I mean have you listened to it by itself? That's the effect I use sometimes. I'm not telling you or anyone they should do that and I'm certainly saying you should only do it if you really understand how it's likely to play in a variety of theaters. If they do low pass my Lfe channel it'll still work. If they don't, I'm confident it'll sound good. And if it sounds good, it is good.

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No, it's not "GOOD"!
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  #23  
Old 10-19-2018, 10:13 PM
KingTor KingTor is offline
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Default Re: Avid LoRo Downmixer

I appreciate you all looking out for me, but we work on movies "worth more than $5," have passed QC, never even seen a note about how I use a sub, and get paid by repeat customers because it sounds good in theaters.

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  #24  
Old 10-20-2018, 12:57 AM
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Default Re: Avid LoRo Downmixer

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Originally Posted by KingTor View Post
I appreciate you all looking out for me, but we work on movies "worth more than $5," have passed QC, never even seen a note about how I use a sub, and get paid by repeat customers because it sounds good in theaters.

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Really?
First off it doesn't sound good.
Second I have seen QC reject a Theatrical Master because of
Full Frequency Content in the LFE. This QC company makes
the vast majority of DCP's that nearly all Movies are done by.
Not looking out for you but looking out for everyone else.
You have your mind made up by thinking your doing something
cool and unique. It's neither.
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  #25  
Old 10-20-2018, 09:38 AM
TheMuffinMan01 TheMuffinMan01 is offline
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Default Re: Avid LoRo Downmixer

Quote:
Originally Posted by KingTor View Post
Have you listened to full bandwidth sound through a subwoofer? I'm sure you have if you've seen any summer action movie (the first Thor movie did it a lot from what my ears told me), but I mean have you listened to it by itself? That's the effect I use sometimes. I'm not telling you or anyone they should do that and I'm certainly saying you should only do it if you really understand how it's likely to play in a variety of theaters. If they do low pass my Lfe channel it'll still work. If they don't, I'm confident it'll sound good. And if it sounds good, it is good.

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Thanks for the explanation! And thanks Marti for your perspective also.
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  #26  
Old 10-20-2018, 02:22 PM
KingTor KingTor is offline
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Default Re: Avid LoRo Downmixer

You're welcome. And Marti, I do respect your experience, and appreciate you sharing it with us, as always. Anyone reading this, and the guy writing it, would do well to go to school on Marti. I was exhausted last night and used the wrong tone.

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  #27  
Old 10-21-2018, 10:48 AM
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Default Re: Avid LoRo Downmixer

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Originally Posted by KingTor View Post
Have you listened to full bandwidth sound through a subwoofer? I'm sure you have if you've seen any summer action movie (the first Thor movie did it a lot from what my ears told me), but I mean have you listened to it by itself?
By itself? No. In the days of 35MM SR•D, the LFE was defined by Dolby to be 120Hz and below. Clearly you weren't doing that in Dolby Digital mixes.
Quote:
The LFE Lowpass Filter is used to band-limit the LFE channel input signal in the Dolby Digital encoder. If this filter is not enabled, wideband signal content fed to the LFE channel input of the encoder will produce significant audible artifacts at the output of the decoder. This filter should always be enabled unless it is known that the LFE channel input signal has already been properly band-limited
So, did you start doing this for DVD, BluRay, DCP?

Lastly, how do you know they used full-bandwidth content in the LFE in Thor? How do you know that it was not the case that the sounds were full-bandwidth coming out of the screen channels (which can go down to 20Hz) and merely augmented by the Sub? Maybe the full sound was sent, filtered, and had an sub harmonic generator inserted into the path and sent to the LFE. Or maybe it was simply filtered and sent. When combined, it was all cohesive. How can you be sure, especially given that screen channels go down to 20, that there is content above 120 in the SUB and not in the screen channel? Low frequencies are omnidirectional so it is very difficult for the ear to locate.
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  #28  
Old 10-21-2018, 11:25 AM
KingTor KingTor is offline
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Default Re: Avid LoRo Downmixer

All good questions, and I'm starting to rethink the whole thing. I started mixing without filtering the sub through a combination of laziness and system limitations (mixing a full feature in the box--one Pro Tools HD Accel 2 rig), and would filter it while mastering. In the process I developed a taste for the effect at times (not always by any means). I would never do it or recommend it on an ac3 master (BluRay / DVD) because ac3"s Lfe track isn't truly discrete and it was against Discovery's spec which was where most of my 5.1 broadcast mixes were going. You're right about Dolby Digital and I've never mastered my own film-based master anyway, so I've always left it to the mastering facility to take good care of my mix. I was under the (apparently mistaken?) impression that the DCP spec did not put a limit on the Lfe track (I'll re-read it).

It's possible I was mistaken about Thor, but sitting in that theater reminded me of the effect I got on our mix stage by saturating all 6 channels with a wide array of frequencies. I wasn't a huge fan of that mix, and least not in the theater we watched it in (too harsh on the ears), so I don't want to imply I was imitating them so much as reminded of things I had done.

I'm rethinking all of this now, and will be rereading the DCP spec and asking questions of QC houses before mastering. I guess the moral I still stand by is you can use the Lfe more aggressively in theaters than you may want to in a mixdown but that you don't necessarily have to mute the Lfe track in Downmixer to accomplish that.

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  #29  
Old 10-22-2018, 05:48 AM
Kuba Pietrzak Kuba Pietrzak is offline
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Default Re: Avid LoRo Downmixer

I downmixed to 2.0 a large number of my 5.1 mixes.


I did it with Avid downmixer and also before this plugin came out, just with proper routing.


And I have never had phase issues.


Yes, Low Pass Filter in LFE channel at 120Hz is (or should be) a rule.
You don't want to blow up a subwoofer in therater.



Kuba
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  #30  
Old 10-22-2018, 08:39 AM
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Default Re: Avid LoRo Downmixer

I do wish the downmixer covered all formats. (Or that PT could act like a mixer and do downmixing without a plugin...).

Also I always thought it would be nice to have a built in filter for the LFE. Set it in Preferences and forget it, or turn it off if you don't like it.
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