bass / kick and bass management

[AdamFrick]

of course, none of this is set yet, there are no standards, and everyone is just doing whatever seems to work.

but,

i've got a video mix i'm doing for dvd, and the music is more or less rock and roll, so there's plenty of kick, bass guitar, and even some nice low rumbly synth pads, etc. i'm monitoring with bass management, trying to be a good boy. so, the mix sounds good, there's plenty of low end in that sub because woofie is putting it there... and i'm inclined to leave it that way since its working.

but, is there any conceivable reason to send the kick, bass, or anything else to the LFE channel in place of or in addition to sending to the main outputs? i guess it comes down to 6 of one, half dozen of the other, but i just thought i'd see if there were any opinions out there on the topic. there are clear lines for something like explosions and other sfx cues, but not so much for music i think.

thanks!

=a=

[john1192]

Adam, is there anyway for you to do a DTS-CD and check your mix on another system. I worked on 2 DVD's this year. And it would have really helped me to hear the mixes in the Bass Management of a home receiver. I tried layback to Da-88 with Woofie and then wire my Da-88 into the 5.1 inputs of my receiver at home but the result was not as true as using the internal decoders for Dolby Digital and DTS. I am relatively happy with what came out on DVD but I would have done things different if not for the deadline and setting up a new and quirky 5.1 Pro Tools system at the same time.....you can email and I will gladly share any info I have. John
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[AdamFrick]

yes i'm able to test via dts, but of course since we're on the top floor, i have no sub with my home system. so its great for checking general balances, but not low end stuff.

-a-

[branco]

In mixes for theatrical release, I always add portions of LF-containing sounds to subwoofer (LFE) channel. One of the main reasons (besides making it easier for screen speakers to reproduce the program) is the fact that LFE effectively extends the response of the system down to 20 Hz region, so you'll get almost one octave more. Other reason is less obvious: 2-track analog Dolby SR in playback uses bass management system that automatically feeds the LFE with portions of signal that goes to main speakers. By adding some LF to subwoofer, you can assure both mixes sound equally when D/A switching occures, as well as giving your digital mix the same LF contents your analog mix will have in theatre.

[CLee]

there is deffinately a reason NOT to put kick & bass on a LFE track. many systems when folding down to stereo and possibly some when playing 5.1 on home systems simply drop the LFE track. in any writing on 5.1 mixing someone will say sometheing like: do not put anything on the LFE track which by its absence will destroy the "integrity" of the performance. be that music or sound for picture. just because bass management sends something to the sub doesn't mean it should be recorded on a LFE track

[branco]

So, what should we use LFE for? Shall we use it at all? Shall we ignore surround, too, as it will dissapear when folded down to 2track stereo? If I'm reading your post correctly, CLee, we shouldn't mix elements to LFE only, because these elements could dissapear when reproduced on some systems, but that doesn't mean never using the LFE.
Branko

[c.evans]

I have mixed several 5.1 releases for DVD and have found that supplementing the kick and bass (already present in the mix ) with a little feed to the LFE helps on most systems that I have listened to.
It is really a "no holds barred" area of surround mixing for music, as is the use of the center channel.
Always filter the final stem at least 120hz and try to make a test disc if at all possible. I have the good fortune of having my authoring house in the same town so that we can do tests with video and PCM audio on the same disc as the AC3. I am soon adding DTS encoding to the disc and I am really anxious to hear the difference.

Good luck!! Chad [img]images/icons/cool.gif[/img]

[CLee]

chad gives you good advice. surrounond mixing in post work is still up in the air as far as rules go- so you can imagine in music you really are out there. When surround gets folded down to stereo the surrounds don't get droped they get mixed in Left & Right at a reduced level (-3db I think, but don't quote me on that).

Remember that any system with a sub and bass management will steer frequency below about 120HZ to the sub and consumer surround systems will send low freq info to both the sub and the other speakers. So to get your kik & bass in the sub you do not need to send it to the LFE track. The LFE track should be thought of as an effects track. Let bass management take care of the rest.

Check out Tomlinson Holmans book for a good explaination of all this. It can be VERY confusing at first- but stick with it, and keep in mind that at this point there really are no rules.