PDA

View Full Version : Can you do 5.1 bass management with Audio MIDI Setup?




serr
Aug 15, 2011, 12:08 PM
I have a powered monitor 5.1 speaker setup. The mains are not full range so I need to do bass management. I've been listening to my 5.1 albums with a DAW like everyone else. There's now a surround capible media player (XBMC) but it doesn't have a bass management feature. This would be great to use. I could store my surround albums as 5.1 flac. So... is there some way to do basic mixing/aux send/crossover eq/build a bass management system with OSX tools?



serr
Aug 16, 2011, 11:00 AM
You misunderstood my question. I'm well aware of WHAT bass management is. My question is if it is possible to do this with 'Audio MIDI Setup'. This is the sound output utility in OSX.

As I said, I'm currently using a DAW where I've manually created a bass management setup (using the Waves linear phase eq's for crossovers). The one and only media player that handles surround sound media (XBMC) does not yet include a bass management feature. This unfortunately makes it completely useless for me.

Anyone around here familiar with the OSX audio tools and know a way to do this?

With a DAW you simply:
-create a 5.1 output and a 5.1 aux with 5.0 and Lf subpaths
-create a 5.1 track, 5.0 aux and 2 mono aux
-bus a 5.1 track to a 5.0 aux with a high pass filter set to your crossover frequency of choice
-prefader send from the 5.0 aux to a mono aux with a low pass filter (same crossover frequency and Q)
-add a mono aux for the Lf channel
These 3 aux's (high passed 5.0, low passed content from all 5.0 and Lf) go to the main 5.1 output.

drumsterdave
Aug 18, 2011, 09:12 PM
your albums should decode as 6 tracks, 5 surround tracks and 1 LFE track, technically you shouldn't need to do anything except make sure that the tracks are sent out of your interface into their respective speaker

output 1 Left
output 2 Center
output 3 Right
output 4 Left Rear
output 5 Right Rear
output 6 LFE

you shouldn't need to do any bass management on any DAW, although you could however boost the low end if need be, but the main thing is that you have 6 outputs from your computer for each speaker.

I hope I understood your question and I hope this helps!

serr
Aug 18, 2011, 10:10 PM
your albums should decode as 6 tracks, 5 surround tracks and 1 LFE track, technically you shouldn't need to do anything except make sure that the tracks are sent out of your interface into their respective speaker

output 1 Left
output 2 Center
output 3 Right
output 4 Left Rear
output 5 Right Rear
output 6 LFE

you shouldn't need to do any bass management on any DAW, although you could however boost the low end if need be, but the main thing is that you have 6 outputs from your computer for each speaker.

I hope I understood your question and I hope this helps!

You missed the part where I said my 5 tops were not full range. Bass management is needed for the 5.1 format. The 5 channels are full range. For small speakers you have to send the lows from the 5 main channels to your sub along with the Lf channel.

Anyway, I'll just answer my own question.

Found an app called Soundflower http://cycling74.com/products/soundflower/ that creates a 16 channel bus in core audio. I can now send the outputs from a media player to a DAW and do whatever I need.

drumsterdave
Aug 18, 2011, 10:41 PM
the tops aren't supposed to be full range for surround sound. If they were, then there would be no need for an LFE (subwoofer)

If your albums are true 5.1 surround, then the production engineers would have done the bass management during mix down, in fact you should be able to pop your album into a 5.1 dvd player and it will reproduce exactly how the engineers wanted it to sound.

Now if you're creating your OWN 5.1 albums then that's a different story, but if it's an already existing 5.1 album you shouldn't need to do anything except dedicate outputs for the 6 channels of audio stream.

unixperience
Aug 18, 2011, 11:06 PM
This is a really cool app, it will be very helpful. I have a nice eq program my friend showed me, but it is for overall sound, not individual channels


EDIT:
The program is called boom, its actually in the app, but it costs a few bucks http://itunes.apple.com/us/app/boom/id415312377?mt=12

serr
Aug 18, 2011, 11:51 PM
the tops aren't supposed to be full range for surround sound. If they were, then there would be no need for an LFE (subwoofer)

You've been misinformed. The 5.1 format is 5 full range channels and an additional bass fx channel. Use it as intended or you will be the one out in left field. The Lf channel is NOT just the subwoofer channel.