Rational Acoustics



cwc5528
September 6th, 2011, 02:54 PM
Hi All,

I have been asked to help in set up a 5.1 playback system in a Lecture Hall and was wondering if anyone out there had any tips that they would care to share about tuning such a system. I have some ideas about what is required but I have not worked with this kind of system before. It will be a hodgepodge of equipment which has not been totally determined as yet but EAW cabinets, both powered and not. I am not sure what the .1 cab will be and either dBx, Galileo or Lake Contour for processing.

Thanks

cwc5528 (Charley)

martindale
September 7th, 2011, 05:09 PM
This is a big subject and can be but doesn't have to be confusing. There is tons of "setup" info on 5.1, you can search Dolby, THX, home theater forums, AES, etc etc.
Some questions: you say "set up" and tune, but seems some of the equipment is not yet in place, and would be good to know the specs.
If it's a 5.1 system, I would assume it would be used for video/ film playback, but if it's a "Lecture Hall", do you also need to have the system provide simple 2 channel (or mono) playback for a lecturer? In other words, go back and forth between 5.1 and voice only?
Is this Hall an appropriate acoustic environment for film playback? I've had to set up film systems in "Lecture Halls" or performance spaces before, absolutely wrong acoustics for film so makes it harder.
You mention processing by DBX, Galileo or Lake, each good stuff, but are you also asking how to program these boxes? Aside from simply "tuning the eq", there is bass management to consider, as well as delay for surrounds, etc.
As you see I've already used a lot of words just asking you prelim questions, contact me PM I'd be glad to discuss more or send links.

cwc5528
September 8th, 2011, 02:13 AM
Thanks for your reply and sorry for being so vague with information.
I will try to answer some of your questions.
There will be a separate system for voice and the 5.1 will be discrete from it. The hall really isn't designed for this kind of playback but the 5.1 play back is for a musical piece that was produced here and lasts about 7 minutes. It is one small but complicated piece of the event.
The Galileo is the box that we will be using and I am familiar with its operation.
Currently, the plan is to use 3 EAW boxes of one type for the LCR and two other boxes of another EAW type, possibly 4, for the surrounds. The reason for 4 is to get coverage in this odd shaped room. Think pie or wedge shaped. The .1 is a Genelec, I believe, possibly two.
One of the things that we are trying to determine is whether to try for a tradition studio approach or more of a theatre style.
While I have some materials on this I am always interested in new information.
Sorry for being so long winded but I hope this give you the idea.

cwc5528

martindale
September 8th, 2011, 07:04 AM
Ah! 5.1 for MUSIC ! Nice. Of course 5.1 is used mainly nowadays for film but "music" setup differs a bit. Generally, surrounds will be equal level as fronts, not down 3dB as in film. Very quick thought is, if possible, either go to or communicate with the facility where the content was mixed, and find out how they set up the playback system, then use same relative settings, so it plays as it was mixed. At any rate, allow for some tweaking by ear in the Hall, as again the Hall's acoustics will influence the playback. I'll send link later when I can but search "Producer's Wing Recording Academy Surround Specifications" or something like that which sets out standards for 5.1 music playback.
As for eq, regardless of film or music, the basic Dolby "X" curve is a good place to start for a larger Hall....and again, tweak to taste.

cwc5528
September 8th, 2011, 02:48 PM
Thanks for the insights. It shouldn't be a problem to find out the particulars since the engineer/producer will be there, so getting any background will be no problem. It was mixed in a studio with a traditional 5.1 setting on active Dynacord near field reference monitors.
We are doing the setup tomorrow so I will let you know how it goes.

cwc5528

Ferrit37
September 11th, 2011, 02:28 PM
Hey Guys,
maybe a little late but maybe this is of some help : http://www.aes.org/technical/documents/AESTD1001.pdf