Dolby Atmos Pipeline Question

[Tony Bandiera Jr]

[QUOTE=Ryan K Georgieff;n37840]Wow you guys gave me a lot to look at! that jbl is pretty awesome I could just run it through my mixer with no questions. but it is the same price as our projector and then I would need speakers! right now I am happy will adding some bed channels and vacuuming my EVs need to replace a cone or two. I grabbed a bargain of an amp from QSC and am going to separate the back Surrounds so we have 7.1 from there I am going to add some more speakers to the screen we have some already back there not doing anything some nice JBL wedges. they have been strict in the pass about having a live set of speakers and a cinema set of speakers which in my opinion is over kill on all fronts.[/QUOTE]

Two major points above that I bolded: (and they directly relate to each other)

First: Not sure what you mean by "JBL wedges" but, having done both cinema and live sound in my 43 years, they are different animals and using cinema speakers for live sound (and live sound for cinema speakers) WILL ALWAYS result in a very messy, often horrible, sounding system. Also, cinema stage (behind the screen speakers MUST BE IDENTICAL or you will end up with "Holes in the sound" and other nasty artifacts.) DO NOT MIX THEM, EVER. You will end up with worse sound. and:

Second point (the underlined/italic one) "They" are absolutely correct. It is not overkill, it is good and proper design practice.

Cinema sound uses somewhat fixed predetermined maximum SPLs (sound levels) and EQ specific to the way the film soundtracks are mastered. For a given room size, cinema requires half or less of the total audio power and SPL/dynamic range capability of live performance sound. And the EQ for live sound is constantly changing due to mic placements and levels, amplification needs for various instruments/sources, etc. Using the same speakers for cinema and live will end up with several compromises and problems, namely:

• EQ will be radically different. Live EQ on cinema is usually very shrill and harsh sounding;
• SPL's that cinema speakers are designed for have a good chance of being far too inadequate to deal with live sound;
• How will you ensure that the calibrated cinema SPL's and EQ will be maintained and/or reset after a live show?
• Feedback, dropped mics, overdriven amplifiers will damage speakers. Combining both systems into one means one mistake and you are screwed for both uses. One live show can ruin your cinema system.
• Cinema speakers and sound mixes require specific speaker locations and placement and aiming, live sound requires totally different placements and aiming to permit higher SPLs while minimizing feedback risk.
• Audio routing and interconnection becomes a nightmare when you have to send both live and cinema to the same amps/speakers. You end up with hum and noise issues, as well as the risk of blowing speakers.

I have designed and built "multi-purpose" venues, one at a University and several others for theaters like yours that do live and cinema. I walked away from several more who insisted on a combined system (including one prominent University) and most of those (especially said University) tried to get me to come back in and sort out the resulting mess. I sometimes said sure, if you pay me a $25,000 fee to redesign the mess. Glad I was busy enough then to not need the headache or money.

Bottom line: Cinema and live sound are radically different. Never try to combine them into a single set of processors, amps or speakers. The end results will never be right for either use.

[Marcel Birgelen]

Stuff like Q-Sys nowadays allows you to actually route multiple sound system layouts over the same infrastructure. It's actually the reason why we switched to Q-Sys in our screening room. But alas, I totally agree with Tony: Live sound is radically different from cinema sound and should be handled by different systems.

Another reason to keep your cinema sound system separated from a live PA system: The performers will usually have their own PA guy, you don't want this guy messing around with your cinema sound system.

[Mike Babb]

A couple notes, one is that the SDP75 and Altitude 32 both have 16 channel input connectors that are TASCAM DB25. The automation commands should be quite similar to the Trinnov Ovation 1 and Ovation 2 processors.

Commercial cinema Atmos is a great product when done right, and I would say the same about home cinema Atmos. But you need the budget and skilled installers to do it right.

What we are seeing a lot of on the Trinnov commercial cinema side is systems that allow full range surrounds via bass management. 7.3, 7.4, even up to 7.7 have been done by various dealers and speaker manufacturers. The investment is lower and the performance is impressive when properly installed.

[Ryan Gallagher]

On the system mixing subject. Our space is mixed use. We keep our audio systems separated... mostly.

We are able in a pinch to send a couple channels to the booth mixer for pre-show talking/music over the cinema system.
And if we are showing ALT content, I'm able to send stereo signal back down to the live console downstairs
Rarely we might run ALT content in stereo through the live mains if the plan is to fly the screen and "reveal" a live act immediately after the screening. (No time to fly in/out the screen channel truss etc).

[Ryan K Georgieff]

you guys do make excellent points and I'm not saying it is an easy job but the cinema and live are only mixed at the speaker level(technically the Amp level) the cinema parameters are in the cp500 and the mixed media Stereo&5.1 from the MiniMac and the live mix are set in the Yamaha tf-1.before I came they just ran the mixer out to the stereo through the cp500 now we have all speakers running and a feedback suppressor for the microphones.

My current speaker complement is L-C-R 1per channel(EV TL606DW for the low and a DH1A for the High) with the LS& RS surrounds on 8 jbl 8330 run From 2 DCA1644s and 1 DCA1622

speakers not in use are 3(4?)JBL SF15 with two JBL MP418S an double bass EV TL550D that I need to replace the cones on and 2 Sonic T1510/EV15 Proline and one HMS-10 we have hanging out in the corner for some reason it has no partner.

Not counting the 4 monitors and 2 miniPAs we have.

My live Mix style is to add the warmth of the venue to the show not blast folks out of their seats. we have had groups that want to blast and we ask that they bring there own speakers. Sadly we have had problems with directors that think it's my job to finish their Film mix not understanding I can't just lower the bass and increase the center on a dcp. sadly the folks that bring me Mp4s never ask, but I do give them the option of up mixing to 5.1 instead of running stereo and many have liked the result. it's not true 5.1 it's just a dirty upmix i would love to do a more skilled on the fly 5.1 but I haven't got the hang of the DAW yeah.

[Ryan Gallagher]

Actually our smaller theatre is probably more comparable. It has a non-transparent roll up screen, as such we deploy a center and cinema subs behind a transparent bottom free standing masking. L+R are sent to the live desk at unity gain channels with no EQ, placement is non ideal being out board of the screen but everything is a compromise in that room.

But over there the C+Rs+LFE are direct from the CP750, not provided as options to the live console, amps not even turned on for live shows.

And during SXSW, none of that gets used except the surrounds and processor. Cinema screen is installed along with it's L+C+R amps and cabinets. Our compromise setup definitely doesn't pass for festivals and premieres.