Film-Tech Forum ARCHIVE: Upgrading to Surround Sound

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Posted by Randy Stankey (Member # 64) on 05-18-2011, 02:13 PM:

Okay, everybody... It's time to start pushing for the next upgrade to the sound system, here at Mercyhurst.

This time, it's surround sound.

We have our CP650, amps and speakers working the way we want them to and it's made great improvement. People are complimenting us on the improvement. I've got forward momentum going, here, and I want to keep it moving.

I have been telling the boss that our CP650 has the capability for surround sound. Because we are only using C/L/R/Sub when the system has surround capability, I have been saying that we're missing half our potential for sound when that signal goes into thin air.

Yes, I'd like to put baffles behind the screen. It would be the cheaper option and it would help the sound quality quite a bit but, strangeley, the boss seems to be more open to the idea of surround sound. I can make baffles any time so I'd better strike while the iron's hot. Right?

Anyhow, here's the specs...

Our hall is 100 ft. long, from screen to back wall of the house, 55 feet wide and about 55 ft. tall. (Open beam ceiling architecutre.)

It's a very "live" room. Designed for classical concert and live stage performance.

Here's a link to the theater's website with pictures:
http://pac.mercyhurst.edu/facilities/mary_dangelo_performing_arts_center.htm

I'm figuring four speakers per side and two more QSC amps would do the trick.

We're going to have to run wire. It's probably going to have to be through the ceiling and down the inside of the walls.

While we're there, I'm hoping to be able to run more wires down to the front speakers to facilitate bi-amping the C/L/R channels.

At this time, I've estimated the cost at around $10K.
I know that's a bit high but we have to account for costs in running the wires and unforeseen expense. I'm secretly hoping I can come down to around $7K.

Is this reasonable?

I'm going to need to start drawing up the plans and costing out the project because my boss thinks we can cover most of the cost with a fund drive.

I'll need to have a tangible plan to show potential donors.

What do you think?

Posted by Gordon McLeod (Member # 33) on 05-18-2011, 02:16 PM:

Well if you were doing 4 per side i think you may want to hang A7's on the wall to get the desired coverage and SPL you would need far more than that

Posted by Louis Bornwasser (Member # 3063) on 05-18-2011, 09:52 PM:

There is no way to have too many surround speakers. Dolby once suggested 3 seats per speaker. (not kidding!)

You can have a few speakers IF the ceiling height is surricient. I have never seen a room that needed less than 12. Louis

Posted by Brad Miller (Member # 2) on 05-18-2011, 09:58 PM:

quote: Randy Stankey

I'm figuring four speakers per side and two more QSC amps would do the trick.

That is so not enough surround speakers. Don't forget you have a balcony to deal with on top of that too, and 4 surround speakers wouldn't even be suitable for your balcony.

Posted by Brian Guckian (Member # 1678) on 05-19-2011, 08:39 AM:

This may seem a little off-the-wall, but given that this is such a beautifully-designed venue, what about the possibility of a flat-panel loudspeaker solution?

The attraction (at first glance, anyway) is:

(a) diffuse sound field (ideal for surround)
(b) easy architectural integration
(c) lower number of transducers needed

I believe low power output was a problem when considering this technology for cinama applications in the past, but perhaps things have progressed to the point where it can be looked at again.

(BTW apologies if this may have been raised here before - I did a search but couldn't find anything on it)

Posted by Louis Bornwasser (Member # 3063) on 05-19-2011, 09:06 AM:

In desperation, on rentals, I have used a few, high powered speakers and aimed them UP, for a ceiling bounce. Worked amazingly well. (1000 seat theatre with 45 ft ceiling, 6 music instrument style speakers. (I am less tolerant on screen channels.) Louis

Posted by Tony Bandiera Jr (Member # 2365) on 05-19-2011, 02:06 PM:

I like Louis' suggestion, and I agree it could and would work well. Remember this is NOT a traditional cinema space and we need to think outside the box in this case.

I'm willing to bet that Randy has access to various speakers as used for live performance..so I would suggest rigging some temporary setups trying different speakers and placements to get the most acceptable results. Start with Dolby's CAT 151 film (center/surround) to get the apparent acoustic level close, then test with various reels of actual, known program for best results. I am confident that you can find a nice balance of speaker placement, aesthetics, and performance as long as you're willing to be patient and open-minded.

The 4 per side of conventional speakers definitely won't cut it at all in a space that big...try more like 8 per side at the minimum. PLUS speakers to cover the balcony. And plan on three DCA's..two bridged to drive each main side and one in stereo mode for the balcony. Be prepared to add some extra EQ and possibly delay for the balcony. (I believe the DCM monitors can do this.)

I wish I were closer to your location Randy..I love a challenge and would love to get this working for you!!

Posted by Gordon McLeod (Member # 33) on 05-19-2011, 03:14 PM:

The university theatre in toronto had A7's mounted on the side and rear walls in there 1200 seat room with balcony

Posted by Randy Stankey (Member # 64) on 05-19-2011, 03:41 PM:

I like Brian's idea of the panel speakers. Would it work?

The reason I like it is because preserving the architecture has been a big reason why this idea has been shot down before. The panel speakers would give a better look if they would work.

Four speakers per side was just a guess. I'm not sure exactly how many it would take.

Under the balcony, there are about eight speakers recessed into the ceiling. They were conceived as fill-in speakers for the house sound system but it is possible to hook into them for the cinema system. The problem is that they are 70v speakers.

We don't often seat customers in the balcony. The booth is not sound proof. There's only a sliding glass wall blocking it off. I usually run movies with the glass open just a crack because it is regular tempered glass, not optical.

Customers who sit in the balcony can hear the projector. If they sit any farther back than the first four or five rows, they can get in the way of the lens, too.

For these reasons, I have not considered surround speakers for the balcony in my plan. I could be convinced to change that if the expense doesn't go too high.

It would be nice if somebody else could visit the theater. Even though I am sure I can complete the project myself it would be a lot better to have a consultant visit at least once, just for reassurance.

Let me see if I can find some blueprints for the auditorium and get them scanned. If I can find them, I'll post/link them.

Posted by Brian Guckian (Member # 1678) on 05-20-2011, 10:18 AM:

More information which might be of interest, Randy:

Novasonar is an interesting range of architectural flat-panel loudpeakers by the German firm ML Audio + Carbons GmbH, which appears to have application in large spaces (they cite "Protected Historical Monuments, Restorations, Museums and Churches":

Novasonar Brochure

For sure, cost may be a consideration, but if feasible, there would be a significant architectural gain which could offset that cost.

NXT, the company that developed Distributed-Mode Loudspeaker / DML technology, was re-named HiWave last year. Their line of stand-alone transducers includes hybrid Balanced Mode Radiator / BMR models that combine the patented DML vibration action with the traditional piston-type:

HiWave Audio Range

Posted by John Hegel (Member # 628) on 05-20-2011, 09:45 PM:

I have heard some nice sounding 70v systems. If someone designed the house system well, I would guess that you have some decent ceiling speakers.

It couldn't hurt to hook them up right now and see if it works with your room.