Outdoor Surround Sound System

[jeffbabcock]

I didn't suggest NOT trying it.
How bad it will be over a large area really depends on how the audio was mixed and how much use is made of the side and rear channels for "primary" sound content etc as opposed to just sound effects and ambience. It can vary considerably between movies. Some will fare better than others, ones that maintain a very front-focused dialogue track will fare the best.

I expect that the OP will be OK if he starts this out as a fairly compact setup.

[TomG]

I have a SACD copy of “Dark Side of the Moon” which we played on our indoor surround sound system. The room is approximately 25’ by 85’ with a ten-foot ceiling. The comments I received from different people were quite interesting. One guy insisted that it was a 7.1 surround recording and wanted to know where I was hiding the two side channel speakers. I was also very impressed how the front and rear channel speakers (spaced 85 feet apart from each other) could create such a solid illusion of sound originating from a point somewhere in-between. There was definitely a sweet spot near the center of the room to get the best sound, but once we found it we were in “Pink Floyd ecstasy”. This was one of the reasons that I thought an outdoor surround might work.

Our crowd at each movie is quite varied. We get the young kids who love to sit so close to the screen that they could almost count the pixels. Then we have the older kids who want volume. A little Distortion is fine as long as the building shakes and it can be heard in the next town over. The majority of the adults love the special effects. It is always funny to see people look behind them when they hear the sound of a ricocheted bullet or distant explosion from the rear speakers. One person commented that we have come a long way from the days of the big tin box that we hung on the car window at the drive-in movie.

Prior to the start of our indoor movies, I will play some 5.1 SACD and DVD audio recordings. This is where I get the most comments about the sound. Many times I will see people move around to experience different listening locations. There are even some people who will arrive early just so they could be in the sweet spot. They are all very impressed when I tell them that our surround sound system cranks out a staggering 90,000 milliwatts of power per channel!

[Mikey]

They are all very impressed when I tell them that our surround sound system cranks out a staggering 90,000 milliwatts of power per channel!

Isn't that "Jiggawatts"?

[TomG]

Jiggawatts! We haven't been able to generate that kind of power since lightning struck the clock tower!!!

[MEGAHERTZ]

I was planning on doing the same thing. Set up a outdoor theater that is. I'm just wondering what kind of surround sound receiver you will use. The one that I have in my house is like most others I've seen. The only "surround" outputs it has is for the speakers. Which would be amplifier power out of the receiver. Which would not be enough power to run a PA speaker and it could be to much power if one tried to wire those outputs to the inputs of larger PA amps.

[LelandCrooks]

Which would not be enough power to run a PA speaker and it could be to much power if one tried to wire those outputs to the inputs of larger PA amps.

Don't do that. Magic smoke time. It has a particularly piquant smell.
The receiver must have line level outputs to run separate amplifiers. They'll be rca jacks labeled with the speaker channels. Not very common, although I think almost all the Onkyo's have it.

[Sydney]

Don't ever feed a power amp's output to another amplifier's input.
Most amp's can handle a line level input range, but you will blow out the input section of the amp if you exceed this.
Don't confuse this with a "bridgeable" amp.

[TomG]

When I did the movies inside, I used a Denon receiver wired directly to the five output speakers. My speakers are homemade horns using Fostex drivers. There are very efficient and produced more that enough volume for our indoor room. My opinion about Fostex drivers is that they are hard to beat for the money. The Denon receiver had a preamp out for the subwoofer that I fed into a separate amplifier to power two 15 inch subs in 13-foot long transmission line enclosures.

As you can imagine, the system is not exactly portable and we never had the opportunity hear it outside. On the outdoor system, I am planning to go with separate "Jiggawatt" amplifiers on all channels. This is still a work in progress, so if anyone has any suggestions, I am really grateful for your input.

Thanks,

TomG

[MEGAHERTZ]

Don't ever feed a power amp's output to another amplifier's input.
Most amp's can handle a line level input range, but you will blow out the input section of the amp if you exceed this.
Don't confuse this with a "bridgeable" amp.

I agree that this is highly not recommended and would be quite risky. I would not do this either, but a friend of mine has done this. Not with a surround receiver but some other older home stereo so that he could run the signal into his electronic crossover so he could use his PA for tv, music, video games etc.. I can't remember why he told me he wired it this way, but I told him he was crazy and that he would blow his crossover (that is only supposed to be feed with line levels). He just said "Na Just don't turn it up too much". He used it in that fashion for quite some time and it sounded good. He still uses that same crossover today and it works fine. Although I'm sure that if he would have accidentally turned it up to much for just 1sec or less he would have seen smoke.
I was just wanting a model or brand name (such as LelandCrooks mentioned) to look for so that I could do it correctly. And I would have warned TomG of the hazards as well. Thanks for the feedback though!

[jcmbowman]

Which would not be enough power to run a PA speaker and it could be to much power if one tried to wire those outputs to the inputs of larger PA amps.

Don't do that. Magic smoke time. It has a particularly piquant smell.
The receiver must have line level outputs to run separate amplifiers. They'll be rca jacks labeled with the speaker channels. Not very common, although I think almost all the Onkyo's have it.

very few consumer home stereo receiver/amplifiers have pre-outs for anything except Tape REC and SUB out. Once you start getting into the prosumer/fanatic level of home AV receivers you start to see pre-outs for everything. Onkyo, Harman Kardon, etc. are good options for that. For the true hardcore home theatre buffs, the next step is going with a dedicated processor/pre-amp - which is basically a receiver/amplifier, minus the receiver and the amplifier. These boxes still manage the A/V source selection and routing as well ass surround sound processing, but don't have any onboard amplifiers or AM/FM reception.

Honestly, I wish that idea would catch on outside the high-dollar world of boutique A/V enthusiasts... I don't see the point in buying a powered mixer for PA use because I'd rather buy a mixer that does what I want and an amplifier that meets my criteria. Same with home stereo... I don't want to make compromises on my signal processing just because it's built into the same box as my amplifier.

[MEGAHERTZ]

I am planning to go with separate "Jiggawatt" amplifiers on all channels.
TomG

You will still need something in your signal path before your amps to process the signal and split it up to get true surround sound right? Or are you just going to do a multi stereo sound with subs?

[maxmercy]

"You will still need something in your signal path before your amps to process the signal and split it up to get true surround sound right? Or are you just going to do a multi stereo sound with subs?"

My receiver has line level/pre-amp outs for every channel (L/C/R/Surrounds/Sub), with the processing already done.

JSS

[MEGAHERTZ]

"You will still need something in your signal path before your amps to process the signal and split it up to get true surround sound right? Or are you just going to do a multi stereo sound with subs?"

My receiver has line level/pre-amp outs for every channel (L/C/R/Surrounds/Sub), with the processing already done.

JSS

What kind?

[maxmercy]

Old Yamaha RXV-800, got it in 2000, if I remember right...

JSS

[TomG]

Unfortunately our Denon does not have preamp outs on the surround channels. Our plan is to first see if our "90,000 milliwatts per channel" would be enough to power the Top 12's. If not (as I suspect), we need to look at different equipment. There goes my budget again!