Outdoor/Indoor System Design for an Off-Grid Cabin

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Hi all,

First time poster, first time audio DIYer, long-time DIYer.

I am hoping to get some advice on not only building my own cabinets, but overall system design such as amp selection, etc...I couldn't find a specific forum so I figured this was the best place to post.

My family just acquired a fairly large cabin on an island near Vancouver. The island is completely off-grid, meaning we have to provide our own electrical power. I am planning on installing a bank of deep cycle batteries, which will be charged by solar panels and a propane generator - all of this will power the cabin self sufficiently. The size of the overall system will be about 4 kW with a battery bank capacity of about 1350 Ah.

The cabin is perched on a cliff facing the ocean (see pics below) and has about 2000 sq-ft of interior space and 5000 sq-ft of deck space (pretty ridiculous). Its situated at the end of a dead-end road with only a neighbor on one side, so I'm not too worried about sound levels (if they are in the right direction). The front of the cabin faces off into ocean so sound can carry out that way.


I'd like to design a PA-style sound system that will provide enough power to fill the air outdoors and in. I'd like the system to be very robust, as I plan on having some parties up there with a DJ playing. It should be designed to handle DJ-style music and volume, and provide clear, crisp sound at both low and high levels.

I originally budgeted 600W for the sound system in my power budget, but I am thinking that for what I want I will go as high as 800W outdoors and 100W indoors. The indoor room is fairly small and I'm not too worried about it. It's mostly the outdoor system I am focusing on.


My plan (which could use your input) was to get two separate amps, a smaller one for inside and a larger one for outside. I then want to build my own cabs for the outdoors which will be weather resistant and rugged, but not to be left outside all year. Take into consideration that there will be lots of salt spray from the ocean.

My question then is what should I purchase and how should I design the system? Take a look at the pictures below and help me out!

There's definitely some options for cabinets. I could go with 4 or more smaller cabinets that could hang underneath the roof, with or without a large sub cabinet under the deck. I could go with two (or more) multi-way cabinets and strategically place them. I could mount the cabinets underneath the roof, or hang them so they can be moved inside when not in use. They could also sit on the deck and not be mounted. As I said before, this should support a DJ playing a party on the deck. I have no cabinet design experience yet, but I'd love to get into it. I don't know what the best setup for outdoor sound is though (style of cab, horns, driver selection, etc). And I'm not sure what I will need to do to weather/water/salt-proof the cabinets.

Budget is not a huge issue right now - I'd like to keep it reasonable, but expenses shouldn't be spared as I want this system to last a long time and sound excellent.

I'd also love help selecting an amp to go along with a 600-800W system, as well as an amp for a 100W indoor system and some speakers for that (probably bought, not built myself).

I'm working on my Masters in EE and have extensive hands-on experience with electrical and mechanical design and tools, so whatever I'm told to build shouldn't be a problem. I have access to PCB fabrication, a full wood-working shop and everything else that goes along with cab building.

Any input is much appreciated!

Pics: 1st one is shot from the ocean towards the front, 2nd is deck facing toward the ocean, 3rd is a further away shot of the same angle, 4th is from the right side of the cabin by the trees looking toward the corner, 5th is main inside room, its about double the size of what you see in the photo.
 

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diyAudio Member
Joined 2007
Big spaces need big speakers.
Music reproduction is inefficient <1%

I am thinking you will need a PRO-Audio set-up for the outdoor area and will need multiple amps ( Subs plus mid-tops ) and your power budget needs rethinking.

Probably more like 2000Watts to be on the safe side ( 2000VA)

BTW I'm jealous ( I like the cabin ) not many of us can say that money isn't a real objection to what we want, most of us work with-in very narrow limits, and high WAF is always a problem.

I favour Bi-amping in almost all situations so Yamaha Pro amps and a small mixing desk??
 
Efficiency is the name of the game here, for amps that means full range class-d (80-95% efficient vs 60% for class-a/b). Don't be to concerned about getting an exact power figure (800 vs 600 watts is only 1db difference - barley audible). First look for efficient amps, then cut down to ones that are proven to be reliable, and then look at which ones deliver the most power within budget, and suit your speaker choice.

Combined with high sensitivity speakers - I wouldn't go less that 95db/1 watt for the outdoor speakers. This will mean you'll most likely be steered towards PA drivers and compression horns/waveguides (I believe compression drivers are fairly weather resistant but do check).
 
If the battery bank runs at 12V, then it would be logical to use car amps. Class-D sub amps should be efficient and plenty powerful. If the battery bank runs at a higher voltage, there's the possibility of building (or modifying) an amp to run directly from battery voltage.

For casual outdoor listening, there's marine rated "car" speakers, but those won't have the efficiency and power handling for a serious party. On the other hand, maybe a line source using multiple 5" or 6" marine drivers would do the job. Check with speaker dealers (Madisound, Qcomponents) to see if they've got some decent-sounding outdoor or marine rated speakers. And, check with pro sound dealers and see if they have some outdoor or marine rated cabinets available. It may be worth buying the real thing.

For subs, this seems an obvious application for horns, since you want efficiency and don't have to move them. Possibly, there could be a marine-rated subwoofer that is suited to horn loading. Maybe a tapped horn could double as a bench on the deck. Or build something like the infamous Royal Device horn. Hornlike efficiency can also be achieved with multiple conventional drivers mounted close enough that they load each other. Doubling the number of drivers adds about 3 dB efficiency, so 8 drivers should be 9 dB more efficient than a single one. Multiple drivers also improves power handling (and reduces power compression).
 
Haha, thanks for the replies guys. I do play the 6-string but some times you just need some amplification...

The battery bank will be 24V, hooked up to a Xantrex charger/inverter, so I don't know if the car amp idea applies - 120VAC will be readily available, and juice can't be sucked off the propane generator if the amps are hooked directly to the battery bank.

The cabin is on Lasqueti Island for those interested...the hippiest of the Gulf Islands! No running water as well, you have to collect your own rain water. We have a lot of work to do on the cabin (it doesn't look nearly as complete as those pics now, we didn't take those), but the sound system is definitely one of the things on my list.

Reading up on biamps, it seems I can get more efficiency while using less power? This would definitely be beneficial. The 800W number is based on the size of the power system and the other loads - I could go much higher as long as there are no other loads, but this isn't always realistic.

I'll have to look into real PA systems as an option, but would love to build something. How important is weather proofing in this environment? If the cones get a bit wet/salty, is this a big deal? If I mostly seal the cabinets, with silicon or something, would this protect them? What's component does water/salt damage, and can this be protected?
 
True Don, but I am interested, having spent so much time on the water and less time on the shores of the islands, I would like to know. Nothing more than that. When someone comes on board and says they have a cabin on an island near Vancouver, my interest is piqued.

EDIT: Besides, I have what he needs and then some. :D

Cheers.
I hear you there, Cal: my first thought also was "hmm, that looks familiar, wonder where it is!"
Nice "cabin"!
Don
 
Go down and buy a Kill-A-Watt metering device and plug your entire system onto it and crank it up. Test tones will use up your power budget but with actual music I think you'd find it to be much more tame than you think. My Adcom GFA-555 (old but OK) idles at 35 Watts alone but the remaining gear gets it up to around 150 - idling. It will surge on a crescendo but will average another 50 to 100 and that's LOUD. Go to a Class-D amp and it will be lower.

Super cabin BTW!

 
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