Building outdoor speakers

CallMeJoe

CallMeJoe

Over Modulator
I have the upgrade bug for my pool-area speakers. Currently I have a pair of small JBLs (control series?) that seem more and more inadequate. I can't find anything purpose-built for outdoors that appears any more than just "adequate", and generally at a premium price. This has me thinking...

I have a pair of Jensen RP-109 horns and a pair of Motorola piezo horns that shouldn't suffer too much from the elements, if I can select an appropriate woofer and build a decent cabinet. This brings me to my questions:

1) What kind of woofer? I want decent bass, so I'd like to go with a 12" or 15" driver. Should I try an automotive unit, or would a poly-cone or composite-cone home audio unit hold up to the temperatures and humidity?

2) What material for the cabinet? Sheathing-grade plywood with polyurethane varnish? Marine-grade plywood? What about sheathing-grade particle board? It could be sealed with polyurethane and made presentable with the wood-grained vinyl that Parts Express sells...

3) What could I do for grills? Fabric seems entirely inadequate, so I'm considering several layers of fiberglass window screening. Would that be sufficiently acoustically transparent?

FWIW, I would also set up some weather shielding, but with cabinets large enough to hold these components, I cant guarantee they wouldn't take some rain in a really bad storm. Winters aren't particularly harsh (Upstate South Carolina) so I might even consider tarping them and leaving them out.

Ideas? Suggestions? Is this a subject that's already been explored in depth? I searched and didn't turn up a similar thread but that doesn't mean one doesn't exist.
 
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Joe
What's your budget? PE traps $64 + BOSS CH12 Chaos Extreme 12" $27 + your Jensen + piezo horn + Eminence PXB:1K6 Crossover $30 + elbow grease Should work out well

Borus
 
Nice suggestions! The only weakness is the crossover; that's a two-way designed for 8 ohm drivers. My RP-109s are 16 ohm, besides which I would use a three-way. I wouldn't use a piezo without shunting it and running it off the crossover.

I don't suppose you know how thick the Baltic Birch is on those cabinets? I didn't see a spec on the PE site.
 
markshan said:
(fiberglass screening for grills) Why several (layers)? I would think that one layer would be quite adequate.
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I thought two or three layers would do a better job of blocking horizontal rain from the drivers if the speakers got caught in a good thunderstorm. Of course, these are just my initial thoughts.
 
one thing I'm considering in my own concepts (also trying to build a better outdoor speaker :-)...

If you can find a tweeter that is weather proof then keep it uncovered but probably fairly recessed so it doesn't become a cup full of water (that will kill ANYTHING). Cover the mid/low frequency driver(s) with something solid but flexible (sheet of thick plastic film maybe? but that could die in the heat so experimentation time!). Your midrange tone and low bass will suffer a bit but overall the sound will work and be much better than you have now while the mid/low frequency drivers will be in a weather sealed container.

Another concept I've been working on is a 360 dispersion speaker concept, with a weather proof full range driver intended for boat installations. not really high quality, but a heck of a good start. facing upwards (magnet down) in a cabinet. above it there's a dispersion cone so sound reflects off and outwards horizontally. that concept has been done before by the way.

The top is going to be removable so it all can easily be cleaned regularly (for mold and mildew etc). there won't be amazing highs or lows, but yea. a good start. Then 4 piezo tweets on each speaker pointing in the 4 compass directions. sitting on top.

hard core low freq would have to be supplied by another sub of some kind if this is going to really kick ass outdoors, no point in my trying to get that kind of bass from these speakers.

but being omnidirectional I'm not going for volume anyway. omnis are inherently much quieter outdoors than directional speakers since the sound doesn't bounce off adjacent walls to reinforce the overall volume like they would do indoors. I'm just going for utility - something musical sounding and really useful that everyone can hear and enjoy.

So there are a couple of concepts, but nothing there is at all revolutionary or original. However possibly practical. Heat, cold and moisture are the obvious problems. Boat speakers (the actual raw drivers) sometimes can handle those problems pretty well - but sometimes at the expense of sound quality. However they're a good starting ground...
 
by the way, I've toyed with some pretty obscure ideas too... multiple drivers, each with limited excursion covered with their own small piece of weather proof semi flexible film (whatever that might turn out to be). that system can of course create a lot of bass and be almost full frequency (calling dr. bose LoL). In a sealed cab it might be a workable solution. Or, create a traditional speaker with fully weather proof (boat again) drivers in a sealed enclosure but with a passive radiator - no weather problems, rubber surrounds, plastic drivers, no metal at all outside (not even screws, mount drivers from inside instead, who cares about imaging, we're out freakin doors here LoL).

that might actually be the best simplest design - but relies the most on the drivers being truly weather proof. Something I'm rather uncertain about...
 
dkelley said:
Another concept I've been working on is a 360 dispersion speaker concept, with a weather proof full range driver intended for boat installations. not really high quality, but a heck of a good start. facing upwards (magnet down) in a cabinet. above it there's a dispersion cone so sound reflects off and outwards horizontally. that concept has been done before by the way.
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That's pretty close to the last design I did for Atlas. We did it upside down though. We had the driver pointing down to keep water from pooling in it. It's an 8" coax and has pretty good highs. They sound pretty good. I had a pair at a Chicagoland AK shindig earlier this year.

The top 2/3 mounts via a bayonet arrangement so you can leave the wiring installed with the bottom and just take the top off and carry it away. They were originally designed for theme parks and the modular design had 2 purposes. First was for installation. You can mount the base and do the wiring, then finish up your landscaping, then add the tops. Second was maintenance. Keep a spare top or 2 around and if 1 goes bad just swap out the top in about 10 seconds and fix the dead one at your leisure.

I spent 4 entire days just doing math on the lens shape to get the dispersion as even as possible over the operating frequency range. That was rough.

Unless you have a rotomold setup in your basement it's a little hard to DIY though.

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Web page here: http://www.atlassound.com/Product.aspx?id=1333&pI=1330
 
I would aim toward the auto types of speakers. CDT Audio still sells a nice 7" "mid" with Kevlar fiber cone and a magnesium frame. I have a set in my work truck and they are seeing their fourth year. The woofer plays well down to 50 hz or a little below. Along with this pair I bought the CDT silk 26mm tweeters and they are outstanding. Stay away from the Titanium domes, though, they are harsh. The tweeters are mounted in pods on the inside door skins and have been dislodged and rained on but keep on ticking. The downside is that you'll have to go to a 4 ohm crossover and will need good power since most auto amps deliver significant watts (maybe 100w+).

Depending on your decor in the outside area, enclosures are available in a variety of materials, plastic, metal, and wood. Having a waterproof enclosure is a must, even the terminals will have to be sealed. If you're able to slightly downfire the cabs, it will probably aid in shedding the elements. Also, positioning the speakers under an overhang would add protection. Even with those options, and if building with wood, I would think that Marine ply would be the most suitable. Grill material is just that, a porous screen and you can count on at least some water getting through it. Allow for it by sealing the front baffle, driver frames, and enclosure seams. A drainage hole would be advisable, if building the enclosure to have an extrusion to fit the grill.

Good luck with your project. I hope you post back with the final results.
 
CallMeJoe said:
Ideas? Suggestions? Is this a subject that's already been explored in depth? I searched and didn't turn up a similar thread but that doesn't mean one doesn't exist.
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http://www.music123.com/Behringer-E...Way-Loudspeaker-Pair-600476-i1320196.Music123

You could go with something like a cheap Behringer as above w/ 12" woofers. Cinch a garbage bag over them during real fowl weather or just bring them inside. The rest of the time I wouldn't worry about it. As long as they can get dry again they should be fine. Over the last 20 years, glues used to hold speakers together has improved dramatically. It is very stable in humid conditions and temperature extremes.

The only thing I'd check on once a year is the condition of the crossovers & woofers. Pull the woofers and look for corrosion on the crossover part leads. Often they are tin-plated steel and if the plating isn't thick, corrosion can start. Paper woofer cones can be treated with Scotch-Gard. I know of some paper coned woofers that spent nearly a decade on a sailboat and that was the only weatherizing they received. The rubber surrounds gave out first. Speakers are far tougher to extreme conditions than you'd think.
 
westend said:
Stay away from the Titanium domes, though, they are harsh.
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yea, JBL never had any luck with titanium domes ;-)

heh heh, only pulling your leg. I expect you're quite right when it comes to titanium domes for car speakers. I don't like too many car tweeters... titanium or not.
 
Joe
The PE trap has 3/4" walls, back and baffle. The crossover would be a two way as the crossover for a piezo is a different thing all together. It would have to be built and attached to the tweeter circuit. At that time and with it in mind you could adjust the crossover for the 16 ohm Jensen.
 
cruise yer local pawn shops and find a big ass pair of pa speakers then bedliner the crap outa them :scratch2: Bertagni made some outdoor speakers these fire sound front and rear if your looking to save space but they are rather hard to find.
 
Shunting a piezo with an appropriate value resistor lets you cross it over like a conventional tweeter, albeit one with an incredibly flat impedance curve. This helps keep the piezo from running in the same frequency range as your mid, and also helps tame the harshness piezos can exhibit. I have access to all the necessary (calibrated) test equipment to measure actual driver impedance at the crossover points, and am no stranger to such things as crossover design and coil winding.

I've seen some great suggestions here; the PE trap cabinet looks nice, and I'd never thought of ScotchGuarding a paper woofer cone! I don't think ScotchGuard would add much mass to the cone, and it might protect as well as doping or lacquer.

I had thought about corrosion problems, and was planning on sealing all the connections as well as generous application of conformal coating to all exposed electronic components.

I'm avoiding buying a commercial speaker because (1) I'd like to do something with the drivers I already have and (2) while glues, etc., used in modern speaker cabinets have improved, the almost ubiquitous MDF doesn't take moisture well at all. If I did buy commercial, I'd have to seal the crap out of it and would still worry. Unfortunately, weather here (I live in the foothills of the Blue Ridge) can be almost as unpredictable as on the Great Plains, and it's all too possible my outdoor speakers could catch the occasional shower.
 
CallMeJoe said:
Shunting a piezo with an appropriate value resistor lets you cross it over like a conventional tweeter, albeit one with an incredibly flat impedance curve. This helps keep the piezo from running in the same frequency range as your mid, and also helps tame the harshness piezos can exhibit. I have access to all the necessary (calibrated) test equipment to measure actual driver impedance at the crossover points, and am no stranger to such things as crossover design and coil winding.

I've seen some great suggestions here; the PE trap cabinet looks nice, and I'd never thought of ScotchGuarding a paper woofer cone! I don't think ScotchGuard would add much mass to the cone, and it might protect as well as doping or lacquer.

I had thought about corrosion problems, and was planning on sealing all the connections as well as generous application of conformal coating to all exposed electronic components.

I'm avoiding buying a commercial speaker because (1) I'd like to do something with the drivers I already have and (2) while glues, etc., used in modern speaker cabinets have improved, the almost ubiquitous MDF doesn't take moisture well at all. If I did buy commercial, I'd have to seal the crap out of it and would still worry. Unfortunately, weather here (I live in the foothills of the Blue Ridge) can be almost as unpredictable as on the Great Plains, and it's all too possible my outdoor speakers could catch the occasional shower.
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The Behringer cabinet is roto-molded plastic not MDF but I see where you are going. MDF can work outside though. It is very porous so it needs to be sealed up. You can use truck bed-liner coating for that. However, if you are going to use something wood-based, OSB or chipboard has far more resin binder in it than other "woods" and tends to be somewhat naturally moisture resistant. Or, you could use something like a plastic beer cooler as enclosures and RTV the lids to the containers to seal them. Conformal coating is a good idea or you could just use epoxy paint from a rattle can and soak them down then soak them again. As long as it isn't a metallic paint (conductive) it will protect nicely. Scotch-Gard works great but does need re-application. It will wear off.
 
Things Change...

I was shopping for Heresy components to turn my Altec 411-8As into Heresies with real bass (HereTecs). I had purchased a pair of K-77 tweeters and some Type E crossovers and was looking for K-55 midranges. Then I found a full set of Forte II components; now instead of modifying my Altecs, I need to build a pair of cabinets for custom Fortes for my main stereo system.

This change of plans leaves that pair of K-77s available to pair with the Jensen RP-109Bs, with Heresy crossovers that I can repurpose for my outdoor speakers. I need now to pick a pair of woofers of appropriate Heresy impedance and build cabinets for them. I think Altec 411-8As are a little upscale for patio woofers.

soundmotor: thanks for the OSB tip. I'll check it out. If I use OSB, I could lacquer it for appearance.
Conformal coating and hermetic heat shrink for sealing because I already have them.


edit: the schematic I have for the Type E crossover shows a woofer impedance of 11 ohms; I'm thinking three 4 ohm woofers in series would be close enough. I'm thinking 8" units, since 3 x 10" or 12" woofers seem like overkill.

On second thought, 3 x 10" woofers might not be excessive for the great outdoors...
 
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What about a "lens" such as on some tweeters to keep the water out, as per my crude diagram above ??

Will that effect the mids and bass ??
 
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CallMeJoe said:
soundmotor: thanks for the OSB tip. I'll check it out. If I use OSB, I could lacquer it for appearance.
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You are welcome!

I actually love the way OSB looks with just spar varnish on it and tinted lacquer really makes it pop.

If your speaker mounting location is well away from any boundaries like a wall, the more cone area the better to get some bass out of them.
 
Ah, welcome to my nightmare, joe. My entire systems serves its duty outdoors. You ever notice how fiberboard tends to become 3 times its size when it encounters water? lol. I figure the best solution to that was to cover the entire enclosure in fiberglass, you know, the resin and strips used in repair kits and such that Ive used doin repair work on boat hulls.
Someone mentioned JBL control series speakers. I have 2 control 28's. people can badmouth them all they want, myself, I dont find the titanium domes harsh at all. In fact, just the opposite, they seem to pick up on the mids the other speakers are lacking, And while the brochure states that they are not completely weatherproof (due to the bass ports exposing the insides), the polycarbonate enclosure isnt affected by water and the speakers arent paper, so,,,,,,
And someone said "forget imageing, we are freakin outdoors", well, patience is a virtue, it takes a long time to find it, but once everything is set up just right, you close your eyes, and the band is right there on my back deck.

P.S. RAYW, you need to hang out in the chat room with us crazies, Id like to pick your brain a bit, but beware, im a layman and might infuriate you with my incorrect usage of terms. lol
 
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