Outdoor audio.....Polk speakers/subs & Crown/Sherbourn amps

[PGT]

I moved into this house in March 2011 and pulled cable for outdoor speakers that May. I pulled Monster 14-4CL3 for a single Polk Atrium subwoofer and Monster 16-2CL3 for two pairs of Polk Atrium 30 Satellites. Everything was run off an Adcom speaker switch box connected to the second zone output of my Yamaha RX-A1000 (using channels 6/7, since I only was running a 5.1 system).

I got the bright idea to run everything off my old Adcom GFA-545mkII, which I got back from my parents when they sold their house in March. I ran RCA's from the Yamaha and then connected to the Adcom switch box. Shortly thereafter, the sub stopped working and then the amp starting clipping and going into protect mode. I yanked it off, tested it on my kitchen counter with some small Snell monitors; the left channel was dead. I checked the internal fuses, replaced them and it worked just fine. Connecting it to the sub again....clipping and blown fuses. I connected the amp back to the Adcom, running the Snells and the left channel was barely audible. Somehow, the left channel out of the Yamaha was not working right. Now it made more sense....the Polk sub is a dual voice coil; running one channel at higher levels then the other killed it and it was presenting a dead short.

I sent the Yamaha in for service as well as the Polk sub. Fast forward three months...finally got everything back. The repaired Yamaha was still having left channel issues. I called Yamaha and there were kind enough to send me a B-stock RX-A1010. During this time, I also saw the Sherbourn 4Z-75 on clearance for $229. I sold my Adcom for $150 or so on eBay and connected to the two pairs of Polk Atrium 30's. I wanted to start "fresh" to ensure I eliminated ANY issues that might have been sticking around.

I scored a second Polk Atrium sub for $188 during Polk's "Friends and Family" sale. Now, the drivers are 4ohm DVC's with a passive 100hz low-pass crossover that presents an 8ohm load to the amp. They're more mid-bass driver than subwoofer. I ordered a paid of Polk DB10's in 4ohm mono load from Amazon for $52/ea. Sure enough, they were a perfect fit and at 375W RMS powerhandling and an Fs of 35hz, they'll act more like subs. Running these at 4ohm mono and no crossover....I needed an active solution. A Crown XLS-1500 fits that bill perfectly and is light and efficient to boot. It will get its input from the loop out of the Sherbourn amp. Nice. The Crown is due in on Tuesday where I'll get everything finished and running.

I spent the afternoon today taking apart the Polk enclosures and removing the drivers and passive LP network. I swapped in the Polk DB10's for each. I also used some clear RTV, letting it tack up solid so as to be a gasket not an adhesive when reassembling things. A concern I have is running a MUCH more capable driver and 3x the power, I didn't want to exceed the capability of the injection molded plastic enclosures to stay together.

Being that these will sit on the deck with openings between boards, I wanted to mount these to 18" round concrete pavers. It didn't appear to be easy to work with those and Home Depot had some recycled car tire pavers that were dense and heavy, so I got a pair of those. They'll help "load" the drivers against a solid base for better output.

Now...on to the pics. Here's the pair of sats on the deck....the subs will sit right in front.



and the second set on the patio below

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here's the recycled rubber paver bases which I drilled holes and put in a 1/4-1.5" galvanized carriage bolt.



Here's the inside of the enclosure, showing the new DB series drivers (bottom mounted....I put a bead of RTV in the flange and let it cure before mounting it to ensure a good airtight seal).

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flipped over with the driver secured by all eight nuts. I also applied a bead of RTV to dampen the optional mesh grilles.

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both units back together.

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and the grille secured. It's got a good 1.5" of clearance given the drivers are bottom mounted inside the enclosure.

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and here's how it will look set onto the pad. I had planned to use galvanized washers and nuts to secure the subs to the pads but due to the multipiece design of the enclosure, it wasn't going to work how I planned. So, these carriage bolts end up being "locator pins" to hold the sub centered on the pad. I'll use an old cut up innertube to make that a tight fit once I'm ready to put them in place outside. On top of the enclosures, I'll put large planters filled half with sand and soil for my wife's choice of flowers. It will easily be 50lbs of total weight on the pads so little chance of things moving around....I'll end up with the tight coupling I was after even without the nuts securing things to the pads.

[PGT]

besides putting the Crown in place in my cabinet and connecting to the cables running outside (and setting levels and crossover points), the last thing I'll need to do is run new wire from the corner where my current 14/4 is pulled I've got nice Delco waterproof four conductor connectors on there...I'll take the female side and run lengths of 16/2 with a 2 connector end on there with a corresponding female 2 conductor end on the pigtail for the sub. I'm concerned that that might be too many junctions so I'll perhaps solder the 4 conductor cable link to the pair of 2 conductor cables and heatshrink it. There's no need to disco there but might be up at the sub pigtail.

I should also note that this is all run off Yamaha's excellent iOS app where I can switch the second zone on/off, choose sources, soundfield, etc...even stream from Pandora, Rhapsody, etc. Its nice to be able to pop music on or off from your phone while out on the deck or patio. My grill is down on the patio so its nice to have music out there.

The two caveats here is by default, I only have the deck speakers on so if I want to run the patio, I've got to push the button on the Sherbourn. This allows me to turn things up on the deck without disturbing my neighbors behind me. The other major issue is somehow controlling the On/Off of the Crown amp. I've got the Sherbourn triggered off the Yamaha. There won't be any signal to the amp unless I power on the second zone from the Yamaha but the Crown amp will always be on if its not triggered like the Sherbourn (even when the entire system is off for the night). Its in an enclosed cabinet....heat shouldn't be an issue as its Class D but I'd have peace of mind if it were Off.

Thoughts on how to somehow control the Crown amp?

[dally]

Looks really good. The polk db series seem to be pretty good drivers for the price. Looking forward to your impressions after you get everything hooked up.

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just hope I don't tear things apart with the higher pressure capability of these drivers and all the extra power. we generally only play at low levels so its not too much of a risk.

[dally]

As far as controlling the crown, would it be hard to pull some wire and put the crowns outlet on a switch near your yamaha?

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There's an outlet under the cabinet where everything plugs in. I guess it would be feasible to put something else daisy-chained off of that with a switch inline. Thinking something like a switch controlled over wifi?

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a little more work tonight....I stripped back the cable on the older enclosure to find fresh copper as it had blackened from exposure. I used the Delphi connectors and they've got water resistant seals. I also used some silicone over the exposed strands for an extra layer of protection (per Polk's recommendation).



I also covered the cables in techflex...overkill as its burial cable but at least it will look a little bit nicer. Last step is to make a pair of jumpers to run to each sub location from the 14/4. I might permanently connect the runs to the 14/4 as there won't be any reason to insert another connection. Not sure how much loss or impedance these Delphi connectors introduce so it would be good to minimize them.

[PGT]

All done. I turned the gain down 50% in the Sherbourn as the Crown needs a lot more signal to balance. Definitely sounds great without ever being "too much"

[novisnick]

What a,n amazing job, thanks so much for the documentation and photos. I love this build.
When I grow up, I want to be able to do things like this. REALLY COOL!
Thanks, Nick

[bub]

Over the top.. A lot of work also .. Great job and you have inspired me to keep going .. I also have a couple of pairs of atriums. Freebees when I bought all my other Polks . And I picked up the 4z -75 also on sale .. So far I've pulled a couple of hundred feet of 12 gauge for speakers and another couple of hundred of 12-2 romex for dedicated lines ..I got the supreme compliment this morning ..when I got back from the gym and my granddaughter was in the HT room watching Netflix..normally she watchs in her bedroom..told me it sounds so much better out here..Asked me if it was going to sound like this for her pool party in Feb? And the work continues. Thanks for all the great pics and in depth descriptions . I'm new to all this and it's guys like you who show me how to do it..

[dust770]

That is great! Even my wife says we need more bass on the deck. I've been looking at these for awhile now but hesitated cause there wasn't a great crossover in the system or the amp I have to run it. Curious how time will treat the pot with more power going to it. Let us know how they hold up after some good use!

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My kid is standing on the second enclosure as "ballast", thus her comments off camera. LOL



And some Lyle Lovett to see how normal music works.



Overall....VERY happy. On Enya's "Watermark", they fill in the bottom end and you can feel the organ through your feet (as you're supposed to).

[Deleted]

Looks awesome!!

[Deleted]

Very nice outdoor system!  I showed my wife your post and video and she is very impressed!  (She likes your dog too.)  

[PGT]

thanks! the pup is ok too....he's a rescue. I need to crank up the system and go back 100 yards or so from the house and see how it sounds...don't want to annoy the neighbors with it, even though there's some room between houses.