# TRIO12 HORN Attic Sub Build



## mose

No, I didn't actually build it in the attic. But that's where I installed it.

Lurked around for quite some time before finding the TRIO12 HORN KIT on the CSS website. I was immediately excited as it met all my criteria:

- LOTS of output
- Low response for HT
- No need for additional HPF, no need for large amps, easily uses an off-the-shelf plate amp.
- Can mount in attic with one simple opening.
- All the design work was done.
- Relatively inexpensive expecially from a db/Hz per $$ perspective.

To repeat what I posted in another thread:

I'm not an audiophile, don't have any microphone/tuning equipment, and don't have anything else to compare this sub with. (My existing sub was a 10" NHT.) That's why a pre-designed 'kit' was so appealing to me. I bought a 300W O-audio Bash to drive it. Any boy does it!

As I mentioned, I don't have much to compare this with. But everyone who hears it gets a big grin on their face and says something like, "I've never heard anything like that." As others have mentioned, it's not like a car with a pair of 12's and 1000 watts that booms. It shakes and moves you. Very low, very clear.

The 'kit' is very nicely put together; it has excellent detail and great pictures and lot's of tips and suggestions. 

I would strongly recommend it to anyone who has the space to put this beast. 

I intended to take a bunch of detailed pictures, but as always I got too caught up in the fun and only took a few cell phone pictures. But I'll post them anyway.

...mose


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## mose

Before any glue at all, I cut every piece to size and dry-fit. I used buscuits for most of the assembly. Not necessary, but allows everything to be mocked up without extensive clamping. Also holds everything in place while during glue-up.

Here's the first glue-up of the perimeter. The interior panels are all just sitting on biscuits.


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## mose

Also glued up the motor board and center divider as separate pieces.


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## mose

Then placed the motor board on the biscuits and clamped everything up all square. The biscuits in the first pic are where the motor board and first segment are located.


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## mose

And glued up first, second, and third segment.

Visible are biscuits for the center divider.


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## mose

Mocking up all the horizontal and vertical bracing while the segments all cure.

I chose not to bother to lighten all the braces. I figured it would only save about 25# on a ~300# unit.


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## mose

And then the lid. I only used biscuits on three of the outside edges. If there were biscuits on all the internal braces and segments, I figured there would be no way to get them to drop in place. Biscuits on the 3 edges helped to drop the lid straight down on the adhesive without smearing it off.

Never thought I'd have a use for this many clamps.


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## mose

And here's the business end during assembly and ready to close.


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## mose

And then the fun began. There were no pictures of it on the ladder. Way to precarious and scarry to stop.

Used rope and a snatch-block up to the trusses and rolled it up the ladder on pipe. NOT as easy as it sounds.


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## mose

A few inferior pictures of the port location and cover.


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## mose

I really like not having anything in the living room. I mounted the O-audio Bash 300W plate amp in the wall behind the TV stand. Easy hook up and tweaking.

I don't know much about placement and room nodes. All I can say is that I think I got lucky as the lows seem to HEAVILY reinforce around the perimeter where the seating is, then there is a dead spot in the middle of the room. 

I had to cut squares out of 1" thick foam to place under the CD player feet as it was BADLY losing it's tracking and would cut out for about 5 seconds when the bass would hit. The most fun thing to play is Dubstep sort of 'music' like Skrillex. So far we've lost a candle and some small photo albums won't stay on the shelf. From outside the house, anything hanging on the exterior walls rattle as the walls vibrate. It's nuts.

...mose


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## kadijk

Mose, really nice job! I've never worked with a biscuit joiner(being a framer there's not much need for one of those) so I wouldn't have thought to use them in a osb application. But they sure make for a strong box! And hiding in the atic is a beast that growls...no large cabinet to deal with. I have a dedicated theater so mine will sit unobtrusively in the corner, waiting to attack. I'm so impressed with Marks design and the efficiency of the system. The only word that comes to mind is awesome. 
You say it's great with music...how about movies? (Mark reassures me it will be incredible).


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## mose

I haven't watched many movies yet. But the first movie I watched, I had to crank the LFE level WAY down from where I had it for my existing 10" sub. Otherwise it was overwhelming. Yes, it really shakes for movies.

As Mark mentioned, you can turn this thing way down to a level that you don't immediately notice. Then it doesn't sound like a traditional sub, where you clearly hear/feel the boom that it adds. Instead, it just reveals added content to nearly everything. Rap, synthetic, and pop music sound ok with really enhanced bass since it's not 'real' anyway. But accoustic music, movie dialog, etc. don't sound good with grossly overboosted bass. Thus there's WAY more than enough output for movies and such. Although it's also impressive when you boost the hell out of the lows and turn your house into a dance club. 

The only problem I've found is that some sources seem to have unwanted content. For example if you have it on when watching 5.1 cable broadcasts, some have undesireable LF noise content. It's almost as if the person who mixes/levels the source doesn't have anything to reveal this content (headphones?), so it goes unfiltered. I really doubt that Brian Williams or Diane Sawyer produce content around 20Hz, but I can hear something going on!

...mose


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## mwmkravchenko

Mose you are one crazy guy!

I like the ladder pic. Up, up and away.

Here is my method:









For one and all. OSB 7/16" is more than enough to build this box. Mose must have worked like a dog to get that box into his attic. But what a thing to scare the pants off of unsuspecting listeners. Where's the bass coming from? Stealth subwoofer I like it!

Mark


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## Oklahoma Wolf

mose said:


> The only problem I've found is that some sources seem to have unwanted content. For example if you have it on when watching 5.1 cable broadcasts, some have undesireable LF noise content. It's almost as if the person who mixes/levels the source doesn't have anything to reveal this content (headphones?), so it goes unfiltered.


Yup - you get used to it. I find many HGTV Canada shows are like that, especially Holmes Inspection. Mike's trying to explain something, and yet the LFE is going nuts. It's kind of fun, actually.

That ladder picture... glad it wasn't me on there. I weigh 260lbs - it wouldn't have held me like that.

Nice work on the build.


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## top_down

Question about the attic mounting and ceiling penetration. It looks like you were able to sit down flush against the ceiling joists so you've got a manifold about 3.5" to the surface of the ceiling below. In my case I've got some pipes and cables up there that I'll have to mount the enclosure about 2" above my 2x6 ceiling joists. That would mean a manifold of about 8" down to the surface of the ceiling. Any problems with that? Can it just be straight or does it need to flare out? What did you use for a grille?

Great build, thanks for posting!


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## mwmkravchenko

You can add a ducted flange out of the exit of the horn without really changing the response. It is already 23 feet long. A few more inches makes little to no difference.

Mark


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## mose

The grille cover is a frame made from some 3/4" stock with a 45 degree bevel ripped on it. I biscuited the corners just to make assemble easy. Then I stretched white grille cloth over it and attached it with hot glue. Screwed it to the truss chords and popped screw covers over the heads.

...mose


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## favelle

That. Is. Amazing. Nice work man....that is LFE dedication.


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## BP1Fanatic

Nice installation!


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