# Which Route To Go With The Trio12?



## Bluenoser (Oct 12, 2009)

Situation: 
I want to replace my current subs with a pair based on the Trio12 driver. The room is about 2500ft^3. The stairwell leading upstairs is on the back wall and is open, so the "real" volume would be greater than what I indicated. The footprint of each sub will be limited to 18” x 20” – absolute maximum. They have to go behind the false wall, between the mains and component stand. There isn’t enough room in the corners as I have superchunk bass traps there. I realize some projector aficionados will question placing a component stand under a screen, but that was the only spot I had to use.

Looks are not important and I’ll paint them flat black. That said, I was wondering about OSB. It’s a bit lighter than MDF and I was wondering if it would be suitable for box enclosures. I’m aiming more for extension, rather than absolute output. Here are three options that I’m considering.

2 x Trio12/APR15/BASH500 Kits:
In 18”w x 20”d x ?”h boxes. I’d install the amp in the top, for access as well as for space restrictions. In keeping with my preference for extension, I thought about going with a larger box and lower tune (6ishft^3, 18-19Hz tuning). Of course, for a larger volume, I have nowhere to expand but up. Would keeping the “standard” volume but lowering the tuning be a good option? 

Pluses: 
>Smaller enclosure than ported.
>Relatively simple to setup.
>No separate HPF required.
>Auto-on amp.

Minuses: 
>Low-end extension limited by amp HPF.
>Tall, narrow enclosure might be unstable with a single PR? I’m guestimating that a 6ish ft^3 box would be 
around 18” x 20” x approx. 38 ½”, plus 2”- 3” for feet. 
>Heavy! They would probably be pushing 130lbs each.

2 x Quartet12 H kits: 
In 18”w x 18” x ?”h boxes. Again, the amp would be installed in the top and the PRs front and back. I’d have to shave a couple of inches off the depth, as compared to the option above, in order to provide breathing room for the PR facing the front wall. 

Pluses: 
>As above.
>One band of EQ is a step up from the BASH.
>Also, a pair of PRs would reduce (eliminate?) the instability of a single PR in a narrow enclosure.

Minuses: 
>As above, except for the instability of a single PR.
>Would be about 4” taller than the single PR box.
>Most expensive option.

2 x Ported Trio12 + EP2000:
I like the thought of a pair of LLT sonosubs. I have the amp now, which is being used with my 2 in-ceiling subwoofers (see my profile). I could get a new one for that application and use the old one for the HT subs after changing the fan. I haven’t changed the fan in the one I have, because it’s in my furnace room and not very audible in the living room. Not sure what volume would be need for such a design. I’m guessing that with an 18”dia sonotube, it would be between 4’ and 5’ tall, including feet. Would that be stable?

Pluses: 
>I have the amp. It’s out of warranty, so fan mod is no big deal.
>Going LLT should negate requirement for HPF? 
>Lowest cost option.
>Lowest possible tuning
>More stable, as forces will be in the vertical direction.

Minuses: 
>No auto-on. I would probably get a Panamax M10-HT-Pro for its 12V trigger.
>Still have to do the fan mod.
>Might have to implement a HPF. Really don’t want to get into that.

So, this is what I'm mulling over right now. Are there other considerations that I might be missing? If I can narrow this down to a single design, I'd appreciate some help with modelling. I've played around with this driver in WinISD, but I don't trust myself to come up with a proper box.:dontknow:


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## Mike P. (Apr 6, 2007)

If it's extension you want then sonotubes would be the way to go. Each driver in 6.5 cu.ft. tuned to 15 hz would need a 6" port 48" long. Power to each driver would be 250 watts.This would require a sonotube 16" in diameter so it's tall enough for the port to fit. With 4" legs the tubes would be 72" tall.


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## Bluenoser (Oct 12, 2009)

Thanks for the response, Mike. Is there any reason that I couldn't/shouldn't use a 4" port? When I plug that into WinISD, it gives a length of 20". Is there something that I'm not getting here? :dontknow:

I don't want to be a bother, but could you model the Quartet12 H kit for best extension? I don't know how you do PR boxes in WinISD.:scratch: I think I'll discount the single PR option, as it would likely be too unstable.


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## Mike P. (Apr 6, 2007)

The port air speed would be too high with a single 4" port, your options are two 4" ports or a single 6" port.

The Quartet12 H kit for best extension would be about 6 cu.ft.


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## Bluenoser (Oct 12, 2009)

Wow, that was quick! Thanks again! I'll have give it some further consideration as to which is best for me - the convenience of the kit, against the lower cost and lower extension of the sonosub.


Hmmm, I just checked the length of 2 x 4" ports and I get 42 1/2". Would that be correct?


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## Mike P. (Apr 6, 2007)

There are small differences between modeling programs, I get 43" for 2 4" ports. 1/2" won't make a noticeable difference.


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## Bluenoser (Oct 12, 2009)

OK, thanks. Hmmmm, which way to go....onder:


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## Bluenoser (Oct 12, 2009)

I'm messing around with the different enclosure options, but I don't know the volume of the Trio12 - can't find it anywhere. So, I can't calculate any precise dimensions. Any help?


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## Mike P. (Apr 6, 2007)

I can't remember off hand, contact Bob at CSS.


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## Bluenoser (Oct 12, 2009)

Mike P. said:


> I can't remember off hand, contact Bob at CSS.


Thanks, I'll do that. 

I was just reading through Steve Callas' "LLT Explained" thread and this caught my eye:



> The larger size of the enclosure also allows you to have lots of clearance between the interior port opening and any surrounding planes, whether that is an MDF wall or brace, a cardboard sonotube, or even the driver itself. You want to have at least as much clearance as the diameter of the port itself in all directions from the openings.


I may have read something about this many moons ago, but had since forgotten. A 6" vent in a 16" tube won't give me a 6" clearance from the sidewall. Nor will 2 x 4" vents give me a 4" clearance from the sidewall of a 18" tube. After a lot of head-scratching, it dawned on me to use a 6" vent in the 18" tube, but to have it protruding from the top enough to accomodate the driver at the bottom. I would imagine that i won't get a full 6 inches clearance from the vent to the sidewalls, because of the tube thickness, but it should be quite close.
I can make flares for both ends of the vent, no problem. 

Is this clearance a very important factor? Or, is it just an extra measure one can implement to fine tune the assembly a tiny bit further?


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## Mike P. (Apr 6, 2007)

The side wall clearance with this setup won't be an issue.


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