# Help with Sub Box Build



## ml92 (May 16, 2012)

Hey guys,

I've got a trio 12 and bash 500 modded to have the 1db boost at 13.9 HPF.

I am looking to build a tuned box for use in mainly home theatre.

Any Ideas?


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## fusseli (May 1, 2007)

What is your current sonotube's net volume (after bracing, driver, and port) and how big is the port? 500W should be fine with the Trio 12. I am guessing that your modified HPF isn't protecting the woofer enough from overexcursion below whatever your system tuning is.


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## ml92 (May 16, 2012)

Well I haven't used it with the new hpf yet.

In our new room config the sonotube is somewhat in the way, so I was hoping to build more of a box setup. I can't remember exactly what volume the sonotube is but I got that build off another post in this site.


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## ml92 (May 16, 2012)

Any ideas anyone?


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## fusseli (May 1, 2007)

I am busy this weekend with the holiday, if you can wait a couple days I will be back and would happily model something for you!


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## ml92 (May 16, 2012)

Sounds good, I'll take a look at my space and see what size of a box would fit best. Thanks


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## fusseli (May 1, 2007)

So what made you want to modify the Bash to that filter setting? The Trio 12 likes 4.0-4.5cuft ported, tuned to around 20Hz (equivalent of three round 4" ports). You would need to modify the boost/HPF setting in order to safely run 500W. Alternatively, your 1dB/13.9Hz filter setting would probably be fine if you go sealed instead of vented. 

http://www.creativesound.ca/pdf/CSS-Trio12-data-051009.pdf

Grossly exceeding xmax below 18Hz with 500W.


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## ml92 (May 16, 2012)

Just felt like I was missing low end tones on some movies. I was looking for about 17hz but just let Bob run with it when he did the mod. So with a sealed box I can get away with a smaller enclosure correct? Will I still be able to get the same volume and punch within a sealed box with the one 12? I would like to be able to run movies loud without worry of bottoming out the sub or having any problems.

Thanks for running the winisd to check that for me.


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## fusseli (May 1, 2007)

Ya, sealed will keep your cabinet size much smaller. How low the sealed design goes will depend on the size and openness of the room that the sub is in. If you have a large open area then I wouldn't recommend going sealed.


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## ml92 (May 16, 2012)

The room is quite large and is open to the kitchen above. Sounds like ported is the way to go. Is there a ported design I could utilize to avoid running into problems below 18hz?


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## Mike P. (Apr 6, 2007)

With your current HPF set at 13.9 hz, white is the best the driver will do. If the HPF was set at 18.7 hz. orange would be the best the driver would do. 
Since you want low end output for movies then sealed is not an option.
You state you want loud in a large room, the bottom line is you are asking too much from a single 12 driver with 18mm Xmax, it simply can't move enough air below 20 hz for your needs.


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## ml92 (May 16, 2012)

what do you figure the best way to go is? What if I could get a second trio 12. Could I use the existing amp to make a box for the 2 of them that would work? I imagine it wouldn't be enough to power the both of them in a sealed box, so how about the 2 of them into a ported enclosure?


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## Mike P. (Apr 6, 2007)

The subs are 4 ohm, two working off a single amp won't work since the subs wired together would be either 2 ohms(amp can't handle the load) or 8 ohms ( amp power is cut in half.). If you buy a second sub then you also need a second amp.


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## ml92 (May 16, 2012)

Puts an end to that idea then. The room is 12x25 and has an opening in the kitchen. I assumed that would be too big for a sealed box, correct?

What if I were to take a crack at the horn loaded trio build found elsewhere on this site? Or do you have any suggestions of what to do?


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## ml92 (May 16, 2012)

Also I am wondering if the amp allows 13.9hz to pass through, am I able to put a cutoff at the receiver around 18hz to solve that problem and then build a box tuned to 18hz?
Reciever is a Denon 1712. Or maybe theres something else that would be able to limit the system to 18hz.


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## Mike P. (Apr 6, 2007)

I doubt if the Denon can hi pass at 18 hz. Even if it did, you would end up with cascading filters when combining the two. Your cheapest option is have the plate amps HPF set ate appropriate frequency.


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## fusseli (May 1, 2007)

I'd suggest that you try the Quartet 12 kit from CSS, that would keep your gross size smaller. If you'd like to build your own box and skip the PRs then just say so! We can whip something up that will work wonderful, since you have a great combo already with the Bash 500 and Trio 12. Is there any chance that you are able to re-modify the amp? That would be key... As Mike says, I highly doubt that an ordinary receiver will be able to apply an HPF to the subwoofer channel.


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## CortGideon (Jul 19, 2012)

ml92 said:


> Puts an end to that idea then. The room is 12x25 and has an opening in the kitchen. I assumed that would be too big for a sealed box, correct?
> 
> What if I were to take a crack at the horn loaded trio build found elsewhere on this site? Or do you have any suggestions of what to do?


I just built a sealed cab, TRIO 12, 500 watt amp. I'm using it in a small bungalow and basically it's open to the entire floor. The room is 8' x 15' then the other side is open to the rest of the unifinished part. 

To be honest, skip all the graphs and go with your ears. I can't put it louder than half-way, tuned at 100 hz, because it will blow the house down. I made mine rear-firing too. You can see pics in my thread below (under my name). I'm debating putting a flared port in it but don't know if that's overkill.

Well... it's already overkill. Too loud


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## ml92 (May 16, 2012)

I would definitely like to build my own box. And if it's a must could get the amp re-modified, but would rather not as I have to ship it to Bob at CSS and just finished with doing just that, which costs about 45$$ round trip.
If there is a custom design I could build to make this thing work the way it is then I'll gladly build it. I have it in a sonotube at the moment. Don't have the exact measurements off hand but know the port length is wrong. I wonder if I tried a sealed sonotube then I could hear what the sound of that could be, in reading the post above it works in some situations.


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## Mike P. (Apr 6, 2007)

What is the diameter and height of the current sonotube that the driver is in? What diameter and length is the port?


> I wonder if I tried a sealed sonotube then I could hear what the sound of that could be,


It will have a lot less low end output compared to ported.

​


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## ml92 (May 16, 2012)

Height of the sonotube inside is about 43" How long should the 6" port be if thats the case?


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## Mike P. (Apr 6, 2007)

*What is the diameter* and height *of the current sonotube that the driver is in? What diameter and length is the port?*
We need the information to figure this out.

​


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## ml92 (May 16, 2012)

height is 43", diameter is 16". Port is 6" diameter, don't have length at the moment. I know the port length is not correct and am looking for the correct port length. Also because of how tall it is, I dont like the way it fits in the room. I would like to build a new box and keep the sonotube for a future sub.


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## Mike P. (Apr 6, 2007)

Yellow is what you origunally had, 4.4 cu.ft tuned to 23.5 hz with a 17.5 HPF which was too low for the tuning frequency and the sub was bottoming out when driven hard.

Pink is what it should have been, 4.5 cu.ft. tuned to 20 hz with a HPF at 18.7 hz. 

Green is the best you can do now since the HPF was changed to 13.9 hz, 4.5 cu.ft. tuned to 16 hz with no more then 250 watts of power, anymore and the sub will bottom out due to the HPF being too low.










Here's the reason for your problem. The red line is the excursion limit of the driver which was being exceeded by the higher then optimal tuning frequency of your cabinet. Pink shows proper tuning and HPF frequency which protects the driver from bottoming out.


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## ml92 (May 16, 2012)

Thanks Mike, not sure what i'll do about that. Is it possible to use the Bash 500 amp to help power my towers and then I could get another amp to run the sub in a properly configured box?

So to get this thing running optimal I should build a 4.5cu.ft box tuned to 20 hz and have the amp hpf at 18.7. What sort of dimensions would I be looking at to build a slot port design?


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## Mike P. (Apr 6, 2007)

Not sure how a sub amp can power your towers. A slot port dimensions depends on how wide the cabinet will be.


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## ml92 (May 16, 2012)

What would the amp in it's current configuration work like with the following sub?
http://www.parts-express.com/pe/showdetl.cfm?partnumber=293-658

Or what if I was to get a cheaper 15"?
http://www.parts-express.com/pe/showdetl.cfm?partnumber=295-420


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## Mike P. (Apr 6, 2007)

The LMS-R12 would be underutilized. Since there are so many different drivers I suggest you download WinISD Pro and start modeling. There is a Tutorial on it here.

http://www.hometheatershack.com/for...wnload-detailed-guide-how-use-winisd-pro.html


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