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Discussion Starter · #1 ·
Hi All,

I think I've finally learned a thing or two and decided on a build to replace an old 10" Klipsch 100W w/12" PR. My proposed build is a 16x16x30" ported box with one 12" CSS TRIO12 and Oaudio BASH 300w amp. (No passive radiators) I plan on adding polyfill to compensate for the smaller volume. This will sit directly below a projector screen with a padded center channel on top.

I chose the Oaudio BASH 300W as it has the correct HPF whereas the PE one has a ~30Hz HPF requiring soldering. The alternative is the Oaudio 500W which I don't mind spending more on if needed. Figured 300W should be enough.

Material will be 3/4" MDF. External volume is 4.45 cu ft, internal ~3.2 cu ft.

Please double check my calculations. In WinISD:
Vented
3.2 cu ft
17.7Hz highpass (I believe this is the default for Oaudio BASH 300W)
240W signal input (300W * .80 efficiency)

Box Tuning:
Red = 20Hz
Yellow = 21Hz
Green = 22Hz
Blue = 23Hz


I don't know which one will give the best results. 23Hz seems to be the flattest graph across the full range.


No problems here



How much bracing is needed? Will one support beam down the middle be enough?

Can polyfill be used in a ported box? If not, what is the recommended lining material?
 

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looks like its gonna be pretty sweet from the graphs but im no expert im sure one of the locals will let ya know whats up soon, but it looks good to my untrained eye lol! is that last graph vent speed? if so i think thats a bit high.
 

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Stuffing can lower the internal box tuning, but it's usually not enough to be significant.

When building a sealed sub the only parameter to pay attention too is the QTC. It should be at .7 for a Trio that models to 2 cu ft.. I'd build it to 1.6 cu ft if you want to stuff it. Since the stuffing will lower tuning. Going bigger will result in an overly tight sub. Smaller will make the sub boomy. :T

If you want to port the sub. 4.3 cuft tuned to 20 hz is the best box I see. I'd only line the back wall in a ported sub.
 

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Discussion Starter · #4 ·
Thanks for the info Isiberian.

So stuffing changes the perceived volume by .2 per cu ft? Why isn't it popular to stuff a vented box? Couldn't you just put pantyhose over the ends of the vents / slot to prevent the stuffing from coming out?

My end goal is to get sound in the 20-30Hz range which I currently don't have with a 10". I'm leaning towards ported as the sealed boxes tend to drastically drop off in the lower frequencies. Any problem with that logic?
 

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Thanks for the info Isiberian.

So stuffing changes the perceived volume by .2 per cu ft? Why isn't it popular to stuff a vented box? Couldn't you just put pantyhose over the ends of the vents / slot to prevent the stuffing from coming out?

My end goal is to get sound in the 20-30Hz range which I currently don't have with a 10". I'm leaning towards ported as the sealed boxes tend to drastically drop off in the lower frequencies. Any problem with that logic?
No there is no problem with that logic. Without a measurement tool you can't really predict how stuffing will change the box tuning. Your best bet is to build the box to the dimensions.

If you overstuff a ported box you will kill the resonance that makes the port go. 4" on the back wall is the most I'd use in any sub anyway.

Subs really don't need a lot of stuffing anyway.
 

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Discussion Starter · #7 ·
If low end output is what you want then ported is the way to go. What are you using for porting?
So far I was thinking of using a 4" tube from PE cut to length with a flare on each end. I'm looking into the "slotted" route but don't know how to do that yet.

Do you have a preference with ported vs slotted? Ported sounds easier to me.
 

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So far I was thinking of using a 4" tube from PE cut to length with a flare on each end. I'm looking into the "slotted" route but don't know how to do that yet.

Do you have a preference with ported vs slotted? Ported sounds easier to me.
I prefer slot ports, but in some applications round ports are much easier. If 4" is all you need I'd go that route.
 
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