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Constructing a new home subwoofer enclosure

post #1 of 17
4/8/09 at 4:30pm
Thread Starter 
Hey there HTForum!

I'm looking for build a subwoofer enclosure, here are the components:

- Dayton TIT280C-4 10" Titanic Mk III Subwoofer 4 Ohm
T/S Parameters here: http://www.parts-express.com/pdf/295-414s.pdf
DUMAX report here: http://www.parts-express.com/pdf/295-414dumax.pdf

- Dayton HPSA500 500W Subwoofer Amplifier
Dimensions: 11-15/16" W x 11-15/16" H x 5-1/4" D.
Cutout dimensions: 10" W x 10" H.

- Prefered material: 1" or 3/4" MDF for the front, 3/4" for everything else.

I've never build a subwoofer before, but i've been reading about the process all over the web for a few months now. I even use the BassBox 6 Pro (latest version & database)(Which includes the driver i wish to use).

My end goal:

- Have a VENTED (round flared) subwoofer enclosure tuned to be as FLAT as possible or very slightly extended (but that is not prefered)
- My amplifier has to be built into the box.
- The inside of the enclosure will be stuffed with a 1 or 2" layer of some sort of polyfill or some other material
- I MUST HAVE PERFECTION where possible (no standing waves, or any of that jazz)

My problem:

- Any design efforts i put into Bassbox 6 Pro (using a Prism, square (optimum)), always give me a box that will never fit the amplifier and a desirable vent.
- I have no idea what will happen if i place the driver near the topside of the box and the amplifier near the bottom backside. (Will there be "standing waves" or any decrease in performance or "reflections"?)
- ??????


Does anyone have any input or I don't know.... COMPLETE design suggestions they'd like to make? I'm trying to get the most out of my box for the money

Things i dont mind:

- Box size does NOT matter, but it can't be some arbitrary size, it must fit the T/S parameters.

Things i do mind:

- A box that has some sort of "extreme" dimension. (Being REALLY long or wide in proportion to the rest of it)
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post #2 of 17
4/8/09 at 7:21pm
Thread Starter 

Re: Constructing a new home subwoofer enclosure

I'd like to apologize in advance for all spelling errors and all that jazz.

MOMENTS after I posted this, my computer crashed. Though I don't thing that would have mattered since I'm a new user, and I can't edit yet
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post #3 of 17
4/8/09 at 8:34pm

Re: Constructing a new home subwoofer enclosure

I'll look at this closer in the morning.

You will not get perfection. Since it is a sub you won't have any standing waves (they are much longer than the box) but everything with a sub is a compromise.

-Robert
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post #4 of 17
4/9/09 at 5:48am

Re: Constructing a new home subwoofer enclosure

3cf / 85L enclosure with a 3" PSP flared port.

In case you need plans here they are - link. Choose the 85L plans. Instead of cutting a hole for a 12" driver, cut a hole for your 10" driver.

-Robert
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post #5 of 17
4/9/09 at 7:07am
Thread Starter 

Re: Constructing a new home subwoofer enclosure

Thx Robert,

Those box designs REALLY help.

With those sizes, i find it quite hard to screw up the dimensions, its great!

Ive got some questions about ports though.

What if i wanted to go with a rectangular port near the bottom of the box?
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post #6 of 17
4/9/09 at 10:41am

Re: Constructing a new home subwoofer enclosure

I would suggest that you don't. Flared ports keep turbulance at a minimum. Also, if you go with a slot port you will have to change the dimensions as the port will take up more space in the enclosure. Finally, it is just easier to install. Cut a circle and screw it in.

But if you must then you need to find the cross section of the 3" port (pi*r^2) and have your port cross section with the same or larger. If you go larger then you must adjust the port lenth. Even though your slot port may have the same cross section, a circle will give you the most area with the least amount of port surface area. Now we are getting into fluid dynamics but there will be less air friction with a round port.

-Robert
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post #7 of 17
4/9/09 at 11:30am
Thread Starter 

Re: Constructing a new home subwoofer enclosure

Thank you Robert,

I've pretty much come up with a design that i like.

A couple more things:

- The plate amplifier's backside will be sticking into the box as much as 10" x 10" x 4.5". I've adjusted the size of the box to make up for the inner volume lost due to braces & amplifier. The TOTAL volume is 100L but the actual volume is about 86L. IS THIS BAD? Anything you would suggest?

- The group delay of the box is around 36ms around the 22hz region. I know that this is related to the box's tuning. There is not much that I can change about the vent or the box that will reduce this value significantly. I know that vented boxes are prone to that thanks to the phase change around the tuned frequency. What is the likelyhood that I will hear the effects/reduced transients of this value when i play music? (Music: Melodic Metal/Heavy Metal/Death Metal/Psy Trance)

If i think of anything more, ill post it.
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post #8 of 17
4/9/09 at 11:35am
Thread Starter 

Re: Constructing a new home subwoofer enclosure

If you have BassBox 6 Pro, I've uploaded my design file to my webspace.

If you'd like to take a look at it, here you go:

http://shcsclan.com/bassbox_deadly4u.bb6
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post #9 of 17
4/9/09 at 4:34pm

Re: Constructing a new home subwoofer enclosure

That design already accounted for the bracing. The amp takes up 1 or 2 L of air space at the most. But as along as you accurately determined the net volume then all is good.

Yes, there is group delay. There is always higher group delay with ported enclosures. Like I stated earlier, it is all a trade-off. You will never get a perfect design. But with the music it should very rarely get down that low in the frequency range.

I'm almost finished with a similar design using the 12" Dayton DVC (Shiva clone) and it sounds amazing. The Titanic 10" should get close to the same output since it has more excursion. Just remember to change the jumper setting on the amp to the Titanic setting. It will keep you from having such a large inductance hump in the 50hz range.

I'm sorry but I don't run Bass Box. I use Unibox since it factors things like driver inductance into the designs. I've used it for the last few years and it has been dead on accurate. And I plot the frequency response of my subs with an SPL meter and test tones after building them.

-Robert
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post #10 of 17
4/9/09 at 5:21pm
Thread Starter 

Re: Constructing a new home subwoofer enclosure

Robert,

Ill give Unibox a try. Ill report back with the results.
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post #11 of 17
4/9/09 at 5:52pm
Thread Starter 

Re: Constructing a new home subwoofer enclosure

Robert,

I've uploaded the specs of the driver and some box/vent settings. Although i'm not sure what is actually exported in these DDB files.

You can download it here:

http://shcsclan.com/DaytonTitMkiii10.ddb
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post #12 of 17
4/9/09 at 5:55pm
Thread Starter 

Re: Constructing a new home subwoofer enclosure

Nevermind Robert,

Forget the file, i've noticed that i missed a whole bunch of stuff that screwed up a bunch of the stats on the other tabs on the excel sheet.

I didnt notice those on the first pass. Silly me.
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post #13 of 17
4/10/09 at 5:30am
Thread Starter 

Re: Constructing a new home subwoofer enclosure

While i work on some other stuff related to this project,

Here's a screenshot of the sub / box stats:

http://shcsclan.com/EPICSTATS.jpg
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post #14 of 17
4/10/09 at 8:56am

Re: Constructing a new home subwoofer enclosure

The screen shots look pretty good. I don't think the cone excursion is quite accurate. It doesn't go low enough at Fb. Other than that it looks pretty much like Unibox. It's time to start cutting MDF.

-Robert
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post #15 of 17
4/10/09 at 9:47am
Thread Starter 

Re: Constructing a new home subwoofer enclosure

Any last minute changes you might recommend before I commit to this?
Any others with expertise that you might recommend showing this too?

Can i have 250 bucks? LOOOL
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post #16 of 17
4/10/09 at 12:50pm

Re: Constructing a new home subwoofer enclosure

Quote:
Originally Posted by deadly4u
Any last minute changes you might recommend before I commit to this?
You can also check out the Creative Sound site. There are links to two different CSS 10" builds. The CSS10 is similar to the Titanic in that they are both high excursion subs. You can also see some different building techniques.

Quote:
Originally Posted by deadly4u
Can i have 250 bucks? LOOOL
As much as I'd like to help everyone get into this hobby that I have enjoyed for over 20 years, I'm already saving my pennies for this. All of my hobbies make really loud booms.

-Robert
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post #17 of 17
4/10/09 at 3:11pm
Thread Starter 

Re: Constructing a new home subwoofer enclosure

Thank you so much Robert.
I must keep contact with you.
You've been an incredible resource.

Do you have any online contact points beyond this forum?

And yes, firearms are awesome, however I'm still student learning my trade. I've been out shooting on many occasions with my father. Revolvers are my favorite choice of pistol
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