HDS312 Vented Enclosure Help (My First Box Build)

[JBGoodnuf]

So this is my first post and of course its about building a proper box,

Heres the equipment:

1X Soundqubed HDS312

1X Sundown SAZ-1200D

Heres my available space:

31"w x 14"h x **"d

**the depth can be changed around

Heres the idea:

I'm thinking about doing a 2.5cu.ft box with two 4" aeroports tuned to low 30's, both sub and ports firing back towards the trunk

Now before this becomes a thread where I'm asking someone to design a box for me, I've been playing around with both Bassboxx Pro and WinIsd and because I'm new to box building I'm not quite sure if the curves I've been getting merit building the box.

I've tried to look around and learn what I should be looking for and how exactly box size, port area and port design changes the output of the box but lets face it its allot of information, and this being my first box build I'm trying to learn as well as build a box that will optimize this driver properly. I'm not a complete noob either I think I'm educated enough to know whats going on by now but I thought I'd get on here and see what some more educated guys had to say.

So if anyone has any pointers, tip/tricks, box designs it would be greatly appreciated!

[Triticum Agricolam]

If you post up what you are getting out of WinISD and BBP we can give you feedback.

There are a lot of "right" ways to design a box, it all depends on what your goals are, such as max SPL vs. even response, ability to fit in a certain space or handle power, etc.

[JBGoodnuf]

Heres the result i get from WinIsd, basically all i did was input the driver paramaters, choose my box size, tuning, and number of ports.

How does this look?

[JBGoodnuf]

bump. anyone have any input?

[dharris2488]

I'm no expert on this, but your output curve looks very similar to all the Soundqubed builds I've completed. I've built 4 enclosures for SQ drivers (HDS and HDC's) and only one turned out shitty. It was for two HDC3 10's, and I used 1.5 c/ft per driver at 32hz (slot port) and the curve looked similar to yours. Sounded muffled and horrible. I rebuilt giving the drivers 1.85 c/ft each and raised tuning to 34hz and they bang hard as hell now off my 2200 @ .5ohm. I've noticed that the larger the peak I've been able to give my SQ drivers, the louder and more musical they tend to be, which seems to go against everything I've learned. lol. Also, the more port area I give my SQ subs, the more musical and loud they tend to be.

When I rebuilt my shitty enclosure to the one I'm using now, my output spike shot up over +3.5db at 34-35hz on WinISD. On the shitty enclosure, my spike was around +2db at 32hz. Take what you can from this info... I think your good to go though... I assume you will be doing aero's? These subs love their port area from my experience with them.

My HDC3 10's now play down to about 27hz before dropping off drastically. They also play up to around 60hz before sounding kind of shitty.

I've built two enclosures for my HDS3 12's and the one I liked best was about 2.4 c/ft per at 35hz. I also built one at 2.25 net tuned to 30hz and it sounded good, but my it seriously lacked on the upper end, 50's and up. I think 2.5 net at 33hz for that sub will sound great if you want to reach down into the mid to upper 20's... That just my 2 cents for what it's worth.

Good luck! Hope it turns out for ya...

[JBGoodnuf]

so i emailed soundqubed and asked for the complete T/S parameters for the driver, read a bunch more articles on how box volume, port area, and port size affect the performance of the enclosure and here is what i came up with, even modeled it in solidworks for your viewing pleasure

2.0ft³, 12.5"x4.0"x53" port, tuned to about 34hz

what do you guys think? the new T/S parameters changed the transfer function a little but it looks like this will work out pretty good and keep port noise generally low.

[Triticum Agricolam]

Looks good! I have a couple suggestions for you. WinISD doesn't use the proper end correction for slot ports, so it ends up telling you your port needs to be longer than it really does to get the tuning you want. For a 34 Hz tune you should shorten your port to be 40-1/2" long. That should save you some space and I really like to keep ports from getting much over 40" anyway since you can start to run into pipe resonance issues. My other suggestion would be to roundover all the edges in and around the port and put in 45's in the corners of the port to smooth airflow. Other than that your box looks great!

Would you mind posting the T/S specs your got from SoundQubed? I'd like to have the updated into for my records.

[JBGoodnuf]

Looks good! I have a couple suggestions for you. WinISD doesn't use the proper end correction for slot ports, so it ends up telling you your port needs to be longer than it really does to get the tuning you want. For a 34 Hz tune you should shorten your port to be 40-1/2" long. That should save you some space and I really like to keep ports from getting much over 40" anyway since you can start to run into pipe resonance issues. My other suggestion would be to roundover all the edges in and around the port and put in 45's in the corners of the port to smooth airflow. Other than that your box looks great!

Would you mind posting the T/S specs your got from SoundQubed? I'd like to have the updated into for my records.

here are the T/S specs

* Model: HDS312

* Piston Diameter = 254.0 mm

* f(s)= 33.65 Hz

* R(e)= 7.39 Ohms

* Z(max)= 73.74 Ohms

* Q(ms)= 6.912

* Q(es)= 0.769

* Q(ts)= 0.692

* V(as)= 22.130 liters (0.782 cubic feet)

* L(e)= 8.62 mH

* n(0)= 0.10 %

* SPL= 82.29 1W/1m

* M(ms)= 364.40 grams

* C(ms)= 0.06 mm/N

* BL= 27.20

i just want to make sure i know where your getting the 40.5 from,

i went into torres and input my desired box volume and port size and then using the same formula went into mathcad and just modified the end correction to 2.227 and therefore the 33.991, is this correct?

btw thanks for your input! that would have sucked building that box and it coming out not sounding how i wanted it to. im just trying to spend the time now and get the box as good as i can get it, the box is the most important part right?!

[Joe X]

A couple of things:

Torres already accounts for the end correction for slot ports so no need to alter the tuning equation, you can see it has already increased the length 2" from 40.5".

Also frequency response WinISD shows is for an anechoic environment and doesn't apply to in-car acoustics.

[Triticum Agricolam]

Thanks for the T/S specs JBGoodnuf. The data you entered in to MathCad is exactly right, the reason I got 40.5" and you got 42.5" from your MathCad formula is I use a little different formula. The one I use is this one: http://www.troelsgravesen.dk/vent_tuning.htm

Most of the boxes I build the tuning ends up being a little on the lower than what I'm shooting for, that's why I use the equation I do. It results in a slightly shorter port which tunes me a little closer to where I want to be. The difference between what the formula I use gets you and what the JL/Torres formula gets you only ends up being like 1/2 Hz, which is never going to make a functional difference in output, so don't stress over it.

I know Torres does compensate for the different end correction of a slot ported box like JoeX said, but I don't like the way it does it. I don't think its as accurate and it will result in a lower tuning than what you want. That's just my opinion though so you can take it for what's worth. Lots of folks are happy with how Torres does.