Question on box design (first time building)

[buildinggam]

So like the title says I've never built a box before and would like to give it a try.  I have a 2012 Nissan Altima Sedan.  My current setup is a pioneer TS-W3003D4 powered by an alpine mrp-m450 amp wired at 2ohm in a 1.32cuft sealed box.  My sub has let go and am in need of a replacement.  It was suggested that I go with an American Bass xd1244.  I made the decision to change to a different box to try and maximize usable space in my trunk and wanted to go ported because it can make a sub louder if the box is tuned correctly. 

I used the calculators on the12volt.com and designed a box tuned to 32hrtz it measures 30" wide by 16" tall and 10" using 3/4" mdf, this equates to 2.03sqft subtracting the space taking up by the sub (0.07sqft) you get 1.96cuft.  I opted for a round port because it seemed simpler to me so using a 2" round port to get to 32hrtz i would need a port that is 2 3/4" long.  So in theory couldn't I just buy a 2" piece of pvc pipe cut it to length and glue it in place?  Also my main question is does this sound correct for a ported enclosure?  If anyone here has recommendations for a different sub by all means feel free to chime in.  I want a 12" sub under $100 that will take a 400w @ 2ohm load.  I've attached a photo (not to scale) of how the box will probably look.

 

[Joe X]

Glad that you ask because with a 2" port you would likely get significant port noise and bad performance, the following will work and is not much larger than you wanted, figure is just an assembly guide:

 

 

[buildinggam]

Thanks i appreciate the additional drawing,  i was going to make a slot port design but figured being my first build the round port seemed easier.  My other question is now this box is tuned for 32hz but correct if im wrong tuning a sub box isnt just a one size fits all because each sub has different specs.

[DLHgn]

He may have made it for that sub but i'm not sure. Didn't specify. It may have been one that was already made and that sub has similar specs. 

[Joe X]

4 hours ago, buildinggam said:

Thanks i appreciate the additional drawing,  i was going to make a slot port design but figured being my first build the round port seemed easier.  My other question is now this box is tuned for 32hz but correct if im wrong tuning a sub box isnt just a one size fits all because each sub has different specs.

 

There are some subs where tuning becomes more important due to the driver like the with the Skar IVX a few threads away, tuning ordinarily is more related with how much you are interested in playing lower notes, 32Hz will let you play rap and such in a decent manner, regardless of the design, in a ported box you need to set up your subsonic filter within 3/4 of the the box tuning (half an octave) to help avoid mechanical damage to it.

[buildinggam]

Well, I listen to a bunch of different music depending on my mood at the time, for instance yesterday I had on Creedence Clearwater Revival, today was a country mix, last weekend is was Vinnie Paz and some Taking Back Sunday.  My musical tastes are all over the place.  I use to have one of those store bought bandpass boxes by DUAL back when I was 18 and it was loud but very big.  This sealed box I have now sounded good till the sub went out but it seemed like something was missing.  I'm going with a ported enclosure because they tend to be louder than a sealed box and maximize trunk space while I'm at it.  I had always read that 32hz was one of the better spots to tune a box that's the only reason I am going with it.  As far as the sub sonic filter according to the specs on my amp it has a 15hz sub sonic filter that is not adjustable.

Here's the specs.

• 220 watts RMS x 1 at 4 ohms (400 watts RMS x 1 at 2 ohms)
• variable low-pass filter (50-200 Hz, 24 dB/octave)
• tuned Bass EQ (0-12 dB bass boost at 50 Hz)
• subsonic filter (15 Hz, 24 dB/octave)

[buildinggam]

Just wanted to come back and say thank you for the help with my box.  I just installed it Saturday and after tuning my amp using a dmm it sounds really nice!  The bass fills the car, it doesn't sound like a thump from the trunk.  After about a month or so I'll tune it by ear.  I just didn't want to hit a brand new sub with a test tone for an extended period of time.