two 15" alpine type r's some ported box questions

[4bannger 10+ year member]

Vehicle : 2004 toyota sequoia

Location in the vehicle: behind third row

Space available (Length x Width x Height): 40x20x18

Subwoofer make and model: Apline type r dual 2 ohm

Subwoofer Size: 15"

Number of Subwoofers: 2

Type of Port (Kerfed, Slot, Aero, etc.): slot or kerfed

What type of music do you like?: rap ; music with good base

Is your goal SPL or Everyday Music?: SPL

Tuning Freq (Hz): 32 hz

Volume : 6 cubes

Questions 1: What is the difference besides look between a kerfed or sloted port

Questions 2: Is having the port on the same side as the subs the best

Questions 3: So when i use my port length calculator and figure im using a 15" high X 8" wide port. going for 32 hertz tuning frequency with 6 cubes. Its giving my a port length of 43.59" which is is too big. how do i account for this?

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[4bannger 10+ year member]

any ideas would really help me here

 

[NASTY08IMPALA 5,000+ posts]

a 8" wide port seems far too wide ..play with the width to get the desired tuning and port area

 

[Audio4ever 10+ year member]

Sell em to me lls

 

[4bannger 10+ year member]

a 8" wide port seems far too wide ..play with the width to get the desired tuning and port area

I was just using that as an example. But I really wanna know if that is where "L" and "U" ports come into play

Sell em to me lls

lmao. I bought them both used for $100 at a local shop. Pretty good deal if you ask me

 

[NASTY08IMPALA 5,000+ posts]

I was just using that as an example. But I really wanna know if that is where "L" and "U" ports come into play

lmao. I bought them both used for $100 at a local shop. Pretty good deal if you ask me

Yea thats where secondary port lengths come into play

 

[4bannger 10+ year member]

Yea thats where secondary port lengths come into play

i will upload my idea in a few and maybe you or someone else can tell me if im right

 

[NASTY08IMPALA 5,000+ posts]

Ok..say u have a port thats 5"wide and needds to be 30" long but ur interior depth is only 30" u would go 25" toward the back the L sideways 5" so u maintain the 5" port width

 

[4bannger 10+ year member]

would a "L" port sound better then a straight port. Spl or sql wise?

 

[NASTY08IMPALA 5,000+ posts]

would a "L" port sound better then a straight port. Spl or sql wise?

The shape of a port isnt used for more or less sq or spl its merely a way to achieve proper tuning and port area...some designs need more than one port length some do nit..u wont here a audible difference if u do the math correct

 

[4bannger 10+ year member]

The shape of a port isnt used for more or less sq or spl its merely a way to achieve proper tuning and port area...some designs need more than one port length some do nit..u wont here a audible difference if u do the math correct

So If I wanted to do a wider port for a better look( the look a perfer) lets say 8" wide x 32.51" long I would then need a "L" port. Would making the port that wide mess with sound quality as long as i was keeping it tuned right.

also. whould it change me tune hertz if i made the port kerfed?

 

[NASTY08IMPALA 5,000+ posts]

So If I wanted to do a wider port for a better look( the look a perfer) lets say 8" wide x 32.51" long I would then need a "L" port. Would making the port that wide mess with sound quality as long as i was keeping it tuned right.
also. whould it change me tune hertz if i made the port kerfed?

Kerf wont change tuning that much...andyea thats way too wide u want around 12-16" of port per cube

 

[Full Tilt 10+ year member]

OP, my port for my dual XFL 12 box is only 4 5/8" wide, and I ended up with 15.8in^2 of port area. An 8" port is way big.

 

[4bannger 10+ year member]

OP, my port for my dual XFL 12 box is only 4 5/8" wide, and I ended up with 15.8in^2 of port area. An 8" port is way big.

Okay so I guess ill go with a smaller kerfed port

 

[bbeljefe]

In short, larger ports equal less possibility for port noise but too large a port lowers power handling and makes the sub(s) more prone to damage when played below Fb. With respect to box tuning, more port area causes you to need a longer port. i.e., a 3" port tuned to 30 Hz will be shorter than a 4" port tuned to 30 Hz, all other things being equal. Larger box volumes will allow for shorter port lengths to achieve the same tuning frequency.

Bent ports won't change increase SPL but they can decrease it if not constructed properly. When you do a bent port, you need to maintain port dimensions as closely as possible throughout the turns, which can be sufficiently achieved using 45° wave guides in the corners.

Lastly, if we assume about 3 cubes per sub for the subs you mentioned, you need ~100in² of port, which isn't too far off from the 120in² of port area you mentioned. And in the end, I'd rather see a little more port area than needed than a little less, as turbulence in a small port can ruin the sound quality of the box.