Least Amount of Port Area For Nightshade

[Mattd0344 10+ year member]

I just got some aero ports in and want to know what is the least amount of port area I should have with two 4" aero ports for a 15" Nightshade in just a little under 4 cubic feet. I'm looking to tune high around 45/46Hz, but I don't think I'll have enough port area. With precision port's calculator, the flared port length comes to about 6.25" for each port. Is this enough port area?

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[Rashaddd 5,000+ posts]

I'd try and get a 3rd at least, if not a 4th one, but 2 4's should be okay

 

[Mattd0344 10+ year member]

I'd try and get a 3rd at least, if not a 4th one, but 2 4's should be okay

I would do three 4'' ports, but then I'd have to cover the third hole when I would want to listen to it daily.

 

[Rashaddd 5,000+ posts]

I would do three 4'' ports, but then I'd have to cover the third hole when I would want to listen to it daily.

Not sure I understand...3 4" ports would be 9" long, giving you a 45hz tune, and then you could plug one and drop tuning 10hz for daily listening, isn't that a good thing?

You could also use 4 4" ports 13" long and have a 45hz tune with all of them, and plug a couple for a 32hz tune

 

[Mattd0344 10+ year member]

Not sure I understand...3 4" ports would be 9" long, giving you a 45hz tune, and then you could plug one and drop tuning 10hz for daily listening, isn't that a good thing?
You could also use 4 4" ports 13" long and have a 45hz tune with all of them, and plug a couple for a 32hz tune

Well, my box is already made and I think I can only fit a third port at most, because I designed it for just two ports. I was looking on prescision ports and three 4" ports would need to be 10.5" long to be tuned between 45/46Hz but if you were to plug one up it'll only drop to about a 37Hz. Right now, I have a 33/34Hz tuning which is 13.3" long for the two ports. I have four brand new ports just laying around so I could just swap out the ports and plug when I want to go daily. If I were to go to three ports, what would be a good method of plugging it up? Just a piece of mdf and screw it on? I don't want to create a bunch of screw holes after I unplug it.

 

[roarzorz 10+ year member]

What is your goal with this setup? If it's loud daily pounding then two 4" ports are fine. If it's spl then three 4" ports is a must. Also 3ft net volume is plenty for a NightShade 15" no matter how you intend to use it.

 

[Mattd0344 10+ year member]

What is your goal with this setup? If it's loud daily pounding then two 4" ports are fine. If it's spl then three 4" ports is a must. Also 3ft net volume is plenty for a NightShade 15" no matter how you intend to use it.

Well my goals are to have a tuning for daily then swap out the ports for SPL. I thought about building a new box that would be 3 cubes but I already had built one that was 3.975cubes after displacement tuned to 33.5Hz and it sounds great in it. I just thought that if something isn't broke why fix it? Also, wouldn't the 3.975 cubes be more efficient anyways and get louder?

 

[roarzorz 10+ year member]

Three 4" ports for spl then block one for daily.

Also, wouldn't the 3.975 cubes be more efficient anyways and get louder?

No. For spl purposes larger boxes are not louder.

 

[Mattd0344 10+ year member]

Three 4" ports for spl then block one for daily.



No. For spl purposes larger boxes are not louder.

I've always heard that a larger box is more efficient but the reason people use smaller boxes when using lots of poweris that it prevents your subwoofer from bottoming out? So if I built a brand new box to 3 cubic feet, it would get louder than my 3.975 cubic foot box?

 

[roarzorz 10+ year member]

In your case I wouldn't build a new box and I won't guarantee that you'll see more deebeez in you do. In my experience though I've seen 0.5db gain with a smaller box over a larger one. NightShades particularly work well in smaller enclosures. My current box is only 2.5ft net volume for a single NightShade 15". I do guarantee though that you'll see better #s with three 4" ports.

 

[Mattd0344 10+ year member]

In your case I wouldn't build a new box and I won't guarantee that you'll see more deebeez in you do. In my experience though I've seen 0.5db gain with a smaller box over a larger one. NightShades particularly work well in smaller enclosures. My current box is only 2.5ft net volume for a single NightShade 15". I do guarantee though that you'll see better #s with three 4" ports.

Ok thanks, I really appreciate the input. Was the 2.5 cubes with your SAZ-1500D or was it with more power when you saw the gain? Did you have dual (daily/SPL) tuning for that small of a box as well?

 

[mledez 10+ year member]

In your case I wouldn't build a new box and I won't guarantee that you'll see more deebeez in you do. In my experience though I've seen 0.5db gain with a smaller box over a larger one. NightShades particularly work well in smaller enclosures. My current box is only 2.5ft net volume for a single NightShade 15". I do guarantee though that you'll see better #s with three 4" ports.

Can you give me your box specs please !!

External dimension, net volume... and ports config

 

[roarzorz 10+ year member]

Can you give me your box specs please !!
External dimension, net volume... and ports config

My box dimensions are specific for my vehicle and useless to anyone else (unless you drive a 1st gen Exlporer). What's your goal for your setup?

 

[mledez 10+ year member]

My box dimensions are specific for my vehicle and useless to anyone else (unless you drive a 1st gen Exlporer). What's your goal for your setup?

I have a SQ setup, but I bought yesterday a Nightshade just for open show music, not for competition, So I think is like a daily setup.

My car is a Toyota Yaris 08' Sedan, so I just need the smallest recomended ported box enclosure...

I was thinking about slot ported, but I think It will add more weight and I don't want to... Maybe 2 Precision Aero ports 4"x17"

Give me some advice please...

 

[roarzorz 10+ year member]

3ft net volume with 2 full length 4" ports.