Port Size Needed

[Old_Slapper]

Hey guys. I don't have a box building program, but I know a couple of you do. I have an NVX VCW124v2 subwoofer. The box is 1.9 cubic feet. I need the port length for a port that has a 3"x8" opening. I'm looking to get 40hz. I know it's high, but my kid listens to rap music, so I want it hit to hit hard between 40hz and 50hz. This subwoofer is the version 2 design and not the newer version 3.

Here's the link for the parameters.

NVX VCW124 12" Subwoofer Driver

Technical specifications NVX VCW124 12-inch subwoofer driver. Thiele-Small parameters, performance data, and box design options.

speakerboxlite.com

Click to read more...

 

[Buck 5,000+ posts]

Subwoofer Port Calculator (Free) – Tune Your Box for Deep Bass - BoomSpeaker

Free Subwoofer Port calculator for audio system design. Enter your values and get instant, accurate results — no signup needed.

boomspeaker.com

Why 3x7? That's only 11 square inches per cube, which might be low for 40 Hz, even with your Fs at 26. I'm not running it through a program, though, just speaking generally.

 

[Old_Slapper]

Subwoofer Port Calculator (Free) – Tune Your Box for Deep Bass - BoomSpeaker

Free Subwoofer Port calculator for audio system design. Enter your values and get instant, accurate results — no signup needed.

boomspeaker.com

Why 3x7? That's only 11 square inches per cube, which might be low for 40 Hz, even with your Fs at 26. I'm not running it through a program, though, just speaking generally.

Yup... You're right. I calculated that wrong. Make that a 3"x8" port. I'll usually try to stick around a 24 Sq Inch port opening. Thanks for catching that. I edited my original post to show the correctio.

That length you sent is not really accurate. I don't think I will need a 14" long port. All subwoofers will require a different size port to reach the same HZ.

 

[Buck 5,000+ posts]

Yup... You're right. I calculated that wrong. Make that a 3"x8" port. I'll usually try to stick around a 24 Sq Inch port opening. Thanks for catching that. I edited my original post to show the correctio.

That length you sent is not really accurate. I don't think I will need a 14" long port. All subwoofers will require a different size port to reach the same HZ.

?

 

[Old_Slapper]

?

The link you sent, stated I would need a port that is 15.73" long, if my opening is 3"x8". I could be wrong, but I want to make sure before I put this thing together.

 

[Deiimos]

Yup... You're right. I calculated that wrong. Make that a 3"x8" port. I'll usually try to stick around a 24 Sq Inch port opening. Thanks for catching that. I edited my original post to show the correctio.

That length you sent is not really accurate. I don't think I will need a 14" long port. All subwoofers will require a different size port to reach the same HZ.

Are you building a box from the ground up, or trying to add a port to an existing box that is 1.9 cubes?

A box is tuned to a specific frequency based on its volume and port area / length.

If building a box from the ground up adding a port is fairly straight forward as the port is designed with it, if trying to drop a port into an already built box, you have to take into account port and sub displacement, or you will end up with a box that doesn't have enough volume for optimal performance (edit and or wrong tuning).

 

[Old_Slapper]

Are you building a box from the ground up, or trying to add a port to an existing box that is 1.9 cubes?

A box is tuned to a specific frequency based on its volume and port area / length.

If building a box from the ground up adding a port is fairly straight forward as the port is designed with it, if trying to drop a port into an already built box, you have to take into account port and sub displacement, or you will end up with a box that doesn't have enough volume for optimal performance (edit and or wrong tuning).

I am building the box from scratch. I will take all dimension into consideration when building it.

 

[Buck 5,000+ posts]

The link you sent, stated I would need a port that is 15.73" long, if my opening is 3"x8". I could be wrong, but I want to make sure before I put this thing together.

That calculator should be pretty accurate, just as long as you've clicked the things correctly.

 

[Mitchell Fosgate III]

Just out of curiosity, do you guys buy the whole set of drill bits and socket ranches with rachet extensions? About $500-$700 dollars. And what do you go on? metric for example 10 mm or 11 mm sockets with 3/8" rachet extensions is the standard measurements. But Home Depot sells them in 7/16" diameter sockets and 3/8" extensions. Which can get confusing or awkward. Because if you go on eye balling the sockets, then going on 10 mm or 11 mm is easier. They even have a bolt that goes in between the 10 mm and 11 mm, which in 7/16" socket. (11 mm) Which still I have not found. It is not 5/8" which is 16 mm socket. And a bit bigger in diameter. Now what? I like the website forum kiasouldforums.com. Because they explain common problems. But the manufacturers are from South Korea, of which they do everything in metric. 2016 Kia's have some front mounted screws or bolts done in 8 mm socket wrenches. So, whoa. Definitely not need to buy a whole $500 socket wrench set then. Just 8 mm will do. Some good points to make. Or you already bought the whole set in drill bits and socket wrenches? If you are one of them making installment kits, this might be you. I saw the kits at Wal-mart. Installment kits. Plastic scalpel, RCA splicer, screw driver-phillips, another pointer or smaller screw driver. They did have a multi-meter with these kits, but they took it out. All for $22 dollars. No sense me buying it because I used a small 12 inch wooden soft ruler as a scapel. Works great. So don't need the kit, made my own. As for the subwoofer box assembly, do everything in bolts. No nails please. Bolts makes it look professional. 10 mm or 11 mm bolts for example. Then cover the indented bolts with some other material. Nicely fit. Professional. This definitely is a good practice to have.​

 

[spokey9 5,000+ posts]

Definitely a bot learning from bad data

 

[Old_Slapper]

Yup. It's a bot.

 

[Old_Slapper]

I'll give that port length a try. At worst, it will be +/- 5hz. It's designed for SPL and not SQ.

 

[Old_Slapper]

Here's the box in it's place. I'll get completed pics up soon. It was hard to make is perfect. It was pretty cold to be using fiberglass and not having an actual shop to do it in.