I need some help with my next box.....

[Grinder1989 5,000+ posts]

Here is what I have to work with.

48" long

23" tall

14" deep

Sub and port will be firing up.

Port area must be 70 square inches

I'm looking around 5 cubic feet after sub displacement but I have no idea what the displacement would be so we'll say the equivalent of an MT.

I do not have any specs on the sub but I'd like it tuned anywhere between 28hz-35hz.

I have tried to design this myself but I'm not sure what to do about port area and all that. Oh and the sub is the 15" Nightshade Prototype. Thanks for the help. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

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[bonesninja 5,000+ posts]

70 sq inches of port with 5 cubes net =port length of around 31.5 to get 30 htz

 

[Grinder1989 5,000+ posts]

70 sq inches of port with 5 cubes net =port length of around 31.5 to get 30 htz

But doesn't that increase the port area? Is it bad if there is too much port area?

 

[bonesninja 5,000+ posts]

the port area is measured at the opening, assuming that the port is the same width/height throughout the port. the port area remains the same regardless of the length, you just go longer or shorter to get the tuning you want

 

[Grinder1989 5,000+ posts]

I meant square port volume. Sorry //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[bonesninja 5,000+ posts]

the volume, measured in cubic units, occupied by the port will go up or down depending on the length but the port area is constant.

 

[Grinder1989 5,000+ posts]

But does the port volume have an impact on the sound? I know the tuning can be changed with it but I wasn't sure if port volume affect anything else.

 

[bonesninja 5,000+ posts]

But does the port volume have an impact on the sound? I know the tuning can be changed with it but I wasn't sure if port volume affect anything else.

The port AREA can have dramatic effects on the sound, too little area and you can have lots of port noise = bad. Also length can have equally dramatic effects due to the tuning differences.

The best advice i can give you is to have one of the more reputable box designers model you a box based on your dimensions, port and space requirements. A properly designed box can be priceless, the best built box in the world can be crap if the design is flawed

 

[Grinder1989 5,000+ posts]

The port AREA can have dramatic effects on the sound, too little area and you can have lots of port noise = bad. Also length can have equally dramatic effects due to the tuning differences.
The best advice i can give you is to have one of the more reputable box designers model you a box based on your dimensions, port and space requirements. A properly designed box can be priceless, the best built box in the world can be crap if the design is flawed

Yea I was looking for that but, my specs are as follows on the box I just designed:

square port area = 86

square port volume = 3526

square port volume displaced = 3551.125

Box volume = 5.177 cubic feet

Its tuned @ ~30

 

[bonesninja 5,000+ posts]

so yeah it looks like 5.177 cubes after port before sub, which if you want 5 cubes net, you're fine. Port looks fine ...its taking up 2 cubes by itself.

 

[Grinder1989 5,000+ posts]

so yeah it looks like 5.177 cubes after port before sub, which if you want 5 cubes net, you're fine. Port looks fine ...its taking up 2 cubes by itself.

So do you think that would be a decent box for that sub?

 

[bonesninja 5,000+ posts]

not familiar with the sub at all, but the box looks nice and loud, should hit the lows pretty good. Do you know what the Fs is of the nightshade?

 

[Grinder1989 5,000+ posts]

not familiar with the sub at all, but the box looks nice and loud, should hit the lows pretty good. Do you know what the Fs is of the nightshade?

Not a clue. I wish I could find the conversation I had with Jake about it. I asked him the specs and he said "loud" //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif. But he never tested it I guess.

 

[Grinder1989 5,000+ posts]

Bump, thanks for the help Bones. //content.invisioncic.com/y282845/emoticons/smile.gif.1ebc41e1811405b213edfc4622c41e27.gif

 

[Grinder1989 5,000+ posts]

Up. OK so I have the plans and I'm going to pick up the wood in a week or two. I have an assload of drywall screws so the only other thing is the glue. I've used liquid nails in the past and never had any problems but I'm sure there are better things out there. What glue do you guys use?