Just designed my first box! (RE Audio box calc - need opinions!)

[Full Tilt 10+ year member]

Hey everybody. I just designed my first box, possibly the one I'm going to use. One of the subs I'm considering is a Sundown SA-15, so I designed a box according to its' specs. Like I said, this is my first box, so forgive me if it's a bit amateur. I just learned to use Google SketchUp, so I've been anxious to get this done. Give me some critique!

*The height does not include the top plate.

**Also, I designed it using RE AUDIO - Box Calculator, what do you guys think of this program? Is it accurate and/or trustworthy? I'll post the numbers I put in and got out of it, you guys tell me what you think.

Box width: 30 in.

Box heigth: 17 in.

Box depth: 18 in.

Wood thickness: 3/4 in.

Square port height: 15.5 in.

Square port width: 3.2 in.

Square port length 1: 14.05 in.

Square port length 2: 9 in.

The numbers I got from it

Box volume: 3.38 cubic feet

Tuning frequency: 33.8 hz

Does it sound accurate?

Click to read more...

 

[dirtyunclerandy 10+ year member]

I think the volume is a little off. Believe its about 3.6, but I would try a four inch wide port and 30 inches of port length

 

[Full Tilt 10+ year member]

I think the volume is a little off. Believe its about 3.6, but I would try a four inch wide port and 30 inches of port length

Thanks a lot for the input. I'd like to get my dimensions right the 1st time so I don't have to pay for 2 boxes. //content.invisioncic.com/y282845/emoticons/laugh.gif.48439b2acf2cfca21620f01e7f77d1e4.gif

 

[Full Tilt 10+ year member]

Would @Buck like to help me out?

 

[THATpurpleKUSH 5,000+ posts]

RE Calc is nowhere near accurate. Volume and tuning and both incorrect

 

[Full Tilt 10+ year member]

RE Calc is nowhere near accurate. Volume and tuning and both incorrect

...great. //content.invisioncic.com/y282845/emoticons/tongue.gif.6130eb82179565f6db8d26d6001dcd24.gif

 

[THATpurpleKUSH 5,000+ posts]

use the calculators on here: Subwoofer Enclosure Calculators, Fraction to Decimal, Parallel, Series, Port Length and Volume Calculators

 

[THATpurpleKUSH 5,000+ posts]

And it might be easier to use a single 6inch aeroport or 2 4inchers. Tuning is as simple as punching in numbers online and using a hacksaw or strong shears to cut the length down to what is necessary for tuning, then mounting is just cutting a circle hole. Its like building a sealed box but with 2 extra steps. IMO round ports are far easier to design and actually build plus they are more efficient so they save space. The only problem is trying to adapt a low tuning with a small airspace and not have port noise, but that only happens when dealing with 8s.

 

[Full Tilt 10+ year member]

And it might be easier to use a single 6inch aeroport or 2 4inchers. Tuning is as simple as punching in numbers online and using a hacksaw or strong shears to cut the length down to what is necessary for tuning, then mounting is just cutting a circle hole. Its like building a sealed box but with 2 extra steps. IMO round ports are far easier to design and actually build plus they are more efficient so they save space. The only problem is trying to adapt a low tuning with a small airspace and not have port noise, but that only happens when dealing with 8s.

Slot ports have always just seemed more simple to me than round ports..

 

[Buck 5,000+ posts]

You need to do the displacement calculations by yourself. It's easy for port displacement, then you just subtract that from the internal air space, all you need is port length calc.