Question About Sub Box Size

[baller95]

If you look at the picture below you'll see that the recommended internal volume for a sealed box for my Alpine Type S 10" is between 0.5 - 0.85 cubic feet. That is the recommended volume for a single sub so if I'm placing two subs in one enclosure with shared air space, I just need to double the volume right? So 1 - 1.7 cubic feet for the two?

Also, I generally listen to EDM and Trap and sometimes hip hop. These genres have lower bass frequency so from what I've read, it's best that I go with the higher side of the recommended volume?

I've decided to go sealed since it's easier to build and I'll be overpowering my subs by about 100 WRMS.

Thanks!

[baller95]

If anyone's got suggestions on how I can make a good ported box tuned to 30Hz that'd be awesome. I really really want ported but I'm leaning towards sealed since it's easier lol.

[Triticum Agricolam]

Generally speaking, the larger you make a sealed box, the better the performance will be, to a point. However you don't want to exceed the manufacturer's recommendations unless you really know what you are doing. If you make the box too big your cone excursion has the potential to be too high and you could damage your sub. Like I said, if you stick to what's recommended that shouldn't be an issue though.

While sealed boxes are a lot easier to build, it sounds like a ported box might serve you better though. What amp are you using? Pushing 100 more watts than what they are rated for really shouldn't be any issue at all.

[Joe X]

If anyone's got suggestions on how I can make a good ported box tuned to 30Hz that'd be awesome. I really really want ported but I'm leaning towards sealed since it's easier lol.

Sealed is nice but the loss of output as compared with ported is serious, even if you don't overpower the subs ported will get way louder than the overpowered subs in sealed, let me know your vehicle, amp models and max dims for a box if you would like to try ported, if you were to go with sealed just pick the max recommended volume for a single sub and double it as you mentioned.

[baller95]

Generally speaking, the larger you make a sealed box, the better the performance will be, to a point. However you don't want to exceed the manufacturer's recommendations unless you really know what you are doing. If you make the box too big your cone excursion has the potential to be too high and you could damage your sub. Like I said, if you stick to what's recommended that shouldn't be an issue though.

While sealed boxes are a lot easier to build, it sounds like a ported box might serve you better though. What amp are you using? Pushing 100 more watts than what they are rated for really shouldn't be any issue at all.

Sealed is nice but the loss of output as compared with ported is serious, even if you don't overpower the subs ported will get way louder than the overpowered subs in sealed, let me know your vehicle, amp models and max dims for a box if you would like to try ported, if you were to go with sealed just pick the max recommended volume for a single sub and double it as you mentioned.

Thanks for the replies guys! I guess it is worth going ported since I want something that sounds good and is loud. I'll be using a Pioneer GM-D9601 amplifier which is rated for 1200 WRMS @ 1 ohm. Since each my subs are 4 ohm DVC I'll be wiring each voice coil in parallel to create a final 1 ohm impedance.

I think my biggest worry about going ported was how to tune a box and how to have the right box volume. After creating this thread I found a video that taught me how to design a ported box with proper tuning and volume using WinISD. Watching that definately gave me a better understanding on how to do things so I think I'm willing to try building a ported box.

I haven't yet measured the space I have in the back of my trunk but I'll be putting it in a 2012 Grand Caravan. I'm thinking upward firing subs with the port facing the back hatch. Thoughts?

More specs (I HAVE THE SWS-10D4) -

[Triticum Agricolam]

If you want to take a stab at designing a ported box, I'm happy to help you. If you download the Torres layout software it can be useful for coming up with basic dimensions. Or you use something like SketchUp too.

I think your idea of having the subs up and the port back sound great.

One area where I would differ from Alpine's box recommendations is port area. The amount of port area they recommend is really small. You are going to want to give those subs 17.5 to 20 sq in of port area each.

[baller95]

If you want to take a stab at designing a ported box, I'm happy to help you. If you download the Torres layout software it can be useful for coming up with basic dimensions. Or you use something like SketchUp too.

I think your idea of having the subs up and the port back sound great.

One area where I would differ from Alpine's box recommendations is port area. The amount of port area they recommend is really small. You are going to want to give those subs 17.5 to 20 sq in of port area each.

Thanks for your help! I checked out the custom enclosures you've done in your sig, they look great!

Alright I've downloaded SketchUp and need to learn how to use it. Is Torres like WinISD? If they are, which one should I use?

[Triticum Agricolam]

Alright I've downloaded SketchUp and need to learn how to use it. Is Torres like WinISD? If they are, which one should I use?

Thanks! I'm glad you like my work.

WinISD and Torres are very different. WinISD is for modeling output, Torres is for determining the physical layout of the box. So you could use WinISD to determine what box specs you want (net volume, tuning, port area, etc), and then use those values and the dimensions of the space you have to work with and put them into Torres to come up with a box layout.

[baller95]

Alright I've downloaded SketchUp and need to learn how to use it. Is Torres like WinISD? If they are, which one should I use?

Thanks! I'm glad you like my work.

WinISD and Torres are very different. WinISD is for modeling output, Torres is for determining the physical layout of the box. So you could use WinISD to determine what box specs you want (net volume, tuning, port area, etc), and then use those values and the dimensions of the space you have to work with and put them into Torres to come up with a box layout.

Damn, I have no idea what I'm doing. I've made it so that there's a box volume (excluding port volume) of 2.6 cu ft and I've decide to tune to 34Hz which gave me a total port volume of 1.55 cu ft. So the entire box will be 4.15 cu ft.

I'm trying to go for this kinda box (Made in MS paint LOL) -

Transfer function magnitude -

Port Air Velocity -

Torres' Tuning Calculator -

But yeah, I'm pretty sure I screwed that right up

[Triticum Agricolam]

Well you are off to a good start, but you did make a few mistakes :-)

So in Torres the volume number we care about is "Net Volume", yours is showing 1.69, you want it to be 2.6, so you need the box to be bigger.

You can probably shrink your port area down a little bit, which will let you shorten your port while keeping tuning the same. If you narrow the port from 3.3" down to 3" that should be fine. Also you will want to change the "# of port common walls" to three, since that's how you have the box laid out in your picture.

Your sub displacement value should be .08 since you have two subs that displace .04 each.

If you would like to do a middle port like you have in your drawing you don't need to have a divider down the middle. You would just make the port 3" wide and then split it into two 1.5" wide ports where it hits the back of the box.