Subwoofer questions! Urgent!

[CivicRF 10+ year member]

So first I'd like to say hello to everyone! I have a 2001 Civic sedan, and I'm now planning on getting a nice audio setup for it. Right now I have a JVC Arsenal KD-AHD79 Head Unit, and some Walmart back speakers. My girlfriend's dad used to be a big audio junkie and has many subwoofers in his garage. He's donating me one of the ones he's not going to be using. I know it's not probably good quality, but it's free. And if it works, I'm happy. It's a JBC (just be cool) 10" 500watt dual voice coil subwoofer from probably the 90's. It has a humongous magnet and looks like it can pack some serious heat. Just last night I ordered myself a Rocksford Fosgate Punch p500-2 amplifier to power that bad boy. The only question I have is, whenever I get my amp I'll need to build myself a box for my subwoofer. Should I go with a sealed or ported box? What dimensions should I use? What materials would I need? I'm very new to all this audio stuff and I'm just learning everything as I go. Any advice would be great.

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[CivicRF 10+ year member]

bump.

 

[skylineTT 10+ year member]

we need to know specs from the sub or at least the model number of the sub so that we can determine which box would be best for it.

 

[hispls 5,000+ posts]

Pics of the sub? Without knowing anything about it, it's really hard to say what box would work well. Safe bet would be 1.5 to 2 cubic feet sealed. "Cabinet grade" plywood or MDF are the usual materials we use 5/8" if it's a small box and low power, 3/4" for preference with some bracing if you're doing more power.

 

[CivicRF 10+ year member]

Thats the problem, the box theyre in is for a different sub. theres no information on the sub itself besides the wattage. No ohm markings, serials, nothing. Trust me I checked. Here are a couple snapshots I took today...

@hispls- thanks for the helpful info. I actually got the sub for free from my girlfriend's dad, who was an audio junkie back in his day. They obviously stopped making these subs so its really hard to find any information what-so-ever. We were planning on bracing it but we really dont know what dimensions to make the box. the sub is about 6 inches deep if that helps...

 

[CivicRF 10+ year member]

I went on Google Sketch-Up and designed an 18" h x 18" w x 12" d, sub box for my 10" subwoofer. It came out with like a 1.57 cubic feet. Would this be a good design to make?

 

[CivicRF 10+ year member]

bump.

 

[THATpurpleKUSH 5,000+ posts]

Ported or sealed box?

For ported I would do 1.25cu/ft tuned to 35hz with a 3in round port

 

[CivicRF 10+ year member]

im thinking sealed. I have everything set to go, i just need some good dimensions for the box.

 

[THATpurpleKUSH 5,000+ posts]

Sealed go with .8-1 cu/ft

Ported will sound better and get louder though

 

[CivicRF 10+ year member]

Thanks kushy. I may actually go with ported. It sounds like a better option. I just don't know much about port placement, how long the pvc should be, if i need a corner piece on the end of the pvc pipe, stuff like that.

 

[THATpurpleKUSH 5,000+ posts]

You can buy aeroports which are the flared looking ones, for a budget you can use pvc pipe and just file the inside edges down so they aren't a hard 90degree edge. I like to use round ports because they are easier to work with imo.

Most 10in subs use 1 3in round port. The length determines the tune and is dependent on the size of the box, the size of the port opening and the desired tune frequency. If you go with a 1.25cu/ft (after sub and port displacements) ported box and a 3in round port, you will need 10.25 inches in length to achieve a 35hz tune. If you use an aeroport (flared) then you will need to add 1 inch to the length to accommodate for the flare part.

If you are putting the box in the trunk then it's usually best to fire the sub and port both to the back. Suv's and hatchbacks usually like sub up port back. If you use a round port, you need to have a clearance of the width of the port at the end of the port and if you can, around all the sides.

If you use 3/4 thick wood you could go with a box thats 17in wide 12in tall and 16in deep, thats 1.36cu/ft. A 3in wide x 10.25in long port will take up .05cu/ft and the woofer should be around .05-.08cu/ft so that will put you right around 1.25cu/ft with a tune of 35-36hz, all of which is a good general size/tune for a 10in woofer.

 

[CivicRF 10+ year member]

wow man. thanks a whole lot. i really think i'll go ahead and do exactly what youre saying there. the only question is port placement. should it be to the left of the sub, below the sub, to the right of it?

 

[CivicRF 10+ year member]

I sketched this really quick on google sketchup. Would this be what I'm aiming to buy?

 

[CivicRF 10+ year member]

double post... i apologize