chio987

i have a rockford fosgate 15in sub. it's old, like from 96 old. well anyway, i wanted to make a new box but i can't find out what size i should make. this is all the info. is VAS the size box that it needs, if so it says 11.336 ft^3 or 321 L

Boomin Boy

no vas isnt the size of box that it needs...if i were you i would email rockford directly for their best box sizes

i dont think they're very quick to respond though so you might try calling them instead

redbird_400

what model is that sub?

>Chose a fiberglass box

chio987

it's a rockford fosgate 15, RFS-1518. i did find out from RF that it needs a 3 cu ft box. the one it's in now is only 2.3, does anybody think it would be worth goin to a 3 cu ft box? and will it sound any better?

Boomin Boy

ya the bigger box you put the sub in, the more sensitive it is. In other words it takes less wattage to get loud, but there is a such thing as going too big.

i think its worth building another box. Is it sealed or ported? Because of its ported you can design boxes with more port area which also gets it louder.

chio987

this is the e-mail i got back from RF
so i should make a bigger box, right now it's a wedge box, should i make another wedge or a simple square?

chio987

also, how should i have this wired up, in the pic is how i think it is now. i just made it so it worked and started playing music. as for the amp it's a pyramid PB580 site with the info . i know it's nothing special AT ALL but the amp, RF 15 in. sub form 1996 it was a grand total of........well?........FREE.... ZERO DOLLA

Boomin Boy

i would say go with the ported box that the recommended...you should notice quite a difference in output

as for wiring your sub, there should be markings on your amps speaker outputs that say "bridged". You just connect your positive VC wire to the positive speaker output on the amp and so on.

Your only setbacks will be that you have a pyramid amp which will put out far less power than it is rated at. The amp is very dirty in other words put out a very distorted signal too. And you have an 8 ohm sub which means the amp wont put out as much wattage to the sub as a 4 ohm sub.

chio987

o it's bridged, but it doesn't matter how i wire it up? and BTW a 4 cu ft box would be way too big for me. i shouldn't do any other wire setup like in this pic?

Boomin Boy

is the sub an 8 ohm dual voice coil or single voice coil?

chio987

does a DVC has 2 sets of +&- hook ups? or are all subs like in the last pic i posted? is there any way to tell by the sub

Boomin Boy

ya a dvc sub will have to posts...most of the time its one on each side

two sets of +and -s

chio987

you know what? i've been searching a little and can't find ANYthing. but bcuz everything i DO find says Voice Coil Diameter: 2" i'm guessing they only mean one. RFS-1815 manual

chio987

the back of mine looks like the subs in that pic i posted, but i'll double check tomorrow

chio987

one other small fact. the RFS-1815 manual says a sealed box should be 20in x 25in x 14in but using RF's calculation for cu ft (H x W x D) / 1,728 it comes to like 4.05092592592592592592592592592593. what's up with that

9177

They are probably assuming you will use .75" think wood of some sort which will give you 3.14 cu ft which will be close to 3 cu ft after the suds displacment. Selaed boxes are pretty forgiving.

chio987

hey Boomin Boy, i finally got pics of the sub. i really don't know how i hooked it up. (it was done fast) so that's what it looks like. how would u hook it up?

chio987

2nd pic

chio987

3rd pic

Boomin Boy

connect both positives on the sub to the positive on the amp and both sub negatives to the negative on the amp

9177

Thats svc there is only one positive and one negitive.

chio987

well if i had a better camera u can see that each thing has 2 connections like my 6x9's. i made a pic real quick to show u what i mean. it's like on each thing it has 2 male connecters.

9177

But it only has one wire. the 2 connectors are there so you can use crimp connectors and add on additional speakers like mids or tweets without splicing wires. If it was dvc the terminals would be split up more and also would have somthing to indicate which ones go to which coil.

chio987

ok cool. so it doesn't mater up i hook it up? just one wire to each.

9177

Make sure the positve and negetive are going to the right terminals

chio987

i'm guessing the side with the red dot is the +. but if they r switched but still works fine, what difference would it make if they r wired up right

9177

The speaker will be moving in opposite directions of what it supposed to and could cause cause cancellation.

Boomin Boy

regardless if they are SVC or DVC just hook up all the positives to the positive on the amp and the same with the negatives...it will either be a 4 ohm load or an 8 ohm which wont hurt your amp either way

wiring the sub backwards will make it excurt (boom) backwards towards the magnet which is fine if you have the sub mounted with the magnet outside the box. But if it is mounted the conventional way you dont want it booming backwards