Rockford Fosgate P3 15" (Custom Box Help)

[Hellbilly429]

Don't worry about it's max box size.

Btw Joe's box is nice, pun intended.

Shoot me the rough ideas, I will gladly look at them

[darksoul989]

Don't worry about it's max box size.

Btw Joe's box is nice, pun intended.

Shoot me the rough ideas, I will gladly look at them

first thing is would larger take away from hard punch on higher Hz? current box gives a very harsh punch, but you can tell it lacks all its low strength.

keep in mind as I mentioned to Joe, measurements look good and possibly usable tho hight cant be any shorter than 16.5"

[darksoul989]

Try 3.5cu ft (16.5 x 25.25 x 18.5)

that one just gave me so really hard to mess with tuning on port width

[Hellbilly429]

Gross box size isn't important, Net is what you need to look at. The bigger the box, the smaller the port has to be to gain lower tuning.

Tuning lower will take away the higher-end impact unless the sub has a high fs, in which case tuning lower won't make it go lower.

Tune to 33-35hz, I think you will like this range better as you will still get safely low (28hz or so) but you will not lose the frequencies where your vehicle and your subwoofer will allow more authority at.

[darksoul989]

Don't worry about it's max box size.

Btw Joe's box is nice, pun intended.

Shoot me the rough ideas, I will gladly look at them

Whats your thoughts on this?

[darksoul989]

[darksoul989]

Gross box size isn't important, Net is what you need to look at. The bigger the box, the smaller the port has to be to gain lower tuning.

Tuning lower will take away the higher-end impact unless the sub has a high fs, in which case tuning lower won't make it go lower.

Tune to 33-35hz, I think you will like this range better as you will still get safely low (28hz or so) but you will not lose the frequencies where your vehicle and your subwoofer will allow more authority at.

Fs on this sub is 22.4Hz

[Joe X]

In your vehicle no one has requested a taller box than 16" but if due to the year or whatever you can fit a box taller then let me know and I will change the above, as suggested build the cardboard box and make sure it goes in and the trunk lid closes errors happen all the time with this, also if you can get more space, that would be nice.

Current box the sub is in is 21" Wide / 18" Deep / 16.5" Tall (subs mounting ring literally at tips of that measurement) Issue is this box is 1/2" mdf and tuned to 49Hz!

Its the box the sub came in when I got it. As for nobody asking for over 16" tall thats cause the very rear of trunk the lip has clearance of 16" if your trying to mount flush against seat.

Im avoiding the flush mount as it creates a wickedly annoying rattle with the ball bearings in the seat belts.

A slightly smaller box may be needed as I tested 27 width and 18 deep it creates a small issue with trying to slide it in.

Note that I still havent managed to get through to Rockford Reps for more info on box size recommendations. Only further info got is fact they recommend 2.66cu ft with 4" aero port.

Also states sealed inclosure being 1.5-3cu ft so i take it that being its smallest and largest unless by chance the sub can handle larger when ported??? If so I assume it would be something like 2.5-3.5cu ft???

Id like to tune as close to the 32Hz as possible. and note that my brackets for mounting would have to be moved if box built taller than 16.5" which i dont mind doing tho anything more than 17" makes it hard to get a good mounting point.

Also needs better measurement as i need to use double front baffle. Single rips screws out place to often.

Ok OP I modded the original box on your feedback you are providing, really doesn't matter what you get for an answer for box specs as there is really no more space to play with in your dimensions, since a double layer baffle would take more internal airspace an alternative is use some bracing.

[Hellbilly429]

Again, Joe's box design is solid and I would follow it.

If you need to brace it, you can use wooden dowels for internal bracing as I have done on my box.

If you're having issues with screws ripping out, you are not using screws with course/aggressive enough threads to bite into the mdf properly.

Also you can trim out a mount ring out of mdf to increase the thickness of the area where the screws go through, glue it to the inside of the box, and tap into that without losing too much airspace.

You do not want to sacrifice that much airspace to gain a lower tuning, especially with a 15" sub.

I understand the sub has an FS of 22hz, but the sub's FS is not the only factor in getting low.

[darksoul989]

In your vehicle no one has requested a taller box than 16" but if due to the year or whatever you can fit a box taller then let me know and I will change the above, as suggested build the cardboard box and make sure it goes in and the trunk lid closes errors happen all the time with this, also if you can get more space, that would be nice.

Current box the sub is in is 21" Wide / 18" Deep / 16.5" Tall (subs mounting ring literally at tips of that measurement) Issue is this box is 1/2" mdf and tuned to 49Hz!

Its the box the sub came in when I got it. As for nobody asking for over 16" tall thats cause the very rear of trunk the lip has clearance of 16" if your trying to mount flush against seat.

Im avoiding the flush mount as it creates a wickedly annoying rattle with the ball bearings in the seat belts.

A slightly smaller box may be needed as I tested 27 width and 18 deep it creates a small issue with trying to slide it in.

Note that I still havent managed to get through to Rockford Reps for more info on box size recommendations. Only further info got is fact they recommend 2.66cu ft with 4" aero port.

Also states sealed inclosure being 1.5-3cu ft so i take it that being its smallest and largest unless by chance the sub can handle larger when ported??? If so I assume it would be something like 2.5-3.5cu ft???

Id like to tune as close to the 32Hz as possible. and note that my brackets for mounting would have to be moved if box built taller than 16.5" which i dont mind doing tho anything more than 17" makes it hard to get a good mounting point.

Also needs better measurement as i need to use double front baffle. Single rips screws out place to often.

Ok OP I modded the original box on your feedback you are providing, really doesn't matter what you get for an answer for box specs as there is really no more space to play with in your dimensions, since a double layer baffle would take more internal airspace an alternative is use some bracing.

Joe what calculations are you using? i get

Here is a suggestion on the tight side, please check well dimensions will work before cutting any wood, power: to sub rated, amp subsonic filter to 28Hz, minimum port clearance 2 3/4", figure is just an assembly guide:

NOTE: If building outside you need to build a cardboard dummy box to test fit in it's way inside.

Again, Joe's box design is solid and I would follow it.

If you need to brace it, you can use wooden dowels for internal bracing as I have done on my box.

If you're having issues with screws ripping out, you are not using screws with course/aggressive enough threads to bite into the mdf properly.

Also you can trim out a mount ring out of mdf to increase the thickness of the area where the screws go through, glue it to the inside of the box, and tap into that without losing too much airspace.

You do not want to sacrifice that much airspace to gain a lower tuning, especially with a 15" sub.

I understand the sub has an FS of 22hz, but the sub's FS is not the only factor in getting low.

Again, Joe's box design is solid and I would follow it.

If you need to brace it, you can use wooden dowels for internal bracing as I have done on my box.

If you're having issues with screws ripping out, you are not using screws with course/aggressive enough threads to bite into the mdf properly.

Also you can trim out a mount ring out of mdf to increase the thickness of the area where the screws go through, glue it to the inside of the box, and tap into that without losing too much airspace.

You do not want to sacrifice that much airspace to gain a lower tuning, especially with a 15" sub.

I understand the sub has an FS of 22hz, but the sub's FS is not the only factor in getting low.

Ok honestly now I'm getting confused using Torres calculator! the measurements from Joe don't match in it and I stumped on how his original one has such short port and changing just lil bit now making it twice as long...