Box question

MuDDoG · #1 02-08-2005, 10:01 PM

I just ordered my new system .. im really happy about it ... the only thing i need now is a box ..... can someone tell me a goood site that sells dual 12" boxes??

my new system
im getting two of these subs
http://www.infinitysystems.com/carau...er=KAP&Cat=SUB

and this amp
http://www.infinitysystems.com/carau...er=REF&Cat=AMP
I know this system aint crazy but .. for the price .. im happy i only paid 350 with shipping and $40 tax

oh yea and can i mount my amp on top or the back of the box??? or just to the back of my seat

thanks

ponchonutty · #2 02-08-2005, 11:38 PM

DO NOT BUY PREFAB. Not sure around you but we build simple boxes to suit for about $50. You need to have a box properly built for the subs AND your ride.

MuDDoG · #3 02-09-2005, 12:09 AM

im not that good with building thins .. are there sites to show you how??

Diceman83 · #4 02-09-2005, 12:15 AM

I'm working on building a box for my single Hx2 Rockford Fosgate 15" to fit in my 93 Honda accord, and I just got a 97x49" sheet of 3/4" MDF for about $23, the silicon sealant for the sub was $3, and the regular glue for the seams was $4. I'm hoping to get a highschool CNC machine to do the hole and some interesting stuff on the front. All in all, the box only really cost me about $30 for material (assuming I don't screw it up when I cut). I probably over engineered it, but it's what fits the way I want it to in my car. I had another thread getting help designing it, and if you remember it, it was a little more ambitious than I think I actually can do. I've revised it, as you can see:

It's fairly easy to design one of your own, even one as angled as this one, you just have to plan it carefully. This design has about 3.25 cu. ft. of volume, which is pretty good for most subs.

Oh yeah, here is a good site to get you started on building your own box. Even though mine is more complicated than the one they do here, it's still all you need to know to do any design.

ponchonutty · #5 02-09-2005, 07:56 AM

[quote=Diceman83] This design has about 3.25 cu. ft. of volume, which is pretty good for most subs.
QUOTE]

No it's not. I tried looking up your info for your sub but could not find anything. I am assuming it is an older sub. Most all of the newer Fosgate subs require 1.5cu/ft for a sealed box for a 15" driver. When you make a box oversized, it tends to make the responce real muddy especially for a larger cone.

Diceman83 · #6 02-09-2005, 09:43 AM

it is an older sub, and it requires at least 2.5 and at most 5.0 cubic feet sealed.

Dang this is a confusing hobby... everyone has their own idea of what makes subs sound good, and half the time it directly conflicts with something someone else said.

Example: I thought (after reading lots of posts and theory websites) you'd get better and better low frequency response as you made the box larger, up to the maximum rated volume. Now you say bigger boxes just make it muddy and don't help anything.

Who am I supposed to believe?

MuDDoG · #7 02-09-2005, 01:13 PM

Quote:

Originally Posted by Diceman83

I'm working on building a box for my single Hx2 Rockford Fosgate 15" to fit in my 93 Honda accord, and I just got a 97x49" sheet of 3/4" MDF for about $23, the silicon sealant for the sub was $3, and the regular glue for the seams was $4. I'm hoping to get a highschool CNC machine to do the hole and some interesting stuff on the front. All in all, the box only really cost me about $30 for material (assuming I don't screw it up when I cut). I probably over engineered it, but it's what fits the way I want it to in my car. I had another thread getting help designing it, and if you remember it, it was a little more ambitious than I think I actually can do. I've revised it, as you can see:

It's fairly easy to design one of your own, even one as angled as this one, you just have to plan it carefully. This design has about 3.25 cu. ft. of volume, which is pretty good for most subs.

Oh yeah, here is a good site to get you started on building your own box. Even though mine is more complicated than the one they do here, it's still all you need to know to do any design.

How did you make that pic of the box??? i want to make one for my subs

to see how it looks

threedd97 · #8 02-09-2005, 01:16 PM

Autocad...?

Diceman83 · #9 02-09-2005, 05:25 PM

SolidWorks 2004, actually, but yeah.

Are there any formulas or websites that explain what all those numbers in that chart above mean?

CBFryman · #10 02-09-2005, 08:05 PM

thoes are T/S (theile small) parameters. THey determine how a woofer performs in a given enclosure. the main things to look at are Drive Q which is Qts (a combination of qes and qms), Fs, DC resistance, Nominal impeadence, voice coil inductance, and Vab (Xmax*Sd). Sensitivity also plays a role in driver performance.

Qts is over all driver Q. Q stands for strength (in lamine terms). Qes is the electrical factor of how powerful a driver is and Qms is how strong the suspension is. a stronger driver is generally better. (its a more acurate way of measuring driver strength as apposed to BL which is dependant on wireing in DVC setups)

DC Resistance and Nominal Impeadence play a roll in factoring out enclosure Q.

Inductance is the ability of a coil to store energy in a magnetic feild surrounding it. it produces impeadence to an AC signal. generally the greather the inductance the more windings there are around the coil former.

Vab is maximum air diplacement in a full cone stroke. Sd (surface area of piston) multiplied by xmax is how it is found. the greater the Vab the louder the woofer can get. end of discussion. some woofers are capeable of producing over 4 liters of vab. this means that in each peak to peak stroke the cone displaces 4l of air. a brahma15 is right around 4.5l which is about the same as a XXX15. Avalanche 15 is just over 4l. when you double displacement you gain 3dB in a sealed/ib enclsorue and 6dB in a ported one. your woofers Vab is 1.2l

Diceman83 · #11 02-09-2005, 08:19 PM

Wow, that was a really good explination... it should go in a sticky somewhere. I always end up buying crap the first time around, even when I think I'm getting something nice. Oh well, live and learn I guess. I got it before I found this site, so I didn't have a chance to ask you guys first. At least I'm making a nice box that can be used with lots of different 15" subs.

POST REPLY TO THIS THREAD