prefab ported box

yea i said it! PREFAB! haha i know its the best thing but im in a hurry and have no time to find someone that can make me one. im planning to put a Type-R in this box. you think it will be loud? i have a 4 door 93` camry. here are the dimensions: 30.75"X15.5"X15.5" & .75 MDF

Are those inside or outside dimensions?  The dimensions of the port will probably help.

i am an idiot wrote: Are those inside or outside dimensions?  The dimensions of the port will probably help.

im not sure if its inside or outside. about the port dimensions.. . do you want the length and width of the port?

Measure the outside demension of the box and post that then all the measures you can do of the inside of the port... ie... LxWxD.... then post that.Jayce

IF it is a Type-R DVC @ 4 Ohms, 12" driver- Using this site's calculator and NOT knowing the port dimensions- It's too big. Alpine recommends a bass reflex (Ported/4th order bandpass) enclosure of 1.7 Cubic feet. The driver displaces a small amount of that space, but the box dimensions you listed without knowing how it's port dimensions in detail calculates out to 3.31771 cubic feet. Find us the port dimensions on that slot and we can tell you more...Life is too short to build slow computers or weak audio!

wolfox wrote: Find us the port dimensions on that slot and we can tell you more...

when you say port dimensions, are you asking the dimensions inside or the outside?

imupabove wrote: wolfox wrote: Find us the port dimensions on that slot and we can tell you more... when you say port dimensions, are you asking the dimensions inside or the outside?

Yes, we need to know the square surface area of the port opening (H x W) and then the depth of the port into the box itself (L). The port's total volume (H x W x L) along with the speaker's displacement will tell us the net internal volume and give us an idea what it is tuned for in Hz.AND tell us how much space is in there. I got my DVC Type-R 12" tuned to 34 Hz in my ported, 1.7 cubic foot box. It sacrifices a little of the total SPL, but it's immensely musical, deep and plenty powerful to shake mirrors and deflect door psnels on a mere MRP-M500 Vpower monoblock. :D It's in a Blazer so the smaller overall dimensions help in maintaining at least half of the cargo area. A consideration to take to heart in your compact car. ;)Life is too short to build slow computers or weak audio!

okay great! thanks for clearing that up for me :]. im going to send an email to the box's company. just to make things for sure .. . so you need to know the (H x W) of port's opening. and the ( L ) of the port inside right?

wolfox wrote: IF it is a Type-R DVC @ 4 Ohms, 12" driver- Using this site's calculator and NOT knowing the port dimensions- It's too big. Alpine recommends a bass reflex (Ported/4th order bandpass) enclosure of 1.7 Cubic feet. The driver displaces a small amount of that space, but the box dimensions you listed without knowing how it's port dimensions in detail calculates out to 3.31771 cubic feet. Find us the port dimensions on that slot and we can tell you more...

Recommended specs are worthless. They are merely just a starting point for no particular install at all. Type R's like big boxes...atleast 2 cubic feet net volume for ported...sealed they sound like crapCustom Enclosure Design

aznboi3644 wrote: Type R's like big boxes...atleast 2 cubic feet net volume for ported...sealed they sound like crap

I got some MDF and other supplies laying about - it will not take much to go up an extra .3 Cubic feet. In your experience, how well does it sound/perform in the larger enclosure? Color me curious and willing to accept input on this too. :D What tuning frequency do you lump in with that and suggest? My fear is the sub unloading at lower freq and larger cabinet volumes even with a steep 24 Hz rolloff with my MRP-M500 (fixed - non negotiable I am afraid) Thanks in advance!Life is too short to build slow computers or weak audio!