ATM i've got a 12" type R in the factory ported box it comes with See HERE (http://www.aussiemagna.com/forums/showthread.php?t=61942).

I am re-building the amp mount on the side of the boot this week and i'd also like to build a sub enclosure.
My reasons being to make it fit in my boot a bit more snug, and make it look nice :)
The alpine box does not sit flush against the back seat as it is too high. I'm planning to make one with less height and more width.

Butttt, i've never built an enclosure before so i'd probably have to build a sealed one.

My question is, is it worth going from the factory ported box to a custom sealed one?

Depending on the size of the box, a sealed enclosure will probably play a bit lower than the ported one as the stock ported box is built for all round use with a generally higher port tune than that you would use for SQ.

You will lose around 3db going to a sealed box, easily made up by doubling your power :bowrofl:

Best thing to do is plug your slot port and add a phone book or 2 and see how you like the way that sounds.

Well first things first.. Is that the sub box that alpine provide for their sub, or is it a prefab from a shop? If it's the latter than you'll prob be doing a good thing by going custom.
If it's one that alpine provided, then you run the risk of lowering the quality of your sub bass.

Subs are like young children, sure you can do nothing and just let them run wild and they'll go crazy and be really noisy, but if you put them in the right play pen with the right toys, you'll have a much more pleasant experience ;)

You'll need to check out what volume box that sub needs, you should be able to find this in the manual, you then also need to make sure that your seals are tight and the materials you use are strong - thick = good.
Don't sacrifice quality for styling, make the sub box the right size, and then if needed you can add mdf around that for it to work with your boot install, but keeping the air behind the sub at the right volumes.

Goodluck :P

Yes, the box is the one provided by alpine for the sub, and i bought it off the shelf as is, unfortunately with no manuals :(
I've looked around on the internet for the specs (a lot of **** sites that have the same useless info out there) and i think my sealed enclosure should be about 1.2 cubic feet, sound about right?
Anyone know the specs for the alpine type r? like the qt and things like that?


P.S. impressive work relating young children to car audio righty :)

Funnily enough, ive just acquired a 12" type R sub as well.

I first tried installing it into my old sealed box (which is apparently 1.4cf). I originally got this box with my $99 audiopipe sub so maybe its build quality is crap or something, but I barely noticed a difference between the audiopipe sub and the type R. The type R would move like crazy, even reach the limit of power it could take, and still there was not that much bass.

I have a friend who works at JB who managed to get me that exact alpine type R box you have for $40, and the sub goes far lower and the sub barely moves to create epic bass. You really notice an increase in air pressure with the new box.

Its quite likely that the sealed box I had was crap, but i've found the ported alpine box made my type R sound at least 2x more powerful across the entire low end.

Any ported box will make a sub sound louder than a sealed box.
But if its ported at the wrong freq it qill be louder... but sound like crap.

Keep the Alpine usa box

Yeah but it looks like **** in my boot, it's too high to go back far and i'd like to make my boot a square shape rather than a 'U' shape.
I could always put two baffle things of carpeted mdf either side of alpine the enclosure to make it look a bit better? and re-carpet the enclosure.

Give me the T/S specs of the sub.

I've got a program that will knock up pretty accurately the box dimensions you need.

Also - maximum height of the box, maximum width you want.

Make sure you measure really, really carefully - I've been caught out by a couple 'indentations' in the parcel tray protruding down into my sub box space.

I can have the program do the dimensions for a ported and for a sealed box - can post up the pics of the expected response curve, the dB output, your xmax limit, etc

Program is bassbox pro.

Yeah i have the CAA enclosure calculator but i just dont have the specs as i didn't get a manual when i bought sub :( and can't seem to find all the specs on the net.
But the first problem still lies, should i even build a new enclosure as the one now was designed for the sub? I might be downgrading sq, annnd spl.

As Charisma said, its an off the shelf (although Alpine) box, its an allrounder.

I personally would build my own box, atleast you have the design you want, in the space you want, and some self satisfaction instead of buying everything off the shelf.

Do you have the exact model number?

If so - try going to http://www.thielesmall.com/database.asp

As Charisma said, its an off the shelf (although Alpine) box, its an allrounder.

The box is made specifically for the Type R 12". Alpine do not do this enclosure with any other woofer

The box is made specifically for the Type R 12". Alpine do not do this enclosure with any other woofer

:bowrofl:

Must be the best sub box ever made lol

Where's the funny? Did I miss something? :confused:

To me its funny.

As soon as its 'Alpine' its got to be the best thing ever made.

Yes, this box was made by Alpine for the Type R sub. Congrats, its an all rounder.

The box is made to fit most cars, to be marketable, and to perform 'ok'.

If you want the best sound, you build your own box.....

Where has he said it's the best thing ever made?

Thanks Ers, that was exactly the sorta website i was looking for!
And yes it's probably an average box, it doesn't fit in my boot properly, or look good, so i wish to make my own.
But i run the risk of losing quality, which is my only problem.
I do wish to build it myself and have the satisfaction of doing it all myself, i would make it look good, but it may sound like ****.

If you use a good calculator (not sure about caa, never used it personally) and built it properly, you shouldnt have any issues.

I would build a sealed box if its your first try, then make a ported box.

I build mine using the following materials:

18mm MDF (16mm if you arnt running more than 500wrms and is braced internally)/
50mm particle board countersinking screws (guide holes pre drilled, the thickness of the shaft)
MDF glue

Internally sealed with Bostik silicone (neutral cure)

Screws every 10cm.

Do not build a perfect cube, that will sound rather bad.

Rectangle is somewhat better, angled back is even better.

You should internally brace your sub box.

Cutting: circular saw, if not available, laser guided jig saw and cut oversize, and plane back (with electric planer)

Try this site for building tips:

http://bcae1.com/carpetenclosure.htm
http://www.diysubwoofers.org/faq.htm

Thanks once again ers!

Another question, do i subtract the volume of the driver when calculating the box volume?

use 18mm mdf as it is the most acoustically dead, also i personally only use internal bracing if I'm using 2 or more sub's.

if it is only 1 sub all i do is skin the box, which is basically laying another layer of 18mm mdf around the first box which will stop a lot of box flex.

or you use both bracing and skinning which i have done for my 2 db drag boxes, 1 holds a digital designs 15" and the other holds 2 digital designs 12" sub's.

as for the size of the box there are box calculators on the net one is http://www.carstereo.com/help/Articles.cfm?id=5 which is a lame but will give you some ideas there are other ones that you enter in your sub's Theil-Small parameters I'm shore I've missed something other than keep the particle board for flooring.

The volume you calculate is just the net volume, without driver, bracing etc.

You add the driver volume to your net capacity.

acdviper - re: skinning / bracing.

If you skin the outside of the box with another sheet of 18mm MDF - why not just use 36mm MDF in the first place?

As for bracing - depending on the box design, and if it has large wide flat area's of MDF, I would brace those sections as they can flex.

Each to their own though.

If you skin the outside of the box with another sheet of 18mm MDF - why not just use 36mm MDF in the first place?
If done correctly the joints will be stronger than using a single sheet of 36mm, what you do is overlay the outer layer so it covers the "end grain" of the sheet underneath that meets it at 90°. It increases the glue surface by 18mm and adds a few angles to increase mechanical shear strength.

a picture to give people an idea of what i am talking about if they are unsure
http://www.aussiemagna.com/forums/attachment.php?attachmentid=37708&stc=1&d=1234780072


The volume you calculate is just the net volume, without driver, bracing etc.
that sub box calculator i put the link to is only one of many that are on the net, it was only an example to give people an idea. i personally use a few different ones then from all the data i get from them i design the box from that as they don't take into account the space you are trying to fit the box.

and last of all
like Ers said and i couldn't of said it better myself

Each to their own though.
i just thought i would put my 2 cents in from the experience i have got from competing here and overseas in db drags through self experience and butting heads with other people.

All good - I didnt quite understand what you meant with the Skin - now I get ya :)

I use bassboxpro for my sub box duties, works rather well, though there's a another US program thats a bit more up to date, some better features, but I guess this will do for now lol

As for the thing about bracing - I just like to use bracing as my dads an engineer, if I start doing something structural thats different to how he would do it, I wont hear the end of it lol

there's a another US program thats a bit more up to date, some better features
i use bassbox pro to but what is this US program your talking about
could always use another program :thumbsup:

To me its funny.

As soon as its 'Alpine' its got to be the best thing ever made.

Yes, this box was made by Alpine for the Type R sub. Congrats, its an all rounder.

The box is made to fit most cars, to be marketable, and to perform 'ok'.

If you want the best sound, you build your own box.....

You really are a knob :nuts:
Yes Alpine built this box specifically for the Type R as in the dont sell it with Type S or Type X.
Where did anyone say it's the best thing ever made? If i believed that I'd have alpine in my car. I don't have a single alpine item in my car.



As Charisma said, its an off the shelf (although Alpine) box, its an allrounder.

It's not an Allrounder.

To get bass box pro i'd have to buy it right?
What is a good free downloadable calc? I have the CAA one, it looks alright but i might be missing something.
Also does around 1 cubic foot sound right?

You really are a knob :nuts:
Yes Alpine built this box specifically for the Type R as in the dont sell it with Type S or Type X.
Where did anyone say it's the best thing ever made? If i believed that I'd have alpine in my car. I don't have a single alpine item in my car.

It's not an Allrounder.

So why even mention the fact that Alpine made the box? This was already stated in a few posts, to me, you saying Alpine only made it for the Type R makes it sound 'special', which to me its not.

As for the box not being an all-rounder - whats the port size, length and tuned frequency then?

To get bass box pro i'd have to buy it right?
What is a good free downloadable calc? I have the CAA one, it looks alright but i might be missing something.
Also does around 1 cubic foot sound right?

1 Cubic foot does not sound too bad for a sealed box, however without specs its just guess work IMO.

Bassbox pro is around $250AUD last time I bought it, and many retailers in Australia have stopped stocking it aswell :doubt:

acidviper I have seen boxes built like that before. You would need alot of PSI to need a skin though, such psi that a DD9 series can produce :D:D Rare that people take the time to mention it.