Video Building a Sub Box for BMW Z3

[Gundun]

they are both interesting solutions.
To date, the best I've seen was when I was still in Italy and some audio shop made a custom install using the enclosure that was used for the battery in the earliest models, within the engine compartment: they molded a fiberglass box that perfectly fit inside that vane and connected the passenger footwell (for you guys would be the driver's) using plastic plumbing pipes, making a hole in the firewall: sounded amazing and was 100% stealth. I have no pics though

 

[hard top]

using the enclosure that was used for the battery in the earliest models, within the engine compartment:

Sorry Gundun, you have lost me here, my car was an Oct 96 and the battery was just bolted down in the boot.

 

[Gundun]

Don't quote me here but I think I once read the battery was initially (1995) in the engine compartment and soon after moved to the back.

EDIT: found it (red circle is irrelevant, look at the left side)

 

[hard top]

EDIT: found it

Well, learn something new every day as they say..!

 

[littlefeller]

they are both interesting solutions.
To date, the best I've seen was when I was still in Italy and some audio shop made a custom install using the enclosure that was used for the battery in the earliest models, within the engine compartment: they molded a fiberglass box that perfectly fit inside that vane and connected the passenger footwell (for you guys would be the driver's) using plastic plumbing pipes, making a hole in the firewall: sounded amazing and was 100% stealth. I have no pics though

this was my thinking, the cubbyhole is too small for a ported sub-box but if i add tubes and pipe it through the speaker holes behind the seats then maybe the volume of the tubes would be enough, might be a lot of hassle for little return though, the sealed box is by far the simplest solution.

 

[Sean d]

@Antm72 did you use a particular set of dimensions for your box or did you measure and build, cheers

 

[Antm72]

@Antm72 did you use a particular set of dimensions for your box or did you measure and build, cheers

I measured and built it Sean the original zed sub box was the inspiration for shape.
You are just limited on space availible you could use 5mm mdf but then it requires batoning so not a big gain.
It will always have its limitations on what's required and what you can gain air volume wise but it has a healthy sound to it.

 

[littlefeller]

been watching this video again, have noticed in the vid the box is 310mm across the back, Susan Fords plans are 365mm across, anyone happen to know why this is, I see in the vid the guy leaves the original sub brackets there but even so it wouldn't take up the missing 55mm, could Susans be for a hoopless Zed?

 

[Jack Ratt]

Yes, the hooped Zed has a smaller box than the non hooped one

 

[littlefeller]

cheers Jack, its just I'm putting together the plans for my hoopless zed and for someone who has hoops, so I guess I just copy the dimensions in the vid for the hoop box.

 

[littlefeller]

my mistake, Susans is 325mm so yes I suppose the brackets would take up this extra width. now next question is how much extra room do I have in a hoopless cubby?

 

[Antm72]

The original hoop brackets slope inwards they also loose alittle clearance on the domed bolts that hold the bracket down.
Mines built as yours is drawn the other dimentions that are key to it working are sub depth and front clearance to the chassis rail.

 

[littlefeller]

the sub depth on Susan's is assuming you replace the cubby lid, i wont be so i have lowered it to account for this, the other problems i have encountered is the hole size for the cone, in the plans the box has a height of 165mm which is just shy of 0.1mm of 6 and a half inches, so im assuming the measurements for the cone is taken from the outer extremities (mounting ring) and the actual cone is not 6 and a half. the front clearance is also a little concern as after reading your thread you had a problem with the front clearance to chassis rail and ended up buying two cones. (shame as the one in your second link would have been my choice too - the Lanzar max) unless i mount the cone on the inside but then i have the problem of fitting it in the box. ok back to the search for that allusive speaker.

 

[Antm72]

This is the profile off mine.

Its under 3" deep and only about 7mm from box face to front.
Clearence to front crossmember is ok....

You could gain alittle more depth my using 5mm Mdf to the rear of the box

 

[littlefeller]

yes i was thinking of the 5mm option, then I thought ok so why not just remove 5mm from a 10mm board, just enough to allow the back of the speaker to fit, if you see what I'm saying (a circular piece) so I'm guessing the lanzar max was to proud at the front, I did have a good look in my cubby box today, I have about an extra 60mm either side so mine could be bigger (wider) the width is still the same, I'm thinking along the lines of still using the Lanzar max with a few small mods to the box to get it to fit. Do you still have your Lanzar?

 

[Antm72]

The lanzer was about 19mm proud of the front face, it had some allen key bolts to the rear and it did not fit in the box flush the bolts hit the back.
Its a well made speaker and its cheap but looked at different ways to fit but couldn't find one
so sent it back.

 

[littlefeller]

thanks Ant, you saved me a few quid. or rather the hassle of returning one, what thickness board have you used? I'm thinking (after doing some math) the front protrusions add about 10% to the volume, but if I used 5mm I would gain more without the front part, just a long oblong box, it would be easyer to build and I have extra space at the sides where the hoops would be giving me the option of going out sideways more. I suppose its always going to be an improvement which ever way you go as its next to your head anyway.

 

[Antm72]

I would go oblong for ease the reason i added the protrusions was to gain as much airspace as possible.
The speaker itself gives air displacement so anything you can gain is worth it.
I used 12mm no room for 18 and using 5mm on a sealed box i thought it may flex.
Battoning out 5mm to joint it on the shape was not going to be easy either easy so 12mm was used and it could be drilled and screwed.

 

[littlefeller]

the 5mm was my concern too, but then I'm not going mega watts so it may work, I suppose if it was space that is needed there is no reason you couldn't add another enclosure somewhere else and connect them. if you used 12mm then by going for 5mm it would actually gain just over 1/4 inch in depth (going from front to rear) question is will it flex and effect the sound. there's only one way to find out.

 

[littlefeller]

made a start today, progress so far.