I'm purchasing a ORION H2 15.2 sub(as i have said before in previous posts) and wondering what kind of box i should be looking at to make myself. I have plenty of time to make one so i dont need to rush it.
So what materials,dimensions etc am i looking at?
Thanks again for the help, i find this is the only site to actually help out a newbie .

And the owner's manual suggests....

In terms of dimensions, consult the user manual or Orions website for dimensions.

Personally I would suggest to put the sub in the recommended box, have a listen for a couple of days, and then make alterations as necessary. For example, I have had my new IDMAX in a recommended sized box for a few days and am considering making the box slightly larger because its tuned slightly high for my tastes.

During the process of trial and error, consider the following:
- ported box versus sealed
- larger box (for lower bass, probably less power handling)
- smaller box (for punchier bass, but you miss out on the deeper lows)

Have a play around if you have the time

The other consideration is the box fabrication material it self. Materials as far as I am aware can have a slight impact on the sound of your sub. I am also keen to know more about this though. Will a stock standard 18mm mdf box sound the same as a 18mm mdf box with the inside dynamatted, coated with some kind of material? What about a full fibreglass box?

well the sub dont have a manual from what i am aware and i have heard from other forums that the ORION specs arnt often right.
Well id like the deeper bass so id say ill look into a larger box. ty

Might help if you also posted the t/s specs for the sub in question.

Not surprisingly, Orion do have user manuals...

http://www.orioncaraudio.com/Support/Guides.aspx

thanks for finding the manual. I was just making sure as i posted b4 that ORION specs arent always right. i read it in forums so im just making sure

Orion specs are about as accurate as any other manufacturer. No more or less special. Their recommended box sizes are always as compromise. RTFM.

What are the advantages and disadvantages of the various box fabrication materials??

hrm...you should be able to think that one through..

MDF:
+ easy to work with
easy to cut
cheap (if you get "packing sheets")
easy to make corners with
easy to sand
flat surface for trimming
non toxic
good for you
the dust tastes sort of like a poor man's half empty chip packet, so get into it.
has no other ill effects on the respiratory system, so no need for any sort of protection.
easier to snort with a $5 note than metal shavings or wet fibreglass resin

-
hard to make curves
heavy



Fibreglass: +
like clag and paper mache for grown ups
smells funky
can make complex curves
lightweight (high strength to weight)
easy to do again if you bugger it up

-
expensive
needs a lot of sanding to get it flat for trimming
smells funky
toxic
bad for you
goes everywhere

Sheet metal: +
looks SICK!

-
expensive
hard to work with
heavy

so ideally, you'd make:
the rear of the sub box in fibreglass, so it corresponds to the curves of your car's interior. The face (baffle) out of 18mm (or greater) MDF for strength and ease of mounting, with a trim ring out of machined and polished aluminium. Nice

So a box made out of sheet metal that is pressumably quite thin VS a box made out of thick MDF wouldn't make a different to the sound at all??

If the sheet metal is thick enough not to flex, and the insides of both enclosures are treated the same (ie using damping material), then I don't think so, no.

The idea you're thinking of is the resonant frequency of the enclosure. As long as the driver plays outside the resonant frequency of the enclosure, then it shouldn't have an audible effect. However, as you've pointed out, the rf of a metal box will be different to the rf of an mdf box or a fibreglass box.

I think someone with more of an idea told me that making a box more rigid raises the rf, and making the box heavier lowers it.

The only problem you'll have with sheet metal, is you need to ensure the resonant frequency is not only outside the passband of the woofer, but outside the passband of the harmonics of the woofer. Try aiming for something above say, the 5th or 6th harmonic, and you'll find that it wont add any 'colour' to the response. Otherwise, you'll tend to hear anomalies.

if its gonna color the sub just make sure its a good color

http://www.worksafe.vic.gov.au/wps/wcm/con...rds+and+control

"This guidance note makes no distinction between dust generated from wood and fibreboard or particleboard such as MDF"

"A rare type of nasal cancer has also been reported in people who have worked in very dusty wood-working environments with little or no dust control in place"

Phil

As long as you don't snort lines of MDF dust with a $5 note you should be pretty safe. Fibreglass I would be more concerned about as far as fumes go.

mdf dust reduces lung capacity by sticking to the walls and the skin grows over it, it will keep doing to! slowly reducing the size of the inside.