2 boxes or 1 big one?

[RoboticCherry-Coke]

Haha yeah, well when I find the time I plan on building a rough cardboard version of the box just to see how things will fit and the physical size of it all before going any further. Then if need be I will cut it back down on size but I will see how things go first.

I have spoken to the local hardware store and they are after $23 for a 18mm thick 1200x900 sheet of MDF and they also said they are happy to cut it for me. Will definitely post up some pics when things start coming together

 

[RoboticCherry-Coke]

Ok so despite the fact that I really want to build this box with a capacity of 5.5 cu.ft but I don't think it is going to happen. I just built a box out of cardboard to make sure it will fit and well you were right acarmody. In theory it should fit, in practice it was a nightmare and that was just a cardboard box.

So looks like I am still stuck in the design phase

 

[acarmody]

Build them nearly exactly half the size and it will be fine. You can twist them in then.

 

[RoboticCherry-Coke]

Well I spent most of this afternoon cutting up cardboard and playing with WinISD and it looks like I can now go out and buy some MDF.

Its one big box with a capacity of 4.8 cu.ft accounting for sub displacement. So still pretty big but I think this should fit a lot more comfortably. If I was to build it as 2 separate boxes I would be looking at 2.4 cu.ft per chamber so I don't really wanna go much smaller than this if I can avoid it.

My biggest concern is access to my spare.

 

[acarmody]

Yeah I built a big box once, bad ending, was 2 inches to long to get in.

So I went and built these.

BUT if you do the measuring properly and with a mock-up box and it works than go for gold, and while my boxes are made from 25mm MDF I know that just lifting one of my boxes is pretty heavy, lifting one huge one will be damn near impossible.

My big one was 5cu.ft and the two smaller ones are 2.5cu.ft each.

If you like I had a thread where these boxes were built, a lot of help from Holdenboy, maybe have a look, http://forums.justcommodores.com.au/car-audio/141891-advice-building-some-spl-sub-boxes.html

 

[RoboticCherry-Coke]

Just had a quick look at that thread. Defiantly going to have a long read through it before I go any further, there seems to be a lot of helpful info there.

You have really made me look at the practicality of one big box again and I am re-considering two smaller boxes.

 

[RoboticCherry-Coke]

I have another quick question that I have been meaning to ask for a while. I am going ported as I am chasing SPL but what frequency should I be tuning the ports to? WinISD's default value is 26.84Hz. Is this to low or a good frequency to be aiming for?

 

[acarmody]

Way too low, mid-20s is good for music, but between 40-50hz is good for a commodore chasing SPL.

With those single boxes of mine, with both ports in, the port frequency is 40hz, but with one covered it drops to 28hz. So I just cap one for music. But both ports also works well for music, it just doesn't go as low, as my LPF is set to 40hz, I've been driving like that for a while now.

 

[RoboticCherry-Coke]

Ok well its going to be used daily so I really want a 50/50 mix of SPL and music I guess. I have read a bit of your thread and I like your original idea of an interchangeable port. My only concern is sealing the port in there.

 

[acarmody]

With mine the ports have to literally be FORCED into the holes, they are that tight so I don't have to worry about them moving, then I just put a bead on sealant around it. When I want to remove the port I just pull up the sealant with a knife or something and just force out the port.