Some one look at this design please

[jarrius]

So I did this design for a mofo 15 and I was wondering if it looks good(specs) don't know if the guy has built it yet but I told him not to until we get more info on it. So what do y'all think. Also this is my first design so yea lol

url="http://s50.photobucket.com/user/Alucard_lvl3/media/123.png.html"][/url]

[jarrius]

Bumping this up. Just want to know if I did it correctly

[mmets]

I would mess around with the port and try to get about 15 inches vs the 10 you have. Also make sure you add what the woofer displacement in and any bracing. It will change your tuning freq. I personally like to be around 34 but thats just me.

[jarrius]

The guy I did this for wanted as close to 31 as I could get. So that's why I came up to 32. And why 15in instead of the 10?

[mmets]

Going to guess but move more air. Tuning down to 32 is fine if thats what he wants. I am not the expert here by any means and for the past couple years the rule of thumb is around 15 for the port. Im sure someone will more expertise can explain the reason behind it. Just make sure you add the sub displacement and any bracing so you can see the final tuning freq

[mmets]

also since i forgot to add this but some subs work better with more port area than others. That 15 may not be for all subs out there but just a good reference point.

[jarrius]

I did not plan on any bracing and could not find the subs displacement thus is why I was thinking it would be at least 4cubes with sub displacement

[Joe X]

Use 0.18-0.2 cubes for each sub driver displacement, also port area is a bit low and the port length seem to be stuck on the corner.

[jarrius]

How do you know how much port area a sub should have? Also what do you mean the ports stuck in the corner.?

[Joe X]

Port area is chosen to limit airspeed and prevent choking or port noise, you can use Small's estimate (there's a calculator online for it), when your port length is such that exceeds the internal depth of the box less the width of the port itself but it's not long enough to generate an extension length then you are at the corner, you need to increase or decrease the port length to get off the corner, if you need that specific tuning you can tweak the net volume or the port area to achieve it.

Using your dims above: