Dual 18" 4th order bandpass

[Mindzor]

Hi there. I'm new to this forum, so i want to say hello to everyone.

So right to the point. My brother just bought two Alphard DB318 woofers.
After some time I came with an idea of 4th order bandpass.
Seald part is 5.5 cu ft and ported part si just above 11 cu ft tuned to 48Hz.

So i just wana see your opinion on box design itself.

[Wasteland_Audio]

The design itself looks good. Here is a thread i started just the other day, it may have some useful info for you.

http://www.stevemeadedesigns.com/board/topic/205225-first-4th-order-attempt-enclosure-experts-welcome/

[Triticum Agricolam]

Hard to tell from the pic, but the port area might be a bit low.

What amp is going to be used? What kind of usable bandwidth are you hoping for?

[Mindzor]

Port area is 200 sqare inch

For now it will be run from DD M3B on0.5 ohms.

Edit: my hope is from 30ish Hz up to 60Hz

[Triticum Agricolam]

OK, that amount of port area should be fine.

My suggestion would be to make the port adjustable or removeable so you can change the tuning once you get it playing. You may want to shift your tuning down a bit once you listen to how the box performs.

[Mindzor]

I was thinking to make a bigger opening where the port is so i can mount and reach woofers and then close it with the port so it stays flush from the front. Front panel will be made from double 3/4in mdf so i can make like a slot where my port will fit.

If you understand what i'm trying to say, my english is not the best.