4th order bandpass

[mathewdylang 2]

So, my daughters MECA Power Wheel got a broken port... So I decided to rebuild... The small sealed enclosure was practically free airing so I was looking at making a loading wall, but I don't know how to tune for just a loading wall which got confusing because it started coming out at a 6th order... So I started looking into 4th order, sealed one half, ported other. plenty of loading surface, as well as the output for the port to under the dash for the kick score. I have it as .35ft^3 sealed side (its a single 8 sealed enclosure is .25-.5ft^3) and ported side .68ft^3 with 2 2" aeros 10" long at 45hz. still fits on the back of the power wheels, and tuning a little higher for better spl with full response. Does that sound right?

[///M5 2,833]

Absolutely not. EVERY box needs to be designed for a particular driver. This is even more so the more complicated the enclosure. ie, when you add a port of any kind this becomes rudimentary. It would be a terribly huge mistake to use a generic 4th order BP enclosure for ANY driver.

[mathewdylang 2]

I don't quite follow? Generic? And must be set up for the driver? I went by sub specs for each side, as well as enough port area and the right frequency tuning

[mathewdylang 2]

This isn't a prefab box, its one I'm looking at building. 2:1 ratio (almost) with a higher frequency for spl.

[///M5 2,833]

2:1 is generic.

I see no reference of drivers or tuning for T/S parameters which if is truly the case sets you up for a big fail. You also are choosing a "higher frequency for spl" which means a 4th order BP isn't the ideal box for you. Just build a normal ported enclosure.

[mathewdylang 2]

a normal ported enclosure unloads to easily, and practically free airs. that is why I wanted to try 4th order. can you give me anything I need to look at in order to build one?

[///M5 2,833]

Then use an SSF or build a 6th order, but design it for the sub in question and the task at hand not some generic ratio.

[mathewdylang 2]

And what needs taken into account. I can't do anything without knowing how to do it or where to start. That's why I asked the question.

[///M5 2,833]

The EXACT same things that need to be taken into account with a standard ported box. If you don't know what those are then a bandpass is not something you should attempt. No such thing as Bandpass 101, so if you need more info you are going to have to try harder yourself.

[onebadmonte 235]

Here is a calculator of sorts

http://www.carstereo.com/help/Articles.cfm?id=27

Here is some info on the terminology

http://www.diysubwoofers.org/bnd/4thord1.htm

Good luck.

[mathewdylang 2]

The box I said I wanted to build was done so by what I thought necessary not the ratio. I didn't know about the 2:1 until after I had designed it by what the sub called for in size and frequency. I didn't know if there was a lot more to it than a normal ported box. The design I had figured up just happened to come close to the ratio which I was told about by someone I know that built one.