ABC Enclosures..

[Eldorado 0]

Has anyone done one of these before ?

I reciently picked up a eD e8a and I wanted to try it in one.

I found a formula that seems fairly simple to follow.

Build a box with 2 chambers, one at 3 cuft and the other one EXACTLY half of that, ie 1.5 cuft. Next cut 3 ports all IDENTICAL in length. Put one in the face of each chamber and the third in the wall separating the two chambers. In this instance each port would be either 12.5" long for a little deeper response or 8" long for a little more SPL.

Now you have a box with a big chamber with a vent in it, a small chamber with a vent in it, and a third vent in the wall between the two. The woofer also mounts in the large chamber.

The way they work is that, at low frequencies, it all functions as one big box with 2 ports, and is tuned to 30Hz (12.5") or 35HZ (8"). At higher frequencies the middle port starts to restrict air movement and the second chamber begins to act more as a resonance chamber but not as part of the box. At this point a second tuning frequency develops 1.9 times (almost an octave) higher than the lower one , ie. either at 57Hz (12.5") or 67Hz (8").

This is similar to a vented bandpass but has more output and smoother sound due to the woofer not being tucked inside the box. The results are that it plays both low and loud, while being relatively nice sounding. The drawback is the box size.

[Tirefryr 1,742]

I did this once with a 12W0. I've seen mixed reviews on the enclosure. Some have stated it to be an output monster, some a control freak. It exhibited neither nature in my testing. I preferred a standard sealed enclosure. I'm sure it will behave differently for every app though. Worth a try if you ask me.

[Eldorado 0]

Any pics ?

[vladd 26]

What are you looking to achieve? Just from the sounds of it, seems like it would be peaky

[Eldorado 0]

A nice sounding sub. Actually, ABC's are less peaky than a ported enclosure.

[///M5 2,833]

I'd give it a try, but build a "normal" box at the same time so you have something to compare it to. Only takes a little extra MDF and not really that much extra time if you do them together. I am really curious as descriptions make it sound logical, but I have never had a vehicle with enough space to do it.

[Eldorado 0]

Its only going to be 1.3ft^3

If i dont like it then i'll just cut off the snd chamber and put a new side on.