Subwoofer Unloading Issues

[OG BudBone]

Post pics, I have a trans am and im curious about your box lol

[Purplehaze]

Yeah is it a prefab box, that says it's tuned @36? Cause if it is, than in reality, it's probably not, and more like 40hz. At least that's what happened to me.

I bought a prefab, with a divider, and it too was supposed to be tuned @36hz. But after I built a box for the same subs, just one more, I realized that my prefab was not tuned at 36. And after that, I tried to measure it myself and see, and I came up with 40hz tuning. I think they just lie to us, to get the prefab's sold.

So my suggestion is to build another box, and then you'll be sure where it's tuned at.

[Joe X]

Let me rephrase my question.

For all you box builders out there, i've always wondered, can insufficient port area cause a subwoofer to unload before it should? for example a prefab box that is indeed tuned to 36hz vs a good custom built enclosure tuned to 36hz will the sub unload less in the better built box simply because it has proper port area?even though the well built box is a bit bigger and tuned to the same frequency?

1) Some low port area will result in lost efficiency, if you further reduce port area you get port noise. Similar thing happens if your area ratio is beyond 9:1 (a thin port).

2) A ported enclosure will loose efficiency below F3 at a rate of 24dB/octave. (without factoring in cabin effects).

But in the end any comparisons that you make with a friends car are almost meaningless, is not the same car, same subwoofer, same electronics same box same noting.

I usually ask all the enclosure data and equipment data upfront to avoid as many assumptions as possible.