This post is in response to this discussion:
Tuyen has a Goto woofer in a 360L box originally intended for an Altec driver. I presume a tuning of 35 Hz here.
The Goto woofer has an extremely high BL of 37! As a result it has a very very low Qts of 0.15!
It is indeed a unique driver. This is how it models in the 360L box tuned to 35 Hz (I may be incorrect on the tuning).
The existing box is shown in white. Do you see a problem here? The high Q peak there means that the box is too large, making the vent overly efficient. There is such a thing as "too much motor strength" - more isn't always better. This driver is very unusual, and certainly not intended for a box like this. The sensitivity is ultra high, but to get any extension out of this driver, some of it will have to be shedded. The blue line shows the same box sealed - no extension at all, however, in a small cavernous room it could actually have more extension than you think. The red line shows a more suitable box - 60L tuned to 40 Hz. In a room with lots of modes, this could work out.
Here is the group delay:
Notice how the large box has an ultra high group delay? It occurs are low frequencies, so it may not be an issue with most music, but this gives us a window to a problem, indicating a poor match.