VAS value???

Nobody can understand those specs. But it does say that the quality is "excellent" in the specs

Here ya go. http://www.speakerplans.com/index.php?id=faq1

The easiest way to look at it is the vas, the smaller the bumber the smaller enclosure it likes. The bl, is the motor strength. Higher numbers mean a more powerful motor force. The mmd is the weight of the cone assembly. None of these necessarily singularly makes a driver good or bad. They work in conjunction with all the rest of the specs which in turn makes the driver good for a specific application. Most pro drivers have high bl but little xmax. Specifically good for producing music loud but not very good for infrasonics. Flip those values around and you have a driver that, depending on some of the other specs, would do well with lower stuff but wouldn't necessarily have that kick you in the chest feeling.

Are you sure its not 86.xxxx liters instead of 86,xxxx?

And also, were the othe half dozen forums you posted this question on not able to help out with this?

Vas = 89.561 Liters, or 3.163 Cubic Feet.

The m M is a misprint as it typically represents Square Meters, which is for area, not volume. Sd is also stated incorrectly which is stated in m M (Sq M). It should read; 0.0531m M. 53 Sq M would be equal to your rooms entire floor space area.

They are obviously using a comma instead of a decimal point in their specs, a common usage in other countries in Europe and Asia. My guess is this is from Asia and there is simply a translation problem in the specs writing department (also common).

Bosso