xtant z104 specs

I have a pair of these Xtant Z104 subs from like 5 years ago that I love, but since becoming an installer at Best Buy and learning alot I think that the boxes I have them in have inadequate air space. But for some reason Xtant.com does not even list these subs even in their archive. So does anyone know or does anyone have a site that will list all the specs of these subs? Ive searched but cannot find anything on the web. I seen a little spec sheet from cardomain.com but was looking for a full and very nice spec sheet on them. Thanks in advance.

If this is actually a x104 the parameters are X104 Fs 29.3hz Qms 3.6 Vas 1.151 cu.ft Cms 0.0273 in/lb Mms 6.646 oz Rms 21.27lb/s Xmax 0.524 in P-Dia 8.72 in Sd 59.68 sq.in Qes 0.48 Re 3.86 ohms Le 3.5 mh Z 4 ohms Bl 3.756 Pe 500 watts Qts .42 No 0.16% 1-WSPL 84.3 db

no, it's a z104, a very old z series xtant.