Pioneer 8 inch full-range B20FU20-51FW
Actual measured specifications for the two samples we bought are averaged and listed below, including our best-fit box properties.  The two speakers differed very little in specification from each other, but differed substantially from the published values.  The resulting sound is very clean and solid in the bass.  We weren't expecting such good bass.  The software projects F3=66 Hz, but our ears say it's lower than that.