6.5 mid, 6.5 sub. The sub looks interesting for a Miata application:
-Fs: 25.7 Hz
-Qms: 6.2
-Qes: 0.46
-Qts: 0.42
-Vas: 11.7 liters
-Re: 3.25 Ohms
-Le: 214 mH
-BL: 9.7 N/A
-Mms: 76.7 grams
-Sd: 130 cm^2
-Cms: 0.5 mm/N
-Xmax: 14mm one way linear
-Xmech: 18mm one way maximum
http://forum.miata.net/vb/showthread.php?p=1473263
-Fs: 25.7 Hz
-Qms: 6.2
-Qes: 0.46
-Qts: 0.42
-Vas: 11.7 liters
-Re: 3.25 Ohms
-Le: 214 mH
-BL: 9.7 N/A
-Mms: 76.7 grams
-Sd: 130 cm^2
-Cms: 0.5 mm/N
-Xmax: 14mm one way linear
-Xmech: 18mm one way maximum
http://forum.miata.net/vb/showthread.php?p=1473263