Small subs are good and they are in a very high demanding position. They have a good number of positive reviews in the market.
Learn more:

Top 5 the Best Slim Line Subwoofers – Guide & Review...

jl_slim
10tw3_d4_review
best_shallow_mount_subwoofer
shallow_mount_12
shallow_mount_12_subwoofer
best_shallow_mount_10
the_best_8_inch_subwoofer
20_inch_kicker_subwoofers