Is $1500 your budget for subs or for your 5.1 system? If for self-powered subwoofer the following are excellent at their price levels: Outlaw Audio LFM-1 @ $579, HSU VTF MKII @ $699, Onix UFW-10 @ $699, Onix UFW-12 with R-DES (6 band parametric EQ for balancing frequencies under 100 hz) @ $1099 or $1999 for 2, SVS PB12-PLUS @ $999, SVS PB12-PLUS/2 @ $1099-$1399, SVS PB12 Ultra @ $1099-$1299,etc.
"If for self-powered subwoofer the following are excellent at their price levels: Outlaw Audio LFM-1 @ $579, HSU VTF MKII @ $699, Onix UFW-10 @ $699, Onix UFW-12 with R-DES (6 band parametric EQ for balancing frequencies under 100 hz) @ $1099 or $1999 for 2, SVS PB12-PLUS @ $999, SVS PB12-PLUS/2 @ $1099-$1399, SVS PB12 Ultra @ $1099-$1299,etc."