ive never heard the spl subs ive heard of them but thats about it....if you want a hard hitting 15 i would recommend the power acoustik mofo 15s that are a low priced sub and are great ones at that...they are 2600 watts max and believe 1300 or 1400 rms...i had two and it was unbelievable....if interested i do have one for sale for $175