flat powered subs in flat enclosures

I KNOW it defeats the object a bit but I get so little bass from my system that I wanted to add a subwoofer under a seat to see if it improves anything. This is a 1984 Rolls Royce Silver Spur. With those cars, putting anything into the trunk and porting it would be a nightmare and there really isnt anywhere else to put it (I had an Audiotop powered sub which was perfect for the purpose, - only about three inches high: But it stopped working and I live in New York City where one can't get anything electronic repaired)

You might try a Bazooka sub.  Gives you the bass without the customization headache.Build the box so that it performs well in the worst case scenario and, in return, it will reward you at all times.

I'm not a big fan of kenwood but this might work for what you want: Kenwood Woox

Hi everyone Don't want to sound like a cheapskate but the units I Have seen so far (the BassLink and the WooX) have a fundamental problem which my broken one seems to have missed: I thought that the whole idea of having a sub was to improve the sound by porting the bass to the sub AND removing those freqs from the signal which goes to the other speakers? My Audiotop has an input, a crossover and (variable) outputs which have the bass signal removed. Neither of these two products do, they only seem to have inputs and a crossover without outputs: Meaning that surely you have to buy Y-phono connectors and another separate crossover to port the remaining signal to the mid-range units (all they will need to handle will be the mid range signal which most should be able to do with ease, with the bass signal removed) and the tweeters. Doesn't any one else make a flat unit which does this? Has BOTH inputs and crossover-regulated outputs?

You can easily turn down the bass on your head-unit considerably and then adjust the gain on the amp/sub unit to match and then your other midrange speakers will be relieved of most bass signals. If the infinity bass link fits under your seat I would reccomend it over the kenwood (it should sound alot better but its a bit chunky so I wans't sure if it would fit under your set). Also, just  a side not both of these units will connect easily to your factory stereo (which it seems you have but correct me if i'm wrong) using their built in LOC (line level convertor).

Or... you could put these 150 hz  Bass Blockers on each of your speakers instead. If your speakers are smaller then 5.25" then I would use the 300 hz at 4 ohms bass blockers instead.