hook up subs without amp?

There have only been a few head units ever made (Pioneer) that were capable of driving subwoofers on their own. Normal head units do not have anywhere near the amplifier capability to drive subwoofers. Sure they will produce sound, but without a crossover and a lot of wattage they won't work like they were meant to. Your neighbor was probably feeding you a pile of $%^# or he knows very little about car audio. You may want to have the the subs checked to see if they are still in good working order as he may have been trying to sell you junk. If they work, get yourself an amp and crossover and have them installed by someone who knows what they are doing so you can enjoy them the way they were meant to be enjoyed.sparky

ANY amplifier can drive any speaker, including the ones built into head units.  Any head unit can drive a subwoofer.  Since most head units lack low-pass filters on the amplified outputs, however, you'll need a passive crossover.  And since most head units put out somewhere between 7 and 18 watts RMS, the results may be less than satisfying.  But it CAN be done.Support the12volt.com

Like DYohn said you can run the subs off the headunit.  You'll most likely have less than anticipated results.  The headunit just can't put out enough power to run the subs.That's my opinion. Take it, leave it, or correct me.

Yeah, the sub will work, but even a cheap 100 watt amp would give you way butter results.  Depending on what your HU produces, an 100 watt amp will add anywhere between 6-12db over the HU's power.There are 3 kinds of people in the world, those who can count and those who can't

you sohuld just get an amp. if you can't afford one or aren't willing to put one in, just ditch the subs... sell them, get rid of them, what ever.

You could sell one sub to fund a cheap amp for the 2nd sub.There are 3 kinds of people in the world, those who can count and those who can't