Im currently replacing my subs and amp, and heres my question:
what is the advantage of having 2 subs over 1?
I was originally going to buy 2 subs and a 2 channel amp to power them (say 300W RMS per channel).. but would it be just as good to get a 600W rms mono amp powering 1 sub (one that can handle the extra power)?
because that would probably save money and room in my trunk
please tell me any reasons having 2 subs is better (ie: SPL, range, sounds better)
There really is no SQ benefit to having 2 subs. Actually, the more equipment you add, the more the chance is of both manufacturing differences and phase issues, usually less is better for SQ. 2 subs are just for added output, everytime you double surface area, you add about 3 db. You can wire a single sub to the same load that two would have, saying 1 ohm stable amps are about as far as they go (there are VERY few .5 ohm amps out there), and DVC 2 ohm subs are quite common. IMO, it's better to get one really good sub than two lesser ones, some people are taken by the "bigger is better" mentality and think they must have 2 twelves, etc. You can buy one sub that would still hit harder than two other lesser subs, with less power sometimes, and have better sound quality. Added trunk space etc is a benefit as well. As far as your situation, it really depends on what your budget is and what kind of equipment you're considering.
Its really all in your box design. If you have a poorly designed box with 2 subs and a properly designed box with 1 sub the 1 sub will outdo the 2 subs. But if you have proper boxes for the 1 sub and 2 sub setup the 2 sub setup will be louder as you have more cone area.
but they are right about the sub part, 1 larger sub is more efficient, has more xmax, and moves more air than 2 smaller subs, plus sub prices dont go up too much by size, they go up by model and quality, so basically by buying 1 15 per say, over 2 10's, youll save money, and get better bass.