Don't overlook the affect that not having a crossover has on the amp powering the speakers - the less complicated load may be easier for the amp.
The suggestion of a powered subwoofer is a good one since not only do you get a bigger sound, but the power directed to your speakers will be less for a given percieved volume. You can find them in my area for between not much and free at the dump. Certainly the plate amps in them don't seem to be very long lasting, but the supply of cast offs seems pretty steady so when a subwoofer fails, I just return it to dump and take another. Not everyone lives where there are dumps, but keep an eye on tag sales, church fairs, and craigslist.
The suggestion of a powered subwoofer is a good one since not only do you get a bigger sound, but the power directed to your speakers will be less for a given percieved volume. You can find them in my area for between not much and free at the dump. Certainly the plate amps in them don't seem to be very long lasting, but the supply of cast offs seems pretty steady so when a subwoofer fails, I just return it to dump and take another. Not everyone lives where there are dumps, but keep an eye on tag sales, church fairs, and craigslist.