Good subs will cost you more then what you paid for your SMGa's. If you don't care how much you have to spend for good results, then skip what I'm gonna tell ya. If you're on a budget, then read on.
I always try to get the best possible sound, for the least amount of money, and since you're using SMGa's, I'm assuming you might be the same way. I had been using SMGa's for about 4 years, and about 8 months ago, I switched to a pair of IIc's (2 steps up from SMGa's, same model year).
If you want good, clean bass extension for cheap, keep your eyes open for a couple of used Velodyne F-1000 servo subs. An older model 10", from the early 90's that can be bought for peanuts, compared to many current models. They work extremely well for music, but not too good for HT since the amps are only 80w, and they can/will run out of steam on those big explosions. My original two F-1000's I bought cost me around $175 each, shipped. I just won another one on Ebay for $148 shipped. I've seen them sell for even less. They're not in demand because of the small amps, but for 2 channel music, they're great.
The 10" ones are quicker then the larger sized ones, and are a good match for maggies, if set up right. You can start with one, but I have found for best possible integration with the main speakers, 2 subs is best, and place each sub right next to each main, with the sub's front firing driver on the same plane as the maggie panels, and with the same toe in. Placing them like this will give you the best integration, as far as phasing and time alignment goes. It may not give you the lowest possible bass in your room, but you'll evently learn that proper blending with the mains is more important then a few extra Hz of extension.
I used to use a single Velodyne F-1200 (12" model) centered between the mains, but never could get the integration just right (mostly phasing issues). Now with the two 10's placed as they are, my integration struggles are over, and I wish I had done this a long time ago!
I always try to get the best possible sound, for the least amount of money, and since you're using SMGa's, I'm assuming you might be the same way. I had been using SMGa's for about 4 years, and about 8 months ago, I switched to a pair of IIc's (2 steps up from SMGa's, same model year).
If you want good, clean bass extension for cheap, keep your eyes open for a couple of used Velodyne F-1000 servo subs. An older model 10", from the early 90's that can be bought for peanuts, compared to many current models. They work extremely well for music, but not too good for HT since the amps are only 80w, and they can/will run out of steam on those big explosions. My original two F-1000's I bought cost me around $175 each, shipped. I just won another one on Ebay for $148 shipped. I've seen them sell for even less. They're not in demand because of the small amps, but for 2 channel music, they're great.
The 10" ones are quicker then the larger sized ones, and are a good match for maggies, if set up right. You can start with one, but I have found for best possible integration with the main speakers, 2 subs is best, and place each sub right next to each main, with the sub's front firing driver on the same plane as the maggie panels, and with the same toe in. Placing them like this will give you the best integration, as far as phasing and time alignment goes. It may not give you the lowest possible bass in your room, but you'll evently learn that proper blending with the mains is more important then a few extra Hz of extension.
I used to use a single Velodyne F-1200 (12" model) centered between the mains, but never could get the integration just right (mostly phasing issues). Now with the two 10's placed as they are, my integration struggles are over, and I wish I had done this a long time ago!