I'll second SVS. They were purchased by another company recently, so time will tell if their customer service remains the same quality. When I bought my PC13-Ultra back in 2007, though, I was floored by how good their service was. Really top notch.
They talk those up on their site, but I struggle with considering it above two PC12-Pluses. A little bit less coin than two powered cylinders (but they might still offer a 5% discount when you buy multiple subs), but also half the power. Looks like they took one of the 800W Sledge amps and repackaged it for use with two cylinders instead of one. The PC12-Plus and Legato have the same response curves, as far as I can tell (which would make sense, as they look to be the same cylinder and driver). Pyrro - am I missing something? I respect your opinion and am wondering if there's something about the Legato that I'm not seeing. Maybe it's just personal preference on active versus passive?
It is primarily as I state in my post above; I like being able to use whatever power amplifier pleases me to use. Often, when a powered subwoofer fails, it is the amplifier that fails; speakers, as a rule, are extremely reliable and last a long time if not abused.
I remember when SVS sold more passive subwoofers, and what they said back then. Although the frequency response curves looked almost identical to the powered models, they said that the passive ones could produce slightly deeper/better bass due to having a slightly larger volume inside the cabinet, as there was no amplifier taking up space. That, of course, is something they could have compensated for by making the cabinet slightly larger, so it is not decisive for preferring one type over the other, though it can make a difference in practice if the manufacturer chooses not to make the cabinet larger to compensate.
Also, by having the amplifier separate, the subwoofer is lighter and easier to move.
But, in favor of having an active subwoofer, it slightly simplifies setup (as one does not have to run speaker wire from an amplifier to the subwoofer driver), and it also takes up less space. And I suspect that the resale value on a powered subwoofer would be higher, as there are many people who don't know anything about equipment and imagine that it has to be built-in to be right, as that is what they are used to seeing. But with the subwoofers we are talking about, one is unlikely to really need to ever upgrade.
And, as you say, it is slightly less money for the Legato pair than for a pair of the PC12-Plus subwoofers, and so one gets identical performance (it seems; contacting SVS about this issue would be a good idea before spending that kind of money) for less money, which is always a good thing. But one is stuck buying a pair, and if one can only afford one, it will not be acceptable.
As for half the power, we are talking about a 3dB difference [each] in volume (if we are looking at continuous power, it is continuous volume that would be different by 3dB, assuming that the drivers can handle the additional power continuously; it is difficult to say what it would be for peak volume without knowing peak power for the different amplifiers), if the sensitivity is the same. However, I believe that the woofers themselves are different, and so the one may not be louder at all.
Given the prices, one would hope that a pair of the PC-12Plus subwoofers would perform slightly better than the Legato pair, but I would contact SVS about that before coming to any conclusions one way or the other.
In my particular case, I have a pair of these:
http://www.hometheaterhifi.com/volume_9_2/svs-cs-ultra-subwoofers-5-2002.html
I use a different amplifier and EQ from those in the review. I do not plan on ever upgrading them, and am very happy with their performance. I could probably live with just one, but I bought them used together from someone who was changing out his system and no longer had room for such large subwoofers. Now that I have the two, I will keep them both for life, or until they fail, which likely means for life for me.
And yes, SVS's customer service is good. Even though I bought mine used, they were happy to sell me the port plugs that were missing from mine at a reasonable price (they called it free and that I only paid shipping, if I remember correctly, but it seemed on the high side for just shipping; still, I am not complaining, as the price was very reasonable for what I got).
I also recently picked up an SVS 20-39PC-Plus that I plan on passing along to my brother, which is a powered model, so I do not have an obsession about this, though I do prefer passive subwoofers for the reasons stated above. This subwoofer, by the way, is also an excellent performer, and I expect my brother will be very pleased with it when he gets his hands on it.
In the case of this 20-39PC-Plus, it made more sense that the guy was selling it, as he was moving and he did not keep the shipping box. Still, I find it odd that anyone would want to part with such great subwoofers, as one loses money buying new and then selling it used. With all three subwoofers, they pretty well look new, and so I am very happy to have acquired them all at less than half retail price. And my experience with these three subwoofers reminds me of something else SVS claimed many years ago, that their Plus models were almost as good as their Ultra models, which I think is true. But I am still happy to have a pair of Ultras.
