I can't speak to the Sierra-2s, but I really like my Sierra-1s. They're attached to my NAD C715 - no powerhouse there, but plenty, given that it's in my bedroom (one man, one house, 4 stereo systems...).
Long ago, I had them hooked up to a Krell KAV-300i with a Carver True Subwoofer. A friend who is a superb jazz upright bassist listened with and without the sub and preferred them without the sub.
Long ago, I had them hooked up to a Krell KAV-300i with a Carver True Subwoofer. A friend who is a superb jazz upright bassist listened with and without the sub and preferred them without the sub.