Looking at the audiophile (i.e. Hypex) Class D amps, they generally max out at 1200 watts into 4 ohms (with a monoblock). Also, stability into 2 ohms is not always clear.
If you're still looking for a big bass amp, one thought would be too look at Crown Amplifiers. I had a Crown CTS2000 years ago. It was their "Class I" type (which is very similar to Class D). It did very well powering a subwoofer and was stable to 2 ohm loads. With the current product line, they have a Crown DSI 6000, which is a stereo amp that provides 2100 watts per channel into 4 ohm, or 3000 watts per channel into 2 ohm loads. You can select the input to use a "mono input configuration", which means you only need to use one of the XLR inputs. Street price for this is just under $2k. The downsides are - only XLR inputs, uses a fan cooled system which means you can hear the fan when amp is under high load, and there is no trigger auto-turn-on function (complete manual power). Just an option.
Beyond that, the absolute best amp I have ever used for subwoofer duty is actually the Emotiva XPR-1 monoblock -- 1000 watts into 8 ohms, 1750 watts into 4 ohms. However, it is a giant beast at 99 lbs and is also a Class AB amp, and does get quite warm when driving 4 ohm load for bass. The thing pounds bass like a mother, however.
If you're still looking for a big bass amp, one thought would be too look at Crown Amplifiers. I had a Crown CTS2000 years ago. It was their "Class I" type (which is very similar to Class D). It did very well powering a subwoofer and was stable to 2 ohm loads. With the current product line, they have a Crown DSI 6000, which is a stereo amp that provides 2100 watts per channel into 4 ohm, or 3000 watts per channel into 2 ohm loads. You can select the input to use a "mono input configuration", which means you only need to use one of the XLR inputs. Street price for this is just under $2k. The downsides are - only XLR inputs, uses a fan cooled system which means you can hear the fan when amp is under high load, and there is no trigger auto-turn-on function (complete manual power). Just an option.
Beyond that, the absolute best amp I have ever used for subwoofer duty is actually the Emotiva XPR-1 monoblock -- 1000 watts into 8 ohms, 1750 watts into 4 ohms. However, it is a giant beast at 99 lbs and is also a Class AB amp, and does get quite warm when driving 4 ohm load for bass. The thing pounds bass like a mother, however.