judging from the specs you list only, I'd say that's not enough amp for those subs. In fact, it wouldn't be enough to sufficiently power one of those subs.

Now, let's list what Crutchfield says about these components:

Type-R 10" subs

RMS Power Range (Watts) 200-500
Peak Power Handling (Watts) 1500
dual 4-ohm voice coils

Alpine MRD-M605
400 x 1 mono subwoofer amplifier

RMS Power Rating (measured at 14.4V):
Into a 4-Ohm Load: 400 watts x 1
Into a 2-Ohm Load: 600 watts x 1
Note: Minimum impedance is 2 Ohms.

With dual voicecoil woofers, you have two options for wiring...

2 DVC drivers with Voice Coils in Series / Parallel
Connecting the two voice coils of each driver in series (+ to -) and the drivers themselves in parallel (+ to +, etc.) will result in the following impedances:
Dual-6 Ohm Subwoofers: 6 Ohms
Dual-4 Ohm Subwoofer: 4 Ohms
Dual-2 Ohm Subwoofer: 2 Ohms

2 DVC drivers with Voice Coils in Parallel / Parallel
Connecting the voice coils of each driver in parallel (+ to +, - to -) and the drivers themselves in parallel (+ to +, etc.) will result in the following impedances:
Dual-6 Ohm Subwoofers: 1.5 Ohms
Dual-4 Ohm Subwoofers: 1 Ohm
Dual-2 Ohm Subwoofers: 0.5 Ohm

Neither of these options yield an optimal resistance load for this amp... to make this amp work for you, you really need for it to see a 2-ohm load. With dual 4-ohm voicecoil woofers you just can't get there.

I still think this amp is too small for these woofers... they might work if they are dual 2-ohm voicecoil woffers, but I still think it's not quite enough power for them.