Peerless SDS-P830657 6½" Midwoofer

I have used a lot of these in the past. They are not quite up to the M16NH for smoothness of response, but you can tame the 6k bump by adding a zoble network to the crossover and more importantly putting sound deadening (butyl or bitumen pads as used in the automotive industry) on the frame. It's a bit fiddly, but it seemed to reduce ringing, which may or may not be part of that 6k bump.
The response I measured was closer to the blue curve shown in the response graph.
These work well in a transmission line paired with a D27TG35-06. Don't be put off by the 44hz FS, these dig down very deep when used in the right cabinet. The clean roll off from 100hz means room gain doesn't cause too much bass boom.
Tonally these have a nice warm but detailed sound with a richness to vocals that is pleasing to the ear.