The two worst drivers for the DCH I have found so far.

Two closed box drivers from well respected manufacturers. Both of them  good drivers in such closed boxes.
* Manufacturer:  KEF
* Model:  B200 SP1014
* Piston Diameter = 172.0 mm
* f(s)= 37.68 Hz
* R(e)= 7.52 Ohms
* Z(max)= 59.42 Ohms
* Q(ms)= 5.965
* Q(es)= 0.864
* Q(ts)= 0.755
* V(as)= 56.650 liters     (2.001 cubic feet)
* L(e)= 1.20 mH
* n(0)= 0.33 %
* SPL= 87.34 1W/1m
* M(ms)= 23.89 grams
* C(ms)= 0.75 mm/N
* BL= 7.02

* Manufacturer:  Seas
* Model:  21TV-EW
* Piston Diameter = 170.0 mm
* f(s)= 34.99 Hz
* R(e)= 5.99 Ohms
* Z(max)= 70.15 Ohms
* Q(ms)= 7.519
* Q(es)= 0.702
* Q(ts)= 0.642
* V(as)= 52.260 liters     (1.845 cubic feet)
* L(e)= 1.88 mH
* n(0)= 0.30 %
* SPL= 86.93 1W/1m
* M(ms)= 28.65 grams
* C(ms)= 0.72 mm/N
* BL= 7.33

The B200 has some inconsistent mode of measurements compared to the other drivers. The black reference trace is the 9710 (lowered by 10dB) and red for the B200. Note the 5 dB peak driver output at 65 Hz and pipe peaking at 60 Hz. This is how it sound boomy and booring.

 Cast chassi Alnico magnets and a rubber suround, and a lower Q than the KEF it looks like it would be an improvements, does it not

Frequeny wise the it is a similar story to the B200 but with a less pronouced peak of the driver at 65 Hz. Soundwise the difference in bigger. The Seas sounds much worse than the B200, the bass lines that stands out at all times brings a smile for a couple of minutes but after a couple of tunes it really start to become irritating. If I wanted to learn to play bass and wanted the bass lines to stand out at all times it would be OK but otherwise...

I have also tested drivers with similar high Q but with higher Fr and they fare better. They are not good but the combination of low Fr high cone mass and high Q really bring out the worst in the construction.
* Manufacturer:  Seas   
* Model:  21F-GW
* Piston Diameter = 175.0 mm
* f(s)= 57.87 Hz
* R(e)= 4.76 Ohms
* Z(max)= 15.09 Ohms
* Q(ms)= 2.971
* Q(es)= 1.369
* Q(ts)= 0.937
* V(as)= 42.030 liters     (1.484 cubic feet)
* L(e)= 0.70 mH
* n(0)= 0.57 %
* SPL= 89.64 1W/1m
* M(ms)= 14.62 grams
* C(ms)= 0.52 mm/N
* BL= 4.30

As I said not good but not to bad either.

* Manufacturer:  Philips
* Model:  AD8001W4
* Piston Diameter = 168.0 mm
* f(s)= 59.22 Hz
* R(e)= 4.16 Ohms
* Z(max)= 17.17 Ohms
* Q(ms)= 4.058
* Q(es)= 1.295
* Q(ts)= 0.982
* V(as)= 39.440 liters     (1.393 cubic feet)
* L(e)= 0.76 mH
* n(0)= 0.60 %
* SPL= 89.90 1W/1m
* M(ms)= 12.64 grams
* C(ms)= 0.57 mm/N
* BL= 3.88 

 Familiar octagonal chassi front, very common in high volume low price speakers in the 1970s

 Not a pretty sight with that lift 70-100 Hz. And while it's sound is not to good it is substantially better than the first Seas.

I do not know why the Seas TV-EW sounds so particulary bad. It has the highest cone mass and it could be that the cone that is twise the mass of the Philps exacerbate som vibration mode in the the lightweight cabinet, but this is speculation.