[morzh]

Terry,

Yes it does matter.
The speaker will work all the way up to the nominal current, but obviously not as loud if the magnet is not as strong, and the magnet strength (Field (or induction) B) is proportional to the current (and inversely proportional to the distance).

So when using a speaker with a different field coil, as long as the current is met the speaker will feel OK. Of course this current might not be what the radio wants if the field coil is used as the filter, if, let's say, the field coil wants to see 30mA and the radio wants 70mA - in this case we are overstressing the coil as it will dissipate more power than it was calculated for.
But if one is using two similar speakers with coils both wanting, let's say, 70mA, but one is being 1K and the other - 500 Ohm, and you add another 500 Ohm to keep the voltages the same (as the sch counts on the coild dropping 70V) your speaker will be OK and work at full capacity.

It is easier to do with the speakers with coils used as a load and not the filter, as then you could adjust the current independently and not upset the voltages, as lon as your load is comparable to the original one.