When you choose a wrong amp model as connected (so, for example, DigiMod 1000 rather DigiMod 2000HV) the different scale factors provide a wrong meters measurements and a wrong limiters behavior.
These scale factors are: current scale factor for the current reading, voltage scale factor for the voltage reading, output scale factor to obtain a gain consistent with the amplifier gain response, temperature scale factor for the temperature reading and finally, “output capacitor value” for the improving of the current reading (in some amplifiers, there is an output capacitor that makes difficult the current reading, so setting this scale factor we can give a virtual capacitor that removes the capacitor value that pollutes the reading)
The last setting regards the “active channel”. This one is used to make compatible the IpalMod and M-Drive with DSP-4, because they have only one output channel, without this selection the DSP-4 “sees” the IpalMod and M-Drive always in protection state.
In this case, if you select DigiMod 3004 38dB for a DigiMod 3004 32dB (really connected), the only difference will be the gain response: DSP-4 applies +6dB in input to the amplifier and so with a sine signal @ 1Vrms in input, the voltage and current response will be different than uses a right gain setting selected. Anyway, the limiter should work well because the other scale factors are the same for both type of amp module, so it will be like increasing the DSP-4 input sensitivity.