Dude - the Emax1 is an awesome module.. Almost identical sampling engine to the SP machines and the Emulator2. Perhaps better than the SP machines as you have control over the cutoff and resonance plus you have 8 physical, dynamic filters rather than the SP's 3 static pairs. Obviously you lose the drum sequencer and the interface but same great sound..
Regarding low-end, I think you are discovering the limitation of samples. If a sample has poor or weak low-end, you can suddenly add it or boost it (you can't boost what is not there). Sure, you can boost slightly if you have some nice EQ available (not usually a good idea on a lot of low end mixers) but generally speaking, EQ is best utilised to reduce frequencies, not boost them.
If you need a certain type of low end you have the following options;
1) it exists in the sample. Job done
if not,
2) find another sample
3) make it yourself using a synth or layering
But yeah, some nice pre amps can add a little low-end boost. HPF with a little resonance are also very good at giving a little boost.
Anyway, give us a little more specific examples and we can take this a little further, ie, what sort of sample are you referring to? A single shot Bass Drum/a break/etc..
