Reply to Hercules RMX - sound quality - combinding it Audio 2 DJ?

Hi.

Im using Mac Book Pro/Traktor Duo/Hercules Rmx when playing at clubs. I usually connect the Hercules (output 1 and 2 with RCA) to the club's mixer. I use mp3 320kbps.

I experience that the sound quality is not great. It's not BAD, but rather low, dull and without the boost I'm getting with CD or turntables. I'm trying to figure out other ways of increasing the sound quality and level. I assume there are certain possibilities:

1) USING JACK 1/4?
I have learned that the sound will probably be better (or at least louder) if I use jack 1/4" output from Hercules, because the jack has a louder output level than the rca. I will then have to use jack-to-rca cable, as the club's mixer does not have jack input, but I assume that does not decrease the sound quality? Correct me if I'm wrong.

2) ADJUSTING SETTINGS?
Is there any settings of Traktor or the Mac which may be adjusted to increase sound level/quality? Now I'm using sample rate 44100 Hz, 4,0 latency, 100 % sound volume of the mac, approx. 85 % sound volume of traktor (avoiding the red as much as I can) and auto-gain.

3) USING ANOTHER EXTERNAL SOUND CARD?
I have read that the sound card of Hercules Rmx is not great (not bad, but average). Is it possible to use another external sound card - in particular I'm believeing about Audio 2 DJ - and deactivate/not use the sound card of Hercules Rmx? My suggestion would be to connect Hercules Rmx to the Mac with one USB, to connect Audio 2 DJ to the Mac with another USB, to further connect the Audio 2 DJ to the club's mixer. By this, I assume that I can control Traktor with Hercules while the sound streams through Audio 2 DJ. Does this work? And what about the headphones? Will the sound card of the Hercules be deactivated so that there will be no sound if I plug the headphones to it? How can I then pre-listen to songs that I am about to play?

4) A COMBINATION?
The three options I have suggested above may perhaps be used in parallell?

5) ANOTHER CONTROLLER?
Should I perhaps buy another controller, such as the Vestax VCI-100?


Thanks in advance for any help.

Rune