[Hybred]

I recently installed a Nexus 7 2013 into my Altima and everything is working great... except the audio. Before the audio in my car was pretty good, even with stock speakers and a mild EQ in the old Kenwood (HX418) radio that was installed previously. Right now the routing is as follows
 
Nexus 7 > OTG Cable /w Charging > E7 > Amp > Speakers
 
The audio quality is there. But the bass just feels.... underwhelming. I don't really 'feel' it anymore. I don't have a sub but and I didn't have one before and the audio sounded really, really good. I'm thinking of picking up this equalizer to maybe compensate for anything the amp/dac isn't pushing, but I'm really clueless on the subject. Any ideas?
 
http://www.amazon.com/gp/product/B000EZV3T8/ref=s9_simh_gw_p422_d1_i1?pf_rd_m=ATVPDKIKX0DER&pf_rd_s=center-2&pf_rd_r=1V02ZERFZY9B5X3K8J04&pf_rd_t=101&pf_rd_p=1688200382&pf_rd_i=507846

 

[Ghog]

I have a crossover  hooked up with my nexus 7 in my kia spectra 5.  To be honest it is the way to go for better sound.  I have 2 amps one for more front and rear speakers and one for my 2 subwoofers.  The cross over is great.