Did you mean ma hk4000? it has an 8v input sensitivity. To get the most out of your amp you would want a line driver that boosts to around 8v, not necessarily a new HU. Something similar to this would work http://www.sonicelectronix.com/item_30401_AudioControl-OVERDRIVE-OVERDRIVE-PLUS-White.html

4,000 WATT RMS DIGITAL MONO AMP
CLASS "X" (MORE EFFICIENT THAN CLASS "D" MONO
2000 RMS @ 4 Ohm
4000 RMS @ 2 Ohm
2 OHM STABLE
Temperature, Voltage & Output Level LCD Display
Thermal, Short & Overload Protection Circuitry
Platinum Plated RCA Jacks
Double Sided Epoxy PCB Board
Platinum Plated Block Terminals
Stainless Steel Finish Heat sink
Quiet, But Powerful Fan Cooled System Built-In
Full Mosfet Circuitry
Frequency Response: 10Hz - 350Hz
24dB Low Pass Filter @ 50Hz - 350Hz
24dB Subsonic Filter @ 15Hz - 50Hz
Variable 0 - 18dB Bass Boost Control @ 45Hz
Input Sensitivity: 0.2 - 8V
Dimensions: 12.4” Wx 2.71” Hx 25.86” D

Yea MA my bad (No idea why the fk i typed MMATS lol, makes no sense)
but yea i suppose a line driver would do the trick, but what about my 4ch which is 6v stable?
Same idea?

This post was edited by ]GS[ Controller on Mar 19 2012 04:19pm

you really wouldnt notice much of a difference on a mids amp so i wouldnt bother, most external eq's usually have built in line drivers too, this clarion boosts to 7v http://www.sonicelectronix.com/item_6655_Clarion-EQS746.html

Well actually if thats a better option lmk, because idk

i just need something for the sub, because it would probably help stabilize my voltage a hair too, and quality from my sub is never bad.

http://www.sonicelectronix.com/viewcat.php?category%5Fid=697&sort%5Forder=price%5Fdesc

Is that any good? I dont want to really spend much on this if i dont have to.

This post was edited by ]GS[ Controller on Mar 19 2012 04:30pm

this would do it for 50$
http://www.sonicelectronix.com/item_27297_RE-Audio-VLS-1.html
13.5 v out

thats much too high, would fry your amps rca inputs. an 8-9v would work