I've got an Arc X2 850.5 Amplifier powering a set of Hertz MPK 163.5 PRO's in the front and a set of Hertz MPX 690.3 PRO's in the back. I think I'm underpowering both of these and would like to bridge the amp to just power the 163.5's and eliminate the 690.3's in the back. I understand I use the positive and negative from 1/2 and 3/4 combined to go out to the front speakers. But I'm unsure what to do with the RCA inputs on the amp. I've included links to everything below;
Amp;
www.arcaudio.com
Hertz MPK 163.5 PRO;
Hertz MPX 690.3 PRO;
Amp;

X2 SERIES AMPLIFIERS | ARC AUDIO
The X2 Amplifier Series has been refined to offer users the highest level of clean and effortless power production possible.

Hertz MPK 163.5 PRO;

Hertz car audio systems | The Sound Experience
Hertz produces high-performance car audio systems driven by research: V-cone®, Boundary Free Surround Tetolon Fibre, Rotary High Frequency Contour
www.hertzaudiovideo.com
Hertz MPX 690.3 PRO;

MPX 690.3 PRO - Hertz car audio systems | The Sound Experience
The three-way MPX 690.3 car audio coaxial, optimized for rear deck mount, features a 28 mm Tetolon tweeter with Neodymium magnet and faceplate profile maximizing the off-axis dispersion.
www.hertzaudiovideo.com