Audio Systems/car audio upgrade


hello sir. i am installing a sony xplod xm-502z 500 watt amp in my car and i have a rockford fosgate punch 2 200 watt 4ohm sub that i am wanting to use with it. i have tried to find out how it is set up to see if i should bridge or not but havent found anything reliable yet on the net. any help would be much appreciated. thank you for your time.

Hello, Patrick.

The amp is more like:
50   watts x2 at 4 Ohms
60   watts x2 at 2 Ohms
120 watts x1 at 4 Ohms you may want to consider a better amp.
If that is all you have then you can bridge the amp by using the BTL + and BTL - outputs located on the regular speaker outputs (it should be labeled).
The Sony amps really are sub-standard turds.  I am just being as direct as possible. Just do not expect it to stand up and salute.

Here is some generic data on the Punch 2, 12" speaker ( you did not specify which one you have by model number)
You'll note the efficiency is not that great  (86Db @ 1 watt) so more power is better.
In a proper enclosure, 120 watts will only give you about 107 Db with one speaker. If you are using 2 speakers you might eeek out 113 Db.   These are generic figures since in the vehicle it will be a bit better depending on the particular vehicle resonances.

I hope this data can help you out.
Good luck and thanks for choosing AllExperts

Jerry Mael

Audio Systems

All Answers

Answers by Expert:

Ask Experts


Jerry Mael


My forte is audio.. Car/Home/Boat. You name it, I will help you even if it is just a link to more assistance. If you want to interface new gear to your factory radio I can do us both a favor and tell you to go to or call them at 1.800.555.7088. They really are top notch at doing that for people with great support. I will re-direct most questions of that nature to them. The rest of it... I am eager to help you with. I am also not a 'Master Installation Technician' that will tell you I cannot assist you with cars not made in the USA. Talk to me about any audio upgrades including 'bang for the buck'.
Specialties include: Overall Acoustics, Gain structure/settings and Enclosure design, system design/consultation, when/where to get which upgrades as well as other pertinent info for the mobile audio enthusiast and much more.
I also am NOT interested in buying your used gear so do not waste our time asking me.


My specialty as it is offered here, is Mobile and Home Audio Consultation.
Eight years IASCA - Pro 251-500 watt class
With Allexperts since 1999 (on and off).
35 years of overall professional sound and acoustical/electronic experience (since 1977) including: Sound Offs, Home audio, Mobile audio, Live sound, Churches, Theater, Live DJ and Studio Recording (analog and digital software and hardware), Effects, Looping, analog/digital mutli-track and mixdown . My mother was a record producer so I picked up a lot of additional professional knowledge and experience through the years. I was a Drum Tech for the Banshee reunion tour and toured as sound man with a regional act called Champion so I have practical knowledge for many aspects of audio.

If I cannot directly answer your question I will use my vast resource network to help you get a usable answer.

Favorite Mobile components:
Any amplifier based on ZED principles. Examples are Diamond, Zapco, Hifonics, Autotek, ect. And of course, Nakamichi (yes, still in business)
McCaulley, Polk and Dynaudio Speakers.
Clarion/Nakamichi headunits and processors.

>35 years of real world, audio experience.

©2017 All rights reserved.