Design Philosophy


Part science, part art, and a whole lot of hard work.  That about sums up the nature of tuning audio systems for vehicles.

Back in the 1970’s our founder, Jim Fosgate, studied the acoustical properties of automobiles and the “perceived loudness” effect of listeners as quantified by Fletcher and Munson. He measured and observed that these problems are common to all cars and developed the PUNCH™ EQ as a solution.

The Rockford Fosgate signature PUNCH EQ compensates for the uneven frequency response perceived by listeners and also overcomes the masking effect of vehicle road noise.

Based on this foundation, Rockford Fosgate has developed - over the last 40 years - a reputation for innovation and passion in providing exceptional high-performance audio products. Bringing this passion and enthusiasm to the vehicle manufacturer is a natural extension of that direction.


Our job in vehicle sound development is to simply create an exceptional audio experience that is never tiring or annoying. What does that mean? Below are a few highlights:

  • Dynamic, hard hitting bass
  • Proper tonal balance
  • Clear, wide sound-stage
  • Accurate imaging
  • Sense of spacious ambience
  • No distortion or abnormal noise


With a well-defined cabin space and fixed speaker locations, you would think audio tuning would be easy. You’d be wrong. While we can’t divulge the recipe for our secret sauce here, what we can share are some key guiding principles we follow during the development process.

  • As stated in our goals, it is imperative that we provide a truly outstanding and exceptional sound experience.
  • We must stay true to the Rockford Fosgate signature sound profile including the PUNCH EQ.
  • We listen carefully to OEM customers and work closely with them to develop results they are as enthusiastic about as we are.
  • Our reputation carries a real responsibility. We must maintain our integrity and cannot compromise values or simply sell-out.

Producing highly dynamic audio that is both accurate and clear requires proper design consideration of each component in the system. A weak link will always end in a marginal final result.

Like the engine in a car, the amplifier is the heart of the system. And like a car, you can never seem to have enough power. Rockford’s design engineering group brings over 100yrs combined experience to this critical area.  Development of robust power supplies, protecting signal integrity, employing high-efficiency components, and incorporation of DSP based equalization and time alignment are just a few of the key priorities in creating an exceptional design.

If the amp is like the engine, then speakers are like the tires – where the rubber hits the road. Proper material choice, structural design, and design parameters of the motor are necessary to create a speaker that is both efficient and accurate. Matching these parameters to the unique needs of each vehicle environment is paramount to yielding a proper final result.


Sound measurement today is truly transformed from what it was only a decade or two ago. The digital revolution has yielded software and tools that would never have been dreamed of when Jim Fosgate first did his work in the 70’s. In the end however, the reality is that music is still a truly analog experience. The complexities of speaker and vehicle interaction still require human perception to guide the final result.  Recognizing this, Rockford Corporation employs state of the art sound-measurement equipment only as a complementary tool to the experienced ear.


Considering the amount of time we spend in our vehicles today, it is no surprise that bringing our high-quality sound experience along for the ride has become an ever increasing priority.  We at Rockford Corporation look forward to helping you enjoy your next premium audio experience.

Jim Fosgate's Original Punch EQ
OEM Punch EQ Implementation