Is it the same as a regular eq?

 

No, they are not the same. A parametric EQ is much more sophisticated. A parametric EQ allows you to adjust the amount of boost and cut just like a graphic EQ. It also allows you to adjust the center frequency that you are adjusting. It isn't fixed at a certain frequency like a graphic EQ. It also allows you to adjust how much the adjacent frequencies are affected by the adjustment. This is known as the Q. You can have a wide or narrow Q when adjusting the EQ. A narrow Q will only effect a narrow band of frequencues around the center frequency. A wide Q will effect a wider band of frequencies around the center frequency.

The main short coming of a parametric EQ is that they typically don't have as many frequency adjustments as a graphic EQ.

 

I was looking at a few stereos and I saw a nice Alpine with a 5 band parametric and also some pioneers with 7 and 13 band regular eq's--I think.

Would you take a parametric eq with fewer bands or a regular one with more bands?

 

It depends on the frequency response of the car's interior. If there are a lot of peaks and dips that need to be corrected then a graphic EQ would be the better choice. If the car's frequency response is already fairly flat then a parametric EQ would be the way to go.

Typically an EQ in an HU, whether it's parametric or graphic, isn't going to be able to correct much in the frequency response. For that you would need something like a third octave or better graphic EQ.