eq make difference?

I was thinking about if a good EQ in the headunit can make a big difference ? Now i got a Sony CDX-GT220 Sony CDX-GT220 (Link is GT130 but they are the same) and my EQ is limited at Low, Mid and High.. So, if i change with a better HU did the SQ will be improve? For info i got a Sub with 4 aftermarket speakers and all of them are amplified.

Not very likely... If you don't have adequate power (and in MOST cases, even if you DO) and EQ can introduce all kinds of additional problems, not the least of which is clipping. EQs in the wrong hands are very bad things. Just use your tone controls.It all reminds me of something that Molière once said to Guy de Maupassant at a café in Vienna: "That's nice. You should write it down."

i use a 9 band graphic EQ in my truck and it makes a whole world of difference, but like haemphyst said it can also cause problems. the way i set my eq was basically listen to a bunch of songs with different qualities over and over until it sounded pretty flat. i got rid of some really harsh upper frequency tones caused by reflections and tuned it until i could hear every instrument in a song clearly and follow any given instrument. but to do this, it took me a really long time, weeks of small ajustments. you adjust something and listen to it for a while. and you also have to realize that when you adjust one band it affects the other bands around it so if you turn one band up a little bit you have to turn the bands next to it down just a little bit so they will stay at about the same level. its also important not to turn it up all the way up because that will give you more noise than anything and will sound very unnatural. try to keep all of the bands as close to center as possible. turning a band down usually works out better than turning it up. not very sure what you are wanting to use the eq for but if you want it just to make things louder than that is not what they are good for and if you use it like that you will get more noise than anything and you might as well not have it at all.