important factors to look for speakers

It is really going to depend COMPLETELY on you. A wide range frequency response, going down to at least 50Hz for door or component systems, and if you can find a specified deviation (the +/- XdB number) then the smaller that deviation, the better. Power handling should be the same or greater than the desired amplifier power. IMO, you CANNOT get both exceptional SQ and SPL from one set of speakers. You can get SQ with reasonable output, or SPL with acceptable SQ, but ANY time you try to do both, you will fail. You have to decide what you want to do FIRST. My system, for example will NOT play loud (loud by many people's definition, but PLENTY for my tastes) but I have had many people tell me it is the most balanced, clean, and accurate overall system they have ever heard in a car. My system was designed, and all components chosen specifically to do just that. I'm not saying it is wrong, or that you must do it "my way", I am just saying that YOU need to decide what you want - overall.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."

[QUOTE=haemphyst]It is really going to depend COMPLETELY on you. A wide range frequency response, going down to at least 50Hz for door or component systems, and if you can find a specified deviation (the +/- XdB number) then the smaller that deviation, the better.

you are talking about the sensitivity right, I wanted to understand if the division is smaller is it better on SPL oe SQ I guess its for SQ am i right?. Another question most brands have frequency response from 50Hz when I set the amplifier at highpass at 80Hz the speaker will not take complete gain (setting to -10dB gain overlap).

Power handling should be the same or greater than the desired amplifier power.

Noted

IMO, you CANNOT get both exceptional SQ and SPL from one set of speakers. You can get SQ with reasonable output, or SPL with acceptable SQ, but ANY time you try to do both, you will fail. You have to decide what you want to do FIRST. My system, for example will NOT play loud (loud by many people's definition, but PLENTY for my tastes) but I have had many people tell me it is the most balanced, clean, and accurate overall system they have ever heard in a car. My system was designed, and all components chosen specifically to do just that. I'm not saying it is wrong, or that you must do it "my way", I am just saying that YOU need to decide what you want - overall

May I know what is your in car entertainment setup.

K. Venugopal Rao

No, the sensitivity is the specification that determines how loud the speaker system will play with a one watt input. The numbers I am asking you to monitor is the deviation, meaning how CLOSE to the adjacent frequency will another frequency play in output, with an identical power input. It is the window that is often referred to as 50Hz to 20kHz, ±1.5dB, or ±3dB. This number will tell you how flat the overall frequency response will be, in an anechoic situation. If you start with a VERY flat response here, it's easier to maintain the same flat response within the car environment. For SQ, this is the number that is very important... It is one of the MOST important numbers to me. My system, as it it sits presently...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."