How do I change speaker size in my car?

Car amp/speaker wattage, and a speaker size question?

• I might be getting 2 speakers, a sub, and an amp I am looking at getting a 4 channel amp. 2 channels for the front speakers, and 2 bridged channels for the single sub. My question is, nearly every amp has an RMS beginning at 50 at the VERY LEAST, the speakers I want are usually rated at 40-45 RMS. I am having trouble finding amps with lower ratings, is it alright to run this much wattage anyways? My next question is about choosing my front speakers. Stock, my car uses 4x10" speakers. I really dont want to buy another set of 4x10s so I am interested in fitting either 4" or 4x6" speakers. would the 4x6 fit? despite it obviously being 4" wide, is there something i dont know that make it slightly larger? possibly the bracket or strange measurement system? Im opting for 4x6" as my front speakers but if there is something i should know please enlighten me. regarding the 4x6 speakers, would i want a speaker that has dual round drivers (Infinity Reference 6422cfp), or a single oval speaker (Infinity Reference 6422cf) keep in mind, these 2 front speakers and sub will be the main sound system. (i might run my stock rear speakers, possibly upgrade those later) But what if i was unable to purchase a sub? i would probably still get a 4ch amp so i can upgrade later but would this effect my speaker choice? thanks

• Answer:

  4 channel amps aren't usually designed to run to Subwoofer, because the power ratings aren't usually high enough because of the class A or B circuitry compared to the class D circuits mono block amps use. If you wanted a louder bass I recommend running a dedicated mono amp to the sub but for something not obnoxiously loud you will be fine with the bridged set up. If i was you i would upgrade to the Infinity 462.9cfp which can handle a little more power and aren't too much more expensive ($30 compared to new speakers.) the 4x6 should fit into a 4x10 the only thing i would worry about is to make sure that you seal the speaker to the mount so there isn't a large gap, allowing for air to flow between the front and back of the speaker. this will make for flat bass notes. also if you are using an amp to power your speakers got with a component system (the tweeter is not mounted in the middle of the speaker) rather then a coax speaker, they handle more power and there SQ you will get is so much better. I would use the alpine mrv f300, I have it in my car and it sounds wayyy better then the head unit, not just louder but better.