[mineo77]

Originally Posted by JimD

I am likely to get negative comments from people who admittedly have more car experience with audio than I have. I am a mechanical engineer and got a little college credit many years ago for papers in this area. I have also built several home systems but my experience in cars is much more limited.

With that background I will say what I have said before. What you hear is speakers, not amps. Driving a poor driver harder with a bigger amp does not make sense to me. Better drivers are often, not always, more efficient. So they make more sound with less power. It is not unusual for the sound output with one watt of input (a typical rating) to vary 3-6 db or more for drivers. To get 3db more sound you need twice the power. I do not know the efficiency rating of what you have but there is a fair chance if you replace it you will gain some efficiency. I know that little ~4 inch woofers with no tweeters and 6 inch under seat subs could use some help.

I would be thinking of better front 4 inch woofers and tweeters to start. If you want loud thumping bass the other drivers at the stop light can hear, then put in a trunk woofer. One of the posters here will supply you a custom enclosure so you have some trunk space left. You will need an amp for it. After that, you can decide if you need to replace the under seat drivers and/or add more power to the speakers in the passenger cabin.

I've only tested my mid-level BMW system but the bass from the 8 inch under seat woofers is if anything a little above the mid and high level frequency response. I used test tones and a radio shack sound meter to see how flat the frequency response is. High frequencies fell of sharply above 10K and low bass was measureable below 40 hz which is commendable for a 8 inch driver. It does not sound like a lot of bass compared to some other systems but what seems popular these days is a big bump in the 100 Hz range. That is not really low bass but to get the bump that seems to be desired may require a fairly large speaker.

More power sounds cleaner up to a point but when you put too much power to a speaker first it distorts and starts to sound bad and then it mechanically breaks. Better speakers will take more power before gross distortion sets in. For multiple reasons, I think you should start with replacing the front drivers - the ones you really hear - and then think about amps.

Jim

agree