Car Audio - Amp suggestions.

[pbkid]

ok, im gonna tune in on this one. sorry for the lengthy post, but for once, i consider myself somewhat of an experienced person on the subject.

everyone posting information- PLEASE for GODS SAKE use RMS ratings... "peak" or maximum ratings are completely useless and make no sense.
Beau was completely right on this one, RMS ratings are 'continual' power. So they are accurate ratings taken on each and every item when its made.

jharris-
one of the most important things for a good sounding and long lasting system is to match your RMS ratings on all your products. The best anology i've ever heard for matching your power is this- give a football player one cup of water and see how long he can perform at 100 percent, give him a whole jug of water and he will take however much of it he wants.
It works the same for 12v systems, overpowering is fine, underpowering is very bad.
first, subs-
the bazooka's you listed are 200w RMS. so, depending on whether they are single or dual voice coil, you theoretically need a 400w RMS amp.
so, first find out if they are single or dual voice coils (also find out if they are 2,4 or 8 ohms per voice coil)... any local shop can throw a DMM (digital multimeter) on them and tell you exactly what they are. Once you find that out, let me know what your shop tells you and i'll be happy to help you find an appropriate amp.

speakers-
90 percent of speakers are 4ohms each. (infinity and bose are good examples of exclusions, they are 2 ohms or 1 ohm)
and speakers can range 40-120w RMS (each).

factory decks are around 8-10w RMS and aftemarket ones range 12-20w RMS. so, your giving your speakers 10w, when they require 50w. they arent gonna last long. although, most people run speakers directly off the deck and work fine for years, they will definately last MUCH longer and SOUND 80 percent better with an amp giving them the proper power.

so, thats the over-analyzed, difficult answer to a relatively basic question

i honestly wouldnt worry much about amplifying your speakers, focus on your subs and you will probably be happy with the results.
go to the local shop and ask them to tell you the resistance per sub, and we'll find a good set up for you.

[tom4bren]

... overpowering is fine, underpowering is very bad.

Sometime when you have an hour or two, you'll have to 'splain that logic to me. From an Electronics Engineer perspective that is bass ackwards.

[pbkid]

The problem with running lower powered amps with higher RMS speakers is that ppl tend to push the amps to try make the more power hungry speakers louder. Running the amps so high (overmodulating) introduces noise which manifests itself as wild fluctuations in audio frequencies that can damage both the amp and the speakers.

Using a speaker with an underpowered amp is not a hazard in and of itself. Its when humans try to turn up the volume to try make them sound good that can be a problem.

yup. very correct grif. especially when referring to midrange and highrange speakers (any amplification is probably more power than the deck provides)

Sometime when you have an hour or two, you'll have to 'splain that logic to me. From an Electronics Engineer perspective that is bass ackwards.

well, i really only understand the basics of it, and the principles taught to me for functionality and longevity of car audio.
What I've always been told, by anyone who i consider an expert (people with 10+ years in the car electronics business) is that its always better to overpower speakers... Basically due to what Grif has said above, that it requires the gain's on the amplifiers to remain to a minimum and creates less distortion.
The best technical explanation that i've heard is that low power causes distortion, which causes 'wild flucuations' as grif said, which damage the voice coils and eventually blow speakers.

[etlsport]

tom I think the part of this theory you are missing is that your overpowered amp isn't used to its full potential. That is what I have always learned.. Use each of your components at 60-80% but never max out.

When setting up my audio in a car I set the amp to 25% or so, then turn the head unit to about 80% of its volume scale. With a song playing I slowly increase the gain on the amp until I hit the loudest volume I would potentially listen to. Any distortion what so ever and I back the amp down until distortion is completely gone.

An amp rated higher than the speakers gives a lot of room to adjust..

Some folks prefer to set their equipment up at normal listening level and 50% volume on the head unit, but I like making sure when doing a demo or just rocking out I won't be doing any damage with distortion