Car audio questions

[Nebulous]

So here's something (slightly) different for this forum.

I was working with a friend today installing a 4 channel amp and sub to his sisters car, and I got thinking about the tech behind it. He doesn't seem to understand the tech side of things, but knows how to install it and make it work, so even though I asked, I didn't get an answer.

From what I remember, in "pro"/ live audio, we run a system where the amp is providing more power than the speaker is rated at (eg, 100w amp into 80W rated speaker with matched imprdance). I seem to have confirmed this by refering back to my "live sound mixing" by Duncan R Fry.

Now, in doing a Wiki search on http://en.wikipedia.org/wiki/Car_audio it states under "amplifiers":
Make sure that the total power handling capacity of the speakers connected to the amplifier or head unit is greater than or equal to the power of the amplifier or head unit.
This rings a bell from what I've heard people saying in relation to car audio.

So are both these concepts correct, meaning that pro vs car audio use oposite concepts equally well without damaging equipment, or is one concept incorrect?


Also, further to that is my main concern with my future plans for a stereo upgrade in my car: a 1997 VW Golf. It came standard with a pair of 4" in dash, 6" front door speakers and 6" component (w/ tweeter) in the rear doors. I'd like to keep that amount of speakers, but upgrade them, running the dash and front doors off my head unit (JVC CD/mp3, 4 x 50W) and the rears plus an added 10" Sub off a 4 channel amp.
So with my initial question answered about the speaker/ amp power matching I'll be able to figure out if I can run the dash/ front door speakers off my head unit, with alot of these speakers being in the range of 40-60W RMS, and then I'll be able to figure out how much power I'll need to run the rear/ sub (which as far as I understand are not a huge problem as the channels will have adjustable gain per pair).

Cheers in advance for any help offered.

 

[colonel kurtz]

here's the thing, man...i would go with the knowledge/advice of pro audio guys before i would car audio guys. i've noticed that a lot of car audio people know about CARS, not electronics and audio devices.

 

[Nebulous]

Yeah, that's where my thoughts are leaning. I'd rather be running speakers through an optimal amp range rather than pushing an amp into distortion to power speakers sufficiently. It's just annoying when you get conflicting concepts, both which make amounts of sense.

 

[Nebulous]

Ok, I just found a resource ( http://www.mobileaudio.com/rac-faq/ ) which has backed up "our" way of doing things. If anyone has some solid reason as to why that should be challenged, please let me know.

Are there many people around here that work with car audio either as a regular hobby or day job?

 

[colonel kurtz]

again, i would stick with the idea that the amp should dish out more power than what the speakers are rated at. regardless of the application, a clipped sine wave coming out of an amp is much more likely to damage a speaker than a proper waveform that has a bit too much power.

i tried getting a job once at a car audio place, but they didn't hire me because i didn't know enough about cars. i knew more than all of those guys put together when it came to matching wattages and resistance, and how to properly EQ a system and set a crossover, but since i didn't have experience in running cables down the length of a car and ripping apart and re-building interiors and shit, i didn't get the job.

=/

 

[Nebulous]

Haha, cheers man.

 

[johnny dove]

my live sound teacher at school told us that the amp should have more power than the speakers, same as live sound.
i mean, you pretty much want headroom in everything so it all works without getting overloaded.

 

[Notuern]

Caraudio guys fill the trunk with subs, and then they put like 2 broadband speakers in the front and krank the bass all the way up and thinks it sounds good.
So I would def. go with the pro dudes.

 

[Meisterjäger]

I have a pretty monster syetm in my car. I have a 1000w monoblock FLI amp powering 2x 12" Sony subs rated at 1200w each, so that 1000w amp is powering 2400w of speakers. Sounds fine to me, never broken in about 4 years, either, but the subs can distort if you push it too hard. On the flip side, my head unit is a 4x 50w Kenwood unit, powering 2x 30w Panasonic component speakers in my door, and 2x 120w Infinity Kappa 6x9's, so I have my head unit overpowering my components, and once again, nothing's ever broken. Apart from my hearing, of course...

Doesn't seem to follow the rules I'm used to when it comes to audio, but it does work, and this is all recommendations from car audio guys I know, so in fairness, it's not cool to paint them all as useless. I've had more guitar amps and seen more PA's blow than I have car stereos.

 

[if6was9]

Wow, I would have never paired my speakers with an amp that can overpower them- I just wouldn't know at what stage I was doing damage- everything could be green and running distortion free and then break.
I've always ran my speakers with an amp equal or just less than what they were rated at so if its not hitting the red I can't be doing damage. I've never blown a speaker like this but obviously there's been tons of times where i would have loved more power. Am I right in saying that if i'm running an amp paired rating wise correctly with my speakers at full but in the green close to being "in the red" but not hitting red ever, then i'm getting the very most out of my speakers without doing damage,
If I understand correctly if you pair the speakers with an amp overpowering the speakers then past the point where I'm running them with the other amp power wise, you'll be doing damage and they'll eventually blow out from running like this