To add to this train of thought... I don't understand 50wpc X 4 backed up with 2000w of sub reproducing 80hz and below. Don'cha think that might just be a wee bit unbalanced? There is more to sound reproduction then the sub-audible.

 

Ah yes, this too. Or even more crazy is using 2 15" subs in a car our size.
My home stereo speakers have a 15" passive radiator in each cabinet and that supplies enough bass to move anything sitting on flat surface anywhere in house.
The bigger the sub the more space you need. The sine wave on a 15" sub is so long that most of the bass being produced can't even be heard inside the car.
More of the bass is heard inside someones house than in the car. You guys who know about this stuff know what I mean.
And you are right Steve, the bass is so poorly matched it drowns out most of the highs and mids where all of the important articulate sounds come from.

Honestly unless you are competing you never need anything close to 2000w. You can get a great sounding high efficiency sub that can get plenty loud on as little as 200w.

The problem is a few years back all the car audio manufactures decided to start exadurating specs and making people think the more watts the better and slapped 2000w ratings amps that likely couldn't hit 300 watts before reaching 20% or more distortion. Its pretty hard to get people past that whole mindset. I remember when I first got into car audio the 2 systems that impressed me most. One was a system that use 3 JL 8W0's in a sealed enclosure on about 300 watts behind the rear seat of a quad cab truck it sounded amazingly clean extremely tight and still got loud enough to hurt my ears! The second was a system using a 12" sub can't recall the brand but it was being run by a 200w old school PPI amp and that thing got stupid loud!

Old school, yeah baby. PPI was kick-ass brand back in the day.
My car audio gear is a/d/s. I am privileged enough to have the PX series speakers and the PQ amps. This stuff can't 'slam' but if you want crazy stupid loud with ZERO distortion, well then...

 

Honestly unless you are competing you never need anything close to 2000w. You can get a great sounding high efficiency sub that can get plenty loud on as little as 200w.

The problem is a few years back all the car audio manufactures decided to start exadurating specs and making people think the more watts the better and slapped 2000w ratings amps that likely couldn't hit 300 watts before reaching 20% or more distortion. Its pretty hard to get people past that whole mindset. I remember when I first got into car audio the 2 systems that impressed me most. One was a system that use 3 JL 8W0's in a sealed enclosure on about 300 watts behind the rear seat of a quad cab truck it sounded amazingly clean extremely tight and still got loud enough to hurt my ears! The second was a system using a 12" sub can't recall the brand but it was being run by a 200w old school PPI amp and that thing got stupid loud!

 

I do it for the extra headroom.

Like you mentioned about your home stereo, the amps have plenty of power to give, but if you never reach that maximum or push towards that maximum they'll run cooler and more efficient. Plus you can really crank it should the mood suit you and not worry about reaching the limits of your equipment.

I run a 2-way active front stage in my car, 2x32.5 to the tweeters, 2x180 to the mids, and 1x850 to the sub. I very rarely play it uncomfortably loud, but it's nice to know that I have the extra headroom if I wanted to.

 

Except that generally 300 to 500 watts is plenty of headroom for a car.as long as you don't use some insane sub that needs 1k watts to even move. Like I said you can easily get uncomfortably loud with not a lot of power.

We haven't even really hit on the damage that can be caused by taxing your electrical system to the extremes.

 

I understand what you're saying. But then again you have to look at the music that people listen to when you see those 1000w systems, there's not much point other than to rattle everything within 50 feet.

 

 

Living room stereo ratings do not directly compare to car audio ratings in terms of wattage.
I did the car audio thing way back in high school so my memory is a bit fuzzy, but the impedance levels between the two are usually different (since home audio has a high voltage/ low current source while car audio has a low voltage/ high current? source). I think car speakers are usually lower impedance which demand more from the amplifiers so the wattage ratings used to sell them will be higher than a home system of similar performance.

After going with some pretty insane setups (enough to justify upgrading the alternator on a cadillac), I settled down with a single sealed 10 Rockford Fosgate Power paired with whatever JL amp was the bee's knees at the time.

 

Wattage is volts times amps (W=VxA). Think of volts as pressure, amps as volume of flow and watts as total amount of work being done. Power amplifiers that run off of household current have 120 volts at their disposal. Internal rail voltages can be anywhere from 40vdc or higher. Power amps for cars only get about 14 vdc to work with so they employ a different strategy. In order to get more work done (more watts) they need to increase volts or amps. They are limited when it comes to voltage so to increase amps they reduce impedance (A=V/R). This is why you see 8 ohm house speakers and 4 ohm car speakers. Also why you see car subwoofer speaker impedances of 2 ohm or lower. The lower the resistance the more amps will flow at a given voltage thus more wattage or more work being done.

The way they measure wattage for rating audio amplifiers is an entire essay of information.

 

Correct.
I'm going to use my home stereo as example again along with my a/d/s stuff. (And yes I understand home audio gear and car audio different, but the basic function is the same between the two)
The lower the impedance the more 'headroom' or available clean power is needed.
My home stereo speakers are sitting at 4.5 ohms (I have the Polk Audio SDA SRS speakers) and with those speakers hooked to my amplifiers, the amps are already working almost twice as hard as a normal 8 ohm speaker. The system gets extremely loud but my amplifiers can't run anything below 2 ohms before having difficulty supplying enough power. This is where low ohm stable and headroom comes in.
Now my a/d/s car audio amps can run continuously at 1 ohm load and still have plenty of headroom left to rachet the volume knob up some extra clicks.
And with the a/d/s amps hooked up to all 4 ohm speakers, the amps are at their sweet spot.

And why is it there's not a standard to measure a amplifiers rating / performance values? The way these companies try to snow over the customer is almost criminal.

This is a fairly vague statement and can't be used soley as a bar of measurement but, figure anything at $10 and above per watt, the heavier the amp the better it's going to be and the higher the number of output transistors the better.

I'm not 100% sure but If I remember correctly my a/d/s amps have 40 power output transistors on the heatsink rail.

 

Essay and also not a standard at all, they all do it differently and each method has different results.

 

Well heavier = better isn't always the case. Most of the weight of an amplifier is in the heatsink and I've seen plenty of crap amps that are very heavy lol.

 

Most of the weight of an amplifier is in the heatsink

With 120v amps it's usually the transformer in the power supply. Some of those things are like lifting a stack of bricks. It's one big hunk of steel and copper.

Another way to get around the 14vdc limit of automobile power is to employ a power inverter section. A power inverter can take in the low voltage and bump it up to a higher voltage. Then the rail voltages could be whatever the designers want them to be. This adds a whole extra layer of parts and design to the device or in other words, it costs them more to make. I don't know how common this is in your typical car power amplifier.

 

I think Soundstream did this with their pure class A amps. DC input voltage, convert to AC voltage and then back to DC voltage.

 

I've always done 1500w and above, why? extra headroom. I did compete and I like to listen to music while driving. I'm a Sound quality guy and not a bass guy. I have more power in my front stage than my subs: 150 x 2 - tweeters, 150 x 2 - midrange, 300 x 2 midbass, and 500 x 1 for single 12" sub or 1000 x 1 for 2 subs..

 

It was a long time ago, but iirc when I was going through my audio installer/technician course it was explained that wattage isnt really a factor unless at liw volume. Higher wattage will produce a fuller sound at lower volumes, and remain clear and crisp through the range.

now granted, the components need to be set up properly. You cant run a 1000w amp on a 200w speaker and expect it to last.

When you use same sizes of speakers, we'll talk subs, its just easier. A properly powered 12" 200w sub will match the decibel output of a 1000w 12" sub to a certain degree. That degree is usually the comfort zone of most people. With assloads of power, you will still produce the same amount of soynd, it will just move more air. This gives tge misconception of a louder output as your ear drums are actually matching the sine wave from the speaker when the air is forcefully moved around you. Its actually some pretty scientific stuff just to make your trunk fart lol

 

Sound quality really has very little to do with watts...... I've heard amp rated at only 10watts or so that completely out perform amps of several hundred watts per channel. In fact my favorite car audio sq amps are Zuki amps which are hand built. He rates them at their lowest distortion which is usually like 5w or so but really they do so much more than that, amazing sound quality though and prices are reasonable.

Watts really matter almost 0, its just a number that people associate with power output even though that's not always the truth either.

 

Thats not what I said/meant. More wattage makes the sound more robust at low volumes, simply because the power output is directly related to the input level multiplied by the staged power in the amp. I cant remember the formula off the top of my head, google will help with that. With more power, there is more capability to move the speaket. More movement from the speaker, more sine waves created thus making a fuller sound.

im very familiar with zuki, and I own 4 monolith amps that im saving for a special project. Those amps are single channel, rated at 3.6w... but yet they can drive a w3 with ease.

 

^
So true.
I have listened to pure class A rated amps at 50 watts that will absolutely blow the doors off of most every other amp that's out there.
These amps will also heat up what ever room your in like a raging campfire would.
They'll set you back a measly $10k - Oh yeah, and you need two of them cause they're mono amps. $20k :icon_eek: And that doesn't even include the pre-amp.

 

They'll set you back a measly $10k - Oh yeah, and you need two of them cause they're mono amps. $20k :icon_eek: And that doesn't even include the pre-amp.

Almost as much as a googlephonic system with a moon-rock needle.

 

I've got a (ballparky) 1000 watts in my car. I like to be able to hear my music while I'm driving down the freeway with the windows and sunroof open. In the neighborhood I turn it down, so back off.

Anyway, I have decent components and you need solid power to make it sound good at high volumes.