Why are home amps so small and expensive?

[Wicks]

Correct me if I am wrong: but don't the home amps have to convert the 120vac into dc power to they can use it? While a car already has dc going in?

Correct, any amplifier needs its own specific power rails to feed the transistors/MOSFETs.

Therefore it would need to rectify the 120VAC from your wall and convert it to DC.

Depending on the level of DC required, it may go through a step-down transformer (more equipment needed internally).

Some home amps use a linear power supply, whereas car amps use a switching power supply. Linear power supplies require a large and heavy transformer (expensive).

[kingoftroy]

If you are looking at home theater receivers a lot of it has to do with internal processing for audio and video. Look at any current A/V receiver and all the inputs and outputs for video and sound. Plus like stated before quality. Very low distortion levels and usually better built comparing a $900 home theater receiver to a $900 car audio amp the receiver will normally last longer.

[GreenSpade]

I haven't seen anyone mention that most home audio amps are class A or B so that the audio QUALITY is higher due to less actual amplification, the more amplification you use inside of your amp (The more juice you get out of it through energy convertion to gain more power from less power) the more you'll hear distortion. This means that for Studio monitors you'll use class A or B (less likely B ) due there being no distortion due to there being next to nothing for power amplification inside of the amp.

Class A

100% of the input signal is used (conduction angle Θ = 360° or 2π); i.e., the active element remains conducting[6] (works in its "linear" range) all of the time. Where efficiency is not a consideration, most small signal linear amplifiers are designed as class A. Class-A amplifiers are typically more linear and less complex than other types, but are very inefficient. This type of amplifier is most commonly used in small-signal stages or for low-power applications (such as driving headphones). Subclass A2 is sometimes used to refer to vacuum-tube class-A stages where the grid is allowed to be driven slightly positive on signal peaks, resulting in slightly more power than normal class A (A1; where the grid is always negative[7]), but incurring more distortion.

Class B

50% of the input signal is used (Θ = 180° or π; i.e., the active element works in its linear range half of the time and is more or less turned off for the other half). In most class B, there are two output devices (or sets of output devices), each of which conducts alternately (push–pull) for exactly 180° (or half cycle) of the input signal; selective RF amplifiers can also be implemented using a single active element.

These amplifiers are subject to crossover distortion if the transition from one active element to the other is not perfect, as when two complementary transistors (i.e., one PNP, one NPN) are connected as two emitter followers with their base and emitter terminals in common, requiring the base voltage to slew across the region where both devices are turned off.[8]

Shortly put: the power that goes in, is more or less what gets sent to your speakers, with no gain in wattage, but with no loss of quality.

Now car audio... is all about ~EFFICIENCY~ *NOT* Quality. Thats how you can take something like your car battory and actually power these "aparently high" wattage amps. I say aparently cuz they're all 2ohm/4ohm, so your looking at ratings that're off anyways. Most Car audio are going to be class D, or if you spend the xtra bit you may have a class C or a hybred a/b (if you really lay down the money that is) But like I said, most are class D

Class C

Less than 50% of the input signal is used (conduction angle Θ < 180°). The advantage is potentially high efficiency, but a disadvantage is high distortion.

Class D

Main article: Switching amplifier

These use switching to achieve a very high power efficiency (more than 90% in modern designs). By allowing each output device to be either fully on or off, losses are minimized. The analog output is created by pulse-width modulation; i.e., the active element is switched on for shorter or longer intervals instead of modifying its resistance. There are more complicated switching schemes like sigma-delta modulation, to improve some performance aspects like lower distortions or better efficiency.

Additional classes

There are several other amplifier classes, although they are mainly variations of the previous classes. For example, class-G and class-H amplifiers are marked by variation of the supply rails (in discrete steps or in a continuous fashion, respectively) following the input signal. Wasted heat on the output devices can be reduced as excess voltage is kept to a minimum. The amplifier that is fed with these rails itself can be of any class. These kinds of amplifiers are more complex, and are mainly used for specialized applications, such as very high-power units. Also, class-E and class-F amplifiers are commonly described in literature for radio-frequency applications where efficiency of the traditional classes is important, yet several aspects deviate substantially from their ideal values. These classes use harmonic tuning of their output networks to achieve higher efficiency and can be considered a subset of class C due to their conduction-angle characteristics.

Shortly put: you get alot more power but you loose out on quality due to the distortion of amplifying that orginal power.

Home audio and Studio audio both use class A power, so they're going to be made of much higher quality parts and be "seemingly" low in wattage and thats why they cost so much, cuz they're trying to get the most power they can, WITHOUT distorting the signal by adding xtra hardware to increase the efficiency.

So the price is for quality. Where the cheaper car audio amps you see with their "seemingly" high wattage, are really just highly efficient amps made of much cheaper and lower quality parts. As a result you get cheaper amps, with "seemingly" more wattage, but with alot of distortion.. Cuz you'll prob be playing music and not notice it anyways, its all about being loud, getting the most power, NOT about the most sound quality, car audio has always been like this, thats why so many Pro-Audio guys bash on car audio gear and also why car audio guys can't figure out why the PA gear sounds better when "on paper" it has less wattage, but its at 2ohm or 4ohm verse a 8ohm or a 4ohm. Car audio is the largest sacrifice of quality for more efficiency out of any audio gear you can buy out there, thats why its so cheap when you compare it to things like Home audio, Pro Audio or Studio audio.

Home audio they assume your going to watch movies and things where things will be quite.. you'll hear everything.. It MUST NOT have distortion cuz you'll notice it FAST.

Car audio they assume your going to have music blasting the whole time and you won't notice the fact your music is distorted due to the amount of efficiency required to make all that run off something like your car battery. Trying to make more out of less power and thus your distortion goes up and your quality goes down.

Hope this clears something up for someone.

[CstrokerV]

http://emotiva.com/xpa1.shtm my home sub amp i want lol expensive and big lol http://emotiva.com/xpa5.shtm and my 5 channel i want not to bad price but big... need to find a 7 channel though

[Omega5002]

Think another reason why Home amps are more expensive is cause they have their own regulated power source to plug in the wall while a car amp has the car's battery. A decent 20 amp 120v ac to 13.8v dc converter is at least $60, and that can only handle 276 watt rms, the ones with higher amps are way more expensive.

[bass28]

my home amp is a tis audio 1800 watt car amp hooked to my xbox originals power supply.just saying

Do u have to ran through a power inverter?

[Miguels]

we used to have 2 amps 1 was 2000 watts the other was 1200 dj amp and the breakers would give out everytime, so no point on getting bigger if you have to go and and mess with breakers

[kirill007]

look at the powe the rockford fosgate t15k makes at 8ohm. Not even 400w. And thats a 25,000 dollar amp. I have a older home power amp with pre amp that puts out 320w at 8ohms, the power amp alone without pre amp weighs about 60pounds i believe.(although its a bit older thats one of the reasons it that heavy)

It sounds great while delivering great sound quality.

You dont have the same dynamics in a car amp.

They are more expensive because there are more things in a home audio amp. And they use expensive converters(¿), there a lot more differences then that. Google would easily help you..

[BobbyG2]

Something no one mentioned, for subs. In car audio you make up for size restraints with higher power. In home audio space is less of an issue, so you have more sensitive speakers due to larger enclosures.