Many Yamaha amplifiers can cost you around $499 or higher.
I assume you are talking about a surround sound system, they have the cheap ones at walmart for about 100 dollars. They just get more expensive from there though.
Alpine, Kenwood and Kicker are good brands of car audio amplifiers. You can go to a local Bestbuy or custom car shop to see what is available in your area as well as listen and compare the sound from test units that are set up in store.
Hifonics amplifiers can be purchased on Amazon at the price of $95.90. Other website such as Online Car Stereo offers more expensive options in the range of $150-$200.
Around 130 or 140 is normal for most everyday amplifiers. But stereos in car shows and competitions can gain up to 180 db. This is usually done with very expensive equipment.
The brand of musical instrument amplifiers that are considered the best are the ones mass produced by Dre Dre, they are his special and loud expensive headphones dr dre beats.
Naim amplifiers are very expensive high end equipment. This is not going to be found at general department store or electronics stores. Stereophile magazine lists dealers. Watkins Stereo and Engineering can order this brand.
The M6i integrated amplifier is the best rated amplifier made by Fidelity Amplifiers. However, this is also one of their more expensive models and the cheaper models are all rated fairly high as well.
Two brands of home stereo amplifiers include McIntosh and Yamaha amplifiers. Other brands that also include home amplifiers are Atlona, Russound, Onkyo, Bose, and Pyle amplifiers.
The most used instrument amplifiers are also some of the most popular amplifiers namely Marshall, Crate and Fox amplifiers. The impedance of these amplifiers does not need to match making it perfect for instrument use.
The positive feed amplifiers are called regenerative because they increase the gain of the amplifiers.
One can purchase phone amplifiers at many electronic stores. Best Buy has a good selection of amplifiers to choose from. Most of these amplifiers are backed by a 90 day warranty.