How to Choose an Amplifier for Home Theater (7 Factors)

If you’re building a home theater, you’ll probably need to invest in several devices for your sound system. This article is here to serve as a guide to make better and well-informed decisions. Here’s how to choose an amplifier for home theater.

For any willing buyer in the market looking for a great amplifier, here’s a list of specifications that you need to consider before buying an amplifier:

  1. Rated output power
  2. Frequency response
  3. Noise 
  4. Distortion
  5. Style (design)
  6. Size
  7. Price
How to Choose an Amplifier for Home Theater (7 Factors) 1

 Manufacturers usually give a list of specs or specifications that products have. This article will provide more information on this list, what these specifications mean and what they should mean to you as a buyer.

Be sure to keep reading for more information. Also read, Does an Amplifier Improve Sound Quality?

As an affiliate, I may collect a share of sales or other compensation from the links on this page.

How To Choose An Amplifier For Home Theater

As brought out earlier, the choice of amplifiers for home theater should be based on the following factors:-

1. Rated Output Power of the Amplifier

Rated output power is also known as power rating. It refers to the highest input of power that any electrical device such as an amplifier can allow to flow through itself. 

The power output in an amp is measured using a unit of value known as watts. From an engineering and design perspective:

watts = voltage x amps

Why do you need power in your amp? It would be best if you had the power to allow your amp to push the signals to the speakers. Before giving a concrete number, it’s best to understand a couple of things about power rating. 

Power rating is excellent because it allows you to know how much power your amp can take. Amps do not use or generate the same amount of power. Some amps will generate more, and others will generate less. 

The power rating, on the other hand, is done according to watts per channel. With this value, you can approximate how much power will go to the speakers. The channels refer to the speakers in this case. 

The ideal power rating in watts per channel would be between 50 and 100 watts. A higher power rating does not mean that the amp will produce a louder sound. It doesn’t work like that.

Whether you have an amp with a power rating of over 100 watts, it won’t change the speakers’ volume. 

So be sure to keep that in mind. 

2. Frequency response

The frequency response shows how the added gain in the amp responds to input signals that the amp transmits at different frequencies. The ideal amp should have a frequency response of 20 Hz to 20 kHz within a reasonable tolerance.

Many new amps will usually skip this range.

Some amps can have a frequency response from 5 Hz to 200 kHz. It’s prevalent in the industry.  

3. Noise 

As long as there are vibrations, there’s a high probability that the amp will generate noise. A good amp will have features and hardware that help in noise reduction. 

Noise will also be a problem if you’re using high-efficiency loudspeakers. It is inevitable. Experts divide noise specification in two ways:

  • Weighted noise
  • Unweighted noise

Weighted noise will take the human ear and its reaction to noise. Especially the ear’s sensitivity in different parts of the frequency spectrum

Unweighted noise will for an amp be over a total 20-kHz bandwidth or more. 

Experts recommend the A-weighted noise specification. The A-weighted noise specification has noise-reducing measurements. An excellent amplifier might have an unweighted signal-to-noise ratio (S/N) of 90 dB or an A-weighted signal-to-noise ratio (S/N) of 105 dB. 

4. Distortion

Distortion refers to the unwanted conversions that the amp generates. The most common distortion specification is the total harmonic distortion (THD). A good 100-Watt amplifier might have a 1-kHz THD. 

How do you know your amp is generating a distorted signal? A signal will always start as a pure signal. The pure signal will have a single frequency component that can either be positive or negative.

These positive and negative components will always be at a similar amount. If the component variation is less than the complete 360⁰ cycle, it’s safe to say that the amp is generating a distorted signal. 

5. Style

Different amps will come in different shapes, sizes, and finishes. It depends on the following factors:

  •  what type of amp do you want
  •  which of your needs you would like the amp to satisfy
  • what size of amp do you want 

Once you have answered these questions, you can now comfortably determine the type of style you want from your amplifier. Manufacturers make amps in the following ways:

  • bipolar transistors
  •  field-effect transistors 
  • Thermionic valves/vacuum tubes
  • Operational amplifiers

Types Of Amplifiers

Amplifiers use the term Amplifier Classes to differentiate between them. Why? Amps do so many different things that they differentiate them from one another in terms of specifications. 

Experts then divide the amplifier classes into two:

  • The classically controlled conduction angle amplifiers
  • The switching amplifier 

The classically controlled amps consist of the following classes:

  • Class A 
  • Class B
  • Class AB
  • Class C

The switching amps consist of the following classes: 

  • Class D
  • Class E
  • Class F
  • Class G
  • Class S
  • Class T

You can use amps in a variety of ways, depending on their functions. The switching amps are the newer amps that use digital signals. The best part about digital signals is that they cannot get easily distorted during transmission. 

As a buyer in the market, experts recommend looking at Class AB amps. With Class AB amps, you get most of the specs listed above for your home theater. Class A amps are the best in the business overall. It’s also an excellent class to start with if you’re new to sound systems. 

The only problem with Class A amps is that they are the least efficient of the bunch. 

However, they provide listeners with the highest sound fidelity, which is essentially what many consumers are looking for when it comes to buying an amp. 

Nevertheless, be sure to do thorough research on the amp classes before purchasing amps. This way, you can know which amp class will satisfy your needs without trading off any critical factors you want from an amp. 

Regardless, home theater experts recommend class AB. 

6. Size

Again, this factor all comes down to what needs you want your amp to satisfy. The amplifier market has multiple amps in various sizes. For your home theater, you want an amp that checks every or most of the boxes on your list, and sometimes, size plays a huge factor. 

Depending on where your channels or objects will be in place in your three-dimensional space, you want an amp whose size won’t impede on the general layout of the sound system.

7. Price

Last but not least on this list is price. When you’re building a home theater, you will have to spend a bit of money to get your desired elements into your theater. They will be a bit pricey if you want a good amp, probably at $1000 heading towards $2000. Most amps for home theaters start at that specific price point. 

However, an amp is an investment in your home theater. It’s a component of your sound system that you should not take lightly. It will change the entire dynamic of your home theater. 

picking the best amplifier can be challenging

Honorable mentions:

Dolby Atmos and DTX:S 

The newer amps in the industry will come with Dolby Atmos or DTX:S support. The surround sound that these audio formats provide to users is incredible. They changed the entire surround sound industry and have become the new staple for sound engineers worldwide. 

So if you’re in the market and want something new and something blue, be sure to check if the amp comes with these audio format supports. Experts in the field will turn to these audio formats because they’re currently the best in what they do. 

There is the issue of whether these new upgrades are worth it. These new audio formats (Dolby Atmos and DTX:S) are the future. Dolby Atmos scraped off the concept of sound channels and replaced it with a mathematically correct and proven new standard. 

So yes, these audio formats are a significant investment and worth consideration if you’re in the market for an amplifier.

However, buying an amp for your home theater might be an arduous path without the proper knowledge and skill. It would be best to list down what you want from an amp to narrow down which amp is the best for your home theater. 

Home theaters are on the rise right now, and there’s a lot of information in books and online on which amps will satisfy your needs as a consumer. It will also be a good idea to consult a professional if you need further assistance. 

A professional may be a tad bit expensive. However, they will provide you with the necessary tips and tricks to ensure that your home theater is on par. 

Lastly, amps will not completely satisfy all the conditions or factors shared above. You will need to point out which factors are the most important to you and go from there. Some tradeoffs are worth it, and some aren’t. It’s up to you to make that decision for your home theater. 

Amplifiers For Home Theater FAQs

1. Do you need an amplifier for a home theater system?

Unfortunately, no. You don’t usually need an amp for your home theater system. However, they are a great addition to your system, and with current advancements in technology, they provide a unique immersive experience with the correct audio formats. 

2. Which things should I consider for a home theater before buying it? 

It would be best if you considered a good number of things for a home theater. Here are some considerations: soundproofing, audio formats, receivers, amps, subwoofers, the size of the room, etc. Home theaters take a lot of time, effort, and money. It would help if you had the proper planning to execute it flawlessly. 

3. Is an AV receiver different from an amp?

Yes, an AV receiver is different from an amp because it has a built-in radio section. 

Sources

1.Bob Cordell, Designing Audio Power Amplifiers (New York: McGraw Hill, 2010) 640.

2.Cambridge Audio, Amplifier, or Receiver – Which Should I Choose? Cambridge Audio, https://www.cambridgeaudio.com/usa/en/blog/amplifier-or-receiver-which-should-i-choose

3.Electronics Tutorial, Introduction to the Amplifiers, Electronics Tutorial, https://www.electronics-tutorials.ws/amplifier/amp_1.html

4.Electronics Tutorial, Amplifier Classes, Electronics Tutorial, https://www.electronics-tutorials.ws/amplifier/amplifier-classes.html

5.Theater Seat Store, Home Theater Amplifiers: The Ultimate Guide for Newbies, Theatre Seat Store, https://www.theaterseatstore.com/blog/home-theater-amplifier

6.Gary Altunian, What Is Total Harmonic Distortion (THD)? Life Wire, https://www.lifewire.com/total-harmonic-distortion-3134704