What is the difference between Class D and Class AB amplifiers?
Class D and Class AB are two amplifier technologies. The main differences are how the amplifier operates, how efficiently it uses power and how much heat it generates.
Both technologies can provide very good sound quality, but have different characteristics.
What is a Class D amplifier?
Class D uses switching amplifier technology with high efficiency. This means a large proportion of the supplied electrical energy can drive the speakers instead of being converted into heat.
Advantages of Class D:
High efficiency and relatively low heat generation.
Often a more compact design.
Can deliver high power without requiring such large heatsinks.
Common in both monoblock and multichannel amplifiers.
Class D is particularly popular in powerful car audio systems where high output and efficient power consumption matter, but it does not guarantee cool operation. Class D can also overheat under heavy loads, with insufficient ventilation or with power supply problems. Follow the model’s load, cooling and installation requirements.
What is a Class AB amplifier?
Class AB is a traditional analogue amplifier technology that has long been used in both car and home audio.
Advantages of Class AB:
Well-established amplifier technology.
Can offer very good sound quality.
Available in many power ratings and designs.
Class AB generally has lower efficiency than Class D. More energy is converted into heat, often requiring larger heatsinks.
Which amplifier class sounds best?
Sound quality cannot be determined from amplifier class alone.
Older Class D designs sometimes had limitations in sound reproduction, but modern Class D amplifiers can offer very high sound quality and are also used in advanced audio systems.
A well-designed Class D amplifier can therefore sound better than a simpler Class AB amplifier, and vice versa.
Which class should I choose?
Class D is often a good choice if you prioritise high power, compact size and efficient power consumption.
Class AB can still be a good option if you want a traditional amplifier for your speakers.
The most important thing is to choose an amplifier with the right power, features and quality for your audio system, rather than focusing solely on amplifier class.
Need help choosing the right amplifier? Contact our customer service team or visit one of our stores for advice.