As tech writer Andrew Robinson has noted, AV receivers lag aesthetically in the new golden age of design and technology. That is so well put. As a novice, you may wonder why an audiophile would purchase one when there are more elegant, compact options, like soundbars, on the market? It turns out that this big ugly box packs a ton of power and features.

AV receivers are so big (and ugly) because they use a ton of power and host many features. Without their oversized frames and topside vents, an AV receiver’s task load would cause it to overheat. The bulky design allows you to position your receiver in a well-ventilated area and keep up routine maintenance.

Read on to learn what is inside an AV receiver and how to keep it from overheating.

What’s Inside That Big Black Box?

If you thought an AV receiver was full of a lot of hot air, you would only be partially right. AV receivers generate a lot of heat, but that is because the features they support are bountiful. If they were more compact, that hot air would have nowhere to go.

Furthermore, an AV receiver is the stage manager of your home theater. It manages a vast assortment of devices. But if it were small, where would you plug everything?

And finally, one of the more important features besides longevity: buttons. Your AV receiver has a UI or user interface that allows you to operate the darn thing. This interface requires controls and a display on the front panel.

Let’s break this down in more detail.


One of the AV receiver’s most essential responsibilities is amplifying your speakers. And not just a couple of speakers. AV receivers power at least five speakers and a subwoofer. Bigger home theaters require a receiver that supports seven speakers and a subwoofer.

But speakers cannot produce sound on their own; they need power from an AV receiver. Receivers do the work to move the drivers of a speaker. These drivers include tweeters, woofers, and mid-range.

It is possible to utilize a system with separate components. Separating your audio system into a preamp and an amp creates the best sound quality. However, that can be a lot of extra pieces for a home theater. AV receivers provide the convenience of including an amplifier and preamplifier in the same package. That’s already a lot for one box.

The wattage required to power a home theater speaker system is relatively subjective. Factors like room size, speaker system quality, and the type of media consumed make a massive difference in how much power you need. Manufacturers often include too much wattage to justify a higher price point. Even worse, they will condense the number of transformers to accommodate the wattage while price-cutting in quality.

In reality, receivers equipped with one transformer for each speaker channel produce better sound. So if you want the best sound, that big black box needs to house at least six separate transformers. That’s a lot of space already!

Lots of power will generate lots of heat, which is why receivers have vents at the top of the system. They allow the hot air to rise through the vents, keeping the system from overheating. That requires even more space!

Lots of Features

Amplification is only one process going on inside of that receiver. The codec programming decodes how sounds get distributed in a surround sound speaker system. Plus, most units also come equipped with Bluetooth and wireless connectivity. And then there are the many speakers and devices that get plugged into the AV receiver.

To see more on this, review the Onkyo section of this AV receiver roundup.

As you can see, there are ports for speaker systems, a port for a radio tuner, six HDMI inputs, two HDMI outputs, digital audio connections, an ethernet port, and a USB port. And that’s not all! An AV receiver decodes and transfers the sound data from all these devices to the correct speakers. And keep in mind, they are powering and amplifying your speaker system at the same time.

User Interface

The workload and tasklist of an AV receiver are truly impressive. But how do you, the user, navigate all of this. Features alone cannot make up for complicated operations. User interfaces present and translate the functions of your receiver, so you know what you are doing. A straightforward UI makes the setup and navigation of your receiver much simpler.

What does a user interface include? Buttons to start. These buttons control simple tasks like switching sound sources and more complex functions like equalizing the sound or calibrating your room. A UI display tells you what you are doing. Some have a simple LCD, while others include a full-color display. There are even AV receivers that use your television as a UI display. Additionally, receiver UIs include remote controls.

That user interface needs front panel space. Think practically: would you enjoy navigating a tiny display screen with buttons crammed too close together? No. Ironically, while an AV receiver may seem like an eye-sore, in this case, its size is a smart design choice.

How to Keep Your Receiver From Overheating

Now that you understand how much an AV receiver does, you can see that possible overheating is a huge concern. Let’s talk about how to avoid that. Below, we will talk about the considerations one should make to keep their receivers cool.


As mentioned earlier, AV receivers generate a lot of heat. That means where and how you position the receiver can inhibit heat travel if you are not mindful. Make sure you do not place your receiver anywhere near another source of heat, like a radiator. Additionally, give the receiver space to vent. Even though large rectangular boxes are often stackable, never stack your electronics on top of each other or place your receiver in a cramped drawer.

How you position your receiver also makes a difference. That is why you should always follow manufacturer instructions when you install your receiver. As a rule of thumb, the vents should be facing up. If you decide to position the receiver on its side, and the side has no vents, the hot air will get trapped in the unit.


Accommodating for adequate ventilation gives heat a path of travel. Positioning solves some of these problems. The furniture you use to house the receiver can also help or inhibit travel. Make sure to buy ventilated cabinets for your electronics. Additionally, you can also install bottom and top fans to encourage heat flow out of the receiver. Just be careful that you are not voiding the manufacturer’s warranty when doing so.


Lastly, like any electronics, proper maintenance will extend the lifetime of your receiver. It is best to dust your unit at least once a month with an air duster and a damp microfiber cloth. Dust traps heat, so neglecting dust build-up is a clear path to overheating.

However, besides preventing malfunction, dusting your receiver will make it run quieter, especially if you installed a fan system.

Final Thoughts

In short, AV receivers are so big (and ugly for now) because they house a lot of power and features. The best models accommodate enough amplification power and transformers to drive your speaker system. Secondly, they sport a lot of features and connect multiple devices. Lastly, the front panel needs to fit a functional, user-friendly interface. These functions and power generate heat that needs a place to travel, which could not happen if the receiver was too compact.