av receiver boy yelling

Did you know that you’re missing out on the best sound your home theatre system can give you? (Without leaving your home or spending a cent.)

Well… you might be, if you’re not taking advantage of your AV receiver’s room correction tools.

Read on to discover… 

  • What “room correction” is and how it works.
  • How to use it (and what you need).
  • When you need to manually adjust things (and how to do that).


  • What Is Room Correction?
  • How Does Room Correction Work?
  • Do The Acoustics Of My Room Matter?
  • When Do I Need To Adjust My Receiver Manually?

What is Room Correction

The technology has many names: Room correction. Microphone calibration. Automatic EQ. Acoustic setup.

All of these mean the same thing:

  • You first set up a microphone in your room. Put it where your main listening position is (ideally at head level).
  • Then while keeping everything as quiet as possible you press START. The AV receiver plays a “test tone” out of each speaker in your surround sound system. The microphone records how each test tone sounds.
  • The receiver uses those readings to adjust the response of each speaker.

Plugging in your new home theater system and hitting play won’t give you the best performance. Your new equipment is capable of much more. Manufacturers design, test and build it to sound amazing in a neutral room. (“Neutral” means the surfaces in the room don’t resonate or dampen the sound coming from the speakers.)

That’s where room correction comes in.

This technology gives audio companies the ability to give users the best sound quality their product can provide, regardless of wonky room acoustics.

That’s why you find it on every recently produced AV receiver (at least, that I know of). Each brand has its own version of this same tech. Denon and Marantz have Audyssey. Yamaha uses YPAO. Bose calls theirs ADAPTiQ.

And so on.

This microphone calibration process is one of the first things you do when you fire up your new receiver. You can skip it and come back later… but it’s usually a good idea to knock it out right away.

Your room needs to be quiet during room correction

If there are any sounds during the test tones, your system will adjust the sound poorly.

I have a little story to illustrate…

One Wednesday I’m talking to a client on the phone and, he’s having a tough time figuring out why his system sounds bad. It was a brand new surround sound system… something had to be wrong. But what?

He said the bass was non-existent and the rest of the sound was distorted. We spoke for an hour and I couldn’t think of any solutions.

So I pay him a visit to investigate. After a lot of troubleshooting, it turned out… an airplane was flying overhead when he did his microphone calibration!!

Or in other words, running a new calibration process with silence fixed his issues right up.

Make sure children, pets, airplanes, trains, parades, blenders and the rest of it pipe down during the test tone process!

AV Receiver

How Does Room Correction Work

how does room correction work

Room correction systems play a test tone through each speaker of your surround sound system, and record the audio in the room using a microphone.

The system “knows” what the test tone should sound like… so the difference between the test tone and the recording is caused by your room’s acoustics.

Each speaker is adjusted to compensate for that difference.

What does room correction adjust?

Two main things are adjusted: volume and frequency response (lows and highs).

Volume gets adjusted to compensate for different size speakers and different distances.

An example: if you have one surround back speaker that’s further away than the other, your AV receiver will automatically adjust them so you hear the same volume from each one. (At the location of the microphone. So you want it to be placed where your listening position is.)

Frequency response gets adjusted to compensate for resonance in your room.

(Resonance is when a particular frequency of sound is boosted by reflecting off a surface. That adds unwanted sound to the mix, causing distortion.)

Imagine you have a huge floor-to-ceiling window near your system. The big panes of glass will boost high frequencies and cause distortion… until you run the calibration process and those frequencies are turned down in relative to the rest. That gives the more balanced sound that’s intended.

There may be other parameters that get adjusted by these microphone systems — like crossover points, which help prevent boomy bass — but volume and frequency are the main ones.

Above: This graph shows a frequency response that’s full of “peaks” and “dips” in grey. It’s an example of what a ‘rough’ room might look like. Then in green is another line which is much tighter. This line is more true to the intended sound — i.e. the test tone.

Do The Acoustics Of My Room Matter?

room accoustics

The room correction system does the best it can to make your system sound great. But… your room’s acoustics still matter.

Room correction can’t fix everything

The system can turn certain frequencies down to compensate for additive distortion, but it struggles to compensate for dips. (Dips are when surfaces in your room absorb sound, which keeps you from hearing them as they’re meant to be.)

There are designer acoustic panels, in-wall treatments, and DIY soundproofing options out there. They tend to be time consuming and expensive.

There’s good news though… there are some inexpensive tricks of the trade you can use to fix most of your acoustic issues.

To discover the secrets read Room Acoustics: Does Your Room Sound Terrible?

When Do I Need To Adjust My Receiver Manually?

For the most part, the room correction systems that come with AV receivers are on point. They do the job right and let you sit back and enjoy.

But there are times when they don’t quite nail it.

That’s why I usually recommend testing your AV receiver’s room correction. After you’ve run the test tones and allowed it to adjust everything, you can switch it on and off. It might be worth trying this just to make sure.

Why wouldn’t the room correction system work?

For one, sound quality can be very subjective. The individual listener might like a certain frequency to be boosted or drawn back. Running the test will help you find a sound that you love.

Two… the room acoustics could be difficult to compensate for. (See the previous section about room acoustics.) If there are dips that the system can’t account for by changing the sound, it may be better to adjust nothing.

How you can test your room correction

Run through the 5-10 minute calibration process on your receiver. That will create the new “EQ” that adjusts based on your room.

Then put on a song that you know and love. I recommend listening to the whole thing so your ears get used to the sound.

Next, jump into your receiver’s settings and switch the automatic EQ off. Play that same exact song again.

Whichever test sounded better is the go. (You can often tell within 5 seconds which you prefer.)

If you can’t tell the difference… I recommend keeping the calibration ON. The reason being, it may help with frequencies that weren’t in your song.

How to adjust things manually

When you don’t use the automatic room correction, you may still have speakers at different distances… or one frequency that’s obviously too strong.

This is when you want to tweak things yourself. Dive into the sound menus of your AV receiver and look for manual EQ (or similar).

There is a “levels” control (volume). Use that to get equal loudness in your listening position from all speakers.

Usually there are also a bunch of sliders that represent different frequencies. You can pull certain frequencies up or down to adjust them.

If your bass is boomy or overwhelming… try adjusting in the lower range (250 or 500 Hz are good places to start). If things are too “bright” and harsh, try pulling down the higher frequencies (like 16 kHz).

The name of the game here is experiment. If something is clearly not right, hop into the menus and make some changes. Listen… and change again if needed.

Just keep in mind… your goal isn’t to “create” a new sound that’s better than normal. Your system is designed to sound right as is. Your goal is instead to compensate for imperfections in the setup or room.

Thanks for reading! If you have any other questions, contact us here.

To learn more, check out these related articles…

Room Acoustics: Does Your Room Sound Terrible?

What AV Receiver Should I Buy For Home Theatre?

Where Should I Put My Rear Surround Speakers?