During my quest for achieving reference playback in my own home theatre, I have found 5 important areas, which I call the 5 Pillars of Reference Playback. These first appeared in the below form in v4 of Secrets of Audyssey, but they are also relevant for YPAO, Dirac Live and all other Room Correction algorithms. They are…
- Room Setup
- Room interactions and how they affect reference playback
- How to treat a room appropriately so these effects are reduced
- How you can position your listening space within a room for the most ideal sound quality
- Speaker Setup
- Speakers have dispersion characteristics which determine how they will interact with the room
- Speaker placement will depend on these characteristics as well as other performance characteristics
- Aiming speakers correctly while keeping these characteristics in mind can improve the sound
- De-coupling speakers from the room means that the amplifier energy is put into driving the speakers, and not resonating your room or the objects in it.
- Amplification
- Speaker efficiency and the load speakers put on an amplifier (including the ones in your AVR) will have a major effect on sound reproduction including distortion, driver control, tonal response, etc.
- Distortion can affect the perceived tonal balance and perceived loudness of the sound, which can limit the maximum EQ curve you can apply and the maximum volume you can achieve without listener fatigue.
- Content Mastering
- Content is mastered at different volume levels and in difference spaces, both of which affect the tonal balance of the recording / mix.
- You need to understand the basics of this so that you can apply the correct EQ curve to the recording – either with Dynamic EQ or with a house curve if you so wish.
- Calibration
- Measurement hygiene is critical if you want to achieve a great sound
- The microphone pattern you choose can determine the imaging, tonal balance, seat to seat variability and surround steering precision you get from Audyssey.
- What you do after calibration to set the receiver up also matters, including levels, crossovers, front to back balance, Dynamic EQ, Dynamic Volume, Midrange Compensation, and so on.
I have discussed these pillars on the high level in different articles over the years, so I wanted to create this overview article that links to them. While I discuss all these pillars in Secrets of Audyssey in detail, you can get started by reading the articles on the site. I have also included an excerpt from the introduction chapter to Secrets of Audyssey at the end of this article with the included diagrams. You can use these to get started in your quest to achieve reference playback with Audyssey.
Articles
| Pillar | Relevant Articles |
| Speaker Setup | Configuring Audyssey – The Right Way What crossovers to choose for your speakers How High to Position Your Surround Speakers for Best Results |
| Room Setup | Configuring Audyssey – The Right Way Why Audyssey Sounds Best with Room Treatment |
| Amplification | Do You Need an External Power Amp for Your AVR? |
| Content Mastering | Loudness Compensation and Yamaha YPAO Volume – intro to Loudness Compensation Audyssey Dynamic EQ and Dynamic Volume are Your Friends |
| Calibration | Configuring Audyssey – The Right Way Failsafe Audyssey Settings Audyssey Settings for Gaming Ideas for Using MultEQ-X to Improve Audyssey Performance My Audyssey Settings per Input Audyssey Midrange Compensation – On or Off? – Denon and Marantz Receivers How to Get Disney+ to Sound Great with Audyssey and Yamaha YPAO The Big Problem with “House Curves” – Points to Dirac Live but also relevant for Audyssey if you are using or thinking of using a house curve. |
The following sections are taken word for word from the introductory chapter to Secrets of Audyssey
What We Mean by Reference
While later on we will cover mastering of different content types, let’s briefly cover what reference playback means. In simple term, reference playback means playing the recorded content with the correct tonal and surround balance according to the original recording intent.
While doing my research, I have found 5 pillars of achieving reference playback and getting well-balanced sound both tonally and spatially.
Once all of these pillars are addressed, all content will play to reference with the correct Audyssey settings discussed later in this guide, and also recommended by Audyssey.
If these pillars are not addressed, tonal and spatial balance will suffer – especially with movies as movies use very aggressive tonal curves due to their original recording volume and dynamic range.
We will discuss these 5 pillars in detail throughout this guide, however, the following diagram and this first chapter is meant to give you an overview – or a map as you will, that will help you navigate this guide effectively.
I would recommend you refer to this chapter and included diagram throughout your Audyssey journey.
Reference Level Offset (RLO)
Audyssey Dynamic EQ has a setting called Reference Level Offset (RLO) which allows us to lower the assumed recording volume from movie reference (85dB) in case that is needed for certain content.
While we will discuss this feature at length, RLO is mentioned a lot in this chapter from the get-go as a way to compensate for deficiencies in setup or content mastering.
If you are new to Audyssey and the science of Loudness, RLO will not make sense yet. However, we will build up this knowledge in stages and by the end of the guide, it will make perfect sense.
For now, ignore any references to RLO and come back to re- read this chapter as your knowledge builds.
The 5 Pillars of Reference Playback
1. Room Setup
While Audyssey is a great room correction solution, there are certain issues that Audyssey is not designed to solve – such as reverberation in the mid- and high-frequencies colouring the sound. Unfortunately, such issues can make Audyssey sound harsh without the right room treatment.
Audyssey’s answer to user requests to resolve this issue and provide more configurability resulted in the Audyssey app which allows users to tailor the correction curve or turn off correction above a certain frequency – normally 500Hz – so the mid- and high frequencies are not corrected at all.
Unfortunately, neither is a great solution. The first option gets us further away from reference – although it is starting to get the right idea. The second option is basically giving up on trying to solve the issue at all – throwing in the proverbial towel.
So what is the root cause of the issue? Mid- and high frequencies will build up and cause (psycho)acoustic issues in untreated rooms. That is, the reverberation time / ringing out for mid and high frequencies is so long in untreated rooms that the brain will interpret this as too much energy in the the affected frequency bands.
Audyssey designed its algorithm to take into consideration the ideal reverberation time (RT60) and its equivalent in smaller spaces.
So it would seem that Audyssey is taking a set time-window for measuring the effect of RT60 within a room. Unfortunately, this isn’t configurable either manually or automatically when setting up Audyssey. While – it is my understanding that – there were plans to look at this issue, and improve on it, this never got looked at.
Therefore, the only way to get around this issue is to use appropriate room treatment to lower RT60. How to do this is described in Chapter 2 of this guide in detail.
Please note that room treatment is NOT OPTIONAL with Audyssey if you want to get great sound. I promise that the hard work will be worth it however.
2. Speaker Setup
Audyssey is particularly sensitive to speakers not being aimed correctly or not being fully decoupled from the room and furniture.
Incorrect speaker setup can therefore result in room interactions that will affect speech intelligibility, tonal balance and surround steering.
While Audyssey is not as sensitive to unideal subwoofer placement as for example Yamaha or even Pioneer, you can get a marked improvement in sound quality by following the subwoofer placement recommendations in this guide.
3. Amplification
There are two main issues with amplification:
- The “voicing” of the receiver’s internal amps, for exampleto sound more “forward”
- The lack of amplifier power – whether continuous ordynamic – to drive the speakers without distortion and without losing control of the speaker drivers, which can create an uneven tonal balance as
volume is increased.
If you have hard to drive speakers, such as 4ohm and / or under 90dB efficiency, you need to consider external amplification – especially if you want to play content at higher volumes.
If you have tried everything else in this guide, and you are still not getting distortion-free sound at higher volumes, you need to consider external amplification. Until I did so, I blamed Audyssey for some of the distortion I was hearing.
For me personally, external amplification was the final piece of the puzzle that I needed to solve before I could use an RLO of 0 for (95% of) movies and still get excellent sound at higher volumes.
4. Content Mastering
The volume and the space content is mastered in will greatly affect the tonal balance of the mix. This is because our hearing is not linear across the frequency spectrum and is affected by volume. In addition, the space affects the tonal balance due to acoustical issues.
To get around our non-linear hearing, the ISO 226 standards (latest is ISO 226:2003) specified the equal loudness contours which tell us the exact equalisation that needs to be applied when listening below the mastering volume.
This is why content mastering is so critical: we need to understand how a particular content was mastered for us to be able to apply the correct loudness compensation curve.
To help us with this, Audyssey has a feature called Dynamic EQ which can be configured with the Reference Level Offset.
We will therefore dedicate a whole chapter on Loudness Compensation and Content Mastering and another chapter on the use of Dynamic EQ and its Reference Level Offset configuration.
5. Audyssey Calibration
Calibration issues with Audyssey can also interfere with the sound resulting in issues with imaging, frequency response, surround steering, speaker delay issues and speaker volume issues – such as when the surround volumes are too high.
It isn’t simply enough to use the correct mic pattern, although that can help, it is also important to follow best practice when it comes to microphone placement and “measurement hygiene” suggestions described within this guide.
Additionally, there are some post- calibration checks that you should perform which I will also walk you through.
Should you hit any problems, the Troubleshooting section of this guide will walk you thought the steps to troubleshoot each issue in detail.
With this in mind, run the calibration as many times as it’s going to take to get a great sounding system – each time adjusting the positions
ever so slightly or perfecting getting it as close to the guide as possible. Audyssey needs precision and it may not work to just run it once. Run it, configure settings and listen. Repeat if not satisfied!
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