Where are these settings applicable and what effect do they have on your high-end Home Theatre and HiFi systems?
Multi-use, multichannel audio systems are definitely in the ascendancy.
People are spending more time in their homes due to government restriction imposed by COVID-19 and are putting much more value in having quality home entertainment systems.
The industry is reacting with more content coming in popular immersive audio formats such as; Dolby Atmos, DTS:X and Auro 3D. This content is leading to the convergence of these once separate systems into one high performance audiophile system.
Whether your content comes from streaming media like; Tidal, Qobuz, Netflix, Amazon Prime Video or via physical media by way of good old fashioned Blu-ray disc you can get the best of both worlds. Therefore the ability to have different configurations and distinct tunings for different content becomes a top priority for a lot of customers. It’s down to your AV Processor or AV Receiver to offer this functionality.
In this document we will delve deeper into some of the more advanced features available to users.
Trinnov’s Optimizer is used in the most demanding applications in over 7000 worldwide installations not only in High End Residential but Pro Audio and Commercial Cinema’s.
At Trinnov Audio we pride ourselves on giving our users and integrators the flexibility to tune the system the way they want by providing the information and the options to make informed decisions.
Most automated room correction systems just give you what they think will yield the best results with little or no option to change parameters to suit your taste or need. You may get to see a frequency response graph and adjust a target curve but that’s really not the whole story.
Having the ability to change the underlying parameters related to algorithms both to see and to hear the consequences of those actions is essential. It is also what makes the Trinnov Optimizer unique and widely regarded as the most advanced digital room correction solution on the market.
In this short article, we will be discussing some of the parameters available to help optimize the system for both movie and music playback.
Music & Movies
There is no reason why a well-designed and well-implemented multi-channel audio system should not be able to reproduce both music and movie media effectively. It may take thought and planning, but it is very achievable. After all, the aim of a good audio system is to recreate the content faithfully and in the way the artist or director intended. This is true for both music and movie content (although there may be somewhat different emphases in each).
We find that movie content is much less subjective as it’s not so much about the way you prefer the sound as it’s about recreating the content and giving it the impact and clarity required to really draw you in. Of course, if you like it bass-heavy or slightly soft in the high frequencies, these preferences may be accommodated within the final calibration.
With Hifi there is an overwhelming bias towards your personal taste and the way you want to hear or believe that content should be heard. This may be partly due to the relative lack of standardization in music production as compared to movie production. But, for whatever reason, one’s musical preferences can be quite personal. Being able to support those two potentially very different scenarios in one system is most definitely a challenge.
Available Tools
Trinnov’s Optimizer has a number of different tools available to you to allow you to create such a dual-purpose system.
One simple example: we have up to 29 presets that can be recalled on the fly. These presets can include any number of different changes and can effectively reconfigure the entire system on the fly, as required.
Digging in a bit deeper, we get to features like Target Curves which change the behavior of the filters and corrections applied to the measured room and speaker responses in order to influence the sound towards the way you want to hear it. For example, you could have four different presets that contain the same measurements, but have different target curves to suit your taste for; Classical, Jazz, Rock, or Electronic music.
It’s very common just to have two presets, one for movies and one for music, but the possibilities are really only limited by the (rather large) number of presets we can store.
These presets can be automatically recalled when you select a source. As an example, you could have the system switch to a preset for a pure 2 channel mode when you select the Roon Ready input and a full multichannel immersive setup when watching a film on your Blu-ray player or Kaleidescape server.
Furthermore, with support for all the major home automation platforms like; Crestron, Control 4, Savant, RTI and Elan, this can be deeply integrated into logic-based programming to commit many changes as part of a 1 button push macro.
There may be instances where maintaining the natural in-room response of a speaker is preferred. For example, you might have invested a significant sum in getting your dream L&R speakers, installed just so, and simply love the way you have managed to get them to sound. But, even in this case, it is unlikely that the rest of your speakers match this dream performance of your Left and Right to any meaningful degree.
We can create a better experience by building on the best parts of the speakers and the room, while also addressing those areas where the sound can be improved. Trinnov’s Optimizer takes this approach by measuring the direct sound of the speaker, the early reflected sound, and the overall energy response in the room using our patented 3D microphone.
The Optimizer then addresses these varied performance characteristics separately, each in its optimal way. We also address the time domain by correcting Impulse Response, Phase, and (as a mathematical consequence) Group Delay.
This means that we can maintain the natural response of the speaker while correcting a lot of the unfavorable interactions that the speaker itself and the room add to the overall listening experience.
Digital Room Correction and DSP are often seen as removing the natural sound from a given speaker. This is particularly the view in HiFi where the thought is that the purity of speakers’ sound should not be interfered with. This is an understandable point of view but in our previous article Does Room Correction remove Loudspeakers Characteristics we discuss the effects of digital correction on your loudspeaker. I invite you to read this article to alleviate the concerns you may have about digital correction and to better understand its potential.
Digital Room Correction is most often associated with Frequency Response but we can still have a dramatic effect on the sound with minimal or no correction in this area. For this, Trinnov’s Optimizer offers a couple of options that I would like to explain in a bit more detail.
According to L&R
“According to L&R” is a correction option that can be chosen from the Optimizer Settings Menu. The function of this mode is to measure the Frequency Response (including the room’s effects) of the Left and Right speakers and to take the average of those two readings.
The Optimizer then applies this average response as the target curve for the system. This mode actually improves the stereo imaging by providing a superior match between Left and Right speakers (obviating small differences potentially introduced by asymmetries in the room, for example).
In this way, it retains the initial tonal balance of the Left and Right speakers while also compensating for phase issues. It can also compensate for low-frequency problems introduced by the room.
“According to L&R” achieves what many people are looking for: compensating for the room’s problems at low frequencies while doing relatively little above the Schröeder frequency, all while still time-aligning the speakers.
Depending on your settings, this new Target Curve (derived from L&R) can be applied just to the stereo pair, or to all channels of a multichannel audio system.
This is a powerful option, but it’s extremely dependent on getting a good measurement. Of course, any correction is only as good as the measurements taken but what I mean by this is that you have to use your common sense and look at the graphs and make sure there are no outside influences affecting your frequency response measurement as this will influence the final correction.
As an example: if a train went by or the air conditioning fires up right after the measurement of the Left speaker, it will be captured when the Right speaker is measured. Of course, this is an extreme example. But this “extra bass” is going to show up in the frequency response graph and will adversely influence the average response of the Left and Right speakers and ultimately affect the correction applied. This is true for a multichannel measurement, but it’s even more influential in this scenario where the average of the two measurements is applied as correction.
You can see from the graph above that the Right speaker (blue line) has a null at 2kHz and this is causing the correction to the Left (green line) speaker to mimic it. This is clearly a room issue rather than a speaker issue, so you may want to move the listening position, mic, or speaker, and re-measure the system to avoid this over-correction being detrimental to the final result.
Excursion Curve
The Excursion Curve is simply another option where you can tell the Optimizer how aggressive it may be, as a function of frequency.
As an example, you could define a window between 20-500Hz within which significant corrections are allowed. What Trinnov Optimizer does differently than other systems is allows you to add points to the excursion curve, so you can decide how much or how little you want it correct across the frequency range.
This creates a tailored approach when you can put limits on any given frequency or band of frequencies to apply the desired amount of correction. This is achieved by telling the system how much boost and attenuation you want at those given points.
All of this is done whilst protecting your speakers. The Optimizer measures and determines the bandwidth of your speakers and won’t apply correction outside of that. This can be seen in the Summary page in the Optimizer Settings menu. So even if you request the Optimizer add +10db at 50Hz, as an example, if your speaker isn’t capable of producing this frequency we won’t push it to do something it can not do and risk damage.
In the graphs below you can see we are allowing a maximum ±10dB boost and attenuation between 20-150Hz and after then a gentle narrowing down to ±2dB between 150-500Hz and maintain that ±2dB correction from 500Hz to 24kHz.
This is a great example of how the Optimizer allows you to tailor the frequency response correction above and below the Schröeder frequency, allowing the high frequencies to remain relatively untouched while addressing the larger issues inflicted by the room on the speaker below 500Hz.
As you can see in the graph above we don’t have the same issue at 2kHz on the Left speaker as the speakers are corrected independently when using this method. I’m not saying that you may not want to address this, but it’s just a good illustration of how the two modes work differently on the same measured response.
Conclusion
In conclusion, creating combined Home Theatre and Hifi systems is possible but requires more than just good speakers and good electronics.
There are lots of options when it comes to digital room correction and not all are created equally.
Trinnov, as always, offers you more options and flexibility than anyone else. These options really allow you to create the best HiFi and Home Theatre systems for your customer to achieve the customized audio system they desire.
Both “According to L&R” and the Excursion Curve are easy to use, powerful, and produce great results.
Importantly, they can be applied, saved, and recalled as presets to set up different listening modes for Movies and Music.