Dirac Live® is a room acoustic solution that enables users to measure and optimize their sound systems to their preferences and reduces sound colorations introduced by the room. Dirac Live® has two features: room correction, included with every software package, and bass control, an add-on feature available as separate purchase. This is one of the main features in Dirac Live’s room correction software and enables Dirac Live to deliver impressive room correction. There's a look-ahead buffer that enables impulse response correction. In addition, minimum-phase and linear-phase room correction filters can’t physically optimise the acoustic impulse response in a room. The sub integration was included in the Room Perfect system from the beginning, it is a hardware and software solution. Big board, as large as some Class D amps, with circuitry. The Room Perfect system has evolved, was 96k/24. Has been 192K/24 for a while. Processing power on board has been increased. Dirac Live does not run using an onscreen display like room correction systems of old. Instead, you use your smartphone, tablet or PC to run the room correction software. This allows significantly more computational power, and the calibration is partly performed in the cloud for additional compute horsepower. With Dirac, you can make the frequency response just how you like it. ARC doesn't measure speaker distance, you have to manually enter it and the resolution is limited to ≥1ft. Dirac sets the distance measurements for each speaker in milliseconds. Dirac runs on windows and mac, whereas ARC is windows only. ARC does not provide any eq above 5Khz.
Summary
- Product Name: Dirac Live Room Correction
- Manufacturer: Dirac
- Review Date:February 13, 2018 00:00
- MSRP: $449.48 (2 channel), $751.06 (8 channel)
- First Impression: Gotta Have It!
Executive Overview
In equalization circles, Dirac Live has been making waves recently with their Dirac Live Room Correction software. It has already been integrated into high-end processors such as Datasat and Theta Digital, as well as luxury automotive sound systems from Rolls Royce, Bentley, and BMW. On a more affordable front, MiniDSP and Emotiva have incorporated Dirac Live into their upper-tier processors as well. In the crowded field of room correction equalization that includes sophisticated programs such as Audyssey, Pioneer’s MCACC, and Yamaha’s YPAO, what is all hubbub about with Dirac Live?
One of Dirac Live’s strongest attributes is that it approaches correction from not just an amplitude response domain but also the time domain. Many room correction equalizers measure the frequency response at a number of positions and then alter the output of the processor to fit a target curve as best as possible by simply boosting or cutting energy in regions in the measured response. This approach can only be consistently successful if the phase of the system’s response were either minimum (usually only at low frequencies only) or entirely linear, or to put that in simpler terms, that approach can only be successful if all of the outputted sound frequencies have the same respective time arrival as when it was produced. In a typical acoustic environment, this is not possible, and conventional loudspeaker design can add further impediments towards this end as well. The frequencies of the signal emitted by the processor do not all arrive at the listener at the same time; much of these frequencies arrive at the listener as a collection of acoustic reflections coming from all of the surfaces near the loudspeaker, and these reflections can cancel out or sum up with the direct sound from the speaker. These cancellations and summations can degrade the integrity of the signal.
By ignoring the time domain, conventional equalization routines can fail to address the causes of an erratic frequency response, and they can even make the overall sound quality worse by distorting important phase relationships between speakers. Changing the arrival of sound in a frequency band from one speaker in a stereo pair by just a few milliseconds can have substantial effects on the imaging and soundstage. A complete reparation of the signal in any normal listening situation involves attention paid to the time domain as well as the amplitude response domain. Dirac Live approaches the time domain by using filters to tame irregularities in the early-reflection time arrival in sound at the measured positions. While lateral early reflections have been shown to be beneficial, front and rear early reflections can be problematic. Dirac Live does not address late-reflections since they are too position-dependent to address well via processing. Late-reflections can add a sense of spaciousness, but those who do want to rid themselves of late-reflections are advised to use acoustic treatments for that goal. .
Dirac Live works by analyzing measurements made with a microphone at multiple positions clustered around the main listening position. It then finds and corrects issues in the time domain that were common in all measurements. Reflective acoustic energy can be significantly reduced in favor of direct sound, and this can give the end sound much greater clarity and less coloration. After the decay times have been reduced, Dirac Live then goes to work on the frequency response to shore up problems without damaging time domain corrections. The result is a flatter response across all listening positions with far quicker decay times.
It’s a complicated process with extremely heavy-duty mathematics involved, but the good news for the end user is that this software is very easy to use and has a simple interface. Simply select your system configuration and listening situation, and take some measurements. Dirac Live does the rest, intuitively guiding the user through the process. The next generation of Dirac Live is due to launch in Q1 of 2018 and supposedly makes this process even smoother.
How Do you Get Dirac Live?
Dirac Live can come with some pre-existing hardware like the Datasat or Emotiva processors, or you can buy it as a software package for Windows or Mac PCs direct from Dirac’s website. The software package allows you to use your computer as the audio processor. It comes in two parts: a calibration tool and a processor controller. As the names suggest, the calibration tool takes the measurements and creates correction filters, while the processor controller applies the filters to sound output from the PC. The user can store any number of filters for any situation. The processor controller interface allows four different filter sets to be loaded at a time for instant switching between them. Dirac Live doesn’t just correct for room acoustics- You can equalize the response to your own taste and make your own target curves.
As a software package, Dirac Live is available in two versions: a two-channel version for stereo systems and a more expensive eight-channel version for surround sound systems. Those who want to see the software’s benefits before taking the plunge can try a trial version that does have a time limitation. Owners of the existing Dirac Live version will be able to receive the next generation of Dirac Live as a free upgrade. In addition to the easier-to-use interface that is more mobile-device friendly, the upcoming second generation will have support for multiple languages, and a new algorithm with improved analysis of stereo speaker pairs. Dirac Live is not the least expensive software solution at approximately $450 for the two-channel package and $750 for the eight-channel package, but it’s considered by many to be the most cutting-edge room correction program available. Considering the cost and time of the many tweaks and accessories that many audiophiles end up investing in, the potential for improvement that Dirac Live offers looks like a bargain for the price.
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Recent Forum Posts:
ryanosaur, post: 1381523, member: 86393
Is that corrected or not? Do you have a measurement that's just the MLP?
This was not corrected. I’m using a different bass management today compared to the graph. Since I’m waiting on upgrade of my NAD and planning to do some acoustic improvements I wait with taking new measurements.
But will check if I have measurement from MLP with today’s set up
1= MLP
2= 20 cm behind , 20cm to the right
3= 20 cm behind , 20cm to the left
4= 20 cm in front, 20cm to the left
5= 20 cm in front, 20cm to the right
35160
So about 250hz is my SF.?.
Niklasmagnus, post: 1381500, member: 89047This is the not-so-scientific way of identifying the Schroeder Frequency.
What do you mean with the comment in bold text, Im not following?
A room response chart will show a lot more peaks and dips below the Schroeder Frequency (where the room is behaving as a resonant chamber) and will smooth out above that point.
Just as an easy example, lets use the post above from AVUser… Don't look at the bright line, but the darker… and assume please that that is the untreated measurement.
You can see large swings from peak to dip up to (in that graph) ~130Hz. After that point, the graph smooths out.
Likewise, look at the graphed example in this link:
http://www.acousticfrontiers.com/2012314the-schroeder-transition-frequency-explained-html/
You can see their example.
Also, a good read is the associated Sound & Vision articles, linked directly here:
https://www.soundandvision.com/content/schroeder-frequency-show-and-tell-part-1
AVUser001, post: 1381504, member: 90312
Like I said, you can shape the curve the way you want! That was my initial iteration with a wip 2 channel system with the default target curve. Once I naturally treat the room, lets see how the amplitute response looks like and repeat the eq process as needed.
Yes I do like a slight boost (think most do) in that region…
Here's another example, I just boosted the 30-60hz you mentioned..
being able to shape the curves to your own taste …think about it ;-)
35157
Optimise your room's acoustics
When it comes to setting up a sound system, the biggest impact to the audio quality comes from the room itself. No matter how good or expensive the equipment, a challenging environment can result in poor sound quality.
There are numerous methods of mitigating a room's negative effects, from optimal speaker and subwoofer placement, to using absorption panels, diffusers and bass traps. There's no doubt that carefully installing speakers and subs in the best locations will help eliminate certain room issues, but using panels and diffusers can get expensive and intrusive.
These days the most effective way of addressing the impact of a room is to use some form of room correction software, and one of the most popular is Dirac Live. This particular system has been licensed by numerous mid-range and high-end manufacturers and integrated into their products. These companies include Arcam, Emotiva, Datasat, Focal, Monoprice, miniDSP, NAD, Rotel, Storm Audio, Wisdom Audio, JBL Synthesis, and Thetal Digital.
What versions of Dirac Live are there?
There are two variants of Dirac Live aimed at two different markets: one for the home market; and another for the professional audio market. Both versions share the same Dirac Live room correction calibration tool, with the key difference being that the professional audio/studio version includes an audio plugin, and therefore does not require compatible hardware to store and apply the filters like the home version does.
The version of Dirac Live aimed at home audio market currently has two key features: Room Correction and Bass Control. For both of these features there are tiered offers, leading to variations in Dirac Live's capabilities. For example, when using the room correction feature, end users can choose to upgrade from limited frequency range correction (Limited) to full frequency range correction (Full). For the bass control feature, end users can choose to upgrade from single subwoofer bass management (Limited) to multiple subwoofer bass management (Full).
What does Dirac Live seek to achieve?
Dirac Live aims to enable users to customise their acoustic experience, ensuring that their sound system performs at its best with minimum impact from the listening environment.
Dirac believes that the reproduction of transients is critical for a truly natural and transparent sound. For example, the stereo image is critically dependent on the time-domain differences and similarities between the sound at the left ear and the right ear. As such, Dirac Live's impulse response correction improves the depth, the positioning and distinction of individual voices and instruments.
How Dirac Live basically works:
The end user installs software on their PC or smartphone (available on Windows, MacOS, Android and iOS) to connect to a Dirac Live-capable system over a network. They then follow the on-screen instructions, allowing them to perform the set up procedures, which include selecting the device, selecting the recording device (including any calibration file for the microphone), setting the calibration volume, selecting the speaker arrangement, taking the actual measurements, designing the filters, and exporting them to the device to create the desired sound.
Measure: The user takes measurements of the room and the audio systems with a microphone (either provided with the device or bought from a third-party) by following the instructions in the Dirac Live calibration software. Dirac Live uses several measurement positions (typically 9) in the listening room, making it possible to accurately locate and correct acoustic problems. These measurements are presented in a clear and easy to interpret graphical interface.
In terms of the impulse response, this means optimisation of the direct wave and very early reflections. Generally, at higher frequencies there is less consistent time-domain behavior. Dirac Live room correction automatically finds consistent problems in a frequency-dependent way and corrects for them. After addressing consistent time-domain behavior, there may still be some late reverberation in the room that causes subtle colouration. Dirac Live corrects these in the frequency domain to achieve just the right resolution.
Filter design: The user then adjusts and sets the desired frequency response using the breakpoints and target curve feature. However, the user doesn't have to do anything with impulse response correction, because that is carried out automatically. The software can show the measurements before and after the application of the filter, either for each individual speaker and subwoofer or all together as a system.
Why is it that the same frequency response can sound so different from room to room? The answer lies to a large extent in the time-domain aspects of the measured frequency response, as well as critical differences in the spatial (angular) domain. By addressing time-domain problems as such, and not as minimum-phase spectral problems, frequency response correction becomes more effective. After conducting time-domain correction, Dirac Live treats the spectral colourations in a room. By paying particular attention to the variations across different measurement positions – not just the average – Dirac Live makes sure not to overcompensate.
A loudspeaker’s impulse response affects clarity, detail and all spatial aspects of the sound. Dirac Live corrects the impulse response throughout the listening area, not just at a single point. By focusing on consistent problems across the measurement positions and correcting only these anomalies, Dirac Live can achieve a faster decay time. Typically, the power ratio between the direct wave and the tail (later-arriving echoes) is improved by 6 dB or more, representing a vastly improved overall sound.
A flat frequency response does not necessarily sound neutral due to the ratio between direct and reverberant sound and the frequency-variable propagation loss. Dirac Live can’t remove late reflections, because they change too much between different positions. Therefore, a slight roll-off is often appropriate when listening at a distance. The Dirac Live algorithm suggests a target response appropriate for your listening environment and speakers, which you can of course adjust to your taste using the simple graphical interface.
Export filter: The user then exports the filter they have created into the compatible hardware or audio plugin.
Apply the filter: The filter is then applied to the audio signal via the hardware (Dirac Live for Home) or audio plugin (Dirac Live for Studio), and adjusts the frequency and impulse responses to eliminate the more egregious aspects of the room.
The beauty of Dirac Live is that you don’t have to be a signal processing or computer expert to enjoy its benefits. All of the measurements, processing and correction is automatically managed by the audio calibration software, making it easy for all kinds of users. All you to do is position the microphone and press “Play” – the software wizard will take care of the rest. Advanced users are free to edit the target response as desired using a simple graphical interface. Otherwise, just press “Optimise” for immediate results.
What’s Bass Control and how does it basically works?
Dirac calls this feature Bass Control, instead of bass management, because it is fundamentally different from simple bass management. The Dirac Live bass control feature works by co-optimising all the speakers and subwoofers in the same system. The speakers, subwoofers and the room are all regarded as a complete system.
To ensure that the system’s bass reproduction is accurate, and the performance is the same at all locations in the room, it aligns the phase between the speakers in correlation. In technical terms, Dirac Live Bass Control reduces the spatial variability of the frequency response in the lower frequencies when more than one subwoofer is available. It also reduces any out-of-phase behaviour between paired speakers in a frequency band around the crossover point. The Bass Control also reduces out of phase behaviour between the full-range speakers and subwoofer(s) in a frequency band around the crossover point.
What makes Dirac Live different from the competition?
Dirac Room Acoustics Software
Dirac Live room correction uses mixed phase technology with advanced impulse response and phase correction. This is one of the main features in Dirac Live’s room correction software and enables Dirac Live to deliver impressive room correction.
There's a look-ahead buffer that enables impulse response correction. In addition, minimum-phase and linear-phase room correction filters can’t physically optimise the acoustic impulse response in a room. At best, they can minimise problems caused by the application of a filter. Room-acoustic responses are non-minimum-phase, which is why Dirac Live uses mixed-phase correction.
Most other room correction systems use minimum-phase, which means they try not to add any time-domain distortion, whereas Dirac Live actually reduces time-domain distortion. Mixed phase technology enables Dirac Live to address some of the key room acoustic problems other solutions struggle to address efficiently. The results are audible in terms of imaging, clarity and bass tightness.
For in depth knowledge about the mixed phase approach, you can read an article written by Dr. Mathias Johansson, CEO and co founder of Dirac.
Traditional EQ systems use IIR (infinite impulse response) filters for the lowest processor usage, and many room correction filters use FIR (finite impulse response) for ease of implementation and sound optimisation. IIR and FIR filters both have their pros and cons. Dirac Live uses a proprietary filter structure that achieves maximum performance at much less processor usage than regular FIR filters. This filter structure also has improved numerical properties, so it doesn’t produce any digital noise, and thus achieves enhanced sound optimisation.
Dirac Room Acoustics Software Type 7841
It is also worth to mentioning that although Dirac Live is sophisticated and delivers a high level of performance, it is very easy to run with its intuitive user interface, visual filter design feature and step-by-step guide. This, together with its leading performance and capability, makes Dirac Live attractive to many processor and receiver manufacturers. It also makes it a great choice for consumers of any kind, whether they're AV enthusiasts or average users.