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Dirac Live Room Correction Offers Sophisticated Calibration and Set Up

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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!
  • Buy Now

Executive Overview

In equalization circles, Dirac Live has been making waves recently with their Dirac Live Room Correction software. It hDiracLiveexample_calibration2.jpgas 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.

DiracLiveImpulse_responses.jpgBy 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.

Dirac_Calibration2.jpg        DiracLivetarget_curve.jpg

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?

DiraDiracLivefilter_shape.jpgc 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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About the author:

James Larson is Audioholics' primary loudspeaker and subwoofer reviewer on account of his deep knowledge of loudspeaker functioning and performance and also his overall enthusiasm toward moving the state of audio science forward.

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Recent Forum Posts:

andy_c posts on March 29, 2018 17:57
Schrodinger23, post: 1234019, member: 81322
Do you have a reference for this? I’d like to see the specific target curve that Harman’s research has found sounds best.

Here's a link to the document in question.
shadyJ posts on March 29, 2018 15:59
Kenco278, post: 1240212, member: 85310
Thanks for pointing that out, I had no idea I could use my computer as a preamp. You piqued my interest so I’m going to look into it. All the best.
You will need a flexible pro-audio sound interface in order to do that. Onboard PC sound cards will not do the trick.
Kenco278 posts on March 29, 2018 08:52
Thanks for pointing that out, I had no idea I could use my computer as a preamp. You piqued my interest so I’m going to look into it. All the best.
shadyJ posts on March 27, 2018 00:48
Kenco278, post: 1239626, member: 85310
Hi and thanks for an interesting review. Based on your description, this software only works with audio files stored on or streamed through a computer since the filters are not only created but also applied in the computer. Is this right? If so it won’t have any effect on audio from CDs, Blu-ray discs, vinyl etc., so it sounds like it would be better (a more complete solution) to have a pre-amp that can receive and apply the filters.
That's correct, although there are some pre-amps that have Dirac onboard too. If you want to use Dirac for outboard sources on your computer, you have to use your computer as a pre-amp, and that is do-able, with the right sound interface.
Kenco278 posts on March 25, 2018 17:21
Hi and thanks for an interesting review. Based on your description, this software only works with audio files stored on or streamed through a computer since the filters are not only created but also applied in the computer. Is this right? If so it won’t have any effect on audio from CDs, Blu-ray discs, vinyl etc., so it sounds like it would be better (a more complete solution) to have a pre-amp that can receive and apply the filters.
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