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Article: Dirac Live 2 Digital Room Correction Software Walkthrough

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18 hours ago, digitaldufferme said:

Complete noob here and was fascinated by your article! You have corrected your sound without the subs connected I believe. I have a 2.2 system (KEF LS50 & REL T9i) how would I do this as I believe the subs have a massive effect on the room sound? I use ROON ROCK on a NUK8i7.


Yes, I did not have the subs connected, but the the little Purifi's have solid output below 30 Hz. But my Rythmik dual F18's go down to 6 Hz in my room. How is your 2.2 system connected? Is it Y cabling or ?

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10 hours ago, blue2 said:

Thanks for another great article! $349 sounds reasonable but what about a trial/evaluation to find out what it can do for my room+system? Do you know if that's available? I can't find anything on the Dirac web site.

Thanks! From: https://www.dirac.com/faq-general it looks the free trial is 14 days. Perhaps @flak can confirm...

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16 hours ago, monteverdi said:

Thanks for your response, Toole and also in a similar version Geddes are proposing to use multiple subwoofers spaced over the room to allow wider zones of bass correction (with specific phase corrections). I wonder if that is something Dirac can do and if that leads to a significant improvement compared to standard 2 woofers/subwoofers? Of course that adds a lot of complexity to the setup both computational and room design wise. REW room simulator shows some benefits but I wonder how real these simulations are?


Yes, I have seen both Toole's, plus Todd Welti's presentation on multiple subs, and Earl's paper, plus Duke LeJeune's swarm system. All show positive benefit's but one still needs room correction to obtain the smoothest bass response based on experiments I have run with multiple subs and locations.


Even if your sub(s) are part of your two channel system (i.e. not using digital XO), room correction is still a major benefit, which is what Dirac does. However, the new Dirac Bass Management will provide further control, but also requires more than 2 DAC channels.


REW Room Simulator works very well and is quite accurate! Room mode calculators are mostly based on the physical dimensions of one's room. Room construction and rooms treatments (to a certain degree as most do little below 100 Hz) have an impact, but below the room's transition frequency, it is all about the room ratio. The reality is that no matter where the speakers/subs are placed in the room relative to the listening positions, there is no escaping room modes. All that happens is that the dips and peaks move in frequency based on these (super)positions. One can get lucky and minimize, so it is worth the effort. However, in the end, still need room eq...

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7 hours ago, Zapuan said:
Thanks mitchco, always very useful your articles and reviews. I have been using Dirac 1.x since 2013 and lately I have been studying Audiolense and Acourate to try to have a (perhaps) better room correction by linearizing the speakers first, and after the room in the sweet spot..
Do you think that a better result can be achieved than Dirac 2.0?

Cheers @Zapuan As mentioned in the review, I did not get a chance to try Dirac 1.x, but according to the manufacturer, there are several improvements upgrading to D2. As I understand it, you are entitled to a free upgrade and given the simplified measurement process, it is worth a shot to try first 🙂

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14 hours ago, digitaldufferme said:

Following the advice of REL, I connect the left speaker and the left sub to one RCA output on the amp and the same for the right channel so that the REL T9i get a full range signal.


There is no reason why this would not work with Dirac. When the free trial is available, you might want to give it a try. The only issue is that Roon does not support VST plugin's at this time. So you would need to temporally try it in a different music player that supports VST plugins. Then at least you could ascertain the sonic benefit, which I think would be significant in your setup.

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@ZapuanSorry for misunderstanding. If you know what you are doing, yes, because of additional features and/or exposing functionality for the user to control:

- create multi-way digital crossovers of varying types, slopes, you have complete control.

- linearize individual drivers.

- time align individual drivers.

- user control over frequency dependent windowing. Both low and high frequency window widths can be independently adjusted for both magnitude and excess phase correction.

- the amount of correction applied.

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1 hour ago, Tonygeno said:

A while back you reviewed the Dynaudio Focus 600XD and raved about this speaker. Additionally you discussed its step response and its importance. Would Dirac benefit this type of active speaker and in doing so, would the step response be compromised?


Nice speaker, a little bright sounding to my ears if I recall... Yes, they are time aligned. No, Dirac would not compromise the time alignment, if anything optimise further if possible. Yes, Dirac would be a benefit as we still have room modes to deal with. The boundary controls on the speaker are helpful, but rudimentary compared to what Dirac can do. 


Here is the 600 XD frequency response in my room. Dirac would indeed smooth out the response below 600 Hz:


Dynaudio Focus 600 XD 9ft in-room frequency response.jpg





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13 hours ago, ted_b said:

Mitch, great review!  As I contemplate, for the first time in my long audio life, the idea of putting my signal through the twists and turns of DSP in order to correct for room interactions (and I'm building said room as I type this) I have two issues, one long-term that is too OT for this thread (is DSP worth not being able to do DSD512, etc) and one very short term:

* why, if you are working hard to alleviate interactions caused by walls and ceilings, first reflections, etc...why change the room before you start (removing coffee table, sofa, etc) and then change it back? 




Thanks Ted, appreciate it. That's awesome about your room build! Would love to hear more about that or perhaps it is an article? Wrt objects between the speakers and/or chair/couch in the way... If using a full range correction, we are correcting mainly for room interactions below 600 Hz and the loudspeakers direct sound (and some near reflections like the speaker baffle, stand), so we want to move any objects that are in the direct sound path. Not move them out of the room, but off to the side temporarily during measurements and then replace when finished. So the DSP is correcting for room and loudspeaker, not room/loudspeaker and coffee table, for example.


Using this approach yields the best sounding correction as one is dealing with the room and the speaker, with it's natural dispersion pattern, not broken up by objects in the way, or reflections from the couch getting in the microphone if using UMIK-1's little stand to sit on the top of the couch. Myself and others have tried corrections with objects in the way of the direct sound field and/or chair couch inches from the measuring mic and then with the objects moved to the side. The consensus is that with the objects temporarily out of the way for measurement and then returned after, sounds better than the correction with objects in the path and/or mic sitting on the chair or couch. 


I have tried this many times, in many rooms, and in every case, the correction sounds better with an unobstructed path to the measurement mic and placing the objects back for listening. Leaving objects in the direct sound path and/or having reflections from the couch back getting into the mic produces an inferior sounding correction. Not so much at low frequencies, but at frequencies above the rooms transition frequency, i.e. 600 Hz and above. It can alter the tone and sound like comb filtering or just unnatural sounding and then folks blame the DSP 🙂 Of course, folks are free to do whatever they want, but myself and others have found this measurement approach works more effectively for achieving the best sounding correction.


Best of luck with your room!


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@One and a half you need digital loopback capability to route the output of Roon to the VST and then to the DAC. On the PC something like https://www.vb-audio.com/Cable/ or https://vac.muzychenko.net/en/ should work.


I see this person got it to work in a basic setup:


There is also a Dirac doc on how to do it as well:



But, I have no idea about DLNA...


Unfortunately, most hardware devices are limited by the processing power required for low frequency control. The lower the frequency, the more "filter taps" required. So most hardware is limited to 8,000 FIR filter taps, whereas on the PC we can easily do 65,536 or even 131,072 taps. https://www.deqx.com/ is about the only hardware solution I would consider, but it is considerably more expensive than Dirac...

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Hi @One and a half yes, once you take the measurements, and happy with them, you are good to go, and can put the measurement mic away. Of course if you change speakers, speaker placement, listening position, etc., then you will need to measure again. Now that you have the measurements, you can play with the target response and try a partial correction from 600 Hz on down, or full range correction, different target curves, etc., and easily A/B them in Dirac Live Processor while listening to music. Once you have settled on what sounds best to your ears, it is set and forget and enjoy the music!

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Great question!! I can offer one perspective with some thoughts:


1) Room correction is a technically complicated subject area as there are several aspects to it. As alluded to in the article, some aspects are; audio digital signal processing, loudspeaker directivity, Schroeder frequency, standing waves, room resonances, early reflections, late reflections, the ears amplitude and frequency response non-linearity’s to sound, what to correct, what not to correct, etc., is what makes it a technically complicated subject area. I have yet to find a well written “layman’s” article on how room correction works and what the results are supposed to be. I go into gory detail in my book, but it isn’t a summary article. There is such a thing as an ideal loudspeaker in an ideal room that can be modelled and emulated. Unfortunately, most explanations are either too technical or are (wildly) incorrect, which leads me to a 2nd reason.


2) Because of the technical complexity, most folks don’t have the technical skills to understand what they are seeing on a chart and how it correlates to what we hear. So it makes it difficult to know what the end result should be or sound like, and most importantly, how to obtain it. There have been several scientific studies that correlates what makes for a good sounding loudspeaker in a room with objective measurements. Floyd Toole and most notably, Sean Olive have undertaken several scientific studies in this area correlating peoples listening preferences with objective measurements with loudspeakers in rooms and room correction systems. I have linked to a few studies in this article, plus other room correction articles I have written. In fact, there are literally dozens of repeatable scientific studies in this area, but again requires some level of technical acumen to spend the time reading and understanding.


3) This ain’t your granddaddies 31 band eq 🙂 Modern Digital Signal Processing (DSP) software is very sophisticated and coupled with powerful computers one can alter the frequency and timing response of a loudspeaker in a room to just about anything you want. Put another way, not all DSP room correction systems/techniques are the same and some are orders of magnitude better than others. Some work in the time domain, others do not. Some offer tailoring of every possible parameter, others do not. The list goes on. But perhaps the most important point is that most folks don't know how powerful software room correction has become.


4) And the elephant in the room, double pun, is that loudspeaker manufacturers (mostly) do not want folks to use room eq with their loudspeakers for a whole pile of reasons (e.g. don’t mess with my voicing, mics aren’t ears, yet those are used in the design of the loudspeaker in the first place, and a laundry list of other myths built up over the years - some justified with very poor eq systems from yesteryear). The biggest reason being that if one were to use state of the art DSP room correction system on Speaker A and then use the same target frequency response for a similar Speaker B and then A/B them (which is difficult to do) one may be hard pressed to tell the two speakers apart. Kudos to some speaker manufacturers, who have the confidence in their products to actually make a statement like that. For example, Martin Mensink, designer of the Dutch and Dutch 8c, “I've had the Kii's and the 8c's side by side in my living room for a while. The Kii's too are remarkably good speakers. With just some subtle EQ the two could be made to sound very similar on most program material - to the extent that I might not be able to distinguish them in a proper blind test. I'm still amazed sometimes by the extent to which differences in sound can be explained by frequency response.” Having performed the same experiment above myself with the speakers mentioned and others, there is considerable truth to this.


The irony is that for around $500, which includes the calibrated measurement microphone and state of the art room correction software, will make the biggest sonic optimization/improvement that one can make to your existing sound system that is both audible and measurable for the $’s spent. The caveat is one must know what one is doing to achieve a successful result. Companies like Dirac are making it easier to obtain a good result by limiting the amount of variables the user can play with. But as I mentioned in the article, that in itself is also a trade-off.


At this stage in the progression of software based room correction adoption, most folks that have experienced good room correction, even just for levelling out the bass frequencies, would not go without it. The audible difference in smooth sounding bass versus uneven bass response, virtually everyone can hear the difference as the difference is considerable. We are talking going from +20 dB peak to peak ripple response in the low end to +- 3 dB envelope. Everybody that has a pair of ears can hear the difference 😉 Again, part of this is the education to know that below the room’s transition frequency into standing waves/room modes, is to know that the room is in control of the bass response, not the loudspeaker. It takes a bit of understanding/time to wrap ones head around that.


Hope some of that is useful. I have considered writing a layman’s article on the subject area to help folks understand what is being measured, what is being corrected and why. Maybe it is time...


Have a great weekend!


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  • 2 weeks later...
  • 2 weeks later...

Bill, great to hear from you! I hope all is well.

Dirac suggests: http://diracdocs.com/Roon_&_Dirac_Live_2.0.pdf to work with Roon. 

I don't know how your other sources are hooked up, but the idea is that the input signal would be routed through Audio Hijack to Dirac Live Processor and then out to your LS50W.

Don't have a Mac or LS50W, so could not say for say for sure...

Hope that helps.



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The miniDSP DDRC-24 should work no doubt. I have never used one, but I know it has a limited amount of filter taps as compared to the processing on a PC. Less taps generally means less low frequency resolution. However, I can't speak about how Dirac 2 is implemented in the miniDSP unit and may or may not be an issue. Perhaps @flak can comment or a post on the miniDSP forum or maybe another member has experience with this combo and can comment...


Wrt 2nd question, hard to say without seeing any before and after graphs. It could be room modes, but could also be the target is a bit too bright that makes the bass sound thin. If you could post some charts that would assist. Also, feel free to add a bit of bass boost like in this target from the miniDSP Dirac 2 user manual: https://www.minidsp.com/images/documents/miniDSP Dirac Live 2.0 User Manual.pdf  See page 36.


Kind regards,


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Hi Bill, Dirac I believe is cut only filters, so if you lower the peaks to be even with the majority and not worry about the narrow dips. Narrows dips we don't hear.


Sure. just use REW's default settings and sweep 10 Hz to 24 kHz using a 48 kHz sample rate of the left and right speakers at the listening position. Just PM me the .mdat or send to [email protected] and once we sort it out, you can post the results here if you wish.





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I agree with @Kal Rubinson. My concern for any hardware DSP is the limited processing power available. Typically they are limited to 4096 FIR filter taps, which is not enough for low frequency control. For example, the miniDSP 2x4 HD in the datasheet talks about 4096 taps. But this is the total number. For 4 channels you have 1024 taps each channel available. The frequency resolution of a 1024 taps filter @ 48 kHz samplerate is 48000/1024 = 46.875 Hz. So below 100 Hz there are just 2 frequency bins at 46.875 and 93.75 Hz. This clearly means that you have no control over the lower frequency range.


I don't know how Dirac is implemented in these h/w devices, but on a PC you typically use 65,536 taps per channel which gives full low frequency control. Remember the primary purpose of DRC is to correct the low frequencies below Schroeder. So my review of Dirac 2 is only in the context of using Dirac on a PC. I make no claims on how it works/effectiveness with miniDSP gear or any other hardware.

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  • 4 weeks later...

Hi @Tp no need to remove the carpet or other objects on walls, etc. What we are trying to avoid is anything in the direct path between the speakers and microphone like plants coffee table, etc. Also, anything around the microphone can cause odd sounding corrections, hence moving the chair or sofa from around the mic.


Hi @mlknez Do you mean DiracLiveProcessor.dll? On my Win10 computer it is located at: C:\Program Files\Common Files\VST2

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  • 3 weeks later...

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