Comparison of DRCs: Dirac Live for Studio, IK Multimedia ARC System 3 and Sonarworks Reference 4 Studio edition

[dominikz]

This is the part I'm not getting. I would describe the process I went through with REW as automated: it took my measurements (averaged over the listening field) to generate 20 filters in each channel, targeting a predetermined curve. When you say you use REW manually, I assume REW is not generating the filters for you, but rather you are typing in specific values for specific frequencies or ranges. Or is there a level of automation in these commercial DRC systems that REW doesn't have?

I tried with both automatic generation of EQ filter coefficients that REW does to match a target curve as well as creating manual filter banks and didn't like the results either way (on this system). For instance, in my opinion it is less-than-trivial to know which dips to EQ and by how much from just the multi-point average curve - REW automatic target match feature doesn't seem to take this into account - so to me that means the user needs to have some experience and do some trial-and-error.
Automatic DRCs seem to have some algorithm to take this into account - for instance notice how Dirac Live and ARC 3 calculated very similar correction curves for me in the 45-210Hz range, although the two use a different number and spatial distribution of measurement points.

However my last attempt calculating EQ with REW was a little while ago and I feel I've learned quite a bit about the topic since then - so maybe now I'd have better results following that approach

EDIT: Just thought a bit about my recent posts and realized one could read them as being very favorable towards commercial DRC solutions and dismissive of REW + EQ approach for room correction. However, that is not really my position - I'm not even sure at this point whether I personally will go for any off-the-shelf DRC solution.
There are for sure pros and cons of each approach - with main benefit of automatic commercial DRC SW being relative ease of use and hopefully somewhat repeatable results without the user needing to learn a whole lot about acoustics and EQ.
For sure I would advise anyone to use free solutions first (like REW and EAPO), learn a bit about it all and then maybe even make some comparisons to DRCs which offer trial/demo modes. I'm fairly certain good results can be had in most cases with some know-how, REW and e.g. EAPO, potentially better than with any commercial SW.

Also note that my impressions on the sound after correction are based on, for the most part, sighted listening - so probably not worth much Better to look at the objective data (various diagrams and sound clips provided - though admittedly I didn't provide any for the REW + EAPO approach ).

 

[martijn86]

I’ve been using Dirac Live for over 5 years and it is excellent product.

It works great for bad speakers and bad rooms/ acoustics, well for ok speakers/rooms, and has minimal positive effects for excellent acoustics and excellent designed speakers.

I would say that’s it’s definitely a game changer and one of most significant developments in the last decade...

That's great to hear! I have fantastic bad speakers in an 'OK' room. Audessey completely lost it when I got these speakers with their rear facing passive radiators and thin cabinets. I resorted to EQ-ing by ear but Dirac should work well then.

 

[hmt]

The in-room measurement clearly shows improvement.

Yep. AFAIK dirac will apply max 7 dB of boosting. This is also the amount of headroom it reserves. A problem can be when there is a slight dip in the bass where you already want to apply a boost.

 

[Tomino]

EDIT: Just thought a bit about my recent posts and realized one could read them as being very favorable towards commercial DRC solutions and dismissive of REW + EQ approach for room correction. However, that is not really my position - I'm not even sure at this point whether I personally will go for any off-the-shelf DRC solution.

Thanks again. @Geert mentioned time-domain corrections in Dirac, which I am interpreting to mean delay to a single channel. That seems like a pretty big feature that REW doesn't have.

Still looking for a good nebulizer-tuning application . . .

 

[dominikz]

Thanks again. @Geert mentioned time-domain corrections in Dirac, which I am interpreting to mean delay to a single channel. That seems like a pretty big feature that REW doesn't have.

Looking at the impulse and phase responses posted earlier it seems to me it is more than just simple inter-channel time-delay Dirac adjusts - so definitely something to keep in mind. Some information on their approach is illustrated in this presentation.
However I'm unsure how much of an audible difference those time corrections make - that would require some blind testing to determine. Probably not as obvious a difference as taming of room modes, at least based on my experience

 

[mitchco]

@dominikz Very nice job! Your analysis and results coincides with mine. I have reviewed Dirac, Audiolense here and here, and Acourate here and here. I have also reviewed REW and rePhase along with ARC3 and Sonarworks, but because the results are less than Dirac and much less than Acourate and Audiolense, I did not publish them.

While REW PEQ's are OK, REW is not marketed as a "digital room correction" product and neither is rePhase. Following the many instructions on the interwebs, I could never get close to what a purpose built DRC program could do using these programs, even though I have been using REW for a decade. I would not put any of the h/w based so called DRC products at this level as they are limited by their hardware implementations as described here: https://www.audiosciencereview.com/...ssey-room-eq-review.12746/page-10#post-380033

As a side note, you may want to look at the timing response as a "step" response instead of an impulse response. The issue with an impulse response display is it is heavily weighted towards high frequencies in the 20 Hz to 20 kHz passband, whereas the step response is more evenly weighted across the passband. Some explanation here.

Re: single measurement versus multiple measurements. Each DRC product has its own algorithms used to analyse the loudspeakers in rooms. While Acourate and Audiolense take single measurements, both can take multi-point measurements. Audiolense has that built in and Acourate can be used with techniques like beamforming which I cover in detail in my DSP book. Here is Acourate's analysis algorithm used in a single point measurement. If one takes the time to read and comprehend what is going on in the analysis, one will realize that using this type of algorithm is just as good if not better than multi-point measurements. Certainly in my tests, this has turned out to be the case and in my DSP book in "Filter Design Verification" section, I show how a single point measurement can cover a couch area with very little deviation in both the frequency and time domains.

Loudspeakers are minimum phase devices. However, as John Mulcahy's excellent article on minimum phase shows, most rooms are not minimum phase. "A simple example of something that renders a response non-minimum phase is reflections that are as large or larger than the direct signal (reflections along paths that are different but the same length can combine to produce higher levels, or a curved surface can focus a reflection). One quick look at the step response of your system can immediately identify this. Having received +100 measurements of different loudspeakers and rooms, including my own room, this is a consistent theme and where most (read: almost all) DRC products fall apart. The irony is that these DRC products are supposed to smooth out the bass response, but do little in the way of dealing with non-minimum phase low frequency reflections. This is where Acourate and Audiolense instantly go to the top as they provide low frequency excess phase correction to deal with these non-minimum phase room reflections and can produce excellent results like this:

This is using REW's default 500ms window with no smoothing. This means measuring the loudspeaker and room, letting in all of the reflections. Notice below Schroeder there are no reflections or more correctly the reflections are following a minimum phase response. The audible difference is between hearing smooth versus smooth and crystal clear bass that is not mucked up with low frequency room reflections. In my tests, there are only two DRC products that can do this.

I hope you get a chance to try out Acourate and Audiolense as they are the state of the art DRC with nothing else coming close. Dirac comes a distant 3rd as a "general purpose" DRC as the only thing you can adjust is the target curve (and whether is is full range or partial correction). Dirac uses IIR filters down low and therefore no excess phase correction. Audiolense and Acourate allow full adjustment of all parameters both in the frequency and time domain. With that one can achieve "accurate sound."

Great job and good luck!

 

[Zoomer]

AFAIK dirac will apply max 7 dB of boosting.

Dirac Live can boost frequencies by as much as 10dB according to mr Mehlau.

I'm unsure how much of an audible difference those time corrections make

The VST has a check box called "Delay Compensation", so it's easy to listen for audible differences real-time.

 

[dominikz]

@dominikz Very nice job! Your analysis and results coincides with mine. I have reviewed Dirac, Audiolense here and here, and Acourate here and here. I have also reviewed REW and rePhase along with ARC3 and Sonarworks, but because the results are less than Dirac and much less than Acourate and Audiolense, I did not publish them.

While REW PEQ's are OK, REW is not marketed as a "digital room correction" product and neither is rePhase. Following the many instructions on the interwebs, I could never get close to what a purpose built DRC program could do using these programs, even though I have been using REW for a decade. I would not put any of the h/w based so called DRC products at this level as they are limited by their hardware implementations as described here: https://www.audiosciencereview.com/...ssey-room-eq-review.12746/page-10#post-380033

As a side note, you may want to look at the timing response as a "step" response instead of an impulse response. The issue with an impulse response display is it is heavily weighted towards high frequencies in the 20 Hz to 20 kHz passband, whereas the step response is more evenly weighted across the passband. Some explanation here.

Re: single measurement versus multiple measurements. Each DRC product has its own algorithms used to analyse the loudspeakers in rooms. While Acourate and Audiolense take single measurements, both can take multi-point measurements. Audiolense has that built in and Acourate can be used with techniques like beamforming which I cover in detail in my DSP book. Here is Acourate's analysis algorithm used in a single point measurement. If one takes the time to read and comprehend what is going on in the analysis, one will realize that using this type of algorithm is just as good if not better than multi-point measurements. Certainly in my tests, this has turned out to be the case and in my DSP book in "Filter Design Verification" section, I show how a single point measurement can cover a couch area with very little deviation in both the frequency and time domains.

Loudspeakers are minimum phase devices. However, as John Mulcahy's excellent article on minimum phase shows, most rooms are not minimum phase. "A simple example of something that renders a response non-minimum phase is reflections that are as large or larger than the direct signal (reflections along paths that are different but the same length can combine to produce higher levels, or a curved surface can focus a reflection). One quick look at the step response of your system can immediately identify this. Having received +100 measurements of different loudspeakers and rooms, including my own room, this is a consistent theme and where most (read: almost all) DRC products fall apart. The irony is that these DRC products are supposed to smooth out the bass response, but do little in the way of dealing with non-minimum phase low frequency reflections. This is where Acourate and Audiolense instantly go to the top as they provide low frequency excess phase correction to deal with these non-minimum phase room reflections and can produce excellent results like this:


View attachment 100689

This is using REW's default 500ms window with no smoothing. This means measuring the loudspeaker and room, letting in all of the reflections. Notice below Schroeder there are no reflections or more correctly the reflections are following a minimum phase response. The audible difference is between hearing smooth versus smooth and crystal clear bass that is not mucked up with low frequency room reflections. In my tests, there are only two DRC products that can do this.

I hope you get a chance to try out Acourate and Audiolense as they are the state of the art DRC with nothing else coming close. Dirac comes a distant 3rd as a "general purpose" DRC as the only thing you can adjust is the target curve (and whether is is full range or partial correction). Dirac uses IIR filters down low and therefore no excess phase correction. Audiolense and Acourate allow full adjustment of all parameters both in the frequency and time domain. With that one can achieve "accurate sound."

Great job and good luck!

Wow, thanks for this! This will take some time for me to digest, though!

The VST has a check box called "Delay Compensation", so it's easy to listen for audible differences real-time.

Sure - though I believe that is just for the inter-channel delay difference compensation between the two channels (0,4ms difference in my case; note there's also a button for gain difference compensation between channels), and not for the whole individual speaker time-domain / impulse response optimization feature. But I may be mistaken!

 

[mlee]

Strange Dirac would not take out the phase wrap at that frequency (around 2khz?). I ran Dirac on PC a few years ago and it definitely took out the phase wrap above 1khz. The resulting impulse looked more like a dirac pulse than the one posted in the first post. Perhaps Dirac filtering has changed in the past few years?

Edit: Opps that is the compensation curve so it is doing the time domain correction. Got the graphs mixed up.

 

[vavan]

AFAIK dirac will apply max 7 dB of boosting. This is also the amount of headroom it reserves

that depends. for me it reserved 12.5dB

 

[Robbo99999]

Hi all,

Lately I was playing a bit with digital room correction (DRC) SW to see if I can tame the bass in our living room with a pair of Revel M16 (no subs) so I thought it could be useful to share my findings. Some of my in-room measurements are available already in this post, and here are the quasi-anechoic measurements of our pair of speakers. As you can see, we get a bit of bloom under ~200Hz, which should be right around the Schroeder frequency of this room.

The three DRCs I tested were:

• Dirac Live 3 for Studio - Price: $349 SW only
• IK Multimedia ARC System 3 - €99.99 SW only or €182.99 with mic
• Sonarworks Reference 4 Studio edition - €299 with mic

All of them offer free trial versions, which is what I used to test them out and compare.

Measurements were done with a Cross-Spectrum Labs calibrated Dayton EMM-6 measurement microphone and RME Babyface Silver edition soundcard.

Here's some of my quick thoughts on each one of them:

Dirac Live for Studio
Usability and UI is very nice in general - though I was having some issues with logging-in to the user account on the Processor component (VST plugin) and was also getting some errors when loading saved projects. I don't like the fact that you can't edit (or even see) the target curve in the plugin (Processor component), and due to issue with loading saved projects it can be tricky to edit saved curves.
The measurement process was relatively straightforward and quick (actually the quickest of these three), and the resulting responses seem in line with what I was getting with REW.
I'd say there's really a lot of power in Dirac - it sounds great, and is really flexible in target curve customization (you can load target curves, edit them, add many break points, freely set range for the correction...).
Here's the correction curve I liked the most:View attachment 100557

IK Multimedia ARC System 3
Not bad UI and usability, though there are a few things I didn't like: e.g. when you load the mic calibration curve, there's no indication that it loaded correctly, and due to this one of my measurement attempt turned out incorrect. Another thing I don't like is that there are only 6 target curve break-points, and the SW applies some correction to FR even outside of the configured range (unlike Dirac) - so you should be careful how you set the breakpoints if you limit the range, as you will need a few of them out of the range set at 0dB to really limit the correction. This means you get really limited with how you can set the target. You can also only set the break points in between the +/-6dB of the reference the SW selected - which can also be limiting when we consider downward-sloping in-room response curves that we get when listening in far field.
However, there's some nice additional features to play with, like two types of filter phase (natural and linear) and 'virtual monitoring' target curves that attempt to mimic other speaker system's FR.
Measurement process was relatively simple, but requires more measuring points (21 in total, with 8 sweeps per point).
Sounds quite good to me too, but the target curve configuration is a bit limiting.
This is the curve I ended-up with (range a bit wider that Dirac, and maybe a bit less bass boost):
View attachment 100558

Sonarworks Reference 4 Studio edition
Maybe the best UI, stability and usability of the three. I enjoyed the gamified concept of the measurement process, but in practice it is quite tedious to do as it takes something like 37 measurement positions to do the calibration - so it's quite a lot of loud sweeping and chirping noises to endure
This is also probably the most complete SW package of the three - it offers systemwide application and plugin version, and on top of offering loudspeaker calibration it also provides a pretty large database of headphone equalization configs. They were obviously aiming for user-friendliness
What I don't like is that target curve customization is very limited (including almost non-existent range limiting). Because of this, most of the result sounded over-processed to me and I couldn't really find any that sounded close to what I thought was natural (and which I could get with the other two).
Here's the best I got:
View attachment 100559

Filter response comparisons
First thing I'd like to show is soundcard loopback frequency response with each DRC after calibration to compare the filter responses:
View attachment 100550
As we can see, Dirac Live and ARC 3 filters were limited to our problem area (45-210Hz) and I was surprised to see that the filters between them end up looking fairly similar. Reference 4 cannot be limited in the same way so here I'm showing 'Reduced' LF limit and 'Normal' HF limit. We can see right away that filters used by Reference 4 are less sharp in the LF range and I couldn't find a way to get a better match to the other two.
Note: the above is with 'Natural' phase and 'Sharp' filter type set in ARC3 - other settings resulted in worse match to Dirac Live (i.e. less sharp filters). For Reference 4 I used 100 Wet config to get most sharpness (although I used it with 60% as that sounded more natural).

Edit: adding the impulse response comparison from post #24 for completeness:
View attachment 100628

Here's full phase and magnitude diagrams (please disregard the 'hairiness' above ~4k for Dirac and ARC - it is an artefact of the way I did loopback testing of these two plugins and not something they do normally):

Dirac Live:
View attachment 100552
What I found interesting was the gradually rising phase response after the filter. Is this due to impulse-response and delay correction/optimization Dirac does?

ARC 3 with 'Natural' phase variant:
View attachment 100553
Notice no rising phase response, unlike Dirac Live.

ARC 3 with 'Linear' phase variant:
View attachment 100555
Notice that filters are less sharp, but phase response is smooth (P.S - this was range limited to ~900Hz and with a different target - here just used to illustrate phase behaviour).

Reference 4:
View attachment 100554

In-room response measurement example
Next here's an in-room loudspeaker response comparison of no DRC (averaged across 9 positions) vs ARC3 correction (averaged across 5 positions):
View attachment 100563
Note that the curves don't overlap very well in the mid and higher frequencies - they were done on separate occasions and the measurement positions and mic height naturally weren't the same between the two measurement runs - but they are roughly close.
Still, we can see how much the bass response got evened out by DRC - peaks got flattened and the dips got filled in, as we could only have hoped for

Sample in-room recordings

Lastly, I thought how to illustrate the audible differences, and decided it might be interesting to do in-room stereo recordings of playback without any DRC as well as with the three DRCs reviewed above.

In-room sample recordings were done with the classic mid-side stereo recording technique, using a combination of Dayton EMM-6 as 'mid' and Rode NT2a in figure-of-eight mode as 'side' at the listening position in our acoustically untreated living-room. I chose mid-side technique for two reasons:

1. Use of omni mic for 'mid' should be good to record realistic low-end response in the far-field
2. It is not critical to have a closely matched pair of microphones

Edit: Listening position is ~2,2m from each speaker and SPL was between 75-80 dB(C) (measured with a cheap SPL meter close to mics) for each clip.

The recordings were not post-processed, except summed for stereo listening and (LUFS) loudness matched.
Here's a picture of the mic setup:
View attachment 100560

The song/recording I used was one of the vary few I have distribution rights for as it was made and recorded by my band - so I guess what follows could also be considered shameless self-promotion. Anyway the source track can be found on most streaming services via this link.

The resulting in-room recordings in FLAC (44,1kHz/16bit) are uploaded here - I suggest to listen on headphones to avoid adding additional room effects to an already quite live recording. These recordings definitely don't convey the full in-room listening experience, but I still thought it was an interesting project and may provide some insight.

Conclusion
All in all, this was quite an interesting little project for me. My takeaway is that there are definitely some really good options on the market for DRC - out of these three my preference would be:

1. Dirac Live 3 - sounds the best to me and offers most flexible target curve config. Natural sounding and with reasonable target configs I thought it was not destructive in any way. Not cheap, though.
2. IK Multimedia ARC system 3 - in my opinion it can be configured to sound close to Dirac, but required a bit more fiddling. It may not be able to satisfy every requirement as far as target curves go though - this is my main gripe with it. However it is quite a cheaper option than the other two.
3. Sonarworks Reference 4 Studio edition - I couldn't make myself agree with this one Sure, there are some nice features there (plus great systemwide version and some extensive headphone EQ options) so I'm sure it works great for many - but lack of filter sharpness, true correction range limiting and detailed target curve editing are for now deal-breakers for me.

There it is - hope some will enjoy the read and maybe even find bits of it useful!

Those are nice easy to EQ room measurements you have there (https://www.audiosciencereview.com/...-m16-speaker-review.11884/page-25#post-578130), I reckon you don't need anything more than REW & a measurment mic like UMIK, then you could EQ those room measurements easily (even manually) in REW to any target curve you like. Given you had (in my eyes) ideal in room measurements, this would be super easy to sort with REW rather than using fancy paid for EQ options.

 

[UliBru]

Loudspeakers are minimum phase devices.

@mitchco In most cases loudspeakers are NOT minimum phase devices!
As most speakers are multi-way speakers with multiple drivers and crossovers. And the addition of minimumphase drivers and crossovers results in excessphase.
Please see also my posting https://www.audiosciencereview.com/...inear-phase-room-eq-filters.11121/post-527044

AFAIK this is not corrected by systems like DIRAC, ARC, Sonarworks, Roomperfect ...

 

[mitchco]

@UliBru agreed! I was trying to keep the topic simple by just talking about the room correction portion... I should have said "ideal" loudspeakers are minimum phase devices ;-)

 

[Zoomer]

Sure - though I believe that is just for the inter-channel delay difference compensation between the two channels (0,4ms difference in my case; note there's also a button for gain difference compensation between channels), and not for the whole individual speaker time-domain / impulse response optimization feature. But I may be mistaken!

Nah, my mistake

 

[dominikz]

I'll try to do a short summary of my thoughts on using these three DRCs in the nearfield setup too - I feel the use-case is different enough to warrant a closer look.

As promised, here are my thoughts on using these DRCs in a nearfield setting.

General comments
My work desk / nearfield setup is arranged around JBL LSR305 (so older MKI) powered monitors connected to RME Babyface silver edition sound card. Speakers are spread ~70cm, close to the back wall and not set symmetrically within the room (which is also untreated). At the listening spot I have a really nasty suckout of energy in the ~60-~90Hz range and a huge peak at ~125Hz.

A note on target curves - in the nearfield I find I'm OK with a relatively flat target curve with less bass boost (I measured with flat bass, but while listening I still preferred 2-3dB boost below 100Hz). This is in contrast to the typical Harmanesque target curves with ~6dB bass boost and constant downward slope I prefer in our living room (which could be considered far field with speakers at around 2,2m distance from the listening position). This I assume is because in the nearfield much more of the perceived sound energy comes from loudspeaker's on-axis radiation.
In any case, flatter target curves play nicer with most of these DRCs so I found in general that fullrange correction worked better in the nearfield for me than it did in the farfield.

Here's the regular 3-band PEQ I use normally in the soundcard's DSP (based on some old REW measurements):

Dirac Live for Studio full-range response used for the measurements:

IK Multimedia ARC System 3 full-range response used for the measurements:

Sonarworks Reference 4 Studio edition full-range response used for the measurements:

In-room measurements

Note: variable smoothing shown.
I'd say we see similar results as before - Dirac and ARC3 seem close, 3-band PEQ is not too far-off either , and Reference4 is a bit less sharp so doesn't fully address the resonances.

This time I'm showing step response (thanks @mitchco for the suggestion!). We see that Dirac is doing its time-domain magic here, Reference4 exhibits some pre-ringing and the rest don't seem to care much about the time-domain

Subjective thoughts and summary
The order of preference for me still hasn't changed between the three (Dirac > ARC3 > Reference4), but I noticed a few things:

• Reference 4 gave quite solid results in the nearfield - perhaps because the target curves it provides work better with on-axis / nearfield responses. Could be confirmation bias from seeing the measurements, but I thought bass wasn't as smooth as the others - all in all still very workable and much better than either 3-band PEQ or listening without correction (which many times sounds like someone blowing in a bottle really loudly )
• I thought ARC3 and Dirac full-range correction sounded nice and non destructive
• Limiting the correction of Dirac and ARC3 to below ~700Hz also sounded great, but I might even prefer the full-range correction. I'd need to do more listening to decide.
• The 3-band PEQ in comparison to all three DRCs sounds hollow - for sure more than 3 filter bands are required to get comparable results - but that is a task for another day (or another person )

 

[ghemink]

Edit: adding the impulse response comparison from post #24 for completeness:​

​

​

Here's full phase and magnitude diagrams (please disregard the 'hairiness' above ~4k for Dirac and ARC - it is an artefact of the way I did loopback testing of these two plugins and not something they do normally):​

​

Dirac Live:​

​

​

What I found interesting was the gradually rising phase response after the filter. Is this due to impulse-response and delay correction/optimization Dirac does?​

Dirac is the only one that has this rising phase response because it seems that Dirac is the only one that corrects the actual phase response of the speaker, the M16 is a two-way speaker and the crossover filter is a 24dB/Oct filter it seems based on the phase response (360 degree phase shift in total), the crossover frequency should be around 2.2kHz or so based on above phase shift data (at the 180 degree shift point). This is why the corrected impulse response from Dirac has pre-ringing, this is due to the phase compensation it does. Dirac will give you a much better impulse response (and step response) than the other two when the speaker response is included. I also tried (actually bought) all 3 of them (Dirac, ARC and Sonarworks), also in my experience, DIRAC is the only one correcting the phase response. I used them on a 3-way speaker (old B&W CDM9 NT) and it manages to nicely correct the crossover phase response and give me a nice impulse response after the speaker response is included.

 

[ghemink]

Edit: adding the impulse response comparison from post #24 for completeness:​

​

​

Here's full phase and magnitude diagrams (please disregard the 'hairiness' above ~4k for Dirac and ARC - it is an artefact of the way I did loopback testing of these two plugins and not something they do normally):​

​

Dirac Live:​

​

​

What I found interesting was the gradually rising phase response after the filter. Is this due to impulse-response and delay correction/optimization Dirac does?​

Dirac is the only one that has this rising phase response because it seems that Dirac is the only one that corrects the actual phase response of the speaker, the M16 is a two-way speaker and the crossover filter is a 24dB/Oct filter it seems based on the phase response (360 degree phase shift in total), the crossover frequency should be around 2.2kHz or so based on above phase shift data (at the 180 degree shift point). This is why the corrected impulse response from Dirac has pre-ringing, this is due to the phase compensation it does. Dirac will give you a much better impulse response (and step response) than the other two when the speaker response is included. I also tried (actually bought) all 3 of them (Dirac, ARC and Sonarworks), also in my experience, DIRAC is the only one correcting the phase response. I used them on a 3-way speaker (old B&W CDM9 NT) and it manages to nicely correct the crossover phase response and give me a nice impulse response after the speaker response is included.

Was writing this reply and saw after posting that dominikz confirmed this with the step response measurements. Only Dirac cleans up the impulse (and thus the step response). I am only using Dirac right now.

 

[dj94030]

How do they compare with audiolense?

 

[BYRTT]

Hi all,

Lately I was playing a bit with digital room correction (DRC) SW to see if I can tame the bass in our living room with a pair of Revel M16 (no subs) so I thought it could be useful to share my findings.....

Thousand thanks and thump up share details and hard work, first i comment subjective feelings resulted from listening to your shared FLAC files, on Dirac FLAC as natural as possible transient for symbols is killed there probably because phase goes north (delayed) as frequency increase and feel that is strange and the wrong way because any tranducers sadly have inductance L(e) and that parameter also delay or distort time domain signal as frequence goes up plus probably also most DACs have excess phase up there, think for ARC3 and Reference 4 that correction fall apart as track material goes complex by the end, so all in all for best natural sounds i really like hear your room how weird that opinion can sound ..

Comment on objective part is because of Amir's detailed acostic reviews and data sharing thousand thanks, then have done some observations that never thought of before and one is below say 1000Hz we mostly have full space coverage that means room sound power will easy be dominated by that full space area down there so if there is any hot peaks in that area that push sound power curve higher relative to ideal and will probably dominate system sound because its full space area verse half space area say above 1000Hz where a certain directivity pattern set in.

Animation bekow is what i mean, in right side graph have marked half space curve (90º) black colour so as to help see the better ballance of sound power, if you like to try that correction its two PEQ's -1,0dB/Q2,81/@94,5Hz & -3,7dB/Q1,23/@128Hz..

A funny observation talking for you should try above simple correction is if we allign your Dirac/ARC3/Reference4 correction curves with above simple correction there is coherence .. (Dirac Live=blue, ARC3=green, Reference4=red, above two PEQ's=black)

Should the two above PEQ's work good have added four more PEQ's in below string that target smooth power response minus XO region directivity..

Animation of modeled prediction for the 6 times PEQ..

 

[Shike]

Let 10 people create a DRC filter using REW and you will get 10 different results. So for sure an REW filter will sound different from Dirac. Not to mention Dirac uses mixed phase filtering, performs time-domain corrections and uses a proprietary algorithm to process multiple measurement points.

Can't say I find any of the features particularly meaningful in my testing. In fact when I first tried Dirac after using REW based correction I thought it was broken, had to change the target curve to confirm it was actually working, went back to the original curve and couldn't tell against my REW curve. Had others try between the two on which sounded better and they were too close to pick a winner.

I used Dirac's recommended target. The REW target at the time was based on improving speaker's natural response to minimize the amount of correction (was still used fullrange). I also used Harman's measurement method that favored MLP. I've since switched to 1dB/oct slope though as I like a bit more bass now (originally was like .5-.7).

I'm sure some think time domain correction is really important but it just isn't in my admittedly anecdotal experience. Given this was back with Dirac 1.2 which I purchased. I ended up returning it - the $736 wasn't a real improvement beyond simplicity IME.