Dirac Reviews

[levimax]

Could you share the measured+corrected curves?

If you have a quite ondulated mid/hi frequency response, Dirac can do more harm trying to linearize it.
Same if there is sufficient difference between L and R in this range.
A wider soundstange from the (mono signal I suppose) pink noise points to more differences between left and right.

Cause could be a smaller room having more reflections, bringing more off-axis signals to what the calibration mic hears.
Correcting these will deform an otherwise flat direct response which makes up the perceived sound.
Something similar happened to me.

Hello: See below measured and corrected curves. In my experience by far the biggest driver of soundstage width is "out of phase" noise or signals. Reverse the polarity on one speaker for an extreme example. For a more subtle example put on a "real" mono LP and "sum to mono" either with a "mono switch" or "sum to mono DSP". Not only is the noise reduced by 90% but the "soundstage" (yes the soundstage of a real mono recording which really doesn't exist outside of the out of phase noise artifacts cause by a stereo cart and the record surface) collapses. Anyway I really can't be sure what going on with DIRAC but to me it "sounds like" out of phase content.

 

[keks8430]

Hi,
I changed the target to my often preferred Bruel&Kjaer-like room curve.
It follows the mid/high range and saturates on mid/bass average.
There is some justification beyond taste (in a strict sense IF your speaker measures flat in free space and has a steady directivity index), see Toole's papers or book.
It should give you a more natural timbre.
And here it points to a possible issue in the range 250-500Hz.
At its lower end, the channels are already well aligned, characteristic of the region above the Schroedinger frequency.
But they do not follow the gentle slope, why?
Either this is really the on-axis response (do the speakers point to the main listening position?), you should equalize as shown.
Or it is caused by an anomaly in directivity (do you have the anechoic off-axis response of your speakers?)
Then you should not (at least not fully) correct the valley. You will surely prefer the curve corresponding to the correct hypothesis.

The change of target curve is only affecting timbre, not phase.
Maybe a changed tonality changes imaging too, see Blauert's bands for example.

But yes, a mono signal should be nailed to the center for any symmetrical stereo setup.

Last idea, what happens above 7kHz? You might pull the curtain and stop correcting above.
At least I can hear the signals with my old ears.

 

[levimax]

Hi,
I changed the target to my often preferred Bruel&Kjaer-like room curve.
It follows the mid/high range and saturates on mid/bass average.
There is some justification beyond taste (in a strict sense IF your speaker measures flat in free space and has a steady directivity index), see Toole's papers or book.
It should give you a more natural timbre.
And here it points to a possible issue in the range 250-500Hz.
At its lower end, the channels are already well aligned, characteristic of the region above the Schroedinger frequency.
But they do not follow the gentle slope, why?
Either this is really the on-axis response (do the speakers point to the main listening position?), you should equalize as shown.
Or it is caused by an anomaly in directivity (do you have the anechoic off-axis response of your speakers?)
Then you should not (at least not fully) correct the valley. You will surely prefer the curve corresponding to the correct hypothesis.

View attachment 342175

The change of target curve is only affecting timbre, not phase.
Maybe a changed tonality changes imaging too, see Blauert's bands for example.

But yes, a mono signal should be nailed to the center for any symmetrical stereo setup.

Last idea, what happens above 7kHz? You might pull the curtain and stop correcting above.
At least I can hear the signals with my old ears.

Thank you very much! Speakers are DIY 3 ways + 2 subs with active 4 way crossovers and seperate amps for each channel. I have struggled with the 300 Hz dip and figured it was a problem at the crossover point (which is 300 Hz between Woofers and Mid range) but then recently I set out to "fix" it and tried many things including changing the crossover point but that did not change the "dip" location so it is something else, possibly the room to some extent. The dip also shows up off access. I find a "partial correction" leaving a slight dip, which is exactly what DIRAC seems to do, to be the sound best. I will try the Bruel & Kjaer curve you mention. Do you have a source for an input file for DIRAC for this curve? Thanks again.

 

[keks8430]

Do you have a source for an input file for DIRAC for this curve? Thanks again.

Welcome - Bruel&Kjaer target curve attached.
Probably you have to mold it to your measurements, shown in the plot above.
You can delete most of the original points and still keep the shape.

I also thought of DIY, creating a special situation (baffle step ..).
If you use crossovers, make sure to set them sufficiently afar from the individual speaker's limits. In other words, you need overlap, otherwise you risk a gap Dirac is not able to fill with its (general 10dB) boost capability.

Probable culprit is the high crossover.

crossover point (which is 300 Hz between Woofers and Mid range)

The 300Hz are high for the woofers, radiated in a narrow range. OK for the direct sound, but the mic sees it lower. Experiment not fully filling the valley.
Good read:
https://www.harman.com/documents/AudioScience_0.pdf

 

[alvigg]

Are there suggestions for sub placement in various scenarios. I will have 3 subs (2 new identical SVS, 1 old Bagend Infrasub 18) and can't find guidance for placement. Any help is welcome. Thanks.

 

[levimax]

Welcome - attached.
Probably you have to mold it to your measurements, shown in the plot above.
You can delete most of the original points and still keep the shape.

I also thought of DIY, creating a special situation (baffle step ..).
If you use crossovers, make sure to set them sufficiently afar from the individual speaker's limits. In other words, you need overlap, otherwise you risk a gap Dirac is not able to fill with its (general 10dB) boost capability.

Probable culprit is the high crossover.

The 300Hz are high for the woofers, radiated in a narrow range. OK for the direct sound, but the mic sees it lower. Experiment not fully filling the valley.
Good read:
https://www.harman.com/documents/AudioScience_0.pdf

Thank you again.

Yes I think it is a baffle step issue as I have very wide baffles (24") for 12" woofers and then much narrower for the 4" mid so the "direct" vs "mic" sound issue you mention is definitely in play. Good news is I have plenty of SPL headroom for all drivers and several ways to easily make adjustments.

I loaded up the BK filter curve and at first listen I really like it. Sounds more natural with less bass than the "Harmon" curves I was using. It especially sound good when playing loud as I think the Harmon Curves can have too much bass with a full range system and loud volume. For "low volume" listening I think the Harmon Curves are good.

 

[levimax]

Are there suggestions for sub placement in various scenarios. I will have 3 subs (2 new identical SVS, 1 old Bagend Infrasub 18) and can't find guidance for placement. Any help is welcome. Thanks.

See attached, this is the best document I have seen on the subject, both theory and practical suggestions. I got it from a member here.

 

[alvigg]

That will give me something to think about! Thanks

 

[RickyC34]

Thanks. Dirac (Flavio) suggested setting the subs to maximum volume and let Dirac turn them down. However, my subs have too much power for that so the +5 dB suggestion is appreciated.

Not sure if you're still trying to dial things in but I feel like he perhaps misspoke or there was some misunderstanding. Start around 12:00 or lower if you would like to play it safe.
Open Dirac's volume calibration
Confirm mic's noise floor is close to -50db.
Play tones for all speakers and exclude subs (+20 db above the noise floor)
Drag the gain lever for the subs down in the Dirac software to match your softest speaker
Hit play on the subs one by one
Is your sub lower than your lowest speaker? Adjust the gain on the rear of the sub so that it is to the desired +5db from the softest speaker. If your sub was louder than the desired +5db lower the gain on the rear of the sub. Repeat for all subs and enjoy.

 

[RickyC34]

Are there suggestions for sub placement in various scenarios. I will have 3 subs (2 new identical SVS, 1 old Bagend Infrasub 18) and can't find guidance for placement. Any help is welcome. Thanks.

REW's room sim could be helpful if not a large open-concept room.

 

[alvigg]

Flavio eventually suggested one in the back.

 

[napfkuchen]

Are there suggestions for sub placement in various scenarios.

As already mentioned you can use REW to simulate your room acoustics, but that won't be 100% accurate. In my living room there are not endless placement possibilities, so I used long powercords and cinch-cables with Dirac. In the end the initial placement (both subs at the front wall, one near a corner and the other at about 1/4 room lenght) resulted in the best overall frequency response.
The room is open to kitchen and hallway, only half of the living room is used for AV. Dirac (DLBC multisub) did an OK job, my rating (better overall bass distribution than Audissey): B
After much room correction measurement and listening to different target-curve-filters I also experimented with seating positions, at least as much as possible (room is 7,5m x 4m, listening area only 3,5m x 4m). Moving the couch just 40 cm towards the back wall seems to have moved me out of a slight bass-dip-area, together with the DLBC measurement this was a very noticeable improvement. Next step will be exchanging the bed-layer-speakers, as their position is currently fixed (wallmount). Freestanding speakers with better directivity hopefully will improve imaging.

 

[dmilller]

Are there suggestions for sub placement in various scenarios. I will have 3 subs (2 new identical SVS, 1 old Bagend Infrasub 18) and can't find guidance for placement. Any help is welcome. Thanks.

Most commonly next to the front speakers is how many/most subs are placed. However with a single sub I couldn't find a good placement. With two subs and Dirac the front placement works fine.

My left and right speakers, and two subs, are a couple of meters from side walls. Needing to place speakers in a corner is often problematic. Subs are usually fine against a wall, but often not good in a corner.

You might start using just the two SVS. When you get those placements good then add in the Bagend. You may get no benefit from a third sub.

 

[fcracer]

Has anyone seen a quantitative list (e.g. a poll) of user ratings for Dirac? I ask because I am astonished at the difference between what I hear versus what is publicly tossed about by professional reviewers (pundits, magazines, audio stores etc.). Nearly all rave about Dirac (including from many that I trust).

I wrote about my experience with Dirac on the NAD M33 here (non-commercial blog) and included some measurements. In summary, it’s the single best improvement in sound I’ve experienced. I would not buy a device that doesn’t have it.

 

[Sparkles]

A/B - I prefer Dirac always on. It is marginally better than my best REW EQ efforts. The REW waterfall shows Dirac is cleaner.

However a 3db downward slope at the high end in Dirac will measure flat in REW for my 2.1 setup so I adjust the Dirac room curve accordingly.

I use a MiniDSP Flex. Preset 1 is REW, 2 is Dirac on movie Harmon-esq curve, 3 is a Dirac on, and 4 is a Dirac on "loudness" curve for lower than conversation level night TV.

 

[GD74]

I'm driving a set of Canton 896DC's with a NAD C658 + C298. Dirac full range.
45m2 L- shaped livingroom, 8x4M rectangular listening area. Speaker spacing 2.6m, 20cm away from the 4M wide wall.

My first correction attempt was with the stock puck microphone which measures at 90 degrees. (upwards)
Ran the wide 17 point setup with the puck mic hooked up to a windows laptop +tripod.
Long story short, it sounded better with Dirac on, but I needed to fiddle around a lot with the manual EQ settings before I got any satisfying results.
Note, it was the older software version without the ëasy Low/High target curve sliders.
At that point I would call it "B" in the poll. Sounded nice, but not much more than that.
And I have to agree that it was lacking some bass in stock form, but I fixed that by adjusting the curve accordingly.

About a year ago I bought a DSP Umik-1 but due to a lot of bad excuses I never got to the point to redo my room measurement. Until today.

I decided to use the 0 degrees calibration values like adviced on the DSP website, and pointed the Umik-1 towards the speakers.
Adjusted the mic level with the Umik, and ran the 17 point wide measurement again.
I took the suggested target curve as default setting, and made some new profiles along the way with more bass, more treble + both with the Hi/Low sliders in the latest SW version.
To finish off, I made a profile with extra setpoints and followed the measured frequency curve of my Canton's.

And boy, did it make a difference
Bass is very deep, tight and pronounced now, while the mids and highs are a lot more clear and full of details.
I'll spare you the long version, but the corrected target curve as suggested by Dirac is the one I was coming back at everytime time as it sounded the most natural to me.
A little bit less bass than with Dirac "off" but the Cantons are already bass monsters so a little bit less bass sounded just right for me.

Knowing all this, I should have done this a year ago right after I had bought the Umik-1
I really wasn't expecting this kind of improvement.
I was very happy with this sound system, but this is next level really.
Funny how you can get used to a sound and be happy with it, until you hear something else.

After recalibration with the Umik it has become a solid "A" for me. What a gamechanger this was.

Regards, Gijs

 

[Rhamnetin]

My rating is a B. I always prefer using it, but I look forward to reevaluating the day I get Dirac ART.

 

[BlairTronica]

Has anyone seen a quantitative list (e.g. a poll) of user ratings for Dirac? I ask because I am astonished at the difference between what I hear versus what is publicly tossed about by professional reviewers (pundits, magazines, audio stores etc.). Nearly all rave about Dirac (including from many that I trust).

I have tried Dirac in two completely different rooms, two amps and three sets of speakers. I have tried it in its limited and its full license version. I have yet to hear it sound any better and usually worse. My own experience is roughly:

• about 2/3 of the time it sounds worse...with less bass, less soundstage breadth
• about 1/3 of the time it has similar or slightly worse bass, with imaging that does 'centralize' the mid and high range, at the expense of a sense of instrument separation

I was beginning to doubt my own hearing (I am getting old that's true HA).

But just yesterday, I went with a friend to a high end audio store and listened to something completely different: A high end McIntosh versus a high end Prima Luna, both running thru speakers I know well. We both agreed 1) there were significant differences and 2) we both agreed at what they were. (by the way, we liked the primaluna a lot more, but that's a different topic.) Point being my hearing was absolutely able to discern (and agree with my friend on) the difference just between two relatively high end and similarly competitive amps.

Back to the topic. I also don't think it should take exhaustive fine tuning, different calibration curves, or god forbid an 'expert' hired to run this. If it's that 'tricky' then it feels more like a science/nerd experiment than a ubiquitous tool for improvement (as it seems to be publicized as).

So here is my suggested poll if you want to participate:

Rate YOUR own experience with Dirac from A to E, where

• A - outstanding/big improvement/difference
• B - good improvement/worth it, not game changing, may use sometimes
• C - no change or no significant advantage with/without Dirac on
• D - marginally worse than without Dirac, not preferred, don't use it
• E - significantly worse sounding, definitely prefer my system without it

My rating? D-

Mike

Just tried the full frequency version. Sounds same as the non full frequency. Which is worse. Reduces the gain and shrinks the stage. Turning it off until I figure it out. Again. My T778 sounds much better without it. D-

Has anyone seen a quantitative list (e.g. a poll) of user ratings for Dirac? I ask because I am astonished at the difference between what I hear versus what is publicly tossed about by professional reviewers (pundits, magazines, audio stores etc.). Nearly all rave about Dirac (including from many that I trust).

I have tried Dirac in two completely different rooms, two amps and three sets of speakers. I have tried it in its limited and its full license version. I have yet to hear it sound any better and usually worse. My own experience is roughly:

• about 2/3 of the time it sounds worse...with less bass, less soundstage breadth
• about 1/3 of the time it has similar or slightly worse bass, with imaging that does 'centralize' the mid and high range, at the expense of a sense of instrument separation

I was beginning to doubt my own hearing (I am getting old that's true HA).

But just yesterday, I went with a friend to a high end audio store and listened to something completely different: A high end McIntosh versus a high end Prima Luna, both running thru speakers I know well. We both agreed 1) there were significant differences and 2) we both agreed at what they were. (by the way, we liked the primaluna a lot more, but that's a different topic.) Point being my hearing was absolutely able to discern (and agree with my friend on) the difference just between two relatively high end and similarly competitive amps.

Back to the topic. I also don't think it should take exhaustive fine tuning, different calibration curves, or god forbid an 'expert' hired to run this. If it's that 'tricky' then it feels more like a science/nerd experiment than a ubiquitous tool for improvement (as it seems to be publicized as).

So here is my suggested poll if you want to participate:

Rate YOUR own experience with Dirac from A to E, where

• A - outstanding/big improvement/difference
• B - good improvement/worth it, not game changing, may use sometimes
• C - no change or no significant advantage with/without Dirac on
• D - marginally worse than without Dirac, not preferred, don't use it
• E - significantly worse sounding, definitely prefer my system without it

My rating? D-

Mike

 

[alvigg]

Dirac has certainly helped quite a bit. I ended up with SVSSB1000's in addition to the bagend I had been asking about. Lots of well balanced bass in 2000 cf room.

 

[BlairTronica]

Just tried the full frequency version. Sounds same as the non full frequency. Which is worse. Reduces the gain and shrinks the stage. Turning it off until I figure it out. Again. My T778 sounds much better without it. D-

Watched a Dirac/NAD Associate tutorial online. I think I now have a better understanding of how the software works. That said, far as my acoustically challenged living room goes, I’ll now give it a C+ when it’s on & an A+ when it’s off.

However, all said & done, if I don’t A/B Dirac (OFF vs ON), I rate it as an A+ as well.