Would Dirac really help me cure my room's acoustic problems?

[nununo]

Hello,

 

The system:

MacMini with Audirvana

DAC LessLoss 2004

Pre-amp Nagra PL-L

Power monoblocks Nagra MPA

Speakers Vivid Audio V1.5

Subwoofer JL-Audio F112

(with dedicated power line)

 

The problem:

Even though these are all high-end components with an amazing resolution and a sound I love, I'm fighting with the fact that the system's performance is being very limited by my current living room.

 

I tried several full range speakers and they all had serious bass problems. Apparently my living room is the culprit. So I decided to go for a pair of monitors and a good subwoofer with room calibration. That kind of made it bearable to listen to music there. But still... my system doesn't sound relaxed. Thanks to the subwoofer my main problem is now with the higher frequencies. I find that when I start raising the volume, the music quickly becomes tiring and confusing. So I end up avoiding music with lots of dynamics or feel tempted to start lowering the volume. But this is not acceptable for me.

 

An acoustics specialist went to my home and after measuring the living room, said its proportions are very bad for listening to music. He said the first thing to take care of were the first reflections but I have a window on one side and a sliding door on the other, both right where treatment should be applied, which makes it a hard case. Still, he said I should install diffusion panels on the back wall and on the ceiling. I'm very reticent to invest so much money into something which will have a serious aesthetics impact and without the possibility of testing it.

 

The salesman is suggesting that I buy Amarra iRC saying it probably solves a good part of my problems. But not only I'm fond to Audirvana, I also don't like the idea of being stuck to Amarra. And then I heard about Dirac Live.

 

The questions:

1. How much of this will Dirac be able to solve? Will it reduce the impact of first reflections for example?

2. Won't the Dirac algorithm reduce the quality of the result (detail, etc), since it's transforming the information?

3. Would it still be advisable to put diffusion in the back wall for example? (I consider putting it in the back wall, but I really would like to avoid installing it in the ceiling, even though I hear it's much more important there)

4. Will Dirac Live (2 channels) work fine even though I have a subwoofer or will I need the full version because of it?

5. How will Dirac's room correction relate to the subwoofer's room correction? Should I turn of the subwoofer's room correction?

 

Thanks in advance!

Nuno

[4est]

I may be in the minority here, but I would work on the room before trying DSP. I'd start with the back corners first. You might want to read what Barry says:http://www.computeraudiophile.com/f12-headphones-and-speakers/speaker-positioning-and-setup-15875/

[alexwgoody]

1. Dirac and similar room correction software do not "reduce the impact of first reflections" as they cannot alter acoustics. Software can not alter the laws of physics, however it can make certain frequencies quieter (or louder) to try and compensate for some room issues. In my experience, it is usually helpful, but simply running the program once is rarely sufficient. You need to be smarter than the computer and able to know when it is wrong.

2. Debate-able. I say it does not alter the quality of the information in any negative way if it is set up competently. some disagree.

3. Room correction via physical objects is always (assuming it is done well) better than Digital Room Correction. You use DRC when you can't do any more to the room's acoustics. Absorbing and diffusing panels (or other objects) will work better than DRC alone under most circumstances.

4. I do not own Dirac Live, but I am certain that if you run the same DAC input/output to both the speakers and sub, that it will correct low frequencies too.

5. You will have to experiment, but personally I would think it is easier to use Dirac for everything. You don't want to have to balance 2 different room correction settings. You could maybe use it with Dirac to help, but that seems complicated for what will not likely give you any benefit.

 

I personally have used other software and hardware to "fix" the problems with my room and have not used Amarra irc, but they all work in basically the same way. They cannot change how sound travels, just the volume of particular frequencies (it can do other things, ie. Linkwitz Transform, but this is much more complicated and you should learn about this kind of dsp separately).

 

Separately, there is quite a bit of debate as far as what frequencies you want to correct. Many argue that DRC is only useful in correcting the bass frequencies. I would argue that this is not entirely correct, but correcting anything higher than standing waves is relatively difficult compared to basic sub correction.

 

DRC is wonderful technology, but is in-arguably inferior to panels and real physical gear to correct room acoustics. Think of it like a band-aid rather than a cure-all.

 

With that said, I use DRC, and will continue to use DRC for the foreseeable future. If set up in an effective manner (a big "if"), my far-from-perfect listening room benefits from the countless hours I've spent reading and setting it up. Remember that you are smarter than the computer, check its work and think logically. Don't just assume that since you ran the test sweeps that you or the computer are setup 100% perfectly. This will take hours upon hours of time to setup perfectly, but the results are often worth it.

[nununo]

Thanks. I'll take all these tips into account.

[flak]

Thanks. I'll take all these tips into account.

 

Hi Nuno,

alexwgoody clearly has knowledge of the subject and hands-on experience but there have been significant advancements in digital room correction in the last few years and he has not tested Dirac Live yet.

So it's not true that "they all work in basically the same way", on the contrary Dirac Live is a unique patented mixed-phase solution which can apply a successful correction in the time domain.

The limitations of conventional minimum-phase (or linear-phase) solutions in correcting our rooms with mixed-phase behaviour are explained in the REW's developers site:

Why%20Can%27t%20I%20Fix%20All%20my%20Acoustic%20Problems%20with%20EQ?]Home Theater Forum - Home Theater Systems - HomeTheaterShack

Dirac's research is very recent... this is the earliest document which has been partially presented in 2007 at the 123rd AES convention in NYC: http://www.dirac.se/media/12044/on_room_correction.pdf

Scientific peer reviewed documents have been published from 2009.

 

I understand your reticence in investing either in passive or active room correction solutions without the possibility of testing them.

You can thoroughly test Dirac Live with your system and in your home for two weeks: Dirac RCS | Dirac Research so you don't have to trust anybody's words... you can listen and measure yourself to then take a decision.

You will find actual audible improvements and much better impulse and frequency response measurements with Dirac Live (or Amarra with iRC) but you will need a calibrated measurement microphone (one option is the following: Dirac Online Store. UMIK-1 USB Measurement Microphone).

I suggest you loan or buy one of the many measurement microphones before starting the two weeks test period.

As far as the demo version that you should download is concerned please note that the stereo version is the one to choose if you use two channels only and there is some kind of passive or active crossovering downstream, otherwise you'll need the full multichannel version.

 

You will learn a lot about your room behaviour and it will be fun too...

 

enjoy your test

Flavio

[alexwgoody]

flak, thank you for your included information. I was not entirely aware that it did time domain correction. My question now is to what extent? This may be better served in a Dirac thread, but I am wondering how the software deals with multiple subwoofer setups. I assume I would need the multichannel software, correct? (for stereo with 2 or more subs) Could you discuss or link me to an article discussing the extent of Dirac's ability to do the time domain analysis for systems with 2 or more subs?

 

Also, I already have the umik bought from miniDSP. Is this the same microphone and will the calibration file they provided work with Dirac?

[flak]

Hi alexwgoody,

 

a multichannel version of Dirac Live is not necessarily required if two subwoofers are used... I personally use a pair of electrostats with a pair of subwoofers, in my case Foobar goes to Stereo Dirac Live (acting as a virtual audio card) which feeds a DAC to go to the preamp and then to a four channel digital crossover... a multichannel version is necessary if one or more subwoofers are used but no downstream crossovering is used as in home-theater multichannel systems.

 

The Umik-1 microphone you have with its calibration file will work perfectly well with Dirac Live... actually all calibrated measurement microphones will work well (a minor modification to the file is necessary if the calibration file shows the correction to be applied instead of the frequency response itself)

 

Finally the extent of time domain correction is the largest possible, that's the reason why nine measurements are required to avoid correcting what should be not corrected... and answering to Nuno's original question a proper mixed-phase filter design is similar to removing reflecting surfaces near the loudspeaker so that Dirac Live would help in his case.

 

Flavio

[nununo]

Finally the extent of time domain correction is the largest possible, that's the reason why nine measurements are required to avoid correcting what should be not corrected... and answering to Nuno's original question a proper mixed-phase filter design is similar to removing reflecting surfaces near the loudspeaker so that Dirac Live would help in his case.

 

Understood. Thanks. So I'll start by trying that since it can be tried without spending money and only then will I consider more physical interventions in the room. I'll find a microphone and give it a try. Thank you.

 

Nuno

[maelob]

If I had money I would hire the author of Get Better Sound to come to my house and really tweak my system. Just another option

[dallasjustice]

You need to measure your room first using REW to get a basic idea about the LF problems in your room. Sidewall reflections are generally not that big of a problem in most rooms. In fact, living rooms can be pretty decent for music depending on the shape and size of the room. Any acoustician that tells you to use DSP before room treatment or speaker/seat reposition isn't plugged in. DIRAC is wonderful, but it should be one the last things you do, not first.

 

You might receive more constructive advice if you posted a diagram of your room and some measurements. Since this is your living room, you might not like how large most bass traps need to be. You might consider a pressure trap instead. They are much smaller and more aesthetically pleasing. I am talking about RPG Modex plates. Decay times can be measured as well but ultimately that is more of a preference related to the type of music you enjoy; longer for big symphony, shorter for speed metal. :-)

[flak]

Hi Dallajustice,

 

everything you say was correct up to now but the new Dirac's mixed-phase correction is different.

I understand you are using Dirac Live, I imagine you are using large and expensive bass traps, modex plates or corners and you are using REW for measurements... so I ask you the courtesy to experiment removing them, and use Dirac Live only.

 

You'll find interesting results and you will understand why I'm suggesting to try Dirac Live first, against conventional wisdom... your comments would be highly appreciated and I thank you if you will find the time to experiment

 

Flavio

[dallasjustice]

I would be happy to remove all 6 Modex plates, 4 MSR spring traps and 4 mounted modified primacpustic corner traps and modified ceiling cloud anchored into the ceiling to do an experiment. Let me know when you can come over to help me do that. :-)

 

I really do love what DIRAC does but I am skeptical that it could do what several well placed Modex plates will do. I think all of the above is the best approach.

 

 

 

Hi Dallajustice,

 

everything you say was correct up to now but the new Dirac's mixed-phase correction is different.

I understand you are using Dirac Live, I imagine you are using large and expensive bass traps, modex plates or corners and you are using REW for measurements... so I ask you the courtesy to experiment removing them, and use Dirac Live only.

 

You'll find interesting results and you will understand why I'm suggesting to try Dirac Live first, against conventional wisdom... your comments would be highly appreciated and I thank you if you will find the time to experiment

 

Flavio

[flak]

I would be happy to remove all 6 Modex plates, 4 MSR spring traps and 4 mounted modified primacpustic corner traps and modified ceiling cloud anchored into the ceiling to do an experiment. Let me know when you can come over to help me do that. :-)

 

I really do love what DIRAC does but I am skeptical that it could do what several well placed Modex plates will do. I think all of the above is the best approach.

 

Thanks anyhow Dallasjustice, it's quite understandable

I thought that there was something that you could temporarily remove with ease... just for the sake of verifying what I'm saying, but I see this is not the case.

 

Good listening,

Flavio

[alexwgoody]

everything you say was correct up to now but the new Dirac's mixed-phase correction is different.

I understand you are using Dirac Live, I imagine you are using large and expensive bass traps, modex plates or corners and you are using REW for measurements... so I ask you the courtesy to experiment removing them, and use Dirac Live only.

 

You'll find interesting results and you will understand why I'm suggesting to try Dirac Live first, against conventional wisdom... your comments would be highly appreciated and I thank you if you will find the time to experiment

 

Flavio

 

After reading some of your posts, it seems that you claim that the software can be a replacement for room treatments and can make up for all acoustic issues within a room. Is it the opinion of Dirac that this is so? Does this "mixed phase correction" mean that acoustic panels, bass traps and the like are unnecessary? Is there not an extent to which room modes, phase issues and the like are simply impossible to overcome with DSP alone?

 

I will download the trial this weekend or when I have some free time to test this on my own.

[flak]

Hi Alexwgoody,

 

mitigating the effects of reflections and room modes within the listening area defined by the nine measurements is the purpose of Dirac Live's mixed-phase solution... so that in a normally furnished listening room, where the usual precautions about speakers and listening point placement have been taken, the results can be excellent even without passive correction.

There is a downside... the sound quality will worsen outside of the predefined listening area.

 

I'm pleased that you are going to download the trial and I'm interested in your comments

thanks, Flavio

[Hipper]

You can employ moveable panels etc. Some GIK Acoustic panels for example can have feet installed and are easily moveable. I do this for first reflection points as it's not convenient to locate the panels there permanently.

[jmdesignz2]

tagged for future reference

[Jim Smith]

Dirac might well be of some assistance, but IMO, the acoustic problems should first be addressed acoustically, prior to using an electronic solution.

[flak]

Dirac might well be of some assistance, but IMO, the acoustic problems should first be addressed acoustically, prior to using an electronic solution.

 

Well, there have been significant advances in the last few years so that in a normal listening room Dirac Live can be all that is needed..... but nobody has to trust my words, it's possible to test it for free for two weeks and evaluate the results

 

Flavio

[nununo]

Jim, even if that is true, one bumps into reality: my living room doesn't accommodate very aggressive acoustic treatment. And the places that need it the most are either impractical (I have a sliding wooden door on one side and a large glass door on the other) or too violent aesthetically (adding lots of panels to the roof). So, the only acoustic treatments that I consider doing are in the wall behind me and on the room corners. Besides, any proper room treatment amounts to thousands of euros.

 

So, I will definitely give it a try! I will invest 110€ in a calibrated microphone and try Dirac for free for 2 weeks. If it's good enough I'll buy it. If it's not good enough... then I'll go for acoustic treatment. And once the possible acoustic treatment is done I'll probably ask Dirac for another trial in the hope that the both together will suffice.

 

Still, I am doing it in the hope that Dirac will invest in creating proper integration with the existing Mac programs in the near future. Particularly, developing an Audio Unit version of its software so that I can use it without taking full advantage of Audirvana's potential. Flavio, I hope you read this

 

Cheers,

Nuno

[flak]

Hi Nuno,

 

of course I've read your message ... as of now Dirac is working on other important developments but a plugin is a possibility for the future.

b.t.w. there are less expensive measurement mics: Dirac Online Store. UMIK-1 USB Measurement Microphone

 

Flavio

[ckpiv]

Jim, even if that is true, one bumps into reality: my living room doesn't accommodate very aggressive acoustic treatment. And the places that need it the most are either impractical (I have a sliding wooden door on one side and a large glass door on the other) or too violent aesthetically (adding lots of panels to the roof). So, the only acoustic treatments that I consider doing are in the wall behind me and on the room corners. Besides, any proper room treatment amounts to thousands of euros.

 

So, I will definitely give it a try! I will invest 110€ in a calibrated microphone and try Dirac for free for 2 weeks. If it's good enough I'll buy it. If it's not good enough... then I'll go for acoustic treatment. And once the possible acoustic treatment is done I'll probably ask Dirac for another trial in the hope that the both together will suffice.

 

Still, I am doing it in the hope that Dirac will invest in creating proper integration with the existing Mac programs in the near future. Particularly, developing an Audio Unit version of its software so that I can use it without taking full advantage of Audirvana's potential. Flavio, I hope you read this

 

Cheers,

Nuno

 

Nuno,

 

I am in a similar situation to you. My Listening area is in the family room and I am restricted in what I can do as the wife and kids use the area as well. I have lots of windows, sliding glass doors and a large glass reptile cage plus your normal furniture. I have been using the trial of Dirac now for coming up on two weeks after investing in a XTZ calibrated mic. I was torn between investing in Dirac or Amarra Symphony with DRC. However, after using Dirac with Audirvana Plus in playlist mode, JRiver MC, Amarra Standard and MOG I do not think I can limit myself to only Amarra Symphony. The results I have obtained in my room using Dirac with the above programs is amazing. I thought my system sounded pretty good but with Dirac its like another veil has been lifted. I definitely had some bass resonance issues that blurred the music as well as my highs being rolled off. With Dirac's default values I am getting great results and am looking forward to tweaking the curve and experimenting with different mic placements. I am so impressed with the results that I do not think I will be able to resist not having it in my system. Even having to use Audirvana without direct/integer mode the sound is still amazing.

 

Good luck with your journey and I hope you fine Dirac as satisfying as I have.

 

All the best,

 

Chuck

[weverb]

I wish Dirac would make an external unit since I have multiple sources (i.e. Oppo, turn table, etc.) and that it worked with Windows XP. Hint, hint! Wink, wink!

[nununo]

Hi Chuck, those are great news. Thanks for sharing. I'm looking forward to giving it a try. And, considering all the positive feedback, I'm quite confident that it will be an improvement to what I have: harsh treble which makes me want to turn down the volume whenever the music is loud, whenever there are big dynamic changes in volume (chamber music for example) or in orchestra pieces (with many instruments at the same time things get all mixed up).

 

Cheers,

Nuno

[nununo]

hi Flavio,

 

Thanks. I hope the plugin becomes a reality! Since AU is just a kind of interface, I hope it's not a big change, since the most of your code should remain unchanged. And I hope those important developments result in improvements to what people are already praising as a great product.

 

About the mic, I did see that one, but since it's coming from HK I fear for how much I'll have to pay in taxes to get it. But maybe it would still be cheaper. Does that measurement mic UMIK-1 have the same quality and thus the same results as the one which costs 110€? I found it strange that this latter one says it will only work with Dirac. If you say it's the same I'll consider buying the UMIK-1.

 

Thanks,

Nuno