My first REW measurements(KEF R3 META)

[TheZebraKilledDarwin]

A new thread maybe of interest. No need to be frightened by the look of absorbers: https://www.audiosciencereview.com/forum/index.php?threads/2-1-setup-with-gik-acoustics.44672/

 

[kolestonin]

I am trying to investigate all my options and I will again need your feedback.

I am seriously considering take the room treatment route but I wonder if a dirac licence can do the job(or 90% of the job) with less cost.
Is this a valid thought? or maybe I compare two different things?

If I decide to do both(room treatment+dirac) what would be the most logic thing to do. Start with room treatment and buy a dirac license in a second phase or the opposite. What should be my priority?

 

[HarmonicTHD]

I am trying to investigate all my options and I will again need your feedback.

I am seriously considering take the room treatment route but I wonder if a dirac licence can do the job(or 90% of the job) with less cost.
Is this a valid thought? or maybe I compare two different things?

If I decide to do both(room treatment+dirac) what would be the most logic thing to do. Start with room treatment and buy a dirac license in a second phase or the opposite. What should be my priority?

UMIK and REW plus RoomEQ eg Dirac. You need to establish a measurement baseline anyhow before even start with room treatment. You will get hopelessly lost otherwise.

 

[TheZebraKilledDarwin]

The problem is, you don't have any experience, how great improved acoustics can sound in your room. And it's not the easy way, compared to buying equipment.
But you are listening in stereo: you could save the money for Dirac now and do the RoomEQ on a computer for free, while you go the way of acoustic improvement.

 

[kolestonin]

My understanding of my measurements is that I have two main issues:

1) some peaks and dips on both listening positions
Peaks main listening position: 50Hz

Dips main listening position: 58Hz, 112-120Hz

Peaks second listening position: 76, 61, 50Hz

Dips second listening position: 80-120

2)Reverb time is over 500ms and under 200Hz it passes 800ms.

I think that peaks and dips can be cured with EQ, but for the reverb time issue(which has a bigger negative impact?) the room treatment is inevitable.

How accurate is above statement?

The options I consider are:

a) share my measurements with an acoustic material selling company and ask for their suggestion(estimated cost: 700-1000eur+aesthetic impact on my living room)

b) buy a dirac live license(cost: 325eur+no aesthetic impact on my living room)

So option b is cheaper, simpler(no panel's installation) and without any aesthetic impact.
There must be some drawbacks though. I have no clues on the advantages of each solution.

 

[HarmonicTHD]

My understanding of my measurements is that I have two main issues:

1) some peaks and dips on both listening positions
Peaks main listening position: 50Hz

Dips main listening position: 58Hz, 112-120Hz

Peaks second listening position: 76, 61, 50Hz

Dips second listening position: 80-120

2)Reverb time is over 500ms and under 200Hz it passes 800ms.

I think that peaks and dips can be cured with EQ, but for the reverb time issue(which has a bigger negative impact?) the room treatment is inevitable.

How accurate is above statement?

The options I consider are:

a) share my measurements with an acoustic material selling company and ask for their suggestion(estimated cost: 700-1000eur+aesthetic impact on my living room)

b) buy a dirac live license(cost: 325eur+no aesthetic impact on my living room)

So option b is cheaper, simpler(no panel's installation) and without any aesthetic impact.
There must be some drawbacks though. I have no clues on the advantages of each solution.

The peaks can be treated with EQ, the dips not so much as these are caused by cancellations. The dips can be “filled” however with one or ideally more adequately placed subs, which need to be aligned with EQ (eg Dirac Bass Management or manually using REW and eg a MiniDSP etc). Look up articles or threads on sub placement.

I definitely start with option 2 as you need it anyway, because room treatment will not be able to completely solve all your problems. Plus room treatment for low frequency involves huge (very very thick ca >1/4 wavelength of the frequency to be treated) panels (bass traps) which I personally I find dead ugly for a living room.

 

[Gruesome]

But doesn't he need to get the RT60 times under control (i.e. to 300ms or so) first?

 

[TheZebraKilledDarwin]

So option b is cheaper, simpler(no panel's installation) and without any aesthetic impact.
There must be some drawbacks though. I have no clues on the advantages of each solution.

The important drawback is, that the acoustics cannot be improved with RoomEQ.
Professionally sounding systems (as differently as they are sounding), have one characteristic in common, which everyone immedialy notices, without knowing the reason: the controlled/low amount of indirect sound and the high amount of direct sound.
IME a professional sound starts to manifest, if RT60 reaches indeed 300 ms or below (for typical room sizes) and Clarity 50 reaches 15 dB for the midrange.

Does reverb time really play such a big role?
Contrary to acoustic concerts, where one single concert hall for all instruments is part of the whole "mix", any other kind of recorded music or audio, uses (very) different spaces and ambiences and amounts of it, for different instruments/sounds. The amount of the sound always created by the listening room, must be adequately low, that we are able to start to hear the ambiences in the mix, and not a reverberated mess imposed on everything.

It does not matter which RoomEQ, how expensive speakers and subs are, the room will continue forever to superimpose the huge amount of his own sound on everything, if it is not reduced. Even if you would spend a million dollars, the room will stay as loud and do his mess, as he is doing now.

RoomEQ cannot reduce the level the room is imposing on the mix and therefore cannot create that professional sound and vibe acoustically controlled setups have in common.
Ofcourse marketing can do a lot. And imagination of customers, who do not want to hear reality, is a strong force.


Filling up dips:
At higher frequencies with EQ can work very well, but certain cancellations cannot be overcome, because you know zero multiplied with any bigger number (frequency level increased by EQ) is still zero.
And be warned: if you look only at the SPL graph and ignore the time domain (the behaviour over time), filling up dips may look much flatter, but may sound worse, because the SPL is showing the energy over the whole time, not when it arrives. It may arrive at a later time, or create a strange kind of pressure in the ears.

You can use a (pulsed) sine wave of the problematic frequency you filled up and listen, how it really sounds, after filling up dips. You may not like it, despite a flatter SPL measurement.

 

[kolestonin]

The importance of room treatment is fully clear to me after the latest posts. I am not happy to hear that I will need some really thick bass traps but I will discuss the matter with an expert and try to keep it as minimal as it possible. I understand it will be hard as my L shape room is difficult.

I just want to know if in terms of RoomEQ same result can be achieved with REW&APO and dirac live.
I understand that dirac is way more simple and user friendly. But what if someone works hard with REW&APO and do a lot experimentation?
Can we say he can arrive where dirac brings him? or no matter the effort the result of dirac will never be achieved by 2 previously mentioned free solutions?

 

[Gruesome]

I would try carpets/runners, drapes, pictures, sofas, rearranging furniture first before installing bass traps and absorber wall coverings etc.. People as absorbers will also work; you could invite friends over, or if you have children, teach them to stand still in certain spots while you are listening to music.

My understanding is REW & APO (or another standalone parametric equalizer that you can feed/enter the REW derived filters into) can do the same things Dirac does, with maybe a little bit more work. REW is a lot of fun though once you get the hang of it.
There are also integrated amplifiers that have either Dirac or something similar installed (and come with microphones). I don't know how well those things work, but that would save you from having to type in or program REW filter curves into anything. Of course, it might be good to look at the filter parameters, besides just trusting your ears.

 

[HarmonicTHD]

The importance of room treatment is fully clear to me after the latest posts. I am not happy to hear that I will need some really thick bass traps but I will discuss the matter with an expert and try to keep it as minimal as it possible. I understand it will be hard as my L shape room is difficult.

I just want to know if in terms of RoomEQ same result can be achieved with REW&APO and dirac live.
I understand that dirac is way more simple and user friendly. But what if someone works hard with REW&APO and do a lot experimentation?
Can we say he can arrive where dirac brings him? or no matter the effort the result of dirac will never be achieved by 2 previously mentioned free solutions?

Yes. REW and APO work well.

Basstraps need to be ca 1/4 of the wavelength thick to be effective, that’s simple physics. As you mainly mention low frequencies, for example 100hz has a wavelength of ca 4m/11feet and therefore you need some 1m thick trap.

There is a thread somewhere here where someone went through everything RoomEQ, passive treatment and active treatment and published results and pictures. Gives you an idea what does what with what efficiency.

 

[napfkuchen]

Basstraps need to be ca 1/4 of the wavelength thick to be effective, that’s simple physics. As you mainly mention low frequencies, for example 100hz has a wavelength of ca 4m/11feet and therefore you need some 1m thick trap.

It's always a compromise between space/cost/aesthetics, everyone can set their own priorities. I think you're exaggerating here. Even in many professional recording studios there isn't that much space for bass absorbers. In my small (14 m²) room, in addition to some standard absorbers, 4 absorbers on the back wall with the dimensions 0.4 x 0.4 x 1m reduced the reverberation at 60 Hz from 0.7s to 0.3s.

 

[TheZebraKilledDarwin]

There is a thread somewhere here where someone went through everything RoomEQ, passive treatment and active treatment and published results and pictures. Gives you an idea what does what with what efficiency.

Very interesting. Do you have a link to the thread?

 

[HarmonicTHD]

Very interesting. Do you have a link to the thread?

No I would have to search for it too. Sorry.

 

[OCA]

First the good news:

Since your source is a Windows PC, you can easily get rid of all the peaks and some dips with digital correction. Just install a free DSP tool like Equalizer APO or Camilla DSP and create two sets of filters for two different listening positions. If you're using a media player like JRiver, you don't even need those, it has its own DSP engine. No need to use the PEQ on your subs either, you can sort everything out more efficiently with high tap count convolution filters from the PC. To try to tame those peaks below 200Hz (you have one at 20Hz) with acoustic treatment is nearly impossible due to the size of the traps required and also unnecessary because proper DRC will do a more precise job without killing your brilliance response and can even correct your speakers crossover phase shifts.

Now some bad news:

You are measuring left and right speaker together which is useless. Each speaker should be individually measured and corrected.
You seem to have a ~60Hz AC noise in your system (strange that it's not around 50Hz since you're in EU) and the peak and dips and phase anamolies between measurements around 58Hz and its harmonics are caused by that. It is not as audible as it looks but it cannot be corrected with DRC or room treatment. Connecting everything into the same wall socket might stop or at least minimize it.
Your speakers are either not toed-in properly for the LP or their tweeters are not at ear height which is causing the steep roll off at the high frequencies. You don't want to touch this area with DRC so better adjust your speaker placement.

 

[TurtlePaul]

I am going to disagree with some of the others here. Yes, there are things that can't be fixed without room treatments. That doesn't mean you can't get absolutely dramatic gains with parametric EQ. The 50 hz problem you are probably not going to be able to fix with room treatments short of EQ (way too much energy at way to low of a frequency). 110 hz can probably be fixed with subwoofer integration adjusting the distance of your speakers to the wall.

Room reverb times are much less important than many are impying in bass frequencies. The first filter below is going to dramatically improve the punchyness of your bass (it is removing 90% of the energy in a wide band around 50 hz).

Based on your main listening position, try the following filters in Equalizer APO:

Preamp -6 dB
Parametric Filter 50 hz -10.0 dB 2.7 Q
Parametric Filter 107 hz +5.0 dB 4.0 Q
Parametric Filter 167 hz -4.4 dB 5.0 Q
Parametric Filter 30 hz +5.5 dB 5.0 Q

Experiment with the following filter and see if you like it:
Parametric Filter 1,075 hz +2 dB 6.0 Q

edit: tweaked filters

 

[theREALdotnet]

I understand that dirac is way more simple and user friendly. But what if someone works hard with REW&APO and do a lot experimentation?
Can we say he can arrive where dirac brings him? or no matter the effort the result of dirac will never be achieved by 2 previously mentioned free solutions?

I’d say, don’t overthink it. Don’t try to optimise something purely speculative. From the pictures you’ve shown I know where I would spend my money first: that TV screen is way too small for the viewing distance. The biggest wow factor in your setup will likely come from getting a properly sized screen between those speakers. And this coming from someone who is usually blasé about TV screens. Next up, get lots of soft furnishings in that room, before thinking of bass traps and other traps for the unwary.

 

[TurtlePaul]

Regarding DIRAC, it is a much simpler solution to do time alignment. However, research seems to suggest that maintaining a flat phase/impulse response does very close to nothing. REW will get you flat frequency response fairly easily. Frequency response is much more important than RT60 and it is much much more important than impulse response.

 

[Gruesome]

But doesn't a 0.6s decay time mean you should mostly play church music? ;-)

 

[OCA]

Regarding DIRAC, it is a much simpler solution to do time alignment. However, research seems to suggest that maintaining a flat phase/impulse response does very close to nothing. REW will get you flat frequency response fairly easily. Frequency response is much more important than RT60 and it is much much more important than impulse response.

I agree that simple FR correction will get you 80% of the way there but phase response between 100Hz-1000hz is accepted to be quite audible. More importantly, phase differences between the left and right speaker in this area cause obviously audible dips and peaks in the combined response and that's what Dirac attempts to correct.