Article: A New Listening Room Part Two: Acoustics, Speakers, DSP

[Le Concombre Masqué]

On 12/14/2019 at 1:17 AM, mitchco said:

Hi @Matias, not directly: https://www.hometheatershack.com/threads/linear-vs-minimum-phase-filters-in-rew-for-minidsp.151513/ 

 

Have a look at @SwissBear article on using rePhase and REW together: 

 

Also have a look at: https://yabb.jriver.com/interact/index.php/topic,87538.0.html

 

Kind regards,

Mitch

Hi Mitch, Swissbear’s article you point to and the tuto linked herein make me wonder about your operational protocol.

My ears told me the averaging method he suggests does not work for amplitude correction.

IMHO Amplitude correction should be performed based on Moving Mic Measures.

 

So, I suggest to start with a Vector average per Swissbear, create in REW a 1/3 smoothing roughly sketched 6dB correction, import it in RePhase and export Impulse Responses as Swissbear suggests. Follow his instructions to generate Excess Phase etc. 

 

But then the fun begins. 

 

One should them perform MMM with those Impulse Responses convolved in solution of choice, would have been Roon for Chris, HQPlayer for me. Then, create more precise eQ in REW, one per channel per target, then go back to Rephase, do more tweaking to the Phase eQ (we need the Vector Average recommended by Swissbear for that to get gorgeous Impulse and Step responses), and then check the exported responses by MMM and maybe add another round for even better results.

 

BTW, my ears told me that Pink Noise, required for MMM, such as the one on old Stereophile CD is not good enough, one can generate one from https://ieeexplore.ieee.org/document/7395532 or consider https://www.arcaudio.com/node/245 good enough. 

 

Or maybe one should call you to come and do that very time consuming process, Mitch !

 

Your explanation about why Chris’ in room response should be almost flat read well.

However, I’d like to stress that the choice of a target curve is not totally subjective.

I think we should aim to have at Listening Position a Tonal Response matching the Mastering engineer’s. A guy who presents himself as “the best mixing engineer on the planet”, certainly with a grain of salt, writes here : https://www.gearslutz.com/board/studio-building-acoustics/521064-main-eq-curve-questions.html :” It is common to use a 'House curve' in professional studios. Digital processors are sometimes used with several curves. One for TV, one for CD, one for Download perhaps.

There are many of us, Bruel and Kjaer included who subscribe to a curve which is very broadly speaking +3 around 100Hz, -3 around 10KHz, and falling. This has been found to enhance the translation of mixes to the outside world.”

 

The Bruel and Kjaer have been widely publicized since 1974. I tend to use it on classical/acoustic/consider it with older stuff/too bass heavy stuff. I use a bass rolled off (slightly : 20 Hz at 200 Hz level, much like Chris) out of respect to my Cabasse’s natural response) Harman (-1 dB/octave) too.

Harman’s extended bass and accentuated treble roll off vs B&K might be a matter of choice/particular mastering ; but I’d recommend to anyone who wants to try DSP to consider +3 around 100Hz, -3 around 10KHz, and falling target.

One can also look at the natural slope of his or her room before correction and see it's probably close to -1dB per octave anyway thus suggesting that even if there was no eQ at LP in the mastering room, there was a downward slope. As Sean Olive wrote( https://seanolive.blogspot.com/2009/11/subjective-and-objective-evaluation-of.htm ) : "The preferred room corrections have a target response that has a smooth downward slope with increasing frequency. This tells us that listeners prefer a certain amount of natural room gain. Removing the rom gain, makes the reproduced music sound unnatural, and too thin, according to these listeners. This also makes perfect sense since the recording was likely mixed in room where the room gain was also not removed; therefore, to remove it from the consumers' listening room would destroy spectral balance of the music as intended by the artist."

 

 

 

 

[Le Concombre Masqué]

On 12/13/2019 at 10:42 PM, mitchco said:

HI @Jud Yes, for example Acourate and Audiolense can generate linear phase DSP filters that maintain linear phase throughout.

Cheers,

Mitch

Hi Mitch, like Jud I also use linear phase filters when I do sample rate conversion (except if percussive sounds prevail). However, based ie on such reading :https://www.gearslutz.com/board/mastering-forum/782708-linear-phase-quot-pre-ringing-quot-audio-examples.html , I opted for the default Minimum Phase eQ banks in Rephase. What is your opinion ?