Jump to content
The Computer Audiophile

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

Rate this topic

Recommended Posts

5 hours ago, mitchco said:

Hello. There are 4 common industry standard target frequency responses used to calibrate monitors in sound production control rooms. B&K, Toole and Olive, ITU and EBU 3276. And overlaid on one chart:

 

Industry Standards Operational Room Response Targets.jpg

 

Given that each target has a +- 3 dB tolerance, effectively each target overlaps one another, all with a downward frequency response at the listening position. This is because loudspeakers are omnidirectional at low frequencies with narrowing directivity at higher frequencies. The rising bass energy yields a steady-state room curve with a downward tilt.

 

This is important to note because ones preference for one target or the other is based on a number of factors, all coming into play at once. Size of listening room, directivity index or polar response of the loudspeakers, distance from speakers to listener (there is a spec with a range), how much direct versus reflected sound is being heard at the listening position based on how lively or dead the listening environment is, also with spec and range of operation. All of these factors play into which target one prefers, with the common theme of how much or little high frequency response is required based on these factors.

 

For example, in my room with narrow directivity loudspeakers and a fairly large and lively room (600 ms broadband decay time) with a 9ft equilateral triangle, I prefer the Toole Olive target response. Sounds neutral to my ears given this combination of loudspeaker/room.

 

On the other hand, Chris's loudspeakers are wider directivity, also larger room. but with a 200ms broadband decay time. In order to hear the same perceived neutral response, more direct high frequency energy is required to arrive at Chris's listening position as compared to my loudspeakers in my room.

 

Normally, I would deliver all 4 target responses at once for your loudspeakers in your room. As Chris has shown in Roon, one can easily flip through different filters as music is playing and choose what sounds best to your ears. Toole and Olive have shown in participant listening studies that as Floyd Toole describes, accurate and preferred are synonymous

 

Due to schedules, I delivered Chris one filter set at a time, instead of all 4. And started with the target with the most rolled off top end 🙂 LOL! Exactly what he did not need. The 4th target delivered, weeks later, should have been the first. I would hazard a guess that is the frustration.

It turned out for the better that I received the other curves first. I learned much more and became very familiar with their differences. 


Founder of Audiophile Style

Share this post


Link to post
Share on other sites

Earlier this month, I purchased 6 of the Vicoustic DC2 Multifuser Panels (same as those purchased by Chris).  I am located in USA.  I found a reputable seller based in the U.K., Gear4Music that is an authorized seller.  Shipped to me in the USA, the 6 panels cost $438.  Dealers in the USA charge $650.  

 

One nice thing, these panels are thick so you can stack them, as I have done in the picture below.

IMG_0056.jpg


Home: EtherRegen | UltraRendu + LPS 1.2 | Berkeley Alpha USB | Denafrips Terminator | Jeff Rowland Coherence II Series 2 | Blue Circle Audio BC-202 | Raidho XT-1 | 2 x Revel Performa3 B112 subwoofers  

 

Desktop: Iso Regen + LPS 1 | Eitr | Chord Qutest  | Aesthetix Calypso pre | Blue Circle Audio BC-28 amp | Scansonic MK-5 monitors | Elac S10 sub

Share this post


Link to post
Share on other sites

What are the materials in these panels?

 

It strikes me that with the availability of photos printed on fabric, if these panels use non-exotic materials and we have a few members who know how to design them, decor- and wallet-friendly acoustic panels might be a very nice DIY project.


One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> eero Pro router -> EtherREGEN -> microRendu -> USPCB -> ISO Regen (powered by LPS-1) -> Ghent JSSG360 USB cable -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

Share this post


Link to post
Share on other sites
1 minute ago, Jud said:

What are the materials in these panels?

 

It strikes me that with the availability of photos printed on fabric, if these panels use non-exotic materials and we have a few members who know how to design them, decor- and wallet-friendly acoustic panels might be a very nice DIY project.

The Vicoustic DC2s are made of expanded polystyrene.


System (i): (iUSB3.0 Nano/RPi 2/Moode > 2Qute+MCRU psu; Gyrodek/SME V/Ortofon 2M Black/EAT E-Glo Petit/Magnum Dynalab FT101A) > Glow Amp One > Klipsch RP-600M

System (ii): iUSB3.0 Nano/RPi 2/Moode > Bel Canto uLink+AQVOX psu > Chord Hugo > (Tandy LX5; JBL LSR305 ; Audeze LCD-3)

Share this post


Link to post
Share on other sites

Mitchco/Others: Specific to the discussion regarding DSP - I have a very nice pair of Focal Sopra 2’s in a bit of a challenging room that has been nicely treated.  As a typical audiophile, I am always wondering if I can improve the sound.  Since I use Dirac (which significantly helps), I occasionally wonder if getting a different pair of speakers would actually make any significant difference.  If a speaker of this level has solid measurements (see “Soundstage!” National Research Council of Canada measurements) would another speaker that measures well (and after the application of room correction) actually improve things? Bringing a pair of Magico’s, Wilson’s, JBL’s, Vandersteen’s, etc., into my room to test out is really not an option. I would like to hear your thoughts.  I do wonder if once a speaker is mostly full range, with solid measurements, if diminishing returns, becomes no returns with DSP/Room correction.

Share this post


Link to post
Share on other sites
22 minutes ago, Richard Dale said:

 

I got some 5mm MDF panels cut, painted them black and then glued the black DC2s to the panels. Then I could mount them on the wall with sawtooth hangers just like I've done with the GIK absorber/diffuser panels on the side walls.

 

 

 

Good idea.  I am still playing around with positioning of the panels.  Once I settle I will use your same method.

 

 


Home: EtherRegen | UltraRendu + LPS 1.2 | Berkeley Alpha USB | Denafrips Terminator | Jeff Rowland Coherence II Series 2 | Blue Circle Audio BC-202 | Raidho XT-1 | 2 x Revel Performa3 B112 subwoofers  

 

Desktop: Iso Regen + LPS 1 | Eitr | Chord Qutest  | Aesthetix Calypso pre | Blue Circle Audio BC-28 amp | Scansonic MK-5 monitors | Elac S10 sub

Share this post


Link to post
Share on other sites
11 minutes ago, Jud said:

What are the materials in these panels?

 

It strikes me that with the availability of photos printed on fabric, if these panels use non-exotic materials and we have a few members who know how to design them, decor- and wallet-friendly acoustic panels might be a very nice DIY project.

A couple dealer friends told me to just make the absorption panels myself. Not confident in my ability to do any such thing, I obviously purchased them. 
 

There’s really nothing to the panels. Just correct materials selection and a look if needed. 


Founder of Audiophile Style

Share this post


Link to post
Share on other sites
12 minutes ago, The Computer Audiophile said:

A couple dealer friends told me to just make the absorption panels myself. Not confident in my ability to do any such thing, I obviously purchased them. 
 

There’s really nothing to the panels. Just correct materials selection and a look if needed. 

GIK use rockwool in their panels, and they don't cost all that much. I think you'll find if you work out how much a DIY panel would cost compared with the GIK panels it wouldn't save all that much and probably wouldn't look as good.

 

Vicoustic and Artnovion have a higher standard of finish than GIK (although GIK are pretty excellent), and the Cherry wood in my Vicoustic Super Bass Extremes looks lovely - unless you are some kind of cabinet maker by trade I can't see how you could get anywhere near that standard of finish with a DIY project.


System (i): (iUSB3.0 Nano/RPi 2/Moode > 2Qute+MCRU psu; Gyrodek/SME V/Ortofon 2M Black/EAT E-Glo Petit/Magnum Dynalab FT101A) > Glow Amp One > Klipsch RP-600M

System (ii): iUSB3.0 Nano/RPi 2/Moode > Bel Canto uLink+AQVOX psu > Chord Hugo > (Tandy LX5; JBL LSR305 ; Audeze LCD-3)

Share this post


Link to post
Share on other sites

all types of panels and tube traps as well can be made DIY from inexpensive materials - for QRD you need an online calculator

 

but it takes time to do so, and some space for at least a chop saw


"The overwhelming majority [of audiophiles] have very little knowledge, if any, about the most basic principles and operating characteristics of audio equipment. They often base their purchasing decisions on hearsay, and the preaching of media sages. Unfortunately, because of commercial considerations, much information is rooted in increasing revenue, not in assisting the audiophile. It seems as if the only requirements for becoming an "authority" in the world of audio is a keyboard."

-- Bruce Rozenblit of Transcendent Sound

Share this post


Link to post
Share on other sites
40 minutes ago, Richard Dale said:

GIK use rockwool in their panels, and they don't cost all that much. I think you'll find if you work out how much a DIY panel would cost compared with the GIK panels it wouldn't save all that much and probably wouldn't look as good.

 

Vicoustic and Artnovion have a higher standard of finish than GIK (although GIK are pretty excellent), and the Cherry wood in my Vicoustic Super Bass Extremes looks lovely - unless you are some kind of cabinet maker by trade I can't see how you could get anywhere near that standard of finish with a DIY project.

 

I have a couple of neighbors with reasonably extensive home wood shops. And if the fabric is photo printed, then that becomes the highlight and you can pull it over the wood frame.


One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> eero Pro router -> EtherREGEN -> microRendu -> USPCB -> ISO Regen (powered by LPS-1) -> Ghent JSSG360 USB cable -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

Share this post


Link to post
Share on other sites
4 minutes ago, Jud said:

 

I have a couple of neighbors with reasonably extensive home wood shops. And if the fabric is photo printed, then that becomes the highlight and you can pull it over the wood frame.

Photo printed similar to this?

 

 


Founder of Audiophile Style

Share this post


Link to post
Share on other sites
4 minutes ago, Jud said:

 

I have a couple of neighbors with reasonably extensive home wood shops. And if the fabric is photo printed, then that becomes the highlight and you can pull it over the wood frame.

OK, but note that tuned membrane panels such as Vicoustic Super Bass Extremes, GIK Scopus Bass Traps and GIK Tri-Traps with a range limiter membrane are not as easy to reproduce in a DIY project as just stuffing a filling into a decorative box. Compared with other audiophile tweaks, acoustic treatment, even designer level acoustic treatment, is much cheaper than say fancy interconnects.


System (i): (iUSB3.0 Nano/RPi 2/Moode > 2Qute+MCRU psu; Gyrodek/SME V/Ortofon 2M Black/EAT E-Glo Petit/Magnum Dynalab FT101A) > Glow Amp One > Klipsch RP-600M

System (ii): iUSB3.0 Nano/RPi 2/Moode > Bel Canto uLink+AQVOX psu > Chord Hugo > (Tandy LX5; JBL LSR305 ; Audeze LCD-3)

Share this post


Link to post
Share on other sites
Just now, The Computer Audiophile said:

So awesome!

 

She (our Chocolate Lab) is 10 years old and her personality hasn't changed a bit. 🙂


One never knows, do one? - Fats Waller

The fairest thing we can experience is the mysterious. It is the fundamental emotion which stands at the cradle of true art and true science. - Einstein

Computer, Audirvana -> eero Pro router -> EtherREGEN -> microRendu -> USPCB -> ISO Regen (powered by LPS-1) -> Ghent JSSG360 USB cable -> Pro-Ject Pre Box S2 DAC -> Spectral DMC-12 & DMA-150 -> Vandersteen 3A Signature.

Share this post


Link to post
Share on other sites

@mitchco Seeing as you have the KEF LS50 and also your comparison of the KEF LS50 with the JBL, I am curious if you have tried the BACCH DSP system from Princeton?

https://www.audiostream.com/content/bacch4mac-3d-audio-playback-system

 

It is also very favorably reviewed by Soundstage.com a few times recently. They test out the $25k+ hardware version. There is a $5K MacMini software even slightly more powerful than the $25K-50K versions. They demo with KEF LS50's.

https://www.theoretica.us/bacch4mac/

 

It would be very interesting to hear your take on this new cutting edge tech.

 

I hope to buy the $5K MacMini variant in a few months and use in my second LS50 system.

 

 

Share this post


Link to post
Share on other sites
5 hours ago, yyz said:

hope to buy the $5K MacMini variant in a few months and use in my second LS50 system.


Would love to see another audiophile going for XTC. Please post your review when you get yours.  

Share this post


Link to post
Share on other sites
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."

 

 

 

 


 

HQP Embedded  (REW + RePhase created convolution filters for correcting frequency and time domains for the actual results presented below/IIR/Wide/overlap-ADD/ [email protected], mqa lp @ above Frequency Rates/DSD5EC) on a cooled mid 2012 15" rMacBP > Cat 6 UTP Ethernet> Airport TC > Cat 6 UTP Ethernet > NAA (Miska's image on UP NUC)> 2.0 certified Supra USB > Green Regen > TEAC UD 501> (balanced output) >Cardas Golden Cross> JRRG all balanced pre> Cabasse 4 ways 8 amps active system played at realistic SPL (key factor IMO). MCH files (matrixed to Stereo) on an attached HDD, the rest on a G-Tech HDD attached to the AirPort and WIFI accessed, as Qobuz, via Audirvana fronting HQPlayer Embedded.

 

 

 

Proofing B&K C @ -9 copie-Modifier-2.jpg

Share this post


Link to post
Share on other sites
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 ?


 

HQP Embedded  (REW + RePhase created convolution filters for correcting frequency and time domains for the actual results presented below/IIR/Wide/overlap-ADD/ [email protected], mqa lp @ above Frequency Rates/DSD5EC) on a cooled mid 2012 15" rMacBP > Cat 6 UTP Ethernet> Airport TC > Cat 6 UTP Ethernet > NAA (Miska's image on UP NUC)> 2.0 certified Supra USB > Green Regen > TEAC UD 501> (balanced output) >Cardas Golden Cross> JRRG all balanced pre> Cabasse 4 ways 8 amps active system played at realistic SPL (key factor IMO). MCH files (matrixed to Stereo) on an attached HDD, the rest on a G-Tech HDD attached to the AirPort and WIFI accessed, as Qobuz, via Audirvana fronting HQPlayer Embedded.

 

 

 

Proofing B&K C @ -9 copie-Modifier-2.jpg

Share this post


Link to post
Share on other sites

Okay, dumb question, but I can't figure this out:

How do I get a "live" (not simulated) measurement of my room sound with the DRC/convolution applied? I can't figure out how to apply the DRC to the test sweep in any of the measurement programs, and measure the result in real time. 

Sorry if this is obvious and I'm just not seeing it. 

 


Main listening (small home office):

Surge protector +_iFi  AC iPurifiers >Isol-8 Mini sub Axis Power Conditioning+Isolation>CAPS IV Pipeline Server + Sonore 12V PS>Kii Control>Audiolense DRC>Kii Three >GIK Room Treatments.
 

Secondary Listening: CAPS Pipeline>IFi iOne DAC>Schiit Freya>Kii Three . Also an SBT and a RB Pi 3B+ running piCorePlayer as an SBT emulator. 

All absolute statements about audio are false :)

Share this post


Link to post
Share on other sites

Create an account or sign in to comment

You need to be a member in order to leave a comment

Create an account

Sign up for a new account in our community. It's easy!

Register a new account

Sign in

Already have an account? Sign in here.

Sign In Now

×
×
  • Create New...