Target Room Response and Cinema X-curve

[sigbergaudio]

Yes it does. Above room transition frequency we mainly perceive tonality from the direct sound which thus should be flat, so if the window would be so short that it would only catch the direct sound and not its reflections the measurement would be flat without sounding harsh. Thus in typical rooms for correction in that region some anechoic loudspeaker measurements are more helpful than a measurements at the listening position where the gap after the reflections is too short for a large enough window.

Some good reading material on the topic:

https://www.aes.org/e-lib/browse.cfm?elib=17839 (free download)

Some comments from Floyd Toole about room curve targets, room EQ and more

Room curve targets Every so often it is good to review what we know about room curves, targets, etc. Almost 50 years of double-blind listening tests have shown persuasively that listeners like loudspeakers with flat, smooth, anechoic on-axis and listening-window frequency responses. Those with...

www.audiosciencereview.com

I'm not sure how this contributes to the discussion. No one has contested that a speaker should be anechoically flat above a typical transition frequency.

 

[thewas]

I'm not sure how this contributes to the discussion. No one has contested that a speaker should be anechoically flat above a typical transition frequency.

It answered your question that a flat in-room response doesn't necessarily always need to sounds harsh/sterile/too lean to most people but it depends on the listening distance and window width.

 

[sigbergaudio]

It answered your question that a flat in-room response doesn't necessarily always need to sounds harsh/sterile/too lean to most people but it depends on the listening distance and window width.

Still not sure what your point is.

I would suggest that if you know enough about measurements to adjust the window, you likely understand what happens when you do. The whole point of doing so is to reduce or remove the effects of the fact that it is an in-room measurement, and then it is no longer an in-room response, is it? It will start to mimic the anechoic response, which will unsurprisingly approach flat.

With regards to smoothing a tilted in-room measurement, it will still be tilted even if you smooth it to 1/1.

The level of tilt will vary depending on room size and listening distance, but in almost every situation it will still have some tilt if the speakers measure ~flat anechoically.

I maintain my previous statement.

 

[thewas]

With regards to smoothing a tilted in-room measurement, it will still be tilted even if you smooth it to 1/1.

I never claimed something else.

The level of tilt will vary depending on room size and listening distance, but in almost every situation it will still have some tilt if the speakers measure ~flat anechoically.

In most cases yes, but there are exceptions like extreme nearfield and/or omnidirectional loudspeakers or reduced room absorption in higher frequencies.

Still not sure what your point is.

That an not windowed in-room response is a poor indicator for perceived tonality (and thus also for equalisation above room transition frequency).

 

[sigbergaudio]

In most cases yes, but there are exceptions like extreme nearfield and/or omnidirectional loudspeakers or reduced room absorption in higher frequencies.
That an not windowed in-room response is a poor indicator for perceived tonality (and thus also for equalisation above room transition frequency).

While this is technically correct, it confuses the point. To the vast majority of readers, the answer to "Will a flat in-room response be too thin/harsh" is YES.

Answering "it depends" is not helpful.

 

[Newman]

No one has contested that a speaker should be anechoically flat above a typical transition frequency.

No one? “Almost 50 years of double-blind listening tests have shown persuasively that listeners like loudspeakers with flat, smooth, anechoic on-axis and listening-window frequency responses.” F E Toole

 

[sigbergaudio]

No one? “Almost 50 years of double-blind listening tests have shown persuasively that listeners like loudspeakers with flat, smooth, anechoic on-axis and listening-window frequency responses.” F E Toole

Maybe I'm using the word contested wrong (I'm not a native English speaker)?

I meant that no one (in this discussion) has challenged that fact. I'm sure someone somewhere has challenged just about everything.

 

[Newman]

Oh okay, I get your meaning now. All good!

 

[Andysu]

you can see the x-curve on direct RTA if some of do a video show your top Dolby movie demo with x-curve

speakers being x curve Eq , please commonly 1/3 octave used and when looking at 1/24 octave trueRTA or 1/48 octave REW look at the mess that speaker you and i everyone has , its a sheer mess ! ! ! that needs a lot of PEQ adjusting at narrow PEQ Q bandwidth first , to get the flatness rule flat then use 2nd EQ to apply prefixed X-EQ-curve , sorted speakers are now X-EQ-curved , otherwise the film mix direct is , but once it leaves the processor to amplifier directly to the speaker/s its a sheer mess on midrange drivers sheer mess on tweeters , sheer mess on HF horns which mind you is what these films are mixed with for screen stage channels , surrounds will be typical JBL 8330 in its day and are still decent enough

so EQ i looked at so many angles , sore can use 1/3 octave mic at seating but face reality the speakers used are far from perfect design there okay , just need a lot of electrically PEQ filters to address the unevenness , look at amp its smooth within 0.5dB or less , speakers are a sheer utter mess , i go though many steps on mine .rest of you only do one step and accept that as the norm gospel , i'm not in the rich snob class hi-fi , thou some will bulllllllllshhhhhhh a lot of others , i''m for truth and EQ , EQ is not bad evil , its used like we , use sandpaper on wood to make it smooth

 

[rrahmanucla]

I have always struggled with one question I have always had when calibrating for home theater and music, is how to compensate for fletcher-munson curves for low frequencies when increasing volume?

This is room and speaker depending, but when I calibrate by system using Dirac I use a harman preferred +8dB curve. This sounds about right for music to me at around ~80 dB listening volume. When listening to home theater approaching THX reference levels or just music at a louder volume, I find myself wanting more bass. So I either change the curve to a Harman +10dB or increase gain on my subs. I could never explain why I preferred this, but...

My suspicion is it's related to fletcher Munson curves, which I would like someone to comment on. From a psychoacoustic viewpoint, a fixed dB increase across the audible range would not be perceived as a fixed dB increase in all frequencies, so for that reason at higher volumes I need a disproportionate larger increase in bass. Likewise for lower volume, I need a disproportionate greater decrease in bass. How does anyone generate a proper target curve for home theater at high volume and music at moderate volume? Or should I have a separate curve for each respective volume I listen at?

 

[DeLub]

Hmm… I thought the increase in bass level should be less then the overall increase according to the FM curves.

Features taking these curves into account are DynamicEQ from Audyssey, or Dolby Loudness and perhaps others…

 

[Andysu]

Hmm… I thought the increase in bass level should be less then the overall increase according to the FM curves.

Features taking these curves into account are DynamicEQ from Audyssey, or Dolby Loudness and perhaps others…

i never understood the dynamic-eq , the principle should be it , modulates the audio levels of LCR so if LR is too high loud and centre is carrying ( centre discrete lets clear that up okay ) LR would be frequency adjusted within instant m/s so as not create audio frequency masking effect

i give one movie for example , heat 1995 , where neil is running across airfield runway with jet plane L only slowly panning with centre phantom within L R only , centre only carries ,l footsteps ( foley ) and breathing out of breath sounds , get the disc and have listen , like see you get the levels so LCR , that is matched proper cinema JBL pa speakers

 

[dlaloum]

i never understood the dynamic-eq , the principle should be it , modulates the audio levels of LCR so if LR is too high loud and centre is carrying ( centre discrete lets clear that up okay ) LR would be frequency adjusted within instant m/s so as not create audio frequency masking effect

i give one movie for example , heat 1995 , where neil is running across airfield runway with jet plane L only slowly panning with centre phantom within L R only , centre only carries ,l footsteps ( foley ) and breathing out of breath sounds , get the disc and have listen , like see you get the levels so LCR , that is matched proper cinema JBL pa speakers

Ummm no... DEQ and Dolby Loudness (and other "loudness" systems) are about perception and Equal-loudness contours:

Equal-loudness contour - Wikipedia

en.wikipedia.org

There are various studies of loudness/frequency perception, and therefore various differing implementations thereof... but the end results are more or less the same, and nothing to do with the directional channel at all.