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Acoustics Issue
Old 4th May 2017
  #1
Gear Maniac
Acoustics Issue

I am working on a tracking/mixing room for a friend and about ready to begin ordering and installing traps/panels.

One item that has me baffled in the drop in the higher frequency range. Can anyone tell me what might be causing or contributing to the the absorption/drop in the highs. The room is 12'x15'x9'h and the musician has carpet on the floor in half the room including the console area.

I can deal with the low/mid issue, but I am just a bit baffled as I haven't seen a room where this has happened. Just need some advice on what could be causing this.

Old 4th May 2017
  #2
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Jens Eklund's Avatar
If you gate your impulse to include only (or mostly) the direct sound, how does that look? Only use one speaker at the time.
Old 4th May 2017
  #3
Gear Guru
Real

L, R, for full range FR, L+R for LF only. https://www.gearslutz.com/board/4217370-post13.html

DD
Old 4th May 2017
  #4
What they said ^^^^^. You do know that a well balanced system will have some HF rolloff to sound right, don't you. In your case if the mic was close to the speaker in a non reflective acoustic, it would probably be the designer dropped down the tweeter to mitigate the rising response of that particular tweeter.
Old 4th May 2017
  #5
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Jens Eklund's Avatar
Quote:
Originally Posted by philsaudio View Post
You do know that a well balanced system will have some HF rolloff to sound right, don't you.
I have measured many rooms and met many sound engineers, and I´ve never ever met one that favors a tilted HF response.

What might happen is if you look at the complete impulse (un-gated) from a room with a lot of thin porous treatment but little to address the lower frequency range; the frequency response will look as if it´s tilted since at high frequencies, the direct sound will dominate but at lower frequencies (including mids) there will be enough contribution from the room (after direct) to boost the response curve in this range in relation to direct only (again; if looking at an un-gated response). This might explain the B&K-curve often seen in these types of discussions, since this curve is essentially the average response (un-gated) from normal living rooms (where the only “treatment” often consists of carpets and curtains and some furniture). Another explanation might be that speakers in a normal living room might not have their acoustic axis pointing straight towards the measurement microphone and since tweeters become more and more directional higher in frequency, a tilt will be the result if not directed straight towards the mic. In control room we tend to aim the monitors so the acoustic axis points directly towards (or very close to directly) the receiver.

In a professional control room on the other hand (although sadly, this does not necessarily mean well treated …), we strive for a flat direct sound (at least above about 1 kHz or so. A tilt in the lower frequency range is personal preference in my opinion). If well treated (no overuse of porous-only panels and effective treatment to control the modal range); there will be little difference if looking at the response gated or ungated (except in the lows naturally due to the time-bandwidth requirement).

So what I’m trying to say is that if a curve looks like it has a tilted HF response, it might be a little more complex. If the room is not “well treated”, a tilted HF response might be “correct” if looking at the entire impulse, but if looking at the direct sound; you might notice that the higher frequency range measures flat … as it should.
Old 4th May 2017
  #6
Gear Guru
Out the Gate

True that, and I would welcome a thread describing detailed use of gating. Particularly any practical aspects of it.
But the typical FR graph, the simple Lingua Franca, does not usually involve published gating. But then neither does the ear/brain. I would suggest the seemingly simple, 'average' graph, say at 1/6 octave, gives a reasonable, and by common use well understood, impression of the tonality we actually hear.
If one were listening in a fully treated, almost idealised, CR, let's say as good as 200mS down to 30/40Hz with little variation, how would one mix? But how would one's work translate into the 500mS + boomy and dulled home environment?
Most CR's do not come even close to time based flat, which is arguably a good thing. Less dissimilar to the customers listening environment. Ultimately, in terms of translation to an average listening environment, I suggest the best place to mix would be IN that same average listening environment.
Which is where most of us review and correct and finally sign off on our work.
EDIT, wandered off into the non room world of headphones, but it is way too complex and OT here. Suffice it to say I use the B&K curve in my CR, which is boomy at low LF but tight from say 100Hz upwards. There is no tonal change when I move to Sennheiser HD650s.
DD

Last edited by DanDan; 5th May 2017 at 07:32 PM..
Old 4th May 2017
  #7
Gear Maniac
Thanks all.....

So I re-tested the room using L only and R only and then averaged them. Low and behold, the SPL graph is a bit elevated in the higher end frequencies as I would have expected.

Who would have thunk.
Thanks

Jake
Old 5th May 2017
  #8
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Quote:
Originally Posted by DanDan View Post
True that, and I would welcome a thread describing detailed use of gating. Particularly any practical aspects of it.
But the typical FR graph, the simple Lingua Franca, does not usually involve published gating. But then neither does the ear/brain.
What do you mean by the last sentence Dan? The ear/brain does a lot of gating. One might even say that's the bulk of what it does.
Old 5th May 2017
  #9
Quote:
Originally Posted by Jens Eklund View Post
I have measured many rooms and met many sound engineers, and I´ve never ever met one that favors a tilted HF response.

What might happen is if you look at the complete impulse (un-gated) from a room with a lot of thin porous treatment but little to address the lower frequency range; the frequency response will look as if it´s tilted since at high frequencies, the direct sound will dominate but at lower frequencies (including mids) there will be enough contribution from the room (after direct) to boost the response curve in this range in relation to direct only (again; if looking at an un-gated response). This might explain the B&K-curve often seen in these types of discussions, since this curve is essentially the average response (un-gated) from normal living rooms (where the only “treatment” often consists of carpets and curtains and some furniture). Another explanation might be that speakers in a normal living room might not have their acoustic axis pointing straight towards the measurement microphone and since tweeters become more and more directional higher in frequency, a tilt will be the result if not directed straight towards the mic. In control room we tend to aim the monitors so the acoustic axis points directly towards (or very close to directly) the receiver.

In a professional control room on the other hand (although sadly, this does not necessarily mean well treated …), we strive for a flat direct sound (at least above about 1 kHz or so. A tilt in the lower frequency range is personal preference in my opinion). If well treated (no overuse of porous-only panels and effective treatment to control the modal range); there will be little difference if looking at the response gated or ungated (except in the lows naturally due to the time-bandwidth requirement).

So what I’m trying to say is that if a curve looks like it has a tilted HF response, it might be a little more complex. If the room is not “well treated”, a tilted HF response might be “correct” if looking at the entire impulse, but if looking at the direct sound; you might notice that the higher frequency range measures flat … as it should.
I can't argue what you and engineers you met prefer, but in real life, the HF roll off naturally more than the LF as distance from the source increases. So in a real life placement the HF will be rolled off more than in a nearfield placement. What I mean is if you want you mix to sound like like your head is 3 feet from the source(s) then make your monitors flat.
Old 5th May 2017
  #10
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Jens Eklund's Avatar
Quote:
Originally Posted by philsaudio View Post
I can't argue what you and engineers you met prefer, but in real life, the HF roll off naturally more than the LF as distance from the source increases. So in a real life placement the HF will be rolled off more than in a nearfield placement. What I mean is if you want you mix to sound like like your head is 3 feet from the source(s) then make your monitors flat.
Are you thinking of attenuation of high frequencies due to the medium at longer distances?

Calculation method of absorption of sound by atmosphere air damping dissipation absorbtion high frequencies attenuation sound during propagation outdoors outdoor - sengpielaudio Sengpiel Berlin

If so, I’d say that’s a non-issue in a “normal” control room … In a large PA setup this effect might be measurable. I see a dozen of other, more likely reasons for a response that looks tilted at HF if not gated. Not saying there are engineers that actually prefers a tilted HF response (even if talking about the direct sound field), it´s just that I haven’t met any yet.
Old 5th May 2017
  #11
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Quote:
Originally Posted by Jens Eklund View Post
Are you thinking of attenuation of high frequencies due to the medium at longer distances?
Hello,

I know professional control rooms where the 50° per speaker is used.

SpiritShooter does not say how the speaker is oriented.

What is the directivity after 5kHz ?
Old 5th May 2017
  #12
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Jens Eklund's Avatar
Quote:
Originally Posted by dinococcus View Post
Hello,

I know professional control rooms where the 50° per speaker is used.

SpiritShooter does not say how the speaker is oriented.

What is the directivity after 5kHz ?
Zaph|Audio

A standard 1” dome tweeter is down about 5 dB at about 12 kHz for 30 degrees off axis. About -5 dB for 20 kHz at 15 degrees off axis.
Old 5th May 2017
  #13
Lives for gear
Seas 27TBCDGB-DXT with unique waveguide design ?
Old 5th May 2017
  #14
Gear Guru
What?

Quote:
But the typical FR graph, the simple Lingua Franca, does not usually involve published gating. But then neither does the ear/brain.
Quote:
What do you mean by the last sentence Dan? The ear/brain does a lot of gating. One might even say that's the bulk of what it does
Mike, I suggest the ear and brain's main function is hearing and understanding. The FR graphs we bandy about do not usually publish their auto gatings, which we simply go along with it. Ditto the Ear/Brain. There are obviously complex time based behaviours, which we simply go along with.

Without interfering with this usual presentation of FR, a HF rolled off response is both desirable and the norm.

Alton Everest suggests two different approaches, both have HF roll offs differing a little on the basis of near-field recording and or near-field listening. John Eargle quotes some 'recommended' monitor curves. e.g.
Film -3dB Octave above 2K
Studio -3dB Octave above 4K
Another Studio -3dB Octave above 8K

Quote:
Suffice it to say I use the B&K curve in my CR, which is boomy at low LF but tight from say 100Hz upwards. There is no tonal change when I move to Sennheiser HD650s.
Afterthought- When I move to another room, currently bare concrete floor, plasterboard walls and ceiling, couch and some furniture, I listen on a Linn Spendor BC1 rig. No tonal change. Pure Radio in bedroom, ditto. iMac, similar MF HF, but not bass obviously.


DD

Last edited by DanDan; 5th May 2017 at 07:34 PM..
Old 5th May 2017
  #15
Gear Guru
What?

Quote:
But the typical FR graph, the simple Lingua Franca, does not usually involve published gating. But then neither does the ear/brain.
Quote:
What do you mean by the last sentence Dan? The ear/brain does a lot of gating. One might even say that's the bulk of what it does
The FR graphs we bandy about do not usually publish their auto gatings, so we simply go along with it. Ditto the Ear/Brain. They obviously have complex time based behaviours, which we simply go along with.
These unadulterated FR graphs represent what we hear very well IMO. It is interesting that they can be made to look flat by omitting some of the data, omitting some of what we hear, but I am not clear as to the point of such an exercise.

DD
Old 5th May 2017
  #16
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Quote:
Originally Posted by dinococcus View Post
Seas 27TBCDGB-DXT with unique waveguide design ?
What is the question? The use of a waveguide completely changes the directivity of the driver, so I wouldn't look at the frequency response chart for that driver/waveguide combo as being indicative of any other drivers.

You can also get a rough idea of directivity using the "ka" values of driver, where "k" is the wavenumber (2pi/λ) at the frequency of interest and "a" is the surface area of the driver.

Then compare the answer to the directivity plot on the left of this image:



Caveat: the ka values of this chart apply to perfectly pistonic motion. In reality, a driver approximates a piston at the lower end of its usable frequency range and becomes less pistonic higher up in frequency, as the center of the driver begins to decouple from the outer edges; this has the implication that the effective radiating area (the "a" in ka) decreases, so the driver will actually be somewhat less directional (more omnidirectional) at the higher frequency ranges than would be the case if you calculated "a" based on the actual driver size. The exact amount of this effect depends on the specific driver. But this is a good starting point.
Old 5th May 2017
  #17
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Quote:
Originally Posted by DanDan View Post
Mike, I suggest the ear and brain's main function is hearing and understanding. The FR graphs we bandy about do not usually publish their auto gatings, which we simply go along with it. Ditto the Ear/Brain. There are obviously complex time based behaviours, which we simply go along with.
I'm still not really sure what you're saying here (the fact that we "go along with" the inherent gating of the ear/brain doesn't really say anything about whether or not gating frequency response measurements is useful). One purpose of gating an impulse response is to view the frequency response of the direct sound, which is what humans tend to "lock onto" (especially higher in the frequency range). The overall frequency response at a specific location can correspond to multiple different frequency responses of the direct sound, because the frequency response of the direct sound may be compensated by the room response. But the frequency response of the direct sound nevertheless has a special relevance in our perception of sound.

To quote JohnPM from the REW manual (pg. 53), explaining the advantage of using a frequency dependent window to view frequency response:

Quote:
Originally Posted by JohnPM
The corresponding octave fraction has an effect similar to applying a smoothing of the same octave fraction, except the variable window excludes progressively more of the late arriving sound as frequency increases rather than just averaging it out - this has similarities with the way the ear increasingly picks out the direct sound from the speaker at higher frequencies.
This is the utility of gating an impulse response.
Old 5th May 2017
  #18
Gear Guru
Utility

If it were desirable or useful to gate out the room contribution, we would all be doing it all the time. If the ear picks out direct HF increasingly then gating out the room is removing the LF Room Tone in a biased tonal manner. Clearly room tone combines with the anechoic response of the speaker. Concurring with JohnPM's statement I suggest the ear blends LF direct and room tone increasingly with lowering frequency. A measurement which in effect removes or hides any part of the spectrum is incomplete, but to hide the LF is a big move.
As I said, I would love to see a thread discuss this use of gating and more interestingly IMO, how this summing actually works. On the other hand, I have seen reference to research, Toole perhaps, which indicated that experienced engineers 'hear through' a wide range of Room Decays. Which kinda harkens back to my comment about listening in an actual or simulated Living Room.

Regarding this thread, the measurement presented was erroneous. That has been fixed.

DD

Last edited by DanDan; 5th May 2017 at 08:58 PM..
Old 5th May 2017
  #19
Gear Maniac
Quote:
Originally Posted by mpos View Post
But the frequency response of the direct sound nevertheless has a special relevance in our perception of sound.

To quote JohnPM [...]
"The corresponding octave fraction has an effect similar to applying a smoothing of the same octave fraction, except the variable window excludes progressively more of the late arriving sound as frequency increases rather than just averaging it out."
Do you happen to have any references for the direct vs late reverb perception? I'd be interested to read more about it.

FWIW, in a domestic living room the direct sound and early reflections can easily contribute most of the total high frequency response simply because highs are progressively attenuated so much faster by typical materials compared to lows and mids.
Old 5th May 2017
  #20
Gear Guru
Dull

Quote:
FWIW, in a domestic living room the direct sound and early reflections can easily contribute most of the total high frequency response simply because highs are progressively attenuated so much faster by typical materials compared to lows and mids.
Furthermore the early reflections are very destructive to the direct sound.
Overall HF is diminished in real world listening scenarios. Exactly as SonarWorks, B&K, Harman, have published.

DD
Old 6th May 2017
  #21
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Quote:
Originally Posted by Antti H View Post
Do you happen to have any references for the direct vs late reverb perception? I'd be interested to read more about it.
Yes. Here are a few, but it's discussed to a greater or lesser extent in virtually every book on acoustics, since they usually have at least a chapter devoted to psychoacoustics. (I should point out for sake of clarity that the issue isn't "late reverb" but reflections more generally.)

Page 51 of Handbook for Sound Engineers, in Chapter 3 "Psychoacoustics" (chapter written by Peter Xinya Zhang).

Quote:
Originally Posted by Peter Xinya Zhang
If our ear was like an ideal Fourier analyzer, in order to translate a waveform into a spectrum, the ear would have to integrate over the entire time domain, which is not practical and, of course, not the case. Actually, our ear only integrates over a limited time window (i.e., a filter on the time axis), and thus we can hear changes of pitch, timbre, and dynamics over time, which can be shown on a spectrogram instead of a simple spectrum. Mathematically, it is a wavelet analysis instead of a Fourier analysis. Experiments on gap detection between tones at different frequencies indicate that our temporal resolution is on the order of 100 ms, which is a good estimate of the time window of our auditory system. For many perspectives (e.g., perceptions on loudness, pitch, timbre), our auditory system integrates acoustical information within this time window.
Recording Studio Design by Philip Newell, pg. 636-637.

Quote:
Originally Posted by Philip Newell
In all cases, the first sound heard for any new note or change in tonality would be the first arriving sound (the direct sound), which by definition must arrive anechoically because it arrives straight from the instrument, whereas all reflexions and resonances suffer arrival delays. It is the first arrival of any sound that the brain ‘locks on to’, and that sound has a characteristic ‘fingerprint’ to which all the subsequent sound is referenced.
Sound System Design by Bob McCarthy, pg. 159. In addition to the general issue of the ear/brain's "windowing", he discusses the frequency dependence of these windows, as mentioned in the REW manual which I quoted in an earlier post.

Quote:
Originally Posted by Bob McCarthy
The road to echo perception is a gradual one. It begins at the highest frequencies and gradually peels apart successively larger portions of the spectrum. It is widely published that the dividing mechanism is time offset... The first perception zone is the tonal fusion zone, which runs for the first 20–30 ms... Beyond the 30 m border, we enter the area of spaciousness, which continues to around 50 or 60 ms, after which we finally emerge to the perception of discrete echoes (above 60 ms)... These, however, should not be viewed as absolute numbers. Attempts to place a single number on any phenomena that ranges over our full frequency range should give us pause. After all, sound system range of 30 Hz to 18 kHz spans a 600:1 ratio of time periods...

As an example, let’s consider two combined signals with 30 ms of delay between them, the limit of the tonal fusion zone. In the case of
33 Hz, the direct and reflected wavelengths are a single wavelength apart. Even if the signal was the shortest duration possible at 33 Hz (30 ms), the reflected sound would commence at precisely the same time as the direct sound would finish. How could we discern whether we heard two cycles of direct sound or direct and reflected when there is no gap of time between them? By contrast, the same amount of delay between direct and reflected sound is 400 wavelengths at 12 kHz. A transient with 200 wavelengths of 12 kHz would have a 200 wavelength gap between the direct and reflected arrivals. This fails our stable summation duration criteria and could be perceived as a separate source: a discrete reflection.
Old 6th May 2017
  #22
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Quote:
Originally Posted by DanDan View Post
If it were desirable or useful to gate out the room contribution, we would all be doing it all the time.
It is done very often. Why else would it the feature be built into every software that does this sort of analysis, why would it be discussed in the manual to every software? I'm certainly not saying it's the only way to look at the room, but it's a valid perspective for specific purposes and invalid for other purposes -- just like the ETC, waterfalls, spectrogram, frequency amplitude response, harmonic distortion, etc.

Quote:
Originally Posted by DanDan
If the ear picks out direct HF increasingly then gating out the room is removing the LF Room Tone in a biased tonal manner. Clearly room tone combines with the anechoic response of the speaker. Concurring with JohnPM's statement I suggest the ear blends LF direct and room tone increasingly with lowering frequency.
Now you're just reiterating what I already said, which is that gating a response has its purposes.

Quote:
Originally Posted by DanDan
A measurement which in effect removes or hides any part of the spectrum is incomplete, but to hide the LF is a big move.
No one has advocated "hiding" the LF response. The lowest frequency of validity for a gated measurement depends on the width of the window. For a gated response to be valid at a given frequency, the window must be, at a minimum, equal to the length of the period of that frequency. The wider the window, the lower in frequency one can analyze the direct sound. (And the "resolution" between frequencies rises as the time increases as well). If you're not familiar with windowing an impulse response, I'd recommend taking a look at the REW manual, in particular pg. 14.

Remember that Jens was asking about for a gated measurement to look at the direct sound of the high frequencies, not the lows.

Quote:
Originally Posted by DanDan
Regarding this thread, the measurement presented was erroneous. That has been fixed.
I'm not convinced of this. I would expect that if the issue were two speakers being measured simultaneously, we would see comb filtering as the primary problem rather than a shelf around 3-4kHz. There is probably smoothing in the frequency response which is hiding the specifics here.
Old 6th May 2017
  #23
Gear Addict
 

Addition to mpos’ quotes above; Chapter 2 ” Psychoacoustics -How we hear” from John Eargles book ”Audio Engineering for Sound reinforcenment”, can be read here: Audio Engineering for Sound Reinforcement: Chapter 2, PSYCHOACOUSTICS-HOW WE HEAR | Pro Audio Encyclopedia (About Eargle, read editors note at the top)

What is shown there in diagrams and written under the headline ”Localization phenomena , Haas and Damaske” is interesting. What I take as imporant there are a couple of things: A) Reflections within 0 to about 5-6 ms are really, really bad. As they haven’t traveled far, compared to direct sound they will be strong. Those 2nd sound sources would come from anything close to the driver or ”stuff”/furniture close to the ear at LP. Localization should then lock to a place somewhere between the driver and the 2nd source. From about 7-25 ms it evens out and the reflections need to be a lot stronger, > -10 dB or so, to be a problem. But …,B) that concerns more frontal reflections. Reflections coming in at a more sensitive angle to the ear need to be attenuated a lot more as can be seen from Figure 2-9 ”The trading value of delay and and amplitude differences due to the Haas effect”. As the text says: ”When the secondary sound is presented from a bearing angle of 90°, it must be about 23 dB lower in level in order to be masked by the frontal signal.”.

As I see it, one needs to evaluate the severeness of each reflection and take into consideration 4 different parameters of it: Amplitude, its timing, angle and frequency. From there, one can think about what kind of treatments that are needed to attenuate the reflection enough at LP. REW is your friend. It will show the extra travel length and with the string method one can find the reflection spot/area. So, then you will also have the angle towards LP. With gating / windowing / frequency filtering in REW one can find out what frequency (range) that is reflected. From there, -is a smaller pillow enough as a fix or is a substantially larger and thicker treatment needed? Perhaps a flat, hard and angled sheet is better than absorbtion?
Old 6th May 2017
  #24
Gear Guru
Test

Quote:
So I re-tested the room using L only and R only and then averaged them. Low and behold, the SPL graph is a bit elevated in the higher end frequencies as I would have expected.

Who would have thunk.
Thanks
You are welcome Jake. Would you post the .mdat of those new measurements please.

DD
Old 6th May 2017
  #25
Gear Maniac
Just for fun I tried both no window, normal 15 ms window and frequency dependent 15 cycle window. At 1/12 octave smoothing there's not much difference between any of the three above 200 Hz in my untreated room. I did the same for my old speakers with similar results (speakers at front wall with measurement position almost 3/4 to the back, so pretty much maximum room contribution compared to direct sound) . This suggests to me that the first reflections contribute most of the tonality and frequency balance apart from possible (or likely) bass issues.

In neither case is there any significant downwards HF slope (perhaps 1-2 dB between 200 Hz and 20 kHz) and I certainly haven't ever felt as if I'd generally prefer lots of treble (My LSR305s have bass boosted +2 and treble attenuated -2 dB and my headphone preference is Sennheiser HD600). It'd be interesting to get access to both windowed and unwindowed responses from more domestic living rooms.

Edit: Using Psychoacoustic smoothing in REW does show a bit more downwards HF slope (3-4 dB 200 Hz - 20 kHz). Whether that means anything in practise, I don't know.
Old 6th May 2017
  #26
Gear Guru
Studio

This is a work in progress measurement from a College Recording Studio CR.
Short Gate vs Auto.
DD
Attached Thumbnails
Acoustics Issue-15ms.jpg   Acoustics Issue-auto.jpg  

Last edited by DanDan; 6th May 2017 at 02:39 PM..
Old 6th May 2017
  #27
Gear Maniac
Quote:
Originally Posted by DanDan View Post
This is a work in progress measurement from a College Recording Studio CR.
Short Gate vs Auto.
Can you post a 1/12 octave smoothed version of the ungated response? That'd allow better comparison of the overall spectrum shape.
Old 7th May 2017
  #28
Lives for gear
Quote:
Originally Posted by Antti H View Post
This suggests to me that the first reflections contribute most of the tonality and frequency balance apart from possible (or likely) bass issues.
Everyone goes there from his literary reference : Sound and reproduction Floyd Toole. With an heretic point of view on the early reflections with tests (ABX tests if i remember correctly).

Book available in free accces.
Old 7th May 2017
  #29
Gear Guru
Slope

Quote:
Can you post a 1/12 octave smoothed version of the ungated response? That'd allow better comparison of the overall spectrum shape.
I will if you want. But I might be able to tweak better if you tell me your quest, what are you looking for? FYT, the two graphs have identical settings except for the gating. More importantly they only go to 1KHz. Above 1KHz if I remember right, there is no difference. Which would suggest that the usual HF rolled off responses won't change to flat with gating. I guess the purpose of my post was to show how gating removes HF information and more importantly the Auto choice works fine for full range FR purposes. Gating could be extremely useful IMO for investing particular Early Reflections at HF in particular. But I do think that is another Thread.
IMO, the Flat vs not debate would be best in another Thread also.
Flat Frequency Response- Not

Many of those links look interesting and I will be visiting them, thanks. Not contradicting anything anywhere, but I will try to find that research which shows how professional engineers 'hear through' the room contribution.
EDIT, try chapter 7 here. http://downloads.bbc.co.uk/rd/pubs/reports/1958-28.pdf
Some personal experience. I have mixed quite a few projects in 'guerrilla' acoustic treated domestic scenarios. I have not been inclined to use any less reverberation or delay effects. Perhaps because an experienced ear can chose to hear it as a distinct entity. Conversely in very dead CR's I have no inclination to use more. Perhaps because it is so audible?
There are some pitfalls to be wary of. An attractively bright speaker room response leads to dull product.
Bass response with the typical nulls in it results in bass heavy mixes.
Long LF decay makes it impossible to mix Kick drum. Headphones.
DD

Last edited by DanDan; 7th May 2017 at 06:37 PM..
Old 7th May 2017
  #30
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Quote:
Originally Posted by DanDan View Post
I guess the purpose of my post was to show how gating removes HF information and more importantly the Auto choice works fine for full range FR purposes.
This is precisely the point of gating -- to remove certain information that we don't care to look at (the contribution of the later sound field) to have a clear view of what we do want (the direct sound). And again, I have explicitly noted that for full range purposes gating doesn't work since there is a limit on the bandwidth of a gated response. This is basic to understanding gating (and more broadly to understanding the Fourier transform).

Quote:
Originally Posted by DanDan
Gating could be extremely useful IMO for investing particular Early Reflections at HF in particular.
Now we're getting somewhere.

Quote:
Originally Posted by DanDan
Many of those links look interesting and I will be visiting them, thanks. Not contradicting anything anywhere, but I will try to find that research which shows how professional engineers 'hear through' the room contribution.
This is exactly what the quotes that myself and Adhoc provided were saying! See for example, the quote I posted by Newell. (Except that it's not just professional engineers who do this, but all humans.)

I know you say you're not trying to contradict anyone, but you're certainly contradicting yourself now that you're admitting that gating is useful for certain purposes and admitting that the ear/brain performs some kind of time gating.
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