What is your favorite house curve

[DonH56]

I suspect a lot of mixes take the curves somewhat into account so the bass may already be boosted so we can hear it better. I prefer some boost because I normally listen at much lower levels than reference, more like 70 dB, but as mentioned earlier my boost is fairly mild (3 dB or so). The HF cut is equally mild but that is for my kids; I can't hear above about 12 kHz or so now. And it used to be ~22 kHz.

 

[RayDunzl]

I suspect a lot of mixes take the curves somewhat into account so the bass may already be boosted so we can hear it better.

My experience/intuition - the player plays it so you can hear it, balanced with the rest of the group, by his ear and their rapprochement.

A little bass in a combo goes a long way. The frequencies don't "step" on each other, so a little soft or loud, it's still there.

The recording engineer captures that.

(synthetic music excluded from these observations)

Carmen McRae Sings Monk in-room RTA, which matches the RTA on the CD well enough for hand-waving examples. String bass, piano, sax, vocal, a little drums, with my bass hole prominently intruding, yet, somehow, not a problem.

The vocal and sax are prominent in this recording, a little hump in the middle, more often the upper bass through mids are flat.

Looks like there is already plenty of rolloff above 1khz, and that leaves me unconcerned about overcooking the higher end. It's crisp, but rarely shrill (recording dependent).

Again, peaks at about 100dB, corresponding to my house curve choice of "flat" on the lows per (my interpretation of) the old equal loudness curves.

 

[RayDunzl]

Hee's something a little "bass heavy", maybe.

Victor Wooten - Palmystery. No change in volume level on the system settings from the prior display above.

Victor plays electric bass, and there's some additional "thump" lower down, as he usually plays a 4 string bass - low E string at 41Hz or so.

Bass hole (at the microphone position), nicely delineated. It's a phase cancellation due to asymetrical room. Stereo bass or off-axis listening will fill the measured hole.

(pipe organ occasionally fills the gap in the 30Hz and below range)

A little less rolloff up top, still headed to 20dB down at 10khz. Rolloff starting at about 1khz. Flat midrange. Bass rolloff (or just not musically there to record) around 50Hz.

I see no "boosting" of bass SPL, just "matching" the midrange (in this case). I assume Victor has a reputable recordist. He's "award winning".

https://www.allmusic.com/album/palmystery-mw0000495107/credits

Green - handy FR response sweep of my system with both speakers playing (last June).
Red - Peak values over the first two tracks.
Black - the in-room signal around the moment I took the picture.

Later in the album, the lower bass filled in a little more when some content came along... He may have switched to the 5-string, low note 30.5 Hz

 

[mitchco]

Good stuff, Mitch. And, I totally agree about the downward sloping curve.

But, I thought at least part of the problem was a measurement issue, owing to the fact that omni measurement mikes pick up HF reflected energy that the ear does not to the same degree, due to its shape, contours, placement on the side of the head, pinnae, etc.

Hi @Fitzcaraldo215 excellent question! Check it out:

From John M, author of REW responding to why do speakers sound bright when eq'd flat at the listening position:

"Your system sounded bad when you equalised it to produce a flat response at the listening position because you boosted the high frequencies. You should not have done that, speakers that have a flat response in anechoic conditions will have listening position measurements that drop at high frequencies if the measurement includes the contribution of the room, as yours did. Your ears and brain are smart enough to distinguish between the direct sound that arrives from the speaker (which it can tell is flat) and the later sound of the room (which drops at higher frequencies) and be happy with the overall result. When you boosted the high frequencies the direct sound was now unnaturally bright, which your ears were smart enough to tell you." https://www.gearslutz.com/board/showpost.php?p=9579685&postcount=58

From Sean Olive:

"A flat in-room target response is clearly not the optimal target curve for room equalization. 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." http://seanolive.blogspot.ca/2009/11/subjective-and-objective-evaluation-of.html

More from Sean:

"Your impression of the sound quality of a loudspeaker in a room is based on a combination of the direct, early and late reflected sounds produced by the loudspeaker.Therefore, to accurately predict the loudspeakers' sound quality you need a lot of anechoic frequency response measurements that characterize the direct sound (on-axis//listening window frequency response curve, the early reflected sound(first reflection frequency response curve), and the late reflected sound (sound power response). We've shown that with this data, you can accurately predict the measured in-room response in a typical room between 200-300 Hz and 10 kHz. Below 300 Hz the room dominates what you hear (room resonances, solid boundary gain). Above 10 kHz or so, the absorption from air and room treatment will influence the late arrivals." http://www.whatsbestforum.com/showt...equency-Response&p=70095&viewfull=1#post70095

Getting into the prediction of the house curve based on Harman's approach, according to Nyal Mellor:

"interestingly enough, Harman research shows that the frequency response at the listening position above the room’s transition frequency can be predicted from the anechoic measurements of the speaker by combining the data together as follows: 14% direct sound + 44% early reflected sound + 44% late reflected sound." http://www.acousticfrontiers.com/20...nse-psychoacoustic-and-subjective-importance/

It is not too hard to work ones way backwards based on the percentages above to figure out the predicted house curve using Harman spins for the M2 or Salon2, for example... As mentioned in one of my above posts, the different windowing algorithms for different measurement software packages also is a factor.

Finally, while speaker directivity has some impact, it seems for modern controlled or constant directivity speakers, this is a small issue. Certainly from the four very different speakers I measured, using the same house curve sounded great on each one. This can be further corroborated by looking at the wide array of DSP loudspeaker and room correction products and the common house curves that are employed out of the box and fine tuned for personal preference.

I.e. if you hang out long enough on those forums and look at the hundreds of measured (corrected) speakers in rooms, there is a high degree of correlation towards a common house curve, which closely relates to Harman's predictive approach above, but coming from the opposite end. However, the end result is virtually identical. No surprise to me.

 

[mitchco]

With respect to playback levels for the right tonal balance... In many recording engineering books and in practice, the way to balance the tone in a mix or master is to be listening at 83 dB SPL C weighting, slow average on an SPL meter, as our ears, relatively speaking, are the flattest response at around 83 dB SPL. There are references you can find in the industry guidelines linked earlier or search around. Or have a look at Bok Katz's excellent: https://www.digido.com/portfolio-item/level-practices-part-2/

For playback, I listen at that level at home if critical listening and want to hear the tonal balance as best as related to the level it was mixed at. Ever notice some early rock recordings did not have a lot of bottom end? That is because the ear is non linear and as the SPL goes up, so does the sensitivity to bass frequencies, so we have a tendency to turn the bass down in the mix, if mixing too loud. Conversely, mixing too soft, adds to much bass to the mix.

I employ JRiver's loudness control. Set it so it has not effect at reference level (i.e. 83 dB SPL), but as the volume is turned down, the amount of loudness control kicks in to boost the lows and highs, so it still sounds balanced, even at low listening levels. Works pretty well for me. https://yabb.jriver.com/interact/index.php?topic=76608.0

 

[Cosmik]

Hi
From John M, author of REW responding to why do speakers sound bright when eq'd flat at the listening position:

"Your system sounded bad when you equalised it to produce a flat response at the listening position because you boosted the high frequencies. You should not have done that, speakers that have a flat response in anechoic conditions will have listening position measurements that drop at high frequencies if the measurement includes the contribution of the room, as yours did. Your ears and brain are smart enough to distinguish between the direct sound that arrives from the speaker (which it can tell is flat) and the later sound of the room (which drops at higher frequencies) and be happy with the overall result. When you boosted the high frequencies the direct sound was now unnaturally bright, which your ears were smart enough to tell you."

In other words, you "hear through the room".

 

[Cosmik]

"interestingly enough, Harman research shows that the frequency response at the listening position above the room’s transition frequency can be predicted from the anechoic measurements of the speaker by combining the data together as follows: 14% direct sound + 44% early reflected sound + 44% late reflected sound."

So 102%..?

 

[Fitzcaraldo215]

In other words, you "hear through the room".

I know that is your "get out of jail free" card, as in Monopoly. It is an easy way to deny that the known physics and acoustics of large modal variations in the bass, for example, just don't matter. We just get used to them, in your view.

But, when one actually listens to DSP EQ in one's room vs. the very same, comfortably adapted to, good old sound of one's unEQed room in AB, one might reach the conclusion that the EQ is preferable. It is, after all, measurably improved at the listening position. Have you ever in your life actually done this?

 

[Cosmik]

It is, after all, measurably improved at the listening position.

Isn't that the whole debate? An analogy is this:
If I use a single RGB 'photocell' to measure and neutralise the colour balance of a computer monitor at a distance in a room that has mildly coloured walls, I can say that it has been "measurably improved at the viewing position". But substitute a calibrated TV camera with a lens - or an eye - and suddenly the coloured walls don't matter because the 'device' is no longer just a dumb omnidirectional spectrum analyser and is 'seeing through the room' and the 'correction' is, in fact, wrong. The only justification for standard 'room correction' is if the human hearing system is a dumb omnidirectional spectrum analyser. Maybe it is; maybe it isn't, but graphs and plots alone don't prove it either way.

 

[Fitzcaraldo215]

Isn't that the whole debate? An analogy is this:
If I use a single RGB 'photocell' to measure and neutralise the colour balance of a computer monitor at a distance in a room that has mildly coloured walls, I can say that it has been "measurably improved at the viewing position". But substitute a calibrated TV camera with a lens - or an eye - and suddenly the coloured walls don't matter because the 'device' is no longer just a dumb omnidirectional spectrum analyser and is 'seeing through the room' and the 'correction' is, in fact, wrong. The only justification for standard 'room correction' is if the human hearing system is a dumb omnidirectional spectrum analyser. Maybe it is; maybe it isn't, but graphs and plots alone don't prove it either way.

Despite my analogy to the game of Monopoly, which I will gladly withdraw, I think arguments using analogies in audio are highly questionable. I believe you are now in high defense, high denial mode, since you are evading my question. Apparently, you have not tried it, and you are now attempting to debate the question on tangents taken by your own biased and less than open minded logic, unconvincing as it is without the benefit of any actual experience.

My suggestion is, repeat the mantra after me, try it, you will like it. But, if not, you will have an empirical data point, you do not appear to be in touch with or interested in now.

 

[Cosmik]

Despite my analogy to the game of Monopoly, which I will gladly withdraw, I think arguments using analogies in audio are highly questionable. I believe you are now in high defense, high denial mode, since you are evading my question. Apparently, you have not tried it, and you are now attempting to debate the question on tangents taken by your own biased and less than open minded logic, unconvincing as it is without the benefit of any actual experience.

My suggestion is, repeat the mantra after me, try it, you will like it. But, if not, you will have an empirical data point, you do not appear to be in touch with or interested in now.

Sorry, I didn't realise that was your challenge. The answer is that I only started down the path of DSP because I was convinced that 'room correction' was the most obviously brilliant idea I had yet encountered in hi-fi and became obsessed with it. But this is where you can just dismiss what I say, because I used a freeware package called DRC with passive speakers and got precisely nowhere with it - it never made any improvement to my ears. But I can't say that I really knew what I was doing with it - it was a few years ago. It killed my interest in 'room correction'.

However... it set me down the road of thinking about active speakers and DSP. My first attempts to build active speakers worked very well, but were too in-your-face. I found that full-range measurements at the listening position (which I did a lot of and then tried flattening) were not giving me the answer. It then dawned on me that speaker manufacturers wouldn't have built anechoic chambers at vast expense if in-room measurements told the whole story. I worked out that because my speakers didn't have a neutral dispersion pattern, all bets were off and that there could be no 'correction' for this; merely 'compensation'. I applied a calculated EQ curve whose depth alone was set by ear, and with the ace card of being able to maintain perfect(-ish) phase and timing from the direct sound. With that, everything seemed to fall into place, and other people who heard it seemed to agree.

I didn't measure the in-room response, but I am sure it pretty much resembles the 'house curve' that everyone talks about. However, that curve was never the target; merely the result, and with different speakers it would have been subtly different.

So you see, there is an empirical, try-it-and-see element to my hardline stance on 'room correction', but I prefer the reasoned argument!

(In the comment above that you took offence at, I was merely summarising the quote correctly, wasn't I..?)

 

[Fitzcaraldo215]

Sorry, I didn't realise that was your challenge. The answer is that I only started down the path of DSP because I was convinced that 'room correction' was the most obviously brilliant idea I had yet encountered in hi-fi and became obsessed with it. But this is where you can just dismiss what I say, because I used a freeware package called DRC with passive speakers and got precisely nowhere with it - it never made any improvement to my ears. But I can't say that I really knew what I was doing with it - it was a few years ago. It killed my interest in 'room correction'.

However... it set me down the road of thinking about active speakers and DSP. My first attempts to build active speakers worked very well, but were too in-your-face. I found that full-range measurements at the listening position (which I did a lot of and then tried flattening) were not giving me the answer. It then dawned on me that speaker manufacturers wouldn't have built anechoic chambers at vast expense if in-room measurements told the whole story. I worked out that because my speakers didn't have a neutral dispersion pattern, all bets were off and that there could be no 'correction' for this; merely 'compensation'. I applied a calculated EQ curve whose depth alone was set by ear, and with the ace card of being able to maintain perfect(-ish) phase and timing from the direct sound. With that, everything seemed to fall into place, and other people who heard it seemed to agree.

I didn't measure the in-room response, but I am sure it pretty much resembles the 'house curve' that everyone talks about. However, that curve was never the target; merely the result, and with different speakers it would have been subtly different.

So you see, there is an empirical, try-it-and-see element to my hardline stance on 'room correction', but I prefer the reasoned argument!

(In the comment above that you took offence at, I was merely summarising the quote correctly, wasn't I..?)

OK. Good. Glad to see you have tried at least some experimentation to form your own judgement about DSP room correction. However, it is not truly room correction unless you measure the in-room response at the listening position and apply corrections as indicated by those measurements. So, I still think your vantage point and experimentation with room correction is quite far from my own and others here, and it does not seem to be a valid proof/disproof of concept.

But, really what I object to is the notion that adaptation to the irregularities caused by the room is so powerful that it eliminates any need for measurement-guided room correction. That simply does not square with the experience of countless users, both here in this thread and elsewhere.

Sure, we adapt to some degree to our systems and rooms. But, just as surely there are bounds to how far that adaptation can take us. And, if we hear something we experience as sounding and measuring better in our well adapted to rooms, can we then blithely dismiss that as an unnecessary frivolity? Any rational person I know would go with it, then adapt to that new, objectively and subjectively improved sound, discarding the older, familiar sound they might have been accustomed to for years.

If adataptation knows no limits, why stop at rooms? Why not listen to 78's via an acoustic horn in mono smeared with peanut butter? Hey, just give it time, you will get used to it. The ear hears through this.

 

[Cosmik]

Sure, we adapt to some degree to our systems and rooms. But, just as surely there are bounds to how far that adaptation can take us. And, if we hear something we experience as sounding and measuring better in our well adapted to rooms, can we then blithely dismiss that as an unnecessary frivolity? Any rational person I know would go with it, then adapt to that new, objectively and subjectively improved sound, discarding the older, familiar sound they might have been accustomed to for years.

If adataptation knows no limits, why stop at rooms? Why not listen to 78's via an acoustic horn in mono smeared with peanut butter? Hey, just give it time, you will get used to it. The ear hears through this.

My claim is that our hearing doesn't "adapt"; it "reads". The example of the video monitor is like that: human vision doesn't adapt to the room the monitor is in, it simply reads the situation and bypasses the room. It is aware of the room, but is able to focus on the monitor - unlike a single photocell without a lens which would be the video equivalent of the omnidirectional mic attached to a laptop doing FFTs. 'Flattening' the response seen by the photocell would make the picture look peculiar to the human observer. What would be needed would simply be a neutral monitor, regardless of the room.

I think people become so enamoured with beautiful graphs that they are convinced that human hearing is just some magnitude-only FFTs. To me, that looks like engineers becoming giddy with the power they think their frequency domain tools gives them, convincing themselves that they are 'seeing' what the brain hears.

As for "You've got to try it before you can comment on it". Isn't that just the same as the Schiit enthusiast who tells you simply to listen to the 'Ziggy'/'Figgy'/'Buggy'/'Gubby'/'Tubby'/'Flubby' rather than measure it? If merely trying something is the criterion, then why stop at 'room correction'? Why not try SuperWideStereo (TM), UltraConcertReverb (TM), etc.? My 'philosophy' is that I could spend the rest of my life randomly trying things out, and in some cases I might even prefer the sound of some algorithm (for a while, on some music, at certain volume settings), but you have to have principles. The aim is not to just please your ears in a superficial bubblegum way, but to have a more meaningful, ultimately more satisfying, musical life.

For me, I am looking for the closest thing to a window onto the music and I think that needs working out rationally rather than try-it-and-see. I might be wrong in what I am doing, but there is some reasoning behind it - and if it sounded rubbish I would change what I was doing, of course!

 

[Fitzcaraldo215]

My claim is that our hearing doesn't "adapt"; it "reads". The example of the video monitor is like that: human vision doesn't adapt to the room the monitor is in, it simply reads the situation and bypasses the room. It is aware of the room, but is able to focus on the monitor - unlike a single photocell without a lens which would be the video equivalent of the omnidirectional mic attached to a laptop doing FFTs. 'Flattening' the response seen by the photocell would make the picture look peculiar to the human observer. What would be needed would simply be a neutral monitor, regardless of the room.

I think people become so enamoured with beautiful graphs that they are convinced that human hearing is just some magnitude-only FFTs. To me, that looks like engineers becoming giddy with the power they think their frequency domain tools gives them, convincing themselves that they are 'seeing' what the brain hears.

As for "You've got to try it before you can comment on it". Isn't that just the same as the Schiit enthusiast who tells you simply to listen to the 'Ziggy'/'Figgy'/'Buggy'/'Gubby'/'Tubby'/'Flubby' rather than measure it? If merely trying something is the criterion, then why stop at 'room correction'? Why not try SuperWideStereo (TM), UltraConcertReverb (TM), etc.? My 'philosophy' is that I could spend the rest of my life randomly trying things out, and in some cases I might even prefer the sound of some algorithm (for a while, on some music, at certain volume settings), but you have to have principles. The aim is not to just please your ears in a superficial bubblegum way, but to have a more meaningful, ultimately more satisfying, musical life.

For me, I am looking for the closest thing to a window onto the music and I think that needs working out rationally rather than try-it-and-see. I might be wrong in what I am doing, but there is some reasoning behind it - and if it sounded rubbish I would change what I was doing, of course!

You misconstrue. Room correction is fundamentally a measurement-based process to deal with known acoustic and psychoacoustic issues. These include slam dunk obvious modal frequency swings of considerable magnitude - many dB, I have seen 10-20dB - which absolutely dwarf any frequency issues caused by any other elements in most systems in most all listening rooms, including the speakers! We appear to disagree about whether "listening through" those issues is or is not an issue. Sure, the music comes through in any case, but why put up with an objectively measured double digit peak/trough caused by the room, not the speakers?

Yes, subjective evaluation of alternative correction schemes, target curves, etc. once calibrated is advisable and highly recommended, and of course it should be compared with noEQ or EQ restricted to just bass frequencies below the transition frequency. Yes, that final assessment is subjective, but one need not hassle with many different alternatives, unless one is curious. So, it becomes a simple preference question, not an extended game in quasi-logical attempts to work it all out in one's mind without actually listening.

I mean, I agree we have issues with those who think they hear something in uncontrolled, subjective listening due to biases, etc. But, seriously, aren't you just as guilty in the opposite direction? You wish to rationalize rather than measure and listen, raising your "we listen through it, we read it inspite of the measurable issues" canard. But, why does that logically stop at just the room? Cannot a vinyl lover, a mono lover, a SET lover rationalize and listen through all the known, glaring objectively measured flaws of those paradigms? Why is your logic any better than theirs?

 

[Wombat]

Is there any research that psycho-acoustical perception is much the same for most individuals or are there definite differences between individuals? I lean towards the latter condition and thus ponder how these algorithms address that.

 

[Fitzcaraldo215]

Is there any research that psycho-acoustical perception is much the same for most individuals or are there definite differences between individuals? I lean towards the latter condition and thus ponder how these algorithms address that.

I think that is obvious, but it depends on how microscopically you wish to draw the line. We know absolutely for sure that humans vary in most all things, including hearing perception and preference. But, we also know that there are general similarities across much of the population in hearing perception and preference, occurring in statistically "normal" distributions.

The analogy to drugs is also relevant. Few drugs cure 100% of the people 100% of the time with no side effects. But, they are still deemed effective if they cure most people even to a varying degree and with controllable, non threatening side effects affecting only a "reasonable" minority. Again, people vary.

So, Harman speaker preference studies, for example, may have large numbers of test subjects giving high scores to some speakers and low ones to others. Yet, neither choice will be unanimous among all test subjects. Some subjects will prefer a speaker rated low by the majority, etc. If a speaker's preference were totally random among the subjects, it would not be considered a good speaker to try to manufacture and market. And, those studies do consistently show a majority preference for certain measured properties, such as smooth frequency response. The good news is that the marketplace offers choices, not one size fits all solutions.

As to DSP Room EQ, which is based on a pretty good theoretical and measurement-based model, there are also choices within the same general operational framework, though finer details may differ. But, better EQ tools also allow for user customization and tailoring of the sound, if desired, starting with the frequency domain target curves discussed here. That user customization can be a mix of measured and subjective adjustments, each to a degree according to the users choice.

There is guidance available and normally a default target curve provided by each tool as a starting point. In previous excellent posts by @mitchco, some common published full range target curves are also compared. Since these are each estimated as an average from separate perceptual testing of human subjects, they differ slightly, though they all have the same general downward sloping shape.

I personally have been satisfied with the unmodified, default target provided by Dirac. It works for me. But, I also cited a friend and Dirac user who feels the need to almost constantly alter the target and switch based on program material. Who is right? Of course, both. And, Dirac does allow target curve adjustment for major or minor tweaking as desired.

 

[pastorbarrett]

Interesting thread, thanks. If I may from the vantage of the non-technical - if using room correction/ DSP such as DIRAC, are differences from similar type/ spec speakers essentially minimised or non-discernible?

 

[DonH56]

No. It can't work magic and a lot of variables like speaker dispersion/directionality in general and over frequency are out of its control. Similarly there is only so much it can do for the room, and the room is a big player in how a speaker sounds due to the speaker's interaction with the room. RC can correct for things like bumps in the speaker's frequency response and high- and low-frequency rolloff, and similarly correct bumps in frequency response caused by interaction with the room and listening position, to a point, but after all the processing your speakers are still going to sound like "your" speakers.

IME/IMO/etc. - Don

 

[pastorbarrett]

Thanks Don, I think that answers my question. Specifically, I was wondering whether to purchase an older (read: cheaper) version of a speaker, as opposed to the contemporary version which has the same drivers/cabinet but an updated crossover. I hadn't considered dispersion/ directionality etc

 

[Chipless]

Overlaying the "house curves" or target responses:

View attachment 10874

Phenomenal info! Thank you for sharing. I am a bit confused in regards to the graphical depiction of the Olive/Toole curve though: Given the preferred "tilt" of the in-room response as shown in Olive's research, why is the curve shown as sloping downward very gradually from 20 Hz to 1,000 Hz, and then sloping downward much more rapidly from 1,000 Hz to 20,000 Hz? I am sure I missed something somewhere, but based on the linked presentations and papers, it seems like the graphical depiction should show a more linear downward titling "curve" beginning at +2 @ 20 Hz and ending at -8 @ 20 kHz. Any clarification would be greatly appreciated. Thanks again for the great info.