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What is your favorite house curve

Matias

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If you're over 40, you want to boost frequencies above 10kHz as well. I don't see the logic in the Harman curve where they attenuate the higher end.
It is on Floyd Toole's book. A flat speaker in near field will measure linear descending tilt in the far field because of frequency directivity. Mids start attenuating to the sides until the highs are forward facing only, and the bass is omni directional. When everything is reflected in the room and reaches the listening position, is tilts down.
 

Floyd Toole

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If you're over 40, you want to boost frequencies above 10kHz as well. I don't see the logic in the Harman curve where they attenuate the higher end.
If you read the relevant papers or my book, you will see that the "Harman" curve is a steady-state room curve, including reflected energy, measured at the listening location. It is what is measured from well-designed loudspeakers that received very high sound quality ratings in double-blind listening tests. These all have a flat on-axis (direct sound) response, and well-behaved off-axis performance. Because lower frequencies - longer wavelengths - radiate more widely than high frequencies, room curves will rise as frequency drops - so there is a downward tilt in the room curve. Perceived sound quality is strongly influenced by direct sound, which is radiated as a "flat" curve. When measured at the listening position there will be an additional small very-high-frequency downward tilt because of air absorption, which is related to listening distance, something that human listeners appear to take into account, as it applies to live sounds as well as reproduced sounds. It is not, as you imply, a "Harman" decision to attenuate the high frequencies.

A person, who by virtue of age, noise exposure, ototoxic drugs, etc. has lost the ability to hear the highest frequencies will find little or no benefit from a high-frequency boost. The loss is usually sensory-neural - the "microphone" is broken - those frequencies are gone.

And, finally, I will repeat that the "Harman/Toole - you name it" room curve is not a generalizable "target" curve. It is what you are likely to get from a well designed loudspeaker. Adjusting a less-well-designed loudspeaker to have the same shape of room curve will not produce the same sound quality. There is no substitute for starting with a properly-designed loudspeaker.
 

Matias

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@Floyd Toole The downward tilt also depends on the speaker directivity and room absorption, so 2 different speakers both perfectly flat in near field will tilt differently in the listening position if they have more wide or narrow directivity. Or the same perfectly flat in near field speaker will tilt down differently in the listening position in a live room or in a well damped room.

I thought that the 1dB/octave tilt (or -10 dB from 20 Hz to 20 kHz) was your suggested "tilt target" considering the factors above, independently of dispersion and absorption? That is, more dispersion needs more absorption, less dispersion needs less absorption to get the desired tilt?
 
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Floyd Toole

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@Floyd Toole The downward tilt also depends on the speaker directivity and room absorption, so even 2 perfectly flat in near field speakers will tilt differently in the listening position if they have more wide or narrow directivity. Or the same perfectly flat in near field speakers will tilt down differently in the listening position in a live room or in a well damped room.

I thought that the 1dB/octave tilt (or -10 dB from 20 Hz to 20 kHz) was your suggested "tilt target" considering the factors above, independently of dispersion and absorption? That is, more dispersion needs more absorption, less dispersion needs less absorption to get the desired tilt?

I hope I have never implied much less stated that this is a "target" room curve, which, if achieved with any Brand X loudspeaker will result in state-of-the-art sound quality. Figure 12.4 in the 3rd edition of my book explains very clearly where the curve came from - it is the steady-state curve that is often measured in "typical" listening rooms, from "typical" cone&dome loudspeakers that have received very high subjective sound quality ratings in double-blind listening tests. Figure 12.5 shows that this is also true for a full-range dipole loudspeaker.

What happens with loudspeakers with much narrower dispersion? I have not tested the large high-directivity cinema and sound reinforcement loudspeakers because they are of little interest in the domestic domain. However, I did show data on an excellent loudspeaker that bridges the gap, the JBL Professional M2, which has a moderately wide dispersion horn, as it was designed as a monitor loudspeaker for recording control room venues. It has been well received in home theaters as well. Figure 11.11 shows steady-state room curves for this loudspeaker in cinema spaces having 161, 211 and 516 seats compared to a small home theater venue. The significant difference is air absorption at high frequencies, which is related to the very different listening distances.

All that said, obviously, if one progressively eliminates reflected sound by virtue of passive absorption on room surfaces or by increasingly directional radiators, the steady-state room curve becomes progressively flatter, until, in the limit one is in an anechoic space measuring the flat on-axis sound, and nothing from reflections. QED.
 

JoachimStrobel

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If you read the relevant papers or my book, you will see that the "Harman" curve is a steady-state room curve, including reflected energy, measured at the listening location. It is what is measured from well-designed loudspeakers that received very high sound quality ratings in double-blind listening tests. These all have a flat on-axis (direct sound) response, and well-behaved off-axis performance. Because lower frequencies - longer wavelengths - radiate more widely than high frequencies, room curves will rise as frequency drops - so there is a downward tilt in the room curve. Perceived sound quality is strongly influenced by direct sound, which is radiated as a "flat" curve. When measured at the listening position there will be an additional small very-high-frequency downward tilt because of air absorption, which is related to listening distance, something that human listeners appear to take into account, as it applies to live sounds as well as reproduced sounds. It is not, as you imply, a "Harman" decision to attenuate the high frequencies.

A person, who by virtue of age, noise exposure, ototoxic drugs, etc. has lost the ability to hear the highest frequencies will find little or no benefit from a high-frequency boost. The loss is usually sensory-neural - the "microphone" is broken - those frequencies are gone.

And, finally, I will repeat that the "Harman/Toole - you name it" room curve is not a generalizable "target" curve. It is what you are likely to get from a well designed loudspeaker. Adjusting a less-well-designed loudspeaker to have the same shape of room curve will not produce the same sound quality. There is no substitute for starting with a properly-designed loudspeaker.
While it is not possible to boost frequencies above 13 kHz by 30db or more for compensation, a more gentle boost of 6-10 dB at 11 kHz or 4-6 at 9 kHz is doable with some loudspeakers. That will not bring back the hearing capacity of younger years but a taste of it which suffices at least in my case to retrain the brain a bit on what it has to recombine. This works well when playing records that I have not played for 20 years, as my brain has not getting used not hearing the high frequencies but imagining them. It does sound harsh and drives people with good hearing crazy, but has a quality of its own as the music does not only sound differently but is perceived much differently.
I do believe a market could exists for amps, loudspeakers and DSPs that would allow a combination of a room curve adjustment with a low distortion boost of frequency ranges at the early slope of age related frequency loss that is specific to the room condition and hence needs to be measured in-situ by the same DSP. It might be not a high revenue market as not many will want to admit the need for such devices.
 

Digital_Thor

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I went from at typical 1" tweeter + 5" midrange combo, to one with a small waveguide (Seas DXT). My room is made of rather soft material and nowhere near symmetrical - either in shape or setup. The small waveguide gave me a much more smooth integration between tweeter and midrange + much better directivity, that I like in everything from movies to music, where I now perceive sound as an image in front of me, where I can easily forget that I have speakers. Low noise, smooth on-axis and off-axis, great dynamic ability and multi-sub - with a twist of mid-woofer EQ to tame a bit of room-interference and personal taste. This seems to me as the most satisfying setup I ever owned and heard.
I measure my speakers in between my tweeter and midrange at 1-1,5m distance - gated. Woofers and subwoofers are measure in the listening position. I might have a little extra bass, but it's clear that I have a "natural" rool-off/house curve in my listening position(4m away), when it measures flat in a gated 1m distance measurement. I see a house-curve as an acoustical thing - not something that should be done by EQ.
 

Albertmato

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Hard knee house curve is my favourite. it’s great for determining if a subwoofer has linear response, and if it’s blending well with the mains.
 

lizhuoyin

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Updated this post after using MMM and added the EQ overlays of both the main system and the office system.
@Matias, I have a pair of Genelec 8030C on desktop. About 1.1m to listen position. I am starting using REW and UMIK-1 to EQ.
I can find Harman curve but could not find a flat house curve.
Can you share your flat target house curve? Much appreciated.
 

Matias

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@Matias, I have a pair of Genelec 8030C on desktop. About 1.1m to listen position. I am starting using REW and UMIK-1 to EQ.
I can find Harman curve but could not find a flat house curve.
Can you share your flat target house curve? Much appreciated.
Hi I do not use a text file with a house curve, instead I set it up on the right side of the EQ window, that is why I kept it in my prints. It is basically 0.8 dB / octave slope before and after a given fixed frequency (REW has this set up this way).

target curve.jpg


PS: don't say "Harman house curve" or Mr. Toole above may get upset. :D
 

lizhuoyin

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Hi I do not use a text file with a house curve, instead I set it up on the right side of the EQ window, that is why I kept it in my prints. It is basically 0.8 dB / octave slope before and after a given fixed frequency (REW has this set up this way).

View attachment 127392

PS: don't say "Harman house curve" or Mr. Toole above may get upset. :D
Perfect. Much appreciated it. I guess Toole/Harman curve will make him happy.
 

Matias

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Yeah, the semantics are quite tricky on this one. Maybe "the room curve that Harman observed as the highest rated for a flat speaker in a regular listening room". Also know and "Harman curve". :D
 

Andysu

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What happens with loudspeakers with much narrower dispersion? I have not tested the large high-directivity cinema and sound reinforcement loudspeakers because they are of little interest in the domestic domain. However, I did show data on an excellent loudspeaker that bridges the gap, the JBL Professional M2, which has a moderately wide dispersion horn, as it was designed as a monitor loudspeaker for recording control room venues. It has been well received in home theaters as well.
Well JBL M2 isn't a fish and chips JBL is now - my JBL 4673A was x6.5 £ times cheaper. I think the 4673A is a wonderful flashback to cinema at fish and chips price but rarely show on ebay least I got the cabs at not gonna say but when I saw x5 I knew I needed them for five-screen matrix. The 2226 was a bit more but still cheaper than usa prices as was the JBL 2445 CD and 2380A horn.

They are covered with foam treatment not shown as I had to slip behind the screen and do it. No snags hearing left to right or half pans with LCR or better sounding when used as five-screen-matrix with left-centre right-centre with two matching decoders Dolby SDU4 with the main avr Denon AVC-X8500H.
140642702_10158856122190149_3186193677952171779_o.jpg
 

Dialectic

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This is stale, but thanks to Dr Toole for disabusing me of a misunderstanding regarding the Harman curve. For reasons probably involving the narrow radiation pattern of my speakers and the treatments in my room, a flatter curve is preferable there.
 

Weeb Labs

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My target is in white, uncorrected response in green and corrected response in yellow. This sounds correct to me.

1622081978027.png


Note that this is simply my desktop configuration, consisting of wall mounted T5Vs. It is by no means optimal.
 

Digital_Thor

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@Otaku+
How do you EQ the two big dips at 90 and 290hz?
Normally I use speakers that has a certain level of headroom and avoid boosting- since 99% of the time I only cut in my DSP. But is there a piece of software that could handle the level of EQ compared to the level of headroom left. I talked to Lyngdorf about his small satellite/sub combo. And he confirmed that they aimed for positioning the system in a way to avoid most dips, so that the DSP only would cut and not boost - cause boosting would very quickly dry out the power and driver excursion.
My DSP has an overall auto-damping-function, that lowers the total SPL, if I boost at any point in the DSP's signal chain. It's an indirect way of avoiding distortion because of excessive boosting, by lowering everything else, instead of boosting the dips - even though it still looks like I've only boosted that one point in frequency. It can be turned off.... but it's actually also a nice reminder to me, whether I have an unwise EQ somewhere in all the input/output blocks of the software. You know.... sometimes I lose track of all the trickery I've done, to obtain that wonderful straight curve o_O:D
 
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Great informative topic.

My favorite “house curve” is still flat (on the Trinnov altitude-32) Wether “right” or “wrong” to me this sounds most transparant, revealing and enjoyable.

I have reasons to believe that our brains adapt to a certain sound over time. So probable I am “adapted” to a flat curve. Any other curve with bass-boost or downwards slope sound unrealistic to me and I always crave back to the flat target curve.

That being said, that is only on the Trinnov. With other room correction system, flat target curves provided less desirable results.
 

Digital_Thor

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Room- correction is a rather silly word.... cause we cant correct the room.... we can only alter the FR and the relative timing of the sound from the speaker. Should it not be called a speaker correction? I'm walking around in semantics here - I know. But I believe that it is rather important to know the clear difference.
Things are easily mixed up. 30 min in... Toole touches upon the very difference between sound from a speaker and the interference from the room:
 

oupee

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The Audyssey (SR8015) worked well for me when I had cheap Klipsh speakers. It removed the hollow and plastic sound. Now I have quality speakers with which I have no problem in stereo. I tried turning on Audyssey on the stereo as they do and praises some here, and I was horrified at what it did to the sound. I haven't used Audyssey in a movie for a week. It's much more dynamic and natural. I only use Audyssey to measure the distance and level of the speakers.
 
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