Headphone Measurements Using Brüel & Kjær 5128 HATS

[HRTF_Enthusiast]

View attachment 166692

I'm fully aware of this statement. However, it would be more useful to have the actual data considering the strong reliance on S. Olive's cluster
analysis paper.

Regarding distortion, as solderdude pointed out, the listening levels weren't very high. However, I still think it would be interesting to repeat the test with HD800.

The main difference between this study and S. Olive's were that users were allowed to control loudness.

 

[GaryH]

I'm fully aware of this statement. However, it would be more useful to have the actual data considering the strong reliance on S. Olive's cluster
analysis paper.

It's not just reliance on that paper, it's Olive's MOA studies too. The audiophile meme that trained (or 'experienced') listeners prefer 'flat bass' (whether on the 45CA or 5128) is not supported by the vast majority of the scientific literature.

Regarding distortion, as solderdude pointed out, the listening levels weren't very high. However, I still think it would be interesting to repeat the test with HD800.

Why the HD800? A decent cheap planar can outperform its distortion.

 

[HRTF_Enthusiast]

It's not just reliance on that paper, it's Olive's MOA studies too. The audiophile meme that trained (or 'experienced') listeners prefer 'flat bass' (whether on the 45CA or 5128) is not supported by the vast majority of the scientific literature.

Where is the proof that listeners prefer Harman bass when allowed to adjust volume themselves?

Why the HD800? A decent cheap planar can outperform its distortion.

Leakage tolerance

 

[GaryH]

Where is the proof that listeners prefer Harman bass when allowed to adjust volume themselves?

Volume is a possible confounding variable for bass preference due to the equal loudness contours, so it needs to be controlled for.

 

[HRTF_Enthusiast]

Volume is a possible confounding variable for bass preference due to the equal loudness contours, so it needs to be controlled for.

So Harman target is only valid for whatever volume was used in the test?

 

[GaryH]

Strictly speaking? Yes. Just as cinema projectors are calibrated for an industry standard peak luminance, so you see the movie as the director intended. Note, the single study with a small sample of listeners you seem to be placing over the entire previous body of research is not only inconsistent with this research, but with the equal loudness contours too, I suspect due to more is better / less is better biases from the listeners:

 

[HRTF_Enthusiast]

Strictly speaking? Yes. Just as cinema projectors are calibrated for an industry standard peak luminance, so you see the movie as the director intended. Note, the single study with a small sample of listeners you seem to be placing over the entire previous body of research is not only inconsistent with this research, but with the equal loudness contours too, I suspect due to more is better / less is better biases from the listeners:

View attachment 166856

? Since when have songs been calibrated for Harman target C-weighting ?

 

[GaryH]

? Since when have songs been calibrated for Harman target C-weighting ?

There are no calibration standards for SPL during mixing/mastering for music, which is one of the (many) reasons for audio's circle of confusion. The point is the ultimate aim should be to break this circle of confusion by introducing some kind of standardization (as has existed in the movie industry for a long time), and seeing as the audio production side is doing nothing to further this, Sean Olive and Harman are attempting this on the audio reproduction side (which will hopefully bleed into the production side eventually) by aiming for playback transducers with a common target frequency response at a standardized reference playback SPL. Incidentally, the 85 dBC SPL he chose is actually both broadly consistent with typical reported (if anecdotal) SPLs from mastering engineers (considering those are for speakers, so headphones would need a few dB higher SPLs to be perceived equally as loud, as noted in McMullin's paper you linked), and Dolby audio production standards for front channel SPL. So this is not an unreasonable choice of SPL by Sean.

 

[HRTF_Enthusiast]

Dolby audio production standards for front channel SPL.

"For film work, pink noise at reference level should produce a sound pressure level
(SPL) of 85 dBC for each of the front channels (left, center, and right). Each surround
channel should produce a sound pressure level of 82 dBC (the lower surround level is
specific to film-style mixing rooms)."
Since, headphones only have two channels and is perceived quieter than speakers, the 85 dBC choice for headphones doesn't exactly apply to Dolby audio production.

Also, a quote from that thread you linked, "[Bob Katz says his colleagues and he discovered that the SMPTE RP200 spec. was a little bit 'off' compared to his K-System target, due to a meter-measurement discrepancy. (...it was explained on his Digido website.) He says it should be 83 dBSPL Slow C-weighted response per soloed loudspeaker (rather than 85) when playing the -20 dBFSD RMS pink noise. Also, Katz has posted online that unless your mastering room is the size of a commercial movie theater (...like a Cineplex), especially that they have many Bass Traps in each seat when there's an audience, so, without the sound-absorbing movie audience in the seats and big space with tall ceilings, you can lower the target SPL (for K-20) by 10 dBSPL."

 

[DualTriode]

There are no calibration standards for SPL during mixing/mastering for music, which is one of the (many) reasons for audio's circle of confusion. The point is the ultimate aim should be to break this circle of confusion by introducing some kind of standardization (as has existed in the movie industry for a long time), and seeing as the audio production side is doing nothing to further this, Sean Olive and Harman are attempting this on the audio reproduction side (which will hopefully bleed into the production side eventually) by aiming for playback transducers with a common target frequency response at a standardized reference playback SPL. Incidentally, the 85 dBC SPL he chose is actually both broadly consistent with typical reported (if anecdotal) SPLs from mastering engineers (considering those are for speakers, so headphones would need a few dB higher SPLs to be perceived equally as loud, as noted in McMullin's paper you linked), and Dolby audio production standards for front channel SPL. So this is not an unreasonable choice of SPL by Sean.

Hello All,

The Circle of Confusion is a term that belongs to photography. Like a reserved word in computer programming; Circle of Confusion has specific meaning, it is not audio.

Even when Floyd Toole misappropriated the term he was confused by discussing microphones used to measure speakers then speakers used to measure microphones. Then years later he changed the term to illustrate the pitfalls in the loop of recording and playback technology.

Audio should grow up and coin its own term, perhaps something like “the recording playback flow-chart of confusion”. It is interesting that the term “Flow-Chart” was originated by the ASME to illustrate a mechanical process.

Thanks DT

 

[GaryH]

"For film work, pink noise at reference level should produce a sound pressure level
(SPL) of 85 dBC for each of the front channels (left, center, and right). Each surround
channel should produce a sound pressure level of 82 dBC (the lower surround level is
specific to film-style mixing rooms)."
Since, headphones only have two channels and is perceived quieter than speakers, the 85 dBC choice for headphones doesn't exactly apply to Dolby audio production.

Also, a quote from that thread you linked, "[Bob Katz says his colleagues and he discovered that the SMPTE RP200 spec. was a little bit 'off' compared to his K-System target, due to a meter-measurement discrepancy. (...it was explained on his Digido website.) He says it should be 83 dBSPL Slow C-weighted response per soloed loudspeaker (rather than 85) when playing the -20 dBFSD RMS pink noise. Also, Katz has posted online that unless your mastering room is the size of a commercial movie theater (...like a Cineplex), especially that they have many Bass Traps in each seat when there's an audience, so, without the sound-absorbing movie audience in the seats and big space with tall ceilings, you can lower the target SPL (for K-20) by 10 dBSPL."

Incidentally, the 85 dBC SPL he chose is actually both broadly consistent with typical reported (if anecdotal) SPLs from mastering engineers (considering those are for speakers, so headphones would need a few dB higher SPLs to be perceived equally as loud, as noted in McMullin's paper you linked), and Dolby audio production standards for front channel SPL. So this is not an unreasonable choice of SPL by Sean.

 

[GaryH]

Hello All,

The Circle of Confusion is a term that belongs to photography. Like a reserved word in computer programming; Circle of Confusion has specific meaning, it is not audio.

Even when Floyd Toole misappropriated the term he was confused by discussing microphones used to measure speakers then speakers used to measure microphones. Then years later he changed the term to illustrate the pitfalls in the loop of recording and playback technology.

Audio should grow up and coin its own term, perhaps something like “the recording playback flow-chart of confusion”. It is interesting that the term “Flow-Chart” was originated by the ASME to illustrate a mechanical process.

Thanks DT

Words and phrases are defined by their current majority usage and evolve meaning over time, whether you like it or not. I just googled "circle of confusion" + photography, got 2.21 million results. And for "circle of confusion" + audio? 2.52 million. The latter is now the majority usage. You "should grow up" and accept this

 

[DualTriode]

Words and phrases are defined by their current majority usage and evolve meaning over time, whether you like it or not. I just googled "circle of confusion" + photography, got 2.21 million results. And for "circle of confusion" + audio? 2.52 million. The latter is now the majority usage. You "should grow up" and accept this

Leave out both the search terms audio and photography.

Put "circle of confusion" into the search. The photo / optics use shows up first and most often. It is pages into the search before audio even shows up. Tell us about the majority usage concept.

 

[GaryH]

Leave out both the search terms audio and photography.

Put "circle of confusion" into the search. The photo / optics use shows up first and most often. It is pages into the search before audio even shows up. Tell us about the majority usage concept.

Doesn't matter. Words and phrases can also have several concurrent differing meanings. Get over it.

 

[AudioManNewb]

Leave out both the search terms audio and photography.

Put "circle of confusion" into the search. The photo / optics use shows up first and most often. It is pages into the search before audio even shows up. Tell us about the majority usage concept.

Or here is a concept you could put to use. Read what context "circle of confusion" is used in and magically you know exactly how there using it. You know kind of like the written words wind and wound.

 

[Berwhale]

Doesn't matter. Words and phrases can also have several concurrent differing meanings. Get over it.

Or to put it another way, put 'circle of confusion' outside of your 'circle of concern'

 

[milosz]

HAHAHAHA

 

[Cowanaudio]

If I used my IEMs more I’d go to an audiologist and get custom made tips for mine. I did find that one of the included silicon tips worked best for me but I still needed to shove them practically to my brain to get best seal.

I use custom ear molds with my ER4XR's and it transformed them. They just don't work reliably with the stock seals.

 

[Mad_Economist]

I use custom ear molds with my ER4XR's and it transformed them. They just don't work reliably with the stock seals.

Beware, the inserting depth changes involved will muck with the higher frequency behavior.

Of course, if you can't get seal without, it's a good tradeoff...

 

[Cowanaudio]

Beware, the inserting depth changes involved will muck with the higher frequency behavior.

Of course, if you can't get seal without, it's a good tradeoff...

My ear molds were made by Australian ACS dealer Pacific Ears. Looking at the way they made my patterns and the final product it appears my ear drums are only one or two mm from the tip of the ear mold.

The foam in the image was pressed against my eardrum before the mold was made. They were following instructions from Etymotic while making the patterns.

When my ear molds aren't properly seated they feel very uncomfortable, but can't be felt at all when they are in properly.