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AKG K371 Impressions
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No, not this.
Sean Olive's research and the measurement rig he uses is the current state of the art. There are no other rigs or measurements or studies published that shows improved preference by people. Maybe something better will come along in the future, but as of today, this is the reference standard.
Thus, @solderdude's claim that different rigs are just as valid or that different rigs are "all good starting points" is false. No offense.
This situation is similar to using calibrated vs uncalibrated mics for speaker measurements. Trying to EQ with uncalibrated mic is not any different from randomly fiddling with EQ. Yeah, it sounds "better", but did you fix anything or did you make it worse?
Toole's spinorama and Olive's GRAS measurements are state of the art measurements. Amir's measurements on these forums are the same. As a consumer, I want accurate specs to compare products, no more, no less. All this fuzzy "yeah, but" without good measurements or good data to me are same as fawning over vinyl and tube.
I don't know any of you saw my post here, but individual headphone manufacturing tolerances is something I'm really curious about. Is it possible with a manufacturing tolerance of say +/- 3db to have a 6 db delta somewhere in say the 1000khz-5000khz range and make a "good" headphone model sound pretty bad? Is that a big contributor to the circle of confusion? The hd650 measurements in that post (if they can be trusted) seem like they would be voiced differently to a trained listener.
Amen.
solderdude
Grand Contributor
If that is considered the reference then one can call it a reference. Just as 1V is 1V etc.
Where did I make this claim ? What I mentioned was that there are many different rigs that all are used to measure headphones that, for technical reasons, all measure differently above 1kHz for obvious reasons.
It is perfectly fine to call a certain transfer function a standard. That's perfectly fine to do so and use it. When one refers to that standard one can see where it deviates. Perfectly reasonable that a very expensive and characterized measurement rig built to strict specs always performs the same way.
I do not disagree with any of this.
The question is whether or not you fixed anything or made it worse when EQíng exactly acc. to a measurement made with the rig.
Don't get me wrong, I like Sonarworks, Rtings, Oratory and all the others that post 'measurements' and EQ exactly on it.
What I am questioning is whether or not the EXACT same averaged 'target curve' or 'corrections' will apply to different headphones.
Are you 100% sure that because a rig is expensive and complies to a certain standard one can EQ on it (exactly) and get trustworthy results ?
Fully agreed, and certainly in the electrical plane absolutely correct.
Also I am not claiming to have more experience nor knowledge than the mentioned guys or other notable figures in this business at all.
What I am saying is that a 'standard' correction curve is just that, an averaged curve so one can compare results under calibrated circumstances.
That does not mean that correction curve exactly compensates perfectly for all headphones.
There will (with 100% certainty in my mind) be substantial errors with different headphones compared to the actual compensation and measured signal.
If one EQ's on those errors opposite the standard then that is just as bad as using an uncalibrated microphone or doodling about with EQ.
It also is not accurate.
But surely... one can be 100% sure the headphones HAVE been measured to a standard with a high precision.
Can you tell me with absolute certainty that all headphones are measured exactly as to how they sound with one single averaged correction curve under all conditions then and that this is so accurate you can EQ small variations on it ?
Honestly, I think this is the more interesting frontier than DACs and AMPs. How can we discovered personalized EQ for headphones based on hrtf, other personal factors, and individual tolerances in headphones, etc, objectively? I am admittedly very naive, but it seems like there is much more room for error in those factors than there is in non-transparent electronics, at this time.
OP
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To bring it back to the K371 for a moment, as the marketing claims and as Oratory's measurements show, it's a headphone that's designed to follow the Harman target, and excepting the excessive sub-bass, I really like the result. There are also some things going on in the treble that don't sound perfect to me and I've been able to improve on those (for myself) with some minor EQ adjustments. Running oratory1990's EQ to bring the headphone fully in-line with the Harman target based on his rig's measurements results in a sound that I personally find less pleasing than even the un-eq'd sound, in particular filling in the 4 KHz dip which coincidentally I see on many of his measurements. It's not a knock on Harman, oratory1990 or the fine people of the IEC, GRAS etc., it's just what sounds good to me.
OP
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- #109
I suspect that this would be much easier with IEMs than with headphones since they bypass the outer ear. I've done some EQ based on IEM measurements from crinacle and have had much more success with this than with any over-ear headphone measurements.
The issue with IEMs is that variability of insertion depth causes individual differences on a larger scale in the 7-8k region than variations on the outer ear. The exception is IEMs that are designed for deep insertion like Etymotic.
OP
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- #111
That would explain why I always end up EQing that bit by ear!
It seems like the validity of the Harman target curve, the methodology behind it, and the goal of designing a headphone to match it - which I have no reason to doubt - is distinct from the question of whether and to what extent it is desirable to EQ headphones to fit the curve. Especially when it comes to applying filters with positive gain.
I'm trying to understand why even though I like the overall tonal balance of the Harman target curve, attempts to EQ to it never sound transparent to me. I've tried Sonarworks, Toneboosters Morphit, oratory1990's filters, etc. to the extent possible on my phone and my PC and they all sounded "off" and lower fidelity. Obviously this is anecdotal, but I wonder about how measurable it is.
Does a simple frequency response graph showing measurements before and after EQ filters correcting to the Harman curve really tell the whole story? Surely the filters (especially the positive ones) can affect distortion or interact with other physical characteristics of the headphones (resonances, etc.). It seems well-accepted, for example, that an HD650 can't take much of a bass boost before it audibly distorts and certainly that is my experience. And then if you are applying a substantial negative preamp gain to avoid clipping, won't the reduced headroom and need to operate at the amplifier at higher gain introduce more distortion? oratory1990's filters for the Fostex TH-X00 Mahogany (chosen since I own them too) call for a preamp gain of -8.3dB to accommodate a gain of +10dB at 4000 Hz.
I'm trying to understand why even though I like the overall tonal balance of the Harman target curve, attempts to EQ to it never sound transparent to me. I've tried Sonarworks, Toneboosters Morphit, oratory1990's filters, etc. to the extent possible on my phone and my PC and they all sounded "off" and lower fidelity. Obviously this is anecdotal, but I wonder about how measurable it is.
Does a simple frequency response graph showing measurements before and after EQ filters correcting to the Harman curve really tell the whole story? Surely the filters (especially the positive ones) can affect distortion or interact with other physical characteristics of the headphones (resonances, etc.). It seems well-accepted, for example, that an HD650 can't take much of a bass boost before it audibly distorts and certainly that is my experience. And then if you are applying a substantial negative preamp gain to avoid clipping, won't the reduced headroom and need to operate at the amplifier at higher gain introduce more distortion? oratory1990's filters for the Fostex TH-X00 Mahogany (chosen since I own them too) call for a preamp gain of -8.3dB to accommodate a gain of +10dB at 4000 Hz.
snowsurfer
Active Member
Nothing to do with 371s, but since this thread seems to have derailed somewhat towards EQ in general, I'll say I really like the EQ profile for HD660s provided by Oratory1990, and I use it all the time, but what I would really like is to learn to EQ properly myself. I don't mean pull a peak filter up or down, but correct usage of shelf, bandpass, etc. I'm just lost with all that.
maxxevv
Major Contributor
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Just took delivery of the K371 a few hours ago.
I have to say, it does have a pretty enjoyable sound profile.
That said, some of the specifications on the headphone seem odd though. Despite its rated sensitivity, it seems to sound " dull " when powered via my LG V40. However, that completely changes when powered up using the KTB via the JDS Atom. ( KTB at full volume, Atom at low-gain, 8-Oçlock knob position).
As enjoyable as it sounds, its no giant slayer, not near the Focal Stellia's level for closed-back. Nor does it come close to open backs such the the HE4XX (with grill modification), for "spaciousness" in the sound. Its very much still a between your ears kind of sound.
I can see why people like it so much, it has the right amount of bass energy without muffling the rest of the frequencies. Enough sparkle in the treble and mids without sounding "bright". I could leave it playing at a moderate volume and not feel fatigue in the eardrums for the 1 solid hour I used it. And it isolates fairly well too!
Negatives ? Limited selection of cables should one want a replacement. Earcups could be a little bigger and deeper for comfort.
Addendum:
The cable unfortunately needs to be unplugged for the headphones to be completely folded away.
I have to say, it does have a pretty enjoyable sound profile.
That said, some of the specifications on the headphone seem odd though. Despite its rated sensitivity, it seems to sound " dull " when powered via my LG V40. However, that completely changes when powered up using the KTB via the JDS Atom. ( KTB at full volume, Atom at low-gain, 8-Oçlock knob position).
As enjoyable as it sounds, its no giant slayer, not near the Focal Stellia's level for closed-back. Nor does it come close to open backs such the the HE4XX (with grill modification), for "spaciousness" in the sound. Its very much still a between your ears kind of sound.
I can see why people like it so much, it has the right amount of bass energy without muffling the rest of the frequencies. Enough sparkle in the treble and mids without sounding "bright". I could leave it playing at a moderate volume and not feel fatigue in the eardrums for the 1 solid hour I used it. And it isolates fairly well too!
Negatives ? Limited selection of cables should one want a replacement. Earcups could be a little bigger and deeper for comfort.
Addendum:
The cable unfortunately needs to be unplugged for the headphones to be completely folded away.
Last edited:
According to this, https://www.rtings.com/headphones/tests/sound-quality/soundstage, soundstage and imaging can depend on a 10khz notch that I don’t think is accounted for in the Harman curve. There is a giant notch in the hd800s and Hifiman Edition X for example. When I get home I’ll play around with some filters in that range and see whether I can perceive a difference.
From the 2018 paper, it looks like it includes the range between 50hz and 10khz.
I don't have a quote in front of me but I recall reading in one of Sean Olives papers that the range approaching 10KHz shouldn't be taken as absolute. Oratory1990 leaves the 10kHz dip unchanged if you look at his PDFs.
Yeah, he calls out in his faq that he never removes that notch at 9-10khz, so you are right that his settings shouldn’t affect the theoretical 10khz notch effect.
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