[MidnightSun]

I don't have the context for the rest of this but the excess bass on the Harman IE target is at least in part due to the 711 couplers lacking the accurate acoustic impedance. This was also confirmed in Dr. Olive's recent talk at CanJam NYC, as the IE work is currently in the process of being redone on the more accurate B&K 5128. Of course the other issue is there's no reason to expect a difference between in ear preference and over-ear preference, and if the methodology had been the same we may end up with similar preference results for both. On the other hand, we also don't know how people would have adjusted the bass when presented with say... a population average baseline starting point.

TLDR: At the very least, Jude was right about the 711 couplers, and that's certainly responsible for this difference. But that doesn't mean there isn't something else going on as well with regards to the overall curve itself, namely the difference in methodology could be having an impact such that the IE result itself is an outlier.

Interesting... so this sort of implies that we don't actually need more bass with IEMs? Because I always had the opposite idea: to sound "neutral", the lower mids and bass can't be a straight, flat line on a 711 coupler, whereas it's generally considered to be ideal on a headphone.

 

[Resolve]

Interesting... so this sort of implies that we don't actually need more bass with IEMs? Because I always had the opposite idea: to sound "neutral", the lower mids and bass can't be a straight, flat line on a 711 coupler, whereas it's generally considered to be ideal on a headphone.

I don't think it's ideal, rather, that's more commonly all that's achievable on open back headphones. There are ways of adding a bass shelf like controlling driver Fs, like with a leak of some kind of front-sealed planars, or introducing an electrical filter, but most don't do this.


When it comes to preference, most people prefer a rise into the bass, as shown by both Harman OE and IE. It's sound at the eardrum in both cases so preferences likely won't be different. The only issue is that since IEMs bypass the pinna, those effects need to be assumed, and this creates all kinds of problems for such a project. Like the preferences are probably the same for bass and treble, but the baseline may need to be different from OE, since with OE all the pinna effects are included.


Unless of course we get new measurement rigs with population average pinnae.

 

[jude]

....No matter now much your own tastes match the harman target, there is indeed a +4db shelf on the in-ear target versus over-ear. I'm not sure about the technical explanation for that but it does correlate with the comment from the Sennheiser engineer that you mentioned....

....At the very least, Jude was right about the 711 couplers, and that's certainly responsible for this difference....

@mobbaddict, check out the video below (time-stamp-linked), which was a video presentation I did back in 2020 for Brüel & Kjær's Product Physics Conference:



Back in February 2020, I contacted Sean Olive to discuss this, and to suggest that if they'd had a 5128 back when they did their body of work for the OE/AE target, and then later the IE target, that perhaps they'd have arrived at similar/identical targets -- that is, that perhaps only one target would be needed for both OE/AE and IE. Sean was no doubt intrigued, and said essentially "maybe" but that testing that theory would be the way to know for sure. He's been discussing this more lately, like in his CanJam New York seminar in March.

 

[Resolve]

@mobbaddict, check out the video below (time-stamp-linked), which was a video presentation I did back in 2020 for Brüel & Kjær's Product Physics Conference:



Back in January 2020, I contacted Sean Olive to discuss this, and to suggest that if they'd had a 5128 back when they did their body of work for the OE/AE target, and then later the IE target, that perhaps they'd have arrived at similar/identical targets -- that is, that perhaps only one target would be needed for both OE/AE and IE. Sean was no doubt intrigued, and said essentially "maybe" but that testing that theory would be the way to know for sure. He's been discussing this more lately, like in his CanJam New York seminar in March.

Yeah, I would expect the preference clusters to be the same, however the confounding variable with IEMs would be additional clustering around pinna anatomy. So a class 3 listener with OE might be a class 1 listener with IE depending on the expectation of their pinna effects and so on. How much that matters... Or how much of an impact this would have in practice, I'm not sure.

 

[mobbaddict]

@mobbaddict, check out the video below (time-stamp-linked), which was a video presentation I did back in 2020 for Brüel & Kjær's Product Physics Conference:



Back in February 2020, I contacted Sean Olive to discuss this, and to suggest that if they'd had a 5128 back when they did their body of work for the OE/AE target, and then later the IE target, that perhaps they'd have arrived at similar/identical targets -- that is, that perhaps only one target would be needed for both OE/AE and IE. Sean was no doubt intrigued, and said essentially "maybe" but that testing that theory would be the way to know for sure. He's been discussing this more lately, like in his CanJam New York seminar in March.

Excellent, thank you! Sound pressure... that would explain the common belief that a bass shelf was seen as a must have for any IEM. This also means that from now on we need to pay closer attention to what gear is being used when looking at IEM measurements!

 

[PixelSquish]

The Harman Target is an okay starting point but it's definitely not where I want to end up.

 

[mobbaddict]

I have the Tanchjim Ola, and that's flat as well with a serious sub-bass roll-off, and it's fine for a lot of genres (it was my office beater set) but it can't match the natural and versatile, all-rounder sound of the Studio4, for example; I found that flat bass is just not enjoyable, and a I'm a far cry from a basshead. It's a loss of information.

This one does have some roll off on the measurements... Recently I got some Moondrop Space Travel just out of curiosity (I was looking for some TWS IEM for the office) and I was very surprised by the monitor profile on these. It's basically a flat line below 1khz with a smart slop in the subbass (below 60hz). I think it sounds great this way, like a HD600 with stronger bass. That's what got me questioning the frequency response of the Timeless suddenly (which are still quite balanced with the right tips).

 

[MidnightSun]

@mobbaddict, check out the video below (time-stamp-linked), which was a video presentation I did back in 2020 for Brüel & Kjær's Product Physics Conference:



Back in February 2020, I contacted Sean Olive to discuss this, and to suggest that if they'd had a 5128 back when they did their body of work for the OE/AE target, and then later the IE target, that perhaps they'd have arrived at similar/identical targets -- that is, that perhaps only one target would be needed for both OE/AE and IE. Sean was no doubt intrigued, and said essentially "maybe" but that testing that theory would be the way to know for sure. He's been discussing this more lately, like in his CanJam New York seminar in March.

Really useful, thank you! So that's why it's said that the 711 "overestimates" bass and lower mids.

 

[MidnightSun]

This one does have some roll off on the measurements... Recently I got some Moondrop Space Travel just out of curiosity (I was looking for some TWS IEM for the office) and I was very surprised by the monitor profile on these. It's basically a flat line below 1khz with a smart slop in the subbass (below 60hz). I think it sounds great this way, like a HD600 with stronger bass. That's what got me questioning the frequency response of the Timeless suddenly (which are still quite balanced with the right tips).

Looks good! The 8 dB envelope also helps a lot in it sounding still natural. What do you think about the Reference setting?

 

[mobbaddict]

Looks good! The 8 dB envelope also helps a lot in it sounding still natural. What do you think about the Reference setting?

Well that's what's really interesting with this IEM, the fact that you can easily switch between profiles... I think the reference profile sounds nice and is in line with how many mainstream IEMs and headphones sound these days, but it's just too much mid-bass overall. The monitor profile gives the midrange a more natural tone IMO while still providing decent level of bass. I think it's a smart approach.

 

[MidnightSun]

...alright, let's get back to on-topic before we incur the wrath of the mods!