[redrol]

Let me throw this discussion a curve-ball. Check out this graph which is Unity by Plunge Audio out of canada. This fellow has has been in pro-audio mastering and mixing for a long time and made his own iem for studio usage.
After I listened to it.. Lets just say I don't think that all the target curves people have been talking about are correct in any real way. Including DF, Harman, Freefield and whatever else. This sounds way WAY more like being in a studio with monitors 3 feet from your ears. It's truely mindblowing in the aspect that it sounds like nothing else,... and very very correct for lack of a better word.

 

[redrol]

Ooops. Same answer though. The occluded ear canal and open ear canal won't have the same resonance, even with the tip at the edge of the entrance, the frequency being boosted will be different. If we believe in the necessity of getting that right, wearing earbud that seat loosely on the ear and don't touch the ear canal entrance, might be the ideal option (but then the level of isolation is 0 ).

You are %100 correct. The best way possible to tune/use IEMS is with an ultra shallow fit using as much of your natural ear canal (ear gain) as possible. The more you plug up the canal and go deep the more you have to do an Etymotic styled 10db ear gain tuning.

Another thing im currently doing is actually creating massive vents in the front of the IEM shell and allowing the driver to vent a lot of its actual sound, leaving maybe %60 going into the ear canal. This absolutely cuts down on resonance peaks... and also im treating the insides of the iem shell with acoustic treatment.

Sorry im going off! I happen to be building an IEM company and I don't follow the normal rules, I do my own thing.

 

[KinGensai]

You are %100 correct. The best way possible to tune/use IEMS is with an ultra shallow fit using as much of your natural ear canal (ear gain) as possible. The more you plug up the canal and go deep the more you have to do an Etymotic styled 10db ear gain tuning.

Another thing im currently doing is actually creating massive vents in the front of the IEM shell and allowing the driver to vent a lot of its actual sound, leaving maybe %60 going into the ear canal. This absolutely cuts down on resonance peaks... and also im treating the insides of the iem shell with acoustic treatment.

Sorry im going off! I happen to be building an IEM company and I don't follow the normal rules, I do my own thing.

That's interesting, open back IEMs aren't that common, the few I have heard (raptgo hook x, bqeyz wind, FH5s, etc) left me wanting a better implementation. What you are doing there sounds like a proper open back HP miniaturized. I'd be interested in something like that.

Let me throw this discussion a curve-ball. Check out this graph which is Unity by Plunge Audio out of canada. This fellow has has been in pro-audio mastering and mixing for a long time and made his own iem for studio usage.
After I listened to it.. Lets just say I don't think that all the target curves people have been talking about are correct in any real way. Including DF, Harman, Freefield and whatever else. This sounds way WAY more like being in a studio with monitors 3 feet from your ears. It's truely mindblowing in the aspect that it sounds like nothing else,... and very very correct for lack of a better word.

You're right, that is a very atypical graph compared to current trends. The shell design is interesting, using nylon with what I'd guess is an SLS printer is going for some serious durability, that's used for mechanical prototyping typically.

The design looks like they are intended for a deeper fit, is that actually how it is? The tubeless tuned nozzle design seems similar to 64 audio's U12t and FatFreq's DD nozzle.

I'm taking a closer look at these, I might give them a try.

 

[KinGensai]

I'm starting to see a trend here that goes beyond tips. I'm starting to think maybe it's actually the acoustic tuning chambers used in these IEMs that makes the difference, not the tips in particular.

@ToneDeafMonk mentioned in his video on the Unity that he perceives a bit of shell vibration when listening, which probably explains why they sound correct vs something like the V14 despite the lower bass tuning. He also brings up a good point about resin shells vs SLS nylon shells.

I have some background in CAD design & 3d printing tech, I have worked with Envisiontec DLP printers, and if that's the process IEM makers use to build their IEM shells, SLS nylon makes a whole lot of sense for making odd shapes like anatomically correct IEM shells. Selective layer sintering doesn't require support structures to maintain print integrity, so you can make shapes that overlap much easier than with DLP and other similar stereolithographic methods.

I have to wonder also if the nylon is imparting an effect on the sound, SLS prints are a bit rough surface wise, so maybe they diffuse sound that way too in addition to their energy absorption properties?

 

[gregorio]

Sennheiser and Beyerdynamic seem to have a very different sound despite both of them using diffuse field in their R&D.

Well yes, of course. ”Diffuse field” just means ”Not a free field”, so that could mean pretty much anything at all, with the exception of an anechoic chamber. My guess would be that Sennheiser and Beyerdynamic are using very significantly different diffuse fields (and potentially different targets anyway). Again, you seem to be trying to over-simplify the issue, there are numerous variables at play here.

Target response is a static representation of what is a dynamic situation aurally speaking, so the idea as I understand it is to set a point of reference for audio engineers to work with to create the illusion of spatiality through psychoacoustic models.

Not anywhere near as much as your response seems to imply. There really isn’t any “point of reference for audio engineers to work with to create the illusion of spatiality through psychoacoustic models” beyond the basics of the stereophonic psychoacoustic model invented by Alan Blumlein nearly a century ago. There’s a recommended range for RT60 (Reverb Time) but many commercial studios apply their own “house curve” to their “B” (monitoring) chain, there’s no reference level, distance from speakers or anything else. The commercial A/V world (sound/music for film or TV) has somewhat more of “a point of reference” than music studios, as there are reference levels, monitor positioning is somewhat more prescribed and individual “house curves” are not employed but it’s still rather vague and there’s still significant variation between studios.

I'm guessing we are on the precipice of this paradigm changing, but from what I understand about audio production (not much at all compared to you, so please be patient lol), generic HRTF models and the engineer's perception is used for expediency's sake …

Typically, no HRTF models are used by the engineers, generic or otherwise. The engineers typically just listen to the straight stereo mix made for speakers with their HPs (without crossfeed, HRTF, Harmon Target or any other EQ/processing), just to check there’s nothing too untoward happening and even that doesn‘t always occur. None of this is really for “expediency’s sake”, it’s because there is no better practical alternative. There are various alternatives but none of them are even dominant in consumer use, let alone standardised or “a point of reference”, the vast majority of consumers just plug their HPs/IEMs in and listen without applying a target curve or any other processing, they typically just accept whatever the default settings are, which varies by service, OS, etc. The paradigm is changing somewhat, loudness normalisation is quite typical these days (although not standardised across services) and Dolby Atmos introduces the possibility of a standardised generic HRTF but Atmos still only accounts for a small minority of music production, it’s optional whether the binaural settings are employed by engineers and even if they are, it’s optional whether distributors pass those settings along to consumers, simply ignore them or employ their own HRTF/binaural processing (such as Apple’s Spatial Audio).

so reproduction of the digital signal on the consumer end will not end up being necessarily hi-fi because the consumer has to be savvy enough to account for as much of their personalized HRTF as possible, a crapshoot at best.

Indeed, “a crapshoot at best”. It’s even somewhat of a crapshoot with a proprietary format such as Dolby Atmos because how can consumers can be “savvy enough to account” not only for their own personalised HRTF but for whatever is already being applied? And, as that’s likely to vary by album, it wouldn’t be practical even if there were any consumers “savvy enough”.

I get the feeling though that we are going to see a huge paradigm shift soon once AI starts getting involved in tuning audio equipment to individuals.

Not only will it take a considerable time between AI “getting involved” and it actually fully solving the issues but it will most probably be a considerable amount of time after that before there’s a widely accepted standard/“point of reference”. Of course, there’s no way to be sure but from history and my personal experience of the commercial and practical issues, I’m guessing that’s still quite a long way off.

This sounds way WAY more like being in a studio with monitors 3 feet from your ears. It's truely mindblowing in the aspect that it sounds like nothing else,... and very very correct for lack of a better word.

Mmmm, that sounds like an oxymoron to me. “Monitors 3 feet from your ears” is not “very, very correct”. Even nearfield monitors should be 1-2 metres away from your ears and nearfield monitors are not “very correct” anyway, “very correct” would be main monitors (mid-field) and probably 10 - 15 feet or so away from your ears.

G

 

[redrol]

It must be tiring being so right when everyone is wrong.

 

[gregorio]

It must be tiring being so right when everyone is wrong.

How many studios do you know/have you been in, what is the design philosophy of the commercial/top studios and how many of the engineers who work in such studios have you discussed the issue with? Unless your answer is “numerous” and can answer how studios are acoustically designed/treated, how can you have any idea of what “everyone” believes/knows and therefore that what I stated is contrary to “everyone”?

G

 

[redrol]

Go away, all you do is argue.

 

[Davesrose]

It must be tiring being so right when everyone is wrong.

While I've had a lot of issues with gregorio (especially when he doesn't consider others may know the consumer or multimedia standards he doesn't know), he does have a valid argument here about reference to sound field. I'm kind of surprised you dismiss Harman curves, for example, because they have a lot of research behind them. Surveying many subjects for each version of their headphone and speaker curves. If I look at your prefered IEM curve, it starts dropping treble in the 3K region like the Harman curve. Seems the main thing is that it doesn't have as much lower bass...but I assume there can also be a difference between IEM eartips vs baffles of a headphone. I can understand that there are critics about the Harman curves: they're merely trying to find the best average. There's always going to be folks who respond to the outlier.

 

[KinGensai]

Looking at the Unity's apparent intended purpose, a flat curve like that seems appropriate. Maybe that curve sounds tonally correct in a professional sense (monitoring unmodified audio for instance, that's what I used Etymotic IEMs for), but I think that's not what the purpose of Harman/Diffuse/Freefield is.

Consumers buying IEMs intended for listening to commercially produced tracks want some measure of room EQ integrated into their IEM tuning because that sounds more correct than a flat IEM when rendering a track mastered in a studio using monitors, which is the vast majority of music on the market that sees active playback. The track will have been mixed and adjusted with playback to an audience in a room in mind, so the audio will sound off when that Room FR is completely removed.

 

[Davesrose]

Looking at the Unity's apparent intended purpose, a flat curve like that seems appropriate. Maybe that curve sounds tonally correct in a professional sense (monitoring unmodified audio for instance, that's what I used Etymotic IEMs for), but I think that's not what the purpose of Harman/Diffuse/Freefield is.

Consumers buying IEMs intended for listening to commercially produced tracks want some measure of room EQ integrated into their IEM tuning because that sounds more correct than a flat IEM when rendering a track mastered in a studio using monitors, which is the vast majority of music on the market that sees active playback. The track will have been mixed and adjusted with playback to an audience in a room in mind, so the audio will sound off when that Room FR is completely removed.

If I look at the graph on this page, it isn't that flat: on the left side you can see the dB range is very wide (IE overall dB swing isn't that much different from others). Speaker monitors are designed to be flat. Have thought all headphones need to have some dips to be perceived flat with speakers due to HRTF of ear canal and tympanic membrane.

 

[gregorio]

Go away, all you do is argue.

I refute statements that are false/incorrect and I continue doing that if further false statements are just “made-up” in order to defend the original false statement!

Consumers buying IEMs intended for listening to commercially produced tracks want some measure of room EQ integrated into their IEM tuning because that sounds more correct than a flat IEM when rendering a track mastered in a studio using monitors, which is the vast majority of music on the market that sees active playback.

That’s where things get interesting and difficult. Essentially, what is that room EQ consumers want integrated? There’s really no answer to this question or rather, there’s multiple different/conflicting answers and therefore the only single answer is “it depends” or “it’s highly variable”. In practice, different rooms cause different EQ results, very large troughs and somewhat large peaks due to phase cancellations and summations that vary considerably from room to room, even between rooms which appear relatively similar. For example, a 6dB boost at say 120Hz or a -30dB trough at that exact same freq in two rooms which don’t appear particularly different. While these peaks and troughs are typically very narrow band, the number of them adds up to significant audible differences and once we get into the mid and high freqs there‘s many more of these peaks and troughs and the freqs at which they occur vary hugely, even in the same room with only a couple of inches difference in the position of the measurement mic. We therefore tend to largely ignore the “room EQ” in the mid and high freqs (except possibly some very broad minor adjustment) and concentrate on freqs up to around 800Hz or so, where the average of the very different peaks and troughs in consumer listening rooms would be a relatively flat FR. This is what‘s behind the idea of studios with a flat FR and what many audiophiles presume is the reality but actually, that’s not the case because that is not the end of the story! There are actually more variables at play here, for example one of the most common ones is that most consumers use “bookshelf” type speakers, actually on a shelf or desk very near a wall or corner and therefore “boundary effect” causes significantly more bass. So typical is this additional bass in consumer rooms, that many studios employ a “house curve” with 3 - 6dB of additional bass to compensate for it. So maybe you should add 3 - 6dB of “room EQ” as you’re not going to get that additional boundary effect bass when listening with HPs/IEMs? Definitely “yes”, PROVIDED you know the mastering studio employed such a house curve and that the engineer didn’t adjust the mix/master to accommodate relatively flat HPs. Unfortunately though you can’t know this, its not generally publicly available information and certainly not all studios employ such a house curve.

In my case for example, after 2-3 decades I’ve found the best results are obtained using a house curve with a 2dB bass boost because I’m a bit of a bass-head and if left to my own devices I’ll tend to make a slightly bass heavy mix but I only use that bass boost when working on my own, when the clients are present I remove that bass boost and just try to compensate mentally.

I understand that you (and some other consumers) want a simple solution, a “rule” you can apply on playback so you get somewhat close to what the engineers and musicians heard/experienced in the studio when they created it. Unfortunately though, there’s just too many variables at play, a close to ideal solution for playing back one album/master could be inappropriate for another album. One thing I’ve learned is that audiophiles are pretty much universally surprised, commonly to the point of being shocked, when listening to music tracks in a very well designed studio compared to consumer systems/environments (even highly specc’ed audiophile systems). The best advise I can give is to either not bother about it or to listen to the tracks/genres you like and play around with EQ (maybe using a Harmon correction curve as a starting point) until you find something you like, because searching for a more accurate/correct rule or solution is a “fools errand”, there’s too many variables at play!

G

 

[KinGensai]

@gregorio I agree, that explains why so many variations in IEM tuning exist and garner their niche consumer bases, each tuning caters to different room EQs and HRTFs. I have accepted that my feel for correct sound is going to have to be enough at this point.

 

[redrol]

While I've had a lot of issues with gregorio (especially when he doesn't consider others may know the consumer or multimedia standards he doesn't know), he does have a valid argument here about reference to sound field. I'm kind of surprised you dismiss Harman curves, for example, because they have a lot of research behind them. Surveying many subjects for each version of their headphone and speaker curves. If I look at your prefered IEM curve, it starts dropping treble in the 3K region like the Harman curve. Seems the main thing is that it doesn't have as much lower bass...but I assume there can also be a difference between IEM eartips vs baffles of a headphone. I can understand that there are critics about the Harman curves: they're merely trying to find the best average. There's always going to be folks who respond to the outlier.

Research that is utterly wrong. Go look up how they came up with that curve.

 

[Davesrose]

Research that is utterly wrong. Go look up how they came up with that curve.

How is sampling many people in several countries, to come up with averaged curves, "utterly wrong"?