JM-1 with 1db per octave tilt target - for IEMs, most authentic version(s) for 711 and 5128?

The HEADPHONE Community
1

Please where can I obtain its definition, in downloadable data points format (frequency and gain values), compatible with 711 and 5128 measurements?. I’m expecting to find one file for each of these two measurement “standards”., so I can use the right version of the target, for comparisons with measurements done in each of these.

Took me a while to grasp the concept, but I think I have eventually assimilated the JM-1, and its optimisation with a minus 1 dB per octave tilt. The resources here and on the headphones Youtube channel have helped. JM’s youtube video on the topic was another excellent one.

On some squigs, I can download the data points, of this target, from different reviewers, but they do not coincide, with the deviation between different reviewers, predominantly in the higher frequencies.

Here is an example - two reviewers Audio Amigo and Paul Wasabii, on squig. Both of these reviewers use 711, so I would not expected their representation of these targets to vary, assuming they obtained the target definition from the same source.

I exported the data points, from each reviewers database, and imported them into Audio Amigo’s page, as FR, to compare. It’s obvious they agree up to about 3K, then deviate quite a bit thereafter.

Wasabii and AA
Wasabii and AA2400×1080 215 KB

I assume the JM-1 with 1dB per octave tilt, was arrived at by some research process, and standardised, and therefore was not expecting this to vary.

I find the idea of a target useful, when I’m looking at IEM measurements vs the target, but it gets uncanny to discover that the target itself, seems to vary. I need the “one ring to bind them all”.

On that note are the standards bodies like ISO involved in maintaining an authoritative single copy of this IEM target, considering how important it seems to have become?

2

I wouldn’t use the term ‘new meta’ to describe this. The whole point of Joel’s video was to show that preference adjusted JM-1 is just neutral - based on population average ear effects.

We’ve been using the term ‘new meta’ to refer to popular IEM releases as of late, where elements of this tuning have been part of the trend - particularly the midrange. But the problem there is that none of those IEMs could be accurately described as ‘neutral’. Something like the CrinEar Reference or the Prisma Lumen are a lot closer to neutral than a ‘new meta’ set like the HiSenior Mega5EST or Dunu Da Vinci, and this is an important distinction. They just adopted a more humanlike ear gain presentation than previous targets did, and this is shared by neutral presentations as well.

3

So what does one call it - the JM-1 with the 1 dB per octave tilt? cos that’s a long name. Does this have a name? I’ll edit the title to whatever is the most appropriate name for this.

I did notice that the CrinEar Reference is pretty close to the JM-1 with 1dB per octave tilt. And my objective is to find something closest to this, but more affordable, since the Reference is beyond my budget for IEMs.

4

I’ve revised the thread title. and revised all references to New Meta.

5

JM-1 with preference adjustment to a downward tilt from bass to treble between 8-10dB is the closest thing to neutral we have. So you can just call it neutral - or JM-1 + tilt. Actually, we recently made some adjustments to JM-1 for the headphones.com IEM diffuse field baseline where it functions the same for population average just with the full 5128 canal transfer function included. Previously it was an estimate that was missing some treble features.

So yeah, mainly I’d just caution you about calling this new meta because there’s already quite a bit of confusion around that as a concept and those products that do/don’t fit that description. Think of it like this: One describes a product trend, the other describes a tuning philosophy.

6

Noted. Thanks.

  1. Where can I obtain the JM-1 + tilt, as well as the JM-1 + tilt + 5128 canal transfer function? So I can compare with IEM measurements done on the 5128?
  2. And where would I be able to obtain the version that would be the best option for comparing with IEMs measured on 711 couplers or clones thereof?
7

I don’t think this exists for 711/clones yet. We’re still working out if we’re going to make all of that public

1 Like
8

Noted and Thank you.

9

Both are altered to suit the specific idiosyncrasies of their couplers, as part of the “Delta” project on squig.link. That’s why they look different.

If you want the canonical, generic versions, they’re on my EQ Playground. I’m basically the keeper/maintainer of the targets.

I would recommend using the ∆ Headphones.com IEM Diffuse Field target instead, which can also be found there.

1 Like
10

To be clear, JM-1 is a Diffuse Field HRTF based on ISO 11904-1 where the weight was slightly shifted to approximate what the 5128’s canal effects would do in the 3 kHz and 8-12 kHz regions. The new Headphones.com IEM Diffuse Field is a direct sum of human blocked canal DF HRTFs and the 5128’s canal transfer function, which is what JM-1 would’ve been if Joel had the canal transfer function data years ago. You can think of it as JM-2.

The canal transfer function is not currently planned to be publicly released.

11

Thank you ever so much. I really really appreciate your response. Will follow up on the web links you provided.

From the bottom of my heart. Thank you.

12

Thanks again. I know it may take me a while to think through all of this and FULLY understand it all, cos it is not my area of expertise.

I will study all of this, and revisit the relevant info already published here on the forum and on headphones.com articles, as well as the Youtube videos. Pretty sure eventually it will sink in.

I did have a look at your squig database (EQ Playground) a few days ago and was wondering why headphones.com had its own different target. Thanks for clarifying. Truly appreciated. Now I have to go back to the drawing board, and study it all, properly. and understand it thoroughly.

I am sure I do not need the canal transfer function, cos its already included in what you call the JM-2.