Inconsistent EQ results between ASH Toolset and Oratory1990 using identical data

[moodkim10-ctrl]

I am seeing a major difference between the EQ settings generated by ASH Toolset and those from Oratory1990, even though both utilize Oratory1990’s measurements and the Diffuse Field target. This occurs consistently across multiple models, including the HD600 and HD800. Could you explain why these two systems produce such different EQs despite having the same input data and target?

[ShanonPearce]

The measurements used are the same however the target is not the same. A customised target is utilised resulting in a different EQ curve in ASH toolset.

In the next release I will include an option to switch between different headphone target curves including the GRAS Kemar diffuse field target. This will allow the user to select their preferred target curve from a range of common targets. When selected, the resulting EQ will more closely resemble the ones supplied by Oratory1990.

[moodkim10-ctrl]

The measurements used are the same however the target is not the same. A customised target is utilised resulting in a different EQ curve in ASH toolset.

In the next release I will include an option to switch between different headphone target curves including the GRAS Kemar diffuse field target. This will allow the user to select their preferred target curve from a range of common targets. When selected, the resulting EQ will more closely resemble the ones supplied by Oratory1990.

Thank you for the clarification. I have a few more questions regarding the ASH toolset and your future roadmap:

1. Current 'Customised Target': Regarding the target response that the ASH toolset aims to achieve, what exactly is it based on? Is it a modified version of a standard Diffuse Field (DF) target, or does it follow a different methodology?
2. HRCFs Low-Frequency Compensation: I noticed that the headphone compensation barely touches the frequencies below 100Hz. Is there a specific technical reason for leaving the sub-bass region relatively untouched?
3. Future Release & B&K 5128: In the upcoming release, do you plan to include measurement data using the B&K 5128 Head and Torso Simulator (HATS)? If so, will the 5128 DF target or JM1 target be included in the toolset?

[ShanonPearce]

1. The ASH headphone target is uniquely generated per measurement set and is derived from an averaged set of headphone measurements, representing a neutral headphone. In ear headphones have an adjusted target (approx. -6dB high frequency roll off) to align the tonal balance with over ear headphones. The target for over ear headphones is similar to a tilted diffuse field curve and for in ear headphones it more closely resembles the IEF Preference 2025 curve.

2. Most of the filters in the ASH filters database originate from the previous ASH-Listening-Set project which were tapered off below 100Hz due to some limitations in accuracy of the low frequencies. Newer filters added since the launch of ASH Toolset including the compilation database no longer have this issue and correct the full spectrum.

3. The next release will include a range of common targets which can be applied according to the user’s preference. JM1 target and 5128 DF target will be included.

[moodkim10-ctrl]

1. The ASH headphone target is uniquely generated per measurement set and is derived from an averaged set of headphone measurements, representing a neutral headphone. In ear headphones have an adjusted target (approx. -6dB high frequency roll off) to align the tonal balance with over ear headphones. The target for over ear headphones is similar to a tilted diffuse field curve and for in ear headphones it more closely resembles the IEF Preference 2025 curve.
2. Most of the filters in the ASH filters database originate from the previous ASH-Listening-Set project which were tapered off below 100Hz due to some limitations in accuracy of the low frequencies. Newer filters added since the launch of ASH Toolset including the compilation database no longer have this issue and correct the full spectrum.
3. The next release will include a range of common targets which can be applied according to the user’s preference. JM1 target and 5128 DF target will be included.

Thank you for your response. Regarding the B&K 5128 measurements, I think it would be great to use the data found at the link below. I believe it would be a very useful reference for the next release update:
https://earphonesarchive.squig.link/headphones/?share=5128_DF_Target,Sennheiser_HD600_(2020)_(center
I look forward to seeing the new targets in the upcoming version.