Please disregard this post and see the latest final A4000 measurements (frequency response graphs) and comparisons with Etymotic ER2XR using v1.0 of my IEM Measurement Rig.
These measurements are made on my DIY IEM measurement rig and are not accurate, and don’t necessarily represent what you might hear, especially before 60 Hz (huge sub-base roll-off) and after 10 kHz (and maybe even after 3 kHz as my ER2XR graph is very different compared to Crinacle’s post that). You can use it just to get a comparative idea, hence the comparison with ER2XR to give you a point of reference. Improving the rig is an ongoing process.
Here is Crinacle’s ER2XR graph for reference
It looks like final went with the mids to bass rise like in the E series and the highs of the A8000 on A4000.
I couldn’t find any info on the driver size of the ER2 series so I contacted Etymotic and got an official number from them.
The official response I got from them is that the driver size of the ER2 series is 5.8mm.
While reviewing the Etymotic ER4SR and ER4XR here is what Tyll had to say about bass response:
For me, the bass level on the ER4SR simply isn’t enough. Frankly, even the ER4XR doesn’t have enough bass for me, but it’s much better. I believe quite strongly that bass response on headphone should have about a 5dB bass boost below about 150Hz.Tyll Hertsens in 25 Years of Making a Good Thing Better: The Etymotic ER4sr and ER4XR on Page 2
Tyll would have loved the ER2XR 🙂:
When the ER4XR was launched, Tyll applauded Etymotic for making the brave move of catering to user preferences and deviating from that they believed to be technically “accurate”. I think Etymotic went further with the ER2XR (and it’s almost like they took his feedback into account) and for that I am grateful as the ER2XR has just the right bass response for my preferences 🤗.
For me, having over 20 years of close experience interacting with Etymotic and the ER4 product evolution, I find it an interesting example of corporate learning at work. On the one hand, Etymotic has very strong reasons to believe they have a grip on what “accurate” means, on the other, they have 20 years of experience with customer feedback about the desire for more bass. Adding bass willy-nilly is simply not something this audiometry company would do; but having strong feedback that customers want more bass can’t be denied either. Making the corporate decision to deviate from technically accurate to cater to user preference is actually a pretty brave move from their point of view. I applaud this development!Tyll Hertsens in 25 Years of Making a Good Thing Better: The Etymotic ER4sr and ER4XR on Page 2