My SR3 arrived 2 days ago! Will try to give it a listen today.
So, I've learned some things.
1) SR3 is NOT an open-back version of the SR2
2) SR3 does NOT use a carbon fiber diaphragm like some of the dealers marketed it to do
3) SR3 and SR2 appear to be (on paper) very similar
I was under the impression that the SR3 is the open-back version of the SR2 due to the following photo:
If you inspect this photo (render) closely, you will see that there is only one grid. If you ever had a chance to hold the SR2, you would know that there are two grids, the outer one (large), and a micro-mesh grid below it. In the photo above, the micro-mesh grid is missing and the driver is visible. Because we confirmed that the SR3 is not the open-back version of the SR2, what should we rename the thread? Share your suggestions. I'm thinking "SR3 — 150Ω version of the SR2".
Contrary to the render picture from iBasso, the SR3 comes with both grids just like the SR2.
Unlike some dealers have said in their marketing, the SR3 does not use a carbon fiber diaphragm. This disinformation was spread for the SR2 as well. For example, it can be seen from Zeppelin & Co., which I don't blame at all! Long story short, it is a Google Translate error, which I confirmed by using it myself. It does in fact translate the bio-cellulose diaphragm driver as "carbon fiber diaphragm driver".
Take a look at the photos below:
Top: SR3
Bottom: SR2
Although the frequency response charts do not share the same same y-axis unit scale, we can draw the following conclusion:
SR3 has less sub-bass, in particular it is 2-4dB quieter between 20-90Hz
SR3 has a small 'dip' at ~1.5kHz
SR3 has a major dip between 2kHz and 3kHz
SR3 is sharper at 4kHz-6kHz
SR3 has a bigger dip at 6.5kHz