In this post I'll include some additional measurements of the Sennheiser IE 900 made on the Brüel & Kjær 5128 that I wanted to include in the video, but, again, I was trying to keep it at/under 15 minutes.
In the video, I included this measurement (Fig.1 below) comparing the frequency response of the Sennheiser IE900 with the Sennheiser HD650, normalized at 1 kHz. Since the other frequency response comparisons shown were normalized at 1 kHz I chose the same for this comparison. The frequency you pick to match up two frequency response curves for comparison can have a substantial impact on its interpretation. I wanted, then, to include the comparison normalized at 500 Hz, too (in Fig.2 below):
Fig.1: Sennheiser IE 900 and Sennheiser HD650 frequency response comparison, normalized at 1 kHz (as shown in the video).
Fig.2: Sennheiser IE 900 and Sennheiser HD650 frequency response comparison, normalized at 500 Hz.
Also, while in the video I mentioned the Sennheiser IE300 (which was released earlier this year), I did not show a frequency response comparison of the IE900 and IE300. Here it is (in Fig.3 below):
Fig.3: Sennheiser IE900 and Sennheiser IE300 frequency response comparison, normalized at 1 kHz.
In the context of discussing the Harman Target, I also thought about discussing the AirPods Max in the video. Deciding it might be a bit of a contextual stretch in a video that's supposed to be about the IE900 (and in the interest of time), I opted not to include it.
The Apple AirPods Max is Apple's first premium over-ear headphone, and AirPods Max has, in my opinion, the best default tuning of any wireless ANC (active noise canceling) headphone I've heard to date. I suspect Apple did extensive research to arrive at the tuning of the AirPods Max (yet will almost certainly never publish
any research of this type), arriving at a tuning that is different from Harman but (to my ears) every bit as safe a tuning. That is, the Apple AirPods Max tuning is one I think many people will like (and that many people seem to like). It's worth reading comments about (and reviews of) the AirPods Max, even in audiophile circles. Is the AirPods Max my top reference headphone of any type? No. Is it the best sounding default tuning in a wireless ANC headphone? For me, so far, yes.
Compared to the AKG K371 (which is one of the closest matches to the Harman AE/OE Target), I find the AirPods Max to have more neutral sounding midband and treble. I understand some will agree and some will disagree, but that's part of the point I was making in the video.
While the IE900 and AirPods Max do not sound the same, they share some qualities I like, so I thought you might like to see the frequency response of the Apple AirPods Max
compared to the Sennheiser IE900 (Fig.4 below):
Fig.4: Sennheiser IE 900 and Apple AirPods Max frequency response comparison, normalized at 1 kHz.
In the Sennheiser IE900 video I only touched on the topic of the Harman Target. There's a lot more discuss, and I think we should continue to do that.
The measurements in this post were made using: