Measurements
1. Close mic
- 2.4kHz crossover
- A lot of the bass extension comes from the port
- There's a jump in the tweeter's response with close-mic, but this does not show up / is not obvious in other measurements. Weird.
- Response is squiggly for some reason
2. Table edge 0 degrees (blue) vs 45 degrees (orange)
Interesting off-axis behavior. Drops fairly early on at 4.5kHz but stays flat after that, until it drops again after 13kHz.
Table edge 0 degrees: Can be interpreted as a shelf filter in treble, or just simply downwards sloping. From eyeball estimates, it's a 5dB variation, but the loudest is in the bass at roughly 100Hz and then it's a straight line downwards until the end at ~16kHz, with some slight boosts in the middle frequencies.
Retake with grilles off, blue is 0 degrees the other two are 45 degrees. The one with less reduction I set measuring point at the phase plug.
3. Listening position, straight
On the table with back against the wall, like how it would be in practice. Mic cal 0 degrees pointing straight on tweeter axis.
Dip at 5kHz is likely due to reflections as it fluctuates upon repeated measurements. Dip at 10kHz... probably not.
Interestingly straight, until the bass where it *might* have peaked slightly before rolling off. Still a downward sloping straight line but now we're at 6 to 7dB total variation.
4. Listening position, 90 degrees
Actual usage scenario, sitting between two speakers and measuring one, no toe in which means 45 degrees off-axis. Mic cal 90 degrees pointing upwards.
I subjectively like that boost below 1kHz
Bass starts rolling off at around 100Hz, but slowly, so we still get usable output at 40Hz before it starts to decrease fast.
Going 45 degrees off-axis means getting less >5kHz. Strangely it doesn't feel that way subjectively, having more HF details than S-520 which measures flat from 2kHz to 10kHz. Maybe that on-axis HF somehow finds its way into my ear but doesn't get picked up by the mic.
