Thanks, very useful. How does the U3/6 compare to the ER4 in terms of sound quality?
I ordered the U10 but I'm pretty intrigued by the U4-SEs...
I've been looking at the 64 audio line up for a while and here's how it seems they have done things. There's really only 3 or so distinct sound signatures they have gone for. With different "levels" of each sig.
U3/u6/u12. These are probably their "house" sound. They're all 3 way with an equal amount of drivers for each band. From my experiences, with each level gaining detail, clarity, and punch. They seem to have a frequency response that favors the low end and slightly decreases as you go up the spectrum. Not dark IMO, but definitely smooth and easy on the ears.
The u4/u8's have added drivers for the bass.
The u5/u10 have more drivers for the mids and highs than the lows. For a more "neutral/reference" signature.
Then there's the u2, and u4se. Not really sure where they fit other than entry level for the u2 and more of a reference sound for the u4se.
I say all that to say the u3 and u6 definitely have a familiar sound to each other. Very similar really, but the u6 does it better. Haven't heard the 12's but if they're another level up in better, they probably are quite amazing.
Now compared to the ety's there is quite a bit of difference. The ety's are much more "in your face" and 2D sounding than the 64's. But IMO that is due to their bump in the 2-3khz response. But the ety's are more instantly detailed. Not saying the 64's aren't. But they're more relaxed and laid back. The details are there. They're just not so blatantly obvious.
Where the 64's kill the ety's is in the lows/low mids. There bass is much more present and punchy than I've ever heard out of the ety's. I can listen to test tones and know the ety's get low. But they just don't have the "weight" to them like the 64's. I would like to see how the new er4xr does. They might be closer to the 64's sig.
In fact once I've tried the u4se's I will probably sell the two pairs I like the least of the 3. And then maybe buy the xr's to compare.
And not what you asked but the 64's actually remind me more of my flare r2pro's than anything else I've tried. Which isn't exactly a lot. But they have similar weight to the low end, with a smooth non-fatiguing high end and good mids. And I haven't done a direct comparison, but the flare mids might have an edge there, while the 64's win in 3D staging. I'll try and add those to the mix when I do my big comparison.