The KZ ED7 is a standard barrel design variation of the new over-the-ear KZ ATR (see my review) which itself is a more refined version of Knowledge Zenith's ever popular ATE. The original ATE is a legend in its own time, not because the ATE outperforms higher tier IEMs, it doesn't. The wonder of the original ATE is that it seems to have an analog warmth to it that just draws you into yesteryear's tube amp-like experience for your cherished acoustic, vocal and jazz genres.
While I thoroughly enjoy Knowledge Zenith's original ATE, it is "not" my preferred sound signature. If you've read my review of the original ATE, you would have noted that, to my ears, the ATE has a somewhat darkish rolled off tone in the higher frequency ranges, which makes them an ideal choice for laid back genres, but not a top pick for energetic genres. The newest crop of KZ IEMs (ATR & ED7) share a more refined ATE sound signature. The rolled off treble on the ATE is now a comfortable laid back sense of detail on the ED7 and ATR. The slight dark tone to the mids of the ATE is now a warm, rich and detailed lush masterpiece of vocals and/or strings on the ED7 and ATR. Now, the ratio of sub-bass to mid-bass (40/60) on the ATE seems to be near perfectly balanced (50/50) on the ATR and 55/45 on the ED7. While technically the soundstage is the same width, the better extension in the highs seem to put more air or space between the instruments to varying degrees, which I'll explain in a moment. The imaging brings everything into focus on all three IEMs for a very natural presentation as if you are there in person.
The new ED7 and ATR with their further refined ATE sound signature appeal to a broader number of genres of music. Conventional wisdom dictates that "broadening the appeal" is a euphemism for trying to please everyone while you end up pleasing no one..... but.....but conventional wisdom holds no water here. The ED7 (ATR) is better than the original ATE. Particularly, the translucent brown ATE, as the silver ATE sounded much more like the new ATR (and by extension this ED7).
Enough! Let's focus on the ED7 for a moment. In my opinion the ED7 is two notches above the original ATE, which I do like. In fact, I have two pairs of the original ATE. This ED7, though. It's more refined and has better extension in the higher frequency ranges and a tighter presentation in the lower frequency ranges. The ED7 has slightly more bass than the ATR (which makes it more fun to me).
ED7 Basic sound signature:
Bass: Relatively clean with just a hint of softness that goes deep. This is one of the ED7's characteristics that contributes to its analog-like sound signature. Bass is north of neutral and compliments the ED7's cohesive and warm-leaning sound signature.
Mids: Somewhat centered, natural and lifelike.
Treble: To my ears the treble is neither emphasized nor rolled off. I find treble neutral with a hint of softness. As was the case with the bass, the treble compliments the ED7's cohesive and warm-leaning sound signature. If there is any lift to the treble it is negligible because I am not hearing it.
Soundstage and Imaging: Imaging is very good, but the soundstage is where the differences show up between the ED7 'standard' and 'mini' (and by extension the ATR) and the differences are due mainly to the driver housing.
What I mean is:
The shape of the driver housing.
The vents/ports in the driver housing.
The volume of unoccupied space inside the driver housing.
The bamboo ED7 (mini) has the smallest housing. This means less volume of unoccupied space inside the driver housing resulting in the entire presentation being more intimate and forward. There is little room for the sound to travel inside the housing so all of the sound moves forward through the nozzle. The soundstage width is the same on both (mini and standard), but there is less space between the instruments on the ED7(mini) and the soundstage depth is more shallow as well.
The ED7 (standard) has a larger bamboo housing. More space in the housing means more room for the sound to travel inside the housing as the sound moves forward through the nozzle giving the ED7(standard) more space between the instruments and more depth in the soundstage. The soundstage width is the same on both (mini and standard).
As a side note, the ATR, having a similar sound signature, has a slightly wider soundstage than either of the ED7's.
In essence what Knowledge Zenith has offered us is a warm sound signature with three different soundstage presentations. The ATR with the most airy presentation, the ED7(standard) having slightly less space than the ATR and the ED7 (mini) having less space than either the ED7 (standard) or the ATR.
While these differences are minor they are there. The small differences make a difference to me because sometimes the ATR can come across as dry, whereas the ED7 does not. The ED7 has simply more energy and it is why I prefer the ED7 (standard) over the excellent ATR.
Actually, the ED7 (standard) is the midpoint between the ATR and the ZS3. If you love the ZS3 but find it a bit too bassy at times, then the ED7(standard) is your perfect pick.
Soundstage : rated from airy to intimate.
ATR > ED7(standard) > ED7(mini)
Bass quantity: rated from most to least.
ED7 (standard) > ED7 (mini) > ATR
Mid-centric focus: rated from most to least.
ED7(mini) > ED7 (standard) > ATR
. ZS3 would be a decent alternative, but you're getting less bass, more treble, and they seem to be having some serious QC issues if the KZ thread is any indication. I definitely recommend looking at the 
