The FiiO F9 has good clarity overall, together with good emphasis on bass and treble. Mids are also very nice, smooth, coherent and consistent with good naturalism in the spectrum. My complaint is that they’re just a little back in the stage but I prefer them to be closer than that. Otherwise, I can’t be negative.
Resolution is quite good, which is always crucial with any headphone/earphone. Micro details are great for this class of an IEM, which was the surprising part for me. They achieved a very good performance regarding the detail level. Separation is also very good and although I didn’t too much like the midbass response, it’s still very natural and smooth in terms of bass and it has good amount of body too.
Sound stage is another plus for the F9, containing good width and depth. The midbass focus gives it good deepness, rather than a super wide sound reproduction. But still you have very good width with a nice channel balance and good clarity altogether. That said, it sets the stage a little higher than I’m used to but that’s not a huge problem. Overall the sound stage is excellent for the money.
The background is good, helping you to single out the elements and enjoy a highly separated sound with good imaging capabilities. So the FiiO F9 gets good points regarding the imaging and 3D feeling.
There’s no need for an amp to drive the F9, any source should be enough to drive it well.
FiiO supplies a balanced cable with the FiiO F9. This is terminated with a 2.5mm jack. FiiO wants to standardize the balanced output with all of their products so the inclusion wasn’t a surprise.
To me the balanced cable is clearly better to the standard cable. You get better imaging and separation, better staging and better frequency response. If you have the F9, go straight to balanced and don’t look back. The balanced cable is much better in terms of build quality too! It’s more like an audiophile type of cable, which looks and feels much better than the standard cable with built-in mic. So I recommend getting this version and hook up the balanced cable.
FiiO F1: The F1 is quite generous for the price it goes for, but it’s of course no match for the F9 in terms of… well, everything.
FiiO F3: This one puts up a better fight but not for long. It’s similar because of also having a v-shape sound, but it’s even more v-shape to me than the F9. It’s not this good in terms of tonality and overall coherency. Also the F9 has better staging and imaging. The build qualities are from completely a different worlds too.
Shozy & AAW Hibiki: I haven’t published its review yet but the Hibiki IEM is also a wonderful piece of work for the price. It doesn’t have the lower treble peak like the F9 does, but it also doesn’t have the tonality in mids. Bass is better controlled and more airy on Hibiki and the sound stage dimensions are similar. But it has very thin mids which is the only thing for the “cons” of it. And of course it’s a 1 DD monitor, so it doesn’t have that clarity.
LZ-A4: The LZ is wonderful in terms of bass and with its open back design it’s really atmospheric and has great stage depth. Mids and trebles are better also, but depend on the filters being used. FiiO has much better fit and isolation, similar amount of treble succession and build quality is better.
For 100$, you get a very solid IEM with a great fit and ergonomic design and also a great sound quality. The only big problem here is the lower treble, which I think FiiO could make better with more precise tuning. There will be a FiiO F9 Pro model soon, and James from FiiO says it has better control overall, so it looks like you don’t need to worry about the peak after getting that version.
To be honest with you, it’s very hard to find an IEM with this quality at this price. Somehow I really associated the F9 to the old Westone 3. Very similar shape and fit, and very similar sound. The Westone 3 had a midbass hump and upper mid-lower treble peak, as well as the recessed mids and good extending treble. It couldn’t have gotten more similar than this. But of course you should remember the price of the Westone 3 back then.
Try out the new FiiO F9, especially with the balanced cable. You will be pleased for this price level.
It’s FiiO’s best & prime IEM.