Discussion in 'IEM Measurements' started by purr1n, Aug 10, 2019.
On paper with the improved bass I should want these, but fuck it I’m happy with my modded ones.
So pretty much the Blue Filter is pretty warm without the V-Shape BS? Sounds like my type of sound on the go.
What do you predict is the most likely cause of difference in bass? Vent mod??
Yes, sort of. Still has some upper mid-3-4kHz emphasis, but lower and mid-treble is fine, even slightly sedated with blue.
I'm already past the point where I trust myself to predict a cause, lol.
First I thought, maybe the nozzles are slightly different (possibly the front mesh)... so I measured both IEMs with both nozzles:
Nada, the difference remains consistent, regardless of whether FD01 or FDX1 nozzles are used.
Then I blocked the front vent on both IEMs, but that has next to zero effect on FR.
At this point I tend to think, if it's not mere product variation, then they must have changed something about the rear damping of the driver. Anyway, the difference may be small, but it is easily and consistently noticeable in an A/B audition.
Or, something in the internal housing geometry.
I mean, if you're going to change the outer geometry to remove the knurling you might as well tweak the inside too.
Yup, could be a simple change in rear air volume, which would change the driver's rear damping.
I've spent two nights now going back and forth between the FDX1 and my modded FD01, listening to many different genres, concentrating mostly on bass.
The result is, I like both. There is an undeniable difference though, my FD01's bass sounds a tad leaner with less kick, making the overall signature a little more analytical. The FDX1's bass sounds a tad fuller and possibly more "life-like".
I think the majority of listeners would prefer the FDX1 over my FD01 in terms of bass. But personally, I would call it a difference in bass characteristics rather than a difference in bass quality.
I appreciate your thoroughness. If my current pair ever die on me, I’ll get the FDX1 as a replacement. Until then, I love the sound out of my modded pair.
And thanks for helping me spend $250 on this. This was what I was looking for, something on the fun side but not too much V-Shape BS and not spending too much money. Also, I'm lazy as fuck on modding anything.
Sorry to keep
the FDX1's bass sound tighter? That's my main beef with the FD01's bass. If it's fuller and I don't have to EQ as much, maybe I can get the response I want as well as a tighter punchier sound.
Kinda hoping James says the bass isn't tighter and I WON'T spend $250.
You can always wait until I send them to @zerodeefex for a 4th opinion on the bass.
I flat out thought the bass on the FD01, especially the below 60Hz bass drops with electronic music was loose with blub blub blub blub. On classical I didn't notice.
I went back to compare and would agree the bass is thicker (tonally / timbre) on the FDX1.
FDX1: thicker, more damped, tighter
FD01: lighter, more lively, blub blub blub
FFS. This has totally confirmed that I don't understand the distinctions between the descriptors you guys use to characterize bass (when I thought I might have been getting close).
Would you care to post a track that exemplifies the "blub blub blub" in sub-bass?
Edit: it seems I may be missing a fast and at the same time sub-bass heavy track from my test track collection. I have tracks with slower electronic sub-bass to check extension and a fast, funky track for speed. However, the latter doesn't have much sub-bass content.
Probably the most demanding track I use in that regard is Modestep's "Damien", particularly the section starting at 01:47. But that may not be demanding enough, since it didn't reveal any loss of bass control with my FD01.
Basically, almost anything from Random Access Memories: Doin' It Right, Lose Yourself to Dance, etc. The tympani in the opening of Copeland's Fanfare for the Common Man from the Telarc disc.
My sub-bass test tracks are listed here.
I can confirm bulb blub blub on FD01, even on classsical. In my review, I described it (rightly or wrongly) as one-note bass.
Thanks for the bass track recommendations! I made myself a little playlist...
... and let the suggested sections play in infinite A-B repeat loops, while switching between the FDX1 and FD01.
Result: I'm afraid I can't discern a difference in bass quality / tightness / control.
However, I certainly hear the mentioned difference in bass characteristics, i.e. FDX1 slightly fuller and more mid-bassy and FD01 slightly leaner and more sub-bassy.
IMHO, there are 3 possible conclusions:
The slight difference in bass decay (as indicated in burst / impulse measurements) is audible, but I don't hear it.
Product variation, some FD01s sound tighter / looser than others.
The "blub blub blub" are pitchless sub-bass vibrations. *)
*) Let me explain: DD IEMs with perfectly sealing tips can easily reach down to 20Hz. However below 40Hz or so, we don't hear a pitch but just feel "pitchless" sub-bass vibrations instead. You can easily test that with a tone generator:
Since the FD01 are a tad more sub-bassy, you hear more of the "blub blub blub". On the FDX1, sub-bass is partly masked by mid-bass, so you hear more bass pitch and less "blub blub blub".
If 3. is indeed the case, the FD01's "blub blub blub" should lessen if you EQ the mid-bass up @100Hz with a wide Q. Likewise, the "blub blub blub" should become audible on the FDX1, if you EQ the mid-bass down @100Hz with a wide Q.
Just my 2c...
What you wrote makes perfect sense as a possible explanation. If the FDX1 is less sub-bassy and more mid-bassy than i pretty sure i will be inclined to the FD01 if i am able to tell the difference.
For me, the modded FD01 is best described as U shaped. The FDX1 is more even sounding, if a hair downward sloping.
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