[james444]

Interesting theory that begets the question, what causes this increased initial "attack" and how does it differ from traditional SPL measurements?

I think I've done some burst-decay graphs as a small isolated test but got no exciting data of note.

Higher inertia mass of DD diaphragms as compared to armatures? Would be interesting to have something like CSDs to visualize energy buildup over time. Just speculating of course...

 

[goodvibes]

A sealed back dynamic could easily sound 'tighter' than a vented (multiple) BA so I think there's more to it. Sealed dynamics are no longer in favor but my old sealed Brainwavz b1 (I think) were cheap sealed earphones that had no 'decay'.

 

[james444]

Just keep in mind, we're comparing IEMs that measure similarly in bass amplitude. I don't think I've ever come across BAs that sounded subjectively bassier than a similarly measuring DDs. But then again, I haven't heard many sealed dynamics.

 

[castleofargh]

I'd be tempted to deal with micro drivers as another specific situation. they are by nature dynamic but the size, damping, usage in sealed condition... make it hard to just amalgam them with bigger dynamic drivers behavior IMO.

 

[crinacle]

I'd be tempted to deal with micro drivers as another specific situation. they are by nature dynamic but the size, damping, usage in sealed condition... make it hard to just amalgam them with bigger dynamic drivers behavior IMO.

Depends on what you mean by "micro" I guess. I have the Carbo Tenore and have had (bad) experience with the AAW Q and neither have really stood up as "BA-sounding" by any means.

 

[james444]

I'd be tempted to deal with micro drivers as another specific situation. they are by nature dynamic but the size, damping, usage in sealed condition... make it hard to just amalgam them with bigger dynamic drivers behavior IMO.

Yup, I agree. Although, imo microdrivers don't quite exude the same bass authority and effortlessness as larger drivers. Meaning, the difference between measured and subjectively perceived bass is smaller to my ears.

All microdrivers I've seen so far have been vented, btw. Apparently there's just no need to vent the outer shells.

 

[castleofargh]

my bad, I was thinking about sealed stuff like my old Ety MC5 or Shure SE215. I don't think those are vented. maybe we need even more classifications ^_^. anyway it doesn't bring me closer to a clear reason why I feel more low end on DD for about the same measurement.

 

[james444]

my bad, I was thinking about sealed stuff like my old Ety MC5 or Shure SE215. I don't think those are vented. maybe we need even more classifications ^_^. anyway it doesn't bring me closer to a clear reason why I feel more low end on DD for about the same measurement.

MC5 driver: https://www.head-fi.org/threads/etymotic-owners-of-er6i-i-need-your-feedback.676950/#post-9727817
SE215 driver: https://inearcustom.wordpress.com/2...om-shure-se-215-re-solder-customized-monitor/

Like all others I've seen so far, they have tiny rear vents between the solder points.
That said, we should probably take this discussion elsewhere and stop spamming crinacle's thread.

 

[crinacle]

Eh, no qualms about continuing anyways. This thread is perfect for nerdy technical measuring talk.

 

[castleofargh]

usually we'd each publish a 500 pages book on what we meant by vented, then form cults out of it, wage wars, then finally end it all with an e-duel at dawn armed with sporks and insults. you know, the usual stuff between 2 people and a simple misunderstanding. but I don't do that because I'm a reasonable man... he knows where I live.

about attack decay and masking, I have no idea. it's just so complicated as soon as impressions are involved. for single tones I get the studies, but beyond that I'm a noob. could be it, could be completely wrong, but right now I wouldn't bet my own money on any outcome.

 

[datranz]

If anyone can answer these questions, it probably be @DanWiggins. He has experience with csd graph of iems.

@DanWiggins, if you are free, can you explain some of the questions above?

 

[james444]

usually we'd each publish a 500 pages book on what we meant by vented, then form cults out of it, wage wars, then finally end it all with an e-duel at dawn armed with sporks and insults. you know, the usual stuff between 2 people and a simple misunderstanding. but I don't do that because I'm a reasonable man... he knows where I live.

about attack decay and masking, I have no idea. it's just so complicated as soon as impressions are involved. for single tones I get the studies, but beyond that I'm a noob. could be it, could be completely wrong, but right now I wouldn't bet my own money on any outcome.

I know where you live, but iirc there's a prison right nearby, so I won't do anything I might later regret.

Well, since crinacle's cool with our banter, I might as well copy my clarification on venting over from our PM:

I guess to me the question is whether it's a self-contained driver in its own housing, like the armatures or microdrivers I know, or a larger driver in a shell that's essential for it to funtion properly. I'm sure, some amount of air volume is needed behind the rear vent of a microdriver, but by and large I think the outer shell is hardly as significant in the overall acoustic design as it's the case with larger DDs.

To give an example, when I was messing around with the Tenores, I noticed that even small changes in damping right behind the driver vent had a significant impact on sound signature, whereas the difference from blocking the outer shell vent was comparably minor. Which makes me think that microdrivers may need considerably less rear volume than larger DDs, in order to behave (almost) like in free atmosphere.

 

[james444]

If anyone can answer these questions, it probably be @DanWiggins. He has experience with csd graph of iems.

@DanWiggins, if you are free, can you explain some of the questions above?

Glad you mention him, because I've come across one of his posts on reddit, in which he states:

Running waterfall plots of a BA versus a dynamic, and you may see the same base FR - but the stuff going on 3-30 msec after the original event, 20 to 40 dB down, is dramatically different.

But then again, I've also come across these posts on Head-Fi, that seem to say we can't hear these differences:
https://www.head-fi.org/threads/headphones-fast-and-slow.734320/page-3#post-10882712
https://www.head-fi.org/threads/headphones-fast-and-slow.734320/page-4#post-10883314

 

[datranz]

Take this as an example from http://periodicaudio.com/faq.html
Spectral decay portion, (sorry, I'm on my iPhone so it's hard to copy and paste)

IMO, the time delay or bass decay is what cause dd iem to have better bass than ba. And it's measurable.

 

[james444]

Take this as an example
IMO, the time delay or bass decay is what cause dd iem to have better bass than ba. And it's measurable.

No one doubts that these measurable differences exist. The question is whether we can hear them. The temporal post-masking effect seems to raise doubt on that.

Like castleofargh said, it's a complicated matter...