[loomisjohnson]

having recently caught this dreaded affliction, i'm now obsessing over which on my new IEM shortlist would be easiest to drive to deafening levels on an htc one phone:
yamaha eph-100
philips fidelio s1 or s2
jvc ha fxt90
rha ma 750
i have attempted to interpret technical specs, but find myself ultimately baffled.
i generally listen to guitar rock, hard bop and other such folderol. not a basshead, but need some low end depth. thanks in advance for your thoughts.

 

[ProtegeManiac]

When it comes to IEMs and smartphones, getting to deafening levels is easy - the problem is how much distortion it'll have at even half of that, so even if you could get it up that loud, you'd pull back on the volume anyway when the THD is too high. Personally I haven't come across any IEM that couldn't blow my ear drums apart, except the phone usually distorts badly long before that.
 
If anything my current IEM - the Aurisonics ASG-1 - usually needs only about 15% to 25% of the volume setting in a quiet room, not more than 35% in public (like on the MRT/subway). At 50% it's barely distorting but it's waaaaaaaaaay too loud - even the intro can hurt my ears. At the same perceived volume at around 60%, my MEE M6P is already breaking up in the midrange and treble.

 

[billybob_jcv]

The loudest will be the one with the highest sensitivity spec. So, if #1 has a sensitivity of 103 dB SPL/milliwatt and the #2 has 113 dB SPL/miliwatt, then #2 will produce a louder sound at the same input level.

HOWEVER, the marketing dweebs at the headphone mfrs are not going to make it that easy for you...

For example, let's take a look at your list. From their respective web sites:

First, the Yamaha EPH-100
Sound Pressure Level 104 dB ±3 dB

Umm, OK - what the heck does that spec have to do with the sensitivity? We don't know what the input power was to achieve that 104 dB level. 1 milliwatt? 1 volt? 10 volts?? And, what does the +/- 3 dB mean? Over what frequency range?

The Yamaha spec is COMPLETELY MEANINGLESS!!

OK, let's try the Philips S1
Sensitivity 107 dB

Well, at least they called it "Sensitivity". But still, we have no idea whether that is for 1 milliwatt, 1 volt or 16 bananas.

The Philips spec is COMPLETELY MEANINGLESS!!

Strike two!! Should we try for 3?

C'mon JVC FXT90!!
Sensitivity 107 dB/1 mW

Ding! Ding! Ding! We have a winner!! This spec actually means something!!

OK - now I'm curious, do we quit now or go for a double?

RHA MA750
Sensitivity 100dB

We should have quit while we were ahead...

But wait, the next line in the RHA specs *might* be trying to tell us something:
Rated/max power 1/5mW

I *think* that *might* be trying to say that the 100 dB is from a "Rated" power of 1 mW. Maybe. Or maybe not. I will give them a grade of "C". Almost RHA, but I think you aren't really trying...

Please note, the impedance spec is also important. It tells us the load being placed on the amplifier. If your amp can't actually drive the load presented by the headphones, then you might not be able to achieve the maximum volume the headphones are capable of generating before the amp starts distorting. That's why it is important to know the input power for that dB SPL spec. If you need 100 mW to reach 113 dB SPL, and your headphones are 64 ohms - then your amp needs to produce 100 mW at a 64 ohm load - or you won't reach 113 dB SPL. This is why we say that a low impedance and high sensitivity headphone is "easy to drive".

 

[ProtegeManiac]

HOWEVER, the marketing dweebs at the headphone mfrs are not going to make it that easy for you...
...
The Yamaha spec is COMPLETELY MEANINGLESS!!

...
We should have quit while we were ahead...

 
Precisely why I didn't even get into those specs, just that they'd either distort or the eardrums will suffer even before a smartphone gets to 100% volume

Then again that might depend on the software controlling the audio chip. Some need to be rooted, and IIRC my brother's HTC One (2012) needed to get up to around 60% volume to get a little bit louder for short-term (ie, when a really good track comes on, especially on power metal concept albums, usually the last track) compared to just around 50% on my Galaxy S. Still, by the time the HTC One hit 75%, the sound was breaking up.

 

[epicFAIL]

I don't know if IEMs any amping at all.They're already quite efficient.Even if  the figures given by the manufacturers is incorrect, it will be more than that of any other type of headphones.
Maybe the flagship IEMs do but i have no experience.
 
EDIT : Sorry!

 i just realised you don't need an amp. I'm an idiot. 

 

[loomisjohnson]

grazie for the very helpful input. with apologies (again) for my technical ineptitude, assuming I'm using the same 1mw amp to drive 'em (and the listed specs are based on said 1mw power), which would sound louder:
a. IEM A rated at 104db/16 ohm
b. IEM B rated at 100db/32 ohm
c. IEM C rated at 107db/12 ohm
d. IEM D rated at 100db/16 ohm
(I understand there may be other factors at play, but) your advise would be appreciated.

 

[ProtegeManiac]

  grazie for the very helpful input. with apologies (again) for my technical ineptitude, assuming I'm using the same 1mw amp to drive 'em (and the listed specs are based on said 1mw power), which would sound louder:
a. IEM A rated at 104db/16 ohm
b. IEM B rated at 100db/32 ohm
c. IEM C rated at 107db/12 ohm
d. IEM D rated at 100db/16 ohm
(I understand there may be other factors at play, but) your advise would be appreciated.

 
Set aside the impedance (in ohms) first. Each of those then will produce their db's at 1mW, assuming they're all rated as such; the difference is how much more power your portable source or amp is making at that given impedance, or can make when you pump up the volume. Power output on most portable devices using comparable integrated audio chips (DAC and headphone driver built into the same chip) are generally 5mW to 15mW at 16ohm or 32ohms. Unlike speaker amps however headphone amp output is not linear - there are amps designed to deliver more power into higher rather than lower impedance for example - and even portable devices may have non-linear output curves. Power might dip higher than 32ohms, but can also be the case below 16ohm.
 
Besides, assuming those ratings are accurate...would you really want to listen at 100db? Because one hour at 92db will cause hearing damage already, assuming the music is recorded at loud enough levels that would actually achieve that rating. Modern recordings are recorded a lot louder so if it's new music you'd definitely hit the rated output at 1mW.

 

[billybob_jcv]

At exactly 1 mWatt of input power, using an amp that has sufficient headroom to handle the fluctuations in impedance that occur over the frequency range, then the loudest headphone will be "C" @ 107 dB.

However, ProtegeManiac is right - buying a headphone based on "which one goes to 11" is just silly, and potentially harmful. I (mis)spent my youth abusing my ears with rock concerts, firearms and off-road vehicles - and now I have hearing loss at specific frequencies in the upper-mids, general upper-frequency hearing loss and tinnitus. I can point to specific events in my youth where I *know* I damaged my hearing (A specific concert at the LA Forum with the Red Hot Chili Peppers & Aerosmith, an afternoon shooting a .38 snub nose revolver without ear protection and many hours on 2-cycle dirt bikes with racing mufflers). Only the young believe they are immortal!

 

[epicFAIL]

Power ratings are fine.
But I suggest you to go for the one WITH THE BEST FIT because I think when it comes to IEMs it's all about fit, the better the sealing and the closer the drivers are to the ears the more eveything will be. be that intensity (or distortion),

 

[epicFAIL]

sorry
double post

 

[loomisjohnson]

first off, let me acknowledge the genuinely cordial and helpful tone of these forums.
i'm not actually bent on ruining my hearing, but mildly concerned that the current iteration of mobile phones might not do justice to certain IEMS. in any event, if understand billybob & protege correctly, all things being equal a lower impedance, high sensitivity IEM would be louder than a higher impedance IEMof the same sensitivity?

 

[epicFAIL]

   a lower impedance, high sensitivity IEM would be louder than a higher impedance IEMof the same sensitivity?

yes,if you plug them into a portable source i.e. one which doesn't generate significant voltage.
 
But then IEM's generally don't have *that* high impedance, since they are made while keeping in mind the fact that IEMs are used strictly in the company of a portable source( which doesn't gives high voltage).
 
and i like loud deafening music too,particularly a tight loud punch of dark bass.

 

[billybob_jcv]

first off, let me acknowledge the genuinely cordial and helpful tone of these forums.
i'm not actually bent on ruining my hearing, but mildly concerned that the current iteration of mobile phones might not do justice to certain IEMS. in any event, if understand billybob & protege correctly, all things being equal a lower impedance, high sensitivity IEM would be louder than a higher impedance IEMof the same sensitivity?

This is correct.

Please understand - the vast majority of IEMs are designed with the mobile market in mind. The highest impedance IEM I can think of off the top of my head in the Ety ER-4S at 100 Ohms. This IEM is made to be used from an amp. If you don't want to use an amp, no problem - just get the ER-4P that is only 27 Ohms and 122 dB/mW. The Shure SE535 is only 36 Ohms. The $1000 Shure SE846 is 9 ohms. The $1300, 12-way :eek:, JH Audio Roaxanne UF is 15 Ohms & 119 dB/mW. In addition, the impedance of IEMs (especially those with balanced armature drivers) simply does not fluctuate dramatically with frequency like it does with some full-size headphones. IMHO People that say their IEMs became dramatically better with an amp are just fooling themselves. At best, they got louder, and the most dynamic of music passages might be a little better. This was my own experience when using the Altec Lansing IM716 (16 Ohms, but not very efficient). From my ipod, I needed a small amp to get the volume level I wanted, and that also made the bass come out - but when using the amp, if I turned down the volume to match the volume level without the amp, the sound was very similar, and it would be really pushing it to call that "significant".

My advice is to stop worrying about whether your phone can drive your IEMs. In a worst case scenario, a tiny and inexpensive portable amp can be added to your phone and you are good to go.

 

[loomisjohnson]

i agree that most iems are designed with mobile phones in mind; however it seems like the current iteration of smartphones aren't designed for iems, or for audio enthusiasts generally. case in point (and what precipitated this whole thread) is i recently upgraded my perfectly serviceable galaxy s2 phone to a lg g2, which has a superfast processor and an amazing hd screen and promised all sorts of a/v nirvana. (btw, you know you're getting old when you get more excited about a phone upgrade than broads). in practice, the audio output was so low that it was barely audible unless maxed out, at which level it distorts significantly.amping with a little fiio didn't help all that much. i tried the galaxy s4 and note 3 (somewhat better but not really loud) before settling on an htc one, which for all of its beats audio hype is still not as dynamic as you'd expect. (the iphone, as with all things apple, is probably the best of the breed). what i surmise is that these phones' amp sections have fallen victim to the inevitable design compromises inherent in making thinner/lighter products. as always, thank you for the feedback.

 

[billybob_jcv]

OK, here's a completely different suggestion for you: How about getting a separate DAP for your music? Maybe try a Sansa Clip+?