[kiteki]

Hi,
 
I commonly look for all technical data I can find on any product, in this case IEM's.
 
I've become very tired lately of frequency response measurements.  It's just volume balance and extension, yet the comments on head-fi and reviews often indicate it's a lot more, such as this one
 
http://www.pcmag.com/slideshow_viewer/0,3253,l%253D251236%2526a%253D250663%2526po%253D3,00.asp?p=n
 

 
 
 
That's a $79 IEM versus a $1350 IEM, by the way.
 
I have lots of examples where FR doesn't seem to indicate very much, if anything.
 
 
I'd like to learn more about how to read square-wave response, how to assess sound-stage / layering / imaging, and how to assess natural tone, metallic tone, etc.
 
Thanks in advance.

 

[xnor]

What's the problem with the graph? Btw, you should also look at THD(+N) and phase response (only important with multi-driver headphones) graphs.
Impulse response, square wave response etc. can be derived from those so it doesn't make much sense to look at those before understanding the frequency and phase and distortion graphs.

 

[kiteki]

Ok, so I should study phase response and THD graphs?  So you can derive impulse response and square wave response from them, anywhere I can learn how to do that?
 
 
There is no problem with the actual graph itself, it's that I think the bass / mids / highs will sound so extremely different on those two IEM's that I don't think slight differences in volume will make much difference, i.e. I don't think the fact the EPH-50 looks 'flatter' than the UE18Pro has much significance compared to the rest of the sound.
 
IEM's tend to sound better with deep insertion, closer to the ear-drum and with a secure seal, I'm not sure if the "Head Acoustics ACQUA" can pick up these differences.

 

[xnor]

Well, the way the FR curves are lined up there's 5 dB more bass and up to 15 dB more treble. If those headphones didn't sound completely different I'd be stunned.
Also, the problem with the EPH-50 I see is that it doesn't gradually decline from ~1 to 10 kHz. That treble peak could be quite annoying on some recordings.
And the UE18 has boosted lower mids. What's funny is that I did a quick search on a UE18 review here on h-f and both of these statements were in the same review:

Strong and flat mids.

My first impression was the presence of the lower mids. I’m not used to having them so emphasized.

x_x

 

[kiteki]

That's interesting, what if you used a good equalizer to try to make them sound as similar as possible in FR?

 

[xnor]

It would not be exactly easy to EQ them to sound very similar by hand. Biggest problems are the peaks in the frequency response, which you don't see in smoothed graphs.
Nevertheless it's not impossible. Bad_Robot @hifi-forum.de has EQ'd a W4, SE535, TF10, UE4Pro by connecting two earphones at once, one in the left ear, the other one in the right one and making adjustments with a stereo EQ (left and right channel can be EQ'd separately).
He noticed that the W4 bass drivers scale very well with volume and that you'd need a parametric EQ and lots of time to make them sound even closer.
I guess it would be easier to use in-ear mics or a dummy head and generate the filter.

 

[proton007]

Quote:

Ok, so I should study phase response and THD graphs?  So you can derive impulse response and square wave response from them, anywhere I can learn how to do that?
 
 
There is no problem with the actual graph itself, it's that I think the bass / mids / highs will sound so extremely different on those two IEM's that I don't think slight differences in volume will make much difference, i.e. I don't think the fact the EPH-50 looks 'flatter' than the UE18Pro has much significance compared to the rest of the sound.
 
IEM's tend to sound better with deep insertion, closer to the ear-drum and with a secure seal, I'm not sure if the "Head Acoustics ACQUA" can pick up these differences.

 
Normally, Magnitude, Phase (Angular) response and Harmonics are obtained as a direct result of output signal analysis using Fourier Transform, so they go together. I'm not sure its possible to derive the impulse response from the phase or thd.
Differences of >5 dB come in the audible range at low frequencies, so I guess there will be some difference. But I feel its got more to do with which part 'peaks' compared to the rest of the curve.