MDR-100AAP (hear.on)

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NO SMOOTHING is applied to the shown plots. Most measurement sites have some smoothing applied which ‘irons flat’ sharp peaks and ‘wiggles’. I do not use smoothing because some info about sound quality is lost when plots are smoothed.

Aside from a small correction of the microphone itself also some correction in the lowest frequencies is applied to the plots to compensate for the perceived loss of bass when using headphones. This is described HERE in more detail.
A ‘horizontal‘ frequency response curve on the shown frequency response plots on this website thus indicates a perceived ‘flat’ tonal signature.

ALL measurements are made with a good SEAL on a flatbed measurement rig.
shape of your head, bone structure, pad size, pad ‘softness,  (compliance), hair or no hair and or wearing glasses may (drastically) change the frequency response of some headphones, so… your personal experience may differ substantially from these plots.

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Sony MDR-100AAP (h.ear-on)


The Sony MDR-100AAP is an elegantly designed headphone. It also exists in yellow, red, blue, pink and green. There is also  a version with bluetooth and noise cancelling called the MDR-100ABN. The matt black version doesn’t scream … fashion statement !.. like the coloured versions do.

The headphone can easily be driven directly from portable devices. The efficiency of the 40mm diameter driver is quite high (103dB/mW). The impedance is around 24Ω.
This headphone folds into its headband making it a lot smaller when taking it along.
The 1.2m cable is detachable and has 3.5mm TRRS plugs on both sides. It is a flat ‘tangle free’ cable and has a microphone + button in the cord. The headphone side has a straight connector, the source side an angled connector.
It also comes with a carrying bag in a simple and small box.

The headphone is not lightweight 220gr (7.8oz).
The pads are very soft and compliant. They provide a good seal, even when wearing (reading)glasses.
They do tend to get a bit sticky when they become sweaty.
The build quality, fit and  comfort is high. The clamping force is just right.

The sound signature is warm and bassy. Well suited for pop music and bright recordings.
For well made recordings the headphone is not entirely accurate/realistic.
It has similarities with the more expensive MDR-1A but is ‘clearer’ sounding and the bass doesn’t bleed into the mids as with the MDR-1A. The bass is tastefully elevated and doesn’t bleed into the mids. Don’t expect a tight and well defined bass though.

The mids are a neutral-ish to warm and lack some ‘brilliance’. For poor recordings this may just be what the doctor ordered but for well made recordings it lacks openness/clarity and ‘bite’ as well as ‘realism’. One gets bored pretty quickly as the overall sound is a bit tame/subdued and lacks a dynamic/lively sound.

The treble is slightly elevated in a particular area but O.K. at other frequencies. The treble sometimes has a small ‘etch’ to it but overall is on a decent, slightly south of neutral level.
A bit ‘boring’ and lacks sparkle / lively-ness / dynamics / realism. The treble quality is somewhat mediocre.
Not particularly highly detailed but rather smoothed.
The upper frequency extension (as well as the lowest octaves) are well extended.

Below the frequency response of the MDR-100AAP. left, right.


The bassy character is obvious. The elevation from 60Hz to 200Hz shows the tastefully elevated bass.
The 5dB decline from, 1kHz to 4kHz results in less clarity and ‘dynamics’ in the sound, especially in voices and instruments.
However, that gradual slope works quite well when listening to compressed (loudness wise, not file size) and not so well recorded music.
The peak around 8kHz gives the impression of detailed sound but may also give a slight sharpish ‘etch’ to it.

The MDR-100AAP has some similarities to the more expensive and luxurious MDR-1A.
Below the differences between the MDR-1A and MDR-100AAP. The differences in amount of bass, especially in the 60-300Hz region is obvious and in favor for the MDR-100AAP unless you prefer overly warm and less ‘clear’ sounding headphones.


below the distortion plots of the MDR-100AAP. Both the left and right channel are shown because they differ.
left plot is the left channel, the right plot is the right channel.

The leftt channel has a slightly higher distortion in the bass and above all in the treble.
It reaches an audible 3% at around 5kHz where the right channel is around 0.6%.
Bass distortion is around 1% which isn’t that bad.

Below the CSD of both channels superimposed, left, right.


Some slight ringing around 5kHz and 8kHz, also visible in the distortion plots. Below 500Hz it rings a bit longer than some other headphones do.
Below the spectrum plot, it shows a fairly normal response with no obvious irregularities that stand out.


For those that are looking for a little less bass/warmth the same ‘port tricks’ can be done as with the MDR-1A. Except, the port is much less effective.
On the right the ports are clearly visible. They are located on the top of the earcup and hidden under the yokes.100aap-port

Port open, only small hole closed, entire port closed.


As can be seem sealing off the small hole lowers only the frequencies below 60Hz by about 5dB. When the whole port is sealed (a piece of tape over it or maleable eraser covering the vent) the frequency response as a whole becomes less bassy. The small elevated part around 100Hz remains so the effect is subtle. In the MDR-1A the effect is much more pronounced.

As with the MDR-1A the peak around 8kHz can be lowered by adding either 1 ply of soft 3ply toilet paper in front of the driver or by using 1mm thick felt.
Below the effect of 1mm thick felt (the type sold in crafts stores) is shown versus stock.


As can be seen the 8kHz peak is lowered by a few dB while the overall amount of treble isn’t lowered that much.
Felt applied + sealed ports measures as shown below versus stock.


Below the CSD which shows that the 5kHz ringing is still there, the 8kHz is lowered and below 1kHz the ringing is lowered by approx 5dB, together with the flatter frequency response this results in a ‘tighter’ bass.


The square-wave and impulse response below also show the changes in response to sealed ports and felt added to the driver.
On the left the stock MDR-100AAP on the right the ports closed and felt in front of the driver.


The square-wave’s show a definite improvement. The felt takes away the resonance at 8kHz but doesn’t damp the other higher frequencies.

Overall this is a very nice looking and comfortable headphone. Quite suited to be connected to mobile phones (microphone/remote in the cable) and the efficiency which is high enough. The sound signature is pleasant. Raised bass, good clear mids but lacking somewhat in finesse. The treble is not its strongest point though.

The good:

  • design
  • weight
  • suited for portable usage
  • foldable
  • clamping force
  • comfort
  • removable pads
  • interchangeable cable
  • tangle-free cable
  • bass and mids

The less good:

  • resolution (finesse)
  • lacks brilliance despite decent clarity
  • A bit ‘boring’ in the treble, lacks sparkle / lively-ness / dynamics / realism.
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