iEMatch gives you the flexibility of 3.5mm TRS or 3.5mm balanced TRRS and a switch between two impedance settings to fine-tune to your IEMs.
While the drive impedance to the headphone varies slightly with the two settings, it is a variance between 1 ohm and 3 ohms.
This is radically different from so-called impedance adapters, which simply add their rated resistance in series with the headphone.
To get the same reduction in hiss and increase of usable dynamic range an ‘impedance adapter’ used with a 32-ohm nominal headphone as the iEMatch in high sensitivity would require a 100 ohms adapter and likely radically affect the frequency response of this headphone.
With iEMatch the headphone drive impedance is 3 ohms which means any change in frequency response is bound to minimal.
If we take the rule that minimum impedance >= 70% of rated impedance and maximum impedance up to 300% of rated impedance, the absolute maximum variation in frequency response with IEMatch would be +0.6dB/-0.3dB (barely audible, if at all), while the ‘impedance adapter’ of 100 ohms would produce +6.1dB/-2.5dB variation in frequency response (grossly audible).
So ‘impedance adapters’ and iEMatch work on very different principles and have very different effects. Therefore any experiences with “impedance adapters” have no relevance to iEMatch.
In other words, 1-3 ohms difference means the iEMatch has the impact of the centre of a donut on the frequency response. One would need a bat-like hearing to tell the difference.
We hope this sheds some light as the iEMatch is not a run of the mill product.
As always, one should try first.
