"Near zero ohms" can mean anything, it's just marketing.
There must be a reason they don't actually give the impedance in their specs.
One very credible source tested and found 1.3 ohms, which would perfectly explain the sound I get with my 9 ohm IEMs.
Another fairly credible source says the output impedance is significantly lower, but I suspect they made a mistake.
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As for inline resistor networks: (H-pads, L-pads, etc) Realize that they typically do NOT (theoretically) change impedance, just resistance. (Including that IEM Match device, which does not claim to help with impedance issues.) - Although I would not bet my life on this, and there ARE a few different ways to construct such a network, so some might be better than others. So Far I have only tried an 80 ohm unit from Ebay-China. It brought my IEM's to "approximately" the same volume as my 600 ohm cans, and it did seem to bring back some LF and remove the harsh mids.
However, it also kills a significant amount of HF. - Enough that I can't stand to listen this way.
I'm in the process of trying a modified H-pad design I recently found on some DIY forum. I have the parts, just have to find the time.....
FWIW, that iEMatch unit is a bit overpriced, though I guess it's convenient for some users. Being passive, it can't be anything more than two separate resistor networks, with a switch. Maybe $20 worth of parts, all-in.
Such is the Hi-Fi world ......
Still, if anyone has used this device, I'd live to know if their claim about "no HF loss" is really true. (I doubt it.)
If so, then there is hope, but numerous negative revues on Amazon say it ruins the sound. so ......
I wish there was some simple, ACTIVE device that could act as a non-coloring, unity-gain (or ideally gain drop) "impedance lowerer." High input impedance & maybe 0.1 ohm output. - But nothing seems to exist, nor can I find any plans for one.