Measured with 1KHz, and I am not talking about reactance, just plain resistance. Should not that be the same regardless of frequency?

No, it shouldn't, because it's a true vector measurement (I know, it's a bit puzzling).

A speaker has huge iron losses (and also some mechanical losses, some of which are converted into sound).

These losses are parallel losses, but when they are converted, the series model (remember, this is all virtual) shows an

*increase* in the series resistance.

Let us try to make it simple: the reactive impedance of your element is the pivotal value; let us say it is 10 ohm.

If you add a physical resistance of 1 ohm in series, it will translate into 100 ohm in parallel (ratio of 1 to 10 translates 10 to 1), and conversely, 100 ohm physical in parallel is equivalent to 1 ohm in series.

Things are more complicated than that, and the rule outlined is only valid when the losses are small compared to the reactance, but it shows the general behaviour of these parameters.

The basic rule is: you can never equate the losses of a reactive element to a single invariant resistive element.

Within limits, I found the ZLCR meter to operate reasonably on this aspect.

Radioman:

1µH isn't nothing: one of my home-made inductance meter has a resolution of 1nH at 100Hz (100fH at 1KHz), yet it isn't a lab instrument (except for my own lab).

But of course, with a sound card the limit is 16bit, which is rather crude compared to an instrument having a fully analogue front-end.