speaker ohm testing

Steven's points are good and you'll be glad to hear them now before you start testing.  If you were testing using my digital multimeter and read 1.9 ohms, you'd probably think you had a 2 ohm impedance.  My meter reads .7 to .8 ohms when I touch the probes together...this is "internal resistance".  So everytime I use it to get a DCR or resistance measurement I have to subtract that .8 ohm internal resistance from the reading.  In the case of getting 1.9 ohms, the real reading would be 1.1 ohms DCR and that figures to be an impedance value of about 1.4 ohms.  Close enough to 1 ohm, better than being under.

When your target value is a very low number, like in your case with wanting to find 1 ohms, the difficulty in getting an accurate measurement is increased because of the factors 1) internal meter resistance, and 2) conversion of DCR reading to nominal impedance (which should be something like DCR X 1.25 = impedance).