Mainlander wrote:

I have some specs here for an audio transformer quoted 10k:10k maximum
level "2V @ 30 Hz"
Another transformer 10K:600R "-10dBm @ 30 Hz"

Which is the higher or lower signal level?

Often times we see levels quoted as dBv, other times dBm, other times mV
or V, how do you work out the equivalences of all these different units?

First, a warning, this is from a long distant memory so may be wrong, but
someone will chime in if it is...

dB are relitive, when you see another measurement, thats what its relitive to,
so dBm is a gain on a 1 millivolt or 1 milliwatt signal, dBV is a 1 volt signal etc.

If its just m, then its usually milliwatts, but you can never be sure on that.

You also see this in RF signal levels for wireless netowrking and TV/Satillite
etc, a 6dBmW output transmitter will have 6dB's of gain over a 1 miliwatt
transmitter, or 4mW

The first transformer specifies a voltage, you would have to work out the power
that 2 volts gives into 10,000 ohms, and compare that with the 100 microwatts
that the second allows. - its 0.0004 watts, so its 4 times the level of the
first, or capable of handling 6dB more power