I have a spanish cedar tele body, It's half done, it's very light. I haven't actually weighed but it's pretty light. I was under the impression that spanish cedar, though it looks like mahogany is less dense than much of the mahogany we see.
You are correct. It is also a much softer wood and rates 600 on the Janka hardness scale, alder rates 590, African mahogany for comparison is 830. Spanish cedar is easy to work with and machine due to its low density.