Measuring a Pair of Retro Tesla ARO 666

[idajourney]

So I live in one of the last houses that will be torn down in a massive to-be development project... which leaves some amazing alleyway finds. I found a giant old Sears-Simpsons phonograph cabinet... thing. Wasn't expecting much, the amp turned on but static all over and the turntable was completely busted. I hooked up the speakers to a different amp, though, and was surprised by the low end. They weren't amazing, but given the setup was 3x tweeters and a single woofer (with a pair of caps as a crossover) with no enclosure I was surprised. The tweeters were trash and the comb was obvious, but the woofers seemed decent. They're Tesla ARO 666's (found a doc here, see page 4).


They're rated at 5W max though, but I thought I'd measure them to see if they'd do well in a low-power nearfield 3-way. I'm very new to audio, so I suspect I measured something wrong. My process was (after disconnecting the tweeters, of course):

• Play a log scaled sine sweep at a decent volume. I'm not trying to get precise SPL, just the approximate response. I don't have a proper measurement mic, more of an all purpose field one.
• Take the F.T. of the recording
• Multiply with the F.T. of the inverse sweep (convolving since this is in frequency domain)
• Use the complex amplitude as the frequency response and the complex phase as the phase

What I got seems too good to be true:

Any advice on what I might be doing wrong, or could I have actually stumbled into a retro gem? If they are that good, how do you go about cleaning and repairing a driver from the 70's? What would be a good use for something with that low of power?