Effect Ohms Have on db and Speaker Sensitivity

Still 97dB, assuming the manufacturer is using the conventional definition of sensitivity -- 97dB at one watt measured at one meter. For a 6 ohm impedance, the voltage for one watt is 2.4 volts. When the impedance swings to 8 ohms then 2.83 volts is one watt of power consumed and 97db SPL will still be measured at one meter.

First, be aware no spec gets fudged more than sensitivity! :) Most speakers are rated 3-5 dB higher than they actually are.

dB at 1W / 1m is "efficiency" and varies by load impedance, which as stated above, is 2.83V at 8 Ohms. Think of it as "power efficiency." With modern SS amps this is a meaningless measure really. You want sensitivity.

dB at 2.83V / 1m regardless of load (and therefore regardlesss of power) is "sensitivity." Again, think of this as "voltage sensitivity" to try to remember why they are not the same.  This measurement makes more sense, since most speakers impedance varies WIDELY at different Hz. Measuring between say 6 to 20 Ohms in the same speaker is quite typical. I don't really care about how much power is being dissipated at 2,450 Hz as much as how loud it will get with a 40 Watt amplifier.

Also, the exact Hz at which the dB are measured varies. I use 1 kHz, but some manufacturers may try to eyeball it.