"What I don't have a clue about is whether the Signatures are capable of slam/dynamics given a much more powerful amp"
Looking at specs of SE version of your Legacy speakers (can't find same for IIs), and assuming they are similar, I'd say, yes they should definitely be capable of "slam" in most rooms if in good working order.
I'd also say that given the power recommendation from Legacy for SE version, assuming similar to yours, of up to 300 watts, a bigger and beefier amp would yield additional dividends in the slam department.
Most vendors underrate the maaximum power handling of their speakers in order to play it safe and so as not to scare off buyers, but in general, I would tend to throw the kitchen sink amp power wise at speakers like those. A good quality 500 w/ch into 8 ohm Class D amp is what I would try. I landed on mine for my big OHM speakers for exactly the same reason. 250 w/ch Class D should deliver nice dividends as well.
I use my 500w/ch Class D amp even with my tiny similarly efficient Triangle Titus monitors, along with all my larger and more power hungry models.
As long as you listen to your ears for any signs of stress or breakup with more challenging recordings at a particular volume before going louder, you are not likely to damage most good quality speakers that are in good condition.
Your more likely to damage a speaker by blowing a tweeter if you attempt to crank up an underpowered amp too high and clipping occurs.
More power keeps clipping out of the equation. That creates dynamics and slam and is also easier for most good speakers to digest to boot.
Looking at specs of SE version of your Legacy speakers (can't find same for IIs), and assuming they are similar, I'd say, yes they should definitely be capable of "slam" in most rooms if in good working order.
I'd also say that given the power recommendation from Legacy for SE version, assuming similar to yours, of up to 300 watts, a bigger and beefier amp would yield additional dividends in the slam department.
Most vendors underrate the maaximum power handling of their speakers in order to play it safe and so as not to scare off buyers, but in general, I would tend to throw the kitchen sink amp power wise at speakers like those. A good quality 500 w/ch into 8 ohm Class D amp is what I would try. I landed on mine for my big OHM speakers for exactly the same reason. 250 w/ch Class D should deliver nice dividends as well.
I use my 500w/ch Class D amp even with my tiny similarly efficient Triangle Titus monitors, along with all my larger and more power hungry models.
As long as you listen to your ears for any signs of stress or breakup with more challenging recordings at a particular volume before going louder, you are not likely to damage most good quality speakers that are in good condition.
Your more likely to damage a speaker by blowing a tweeter if you attempt to crank up an underpowered amp too high and clipping occurs.
More power keeps clipping out of the equation. That creates dynamics and slam and is also easier for most good speakers to digest to boot.