Slam to me is the ability of the system to reproduce soft to loud passages and back again. For an example, I use a track with two acoustic guitars. During a passage with both guitars strumming, one guitarist is wrapping his hand/knuckles ont he guitar. I was thinking about how hard could a person strum and wrap his hand on the guitar and how loud would and should that sound versus the rest of the instruments that were playing. In the beginning I thought wow that guitarist is really knocking on the guitar. Then I thought to myself, man that has to be a really close miked wrap or my system is not reproducing that correctly. I also play guitar so I used that as my comparison. I thought that was slam. When I switched to a more refined speakers that sound changed to less hit me in the gut sound and the wrap seemed to come more from the location of the one guitar, had less overall hit me in the gut impact, but it seemed to me that the "slam" was much more correct. The speakers were similar in design, both time aligned but the one pair had a more solid cabinet that the other which seemed to deaden the sound, some may call it having less of an impact or maybe even duller, (not as dynamic), but the more I listened the more I thought that the sound was more accurate. Kind of like first row presentation versus 15th row. The sound was fast and dynamic with the right amount of slam for what I thought could be reproduced by the wrapping of the hand on the guitar. So that is how I would define slam. How fast can the system go soft to loud and back again and retain the tone and resolution of the sound.
Happy Listening.
Happy Listening.