Focal Aria 948

Make sure you don’t toe them in very much. Focals like to be pointed at 90 degrees to the rear wall, or with minimal toe-in.

The imaging will improve and hopefully you will hear them as less bright and more bass. However, Focals do tend to soak up current in the bass and are not very tolerant of lesser amps. This is not, IMHO a good thing, just experience.

A non-destructive experiment you might also try is to plug the ports and back them up to the wall as much as you can.  Make sure to only use clean socks, as dirt and body oils can affect the port refraction.  <j/k>  but I do actually suggest trying it.

Josef Anton Hoffman, the 'H' in KLH was an audio engineer with a storied career that included working on the Manhattan Project in WWII, after which he returned to school at Harvard where he earned his PhD. In his career, he worked at KLH, AR, and Advent.

Hofmann's Iron Law
"There are three parameters that cannot all be had at the same time. They are low-bass reproduction, small (enclosure) size, and high (output) sensitivity." Hofmann stated that designers could pick two of these three parameters, but in doing so, it would compromise the third parameter.

The Focal Aria 948, with 92.5 dB sensitivity, gives up almost an octave of bass potential for that sensitivity. if were re-engineered to give up 3dB of sensitivity it could probably reclaim bass down to near 40 Hz. The best you can do is locate it closer to your rear walls to increase the acoustic loading. but that may have other tradeoffs you don't care for regarding soundstage and imaging. 

Amps like the Pioneer SX 1250, while measuring at 160 wpc had very low current… the real thing that supplies impact. High current designs did not start becoming common until the 1980’s and then only I expensive amp only components.

I’ve never heard the complaint the 948 had not sufficient bass extension but the opposite it was bass heavy. I had 906 for a while and they had excellent bass extension for the size, very room filling kind of bass. It was a little on the slow side but nice sounding speaker none the less just not very punchy. 

i have Aria 936 powered by Parasound A21+. I think you'll like JBL HDI-3800. I have gotten 3800s a few months ago (March 2023) and like them more than 936s. Specifically bass.