I'm still not quite sure what you're looking to improve in terms of sound quality.
Also, what was difficult about placement? The SP1/2 has fairly tight dispersion characteristics and is less sensitive to side wall asymmetry than many other speakers when one is in the sweet spot. If a room is difficult for Spendors, it is likely going to be problematic for many other speakers, though the anomalies may be different in character.
I think the answers you receive will improve if people have a better of idea of the improvement you're seeking.
Also, what was difficult about placement? The SP1/2 has fairly tight dispersion characteristics and is less sensitive to side wall asymmetry than many other speakers when one is in the sweet spot. If a room is difficult for Spendors, it is likely going to be problematic for many other speakers, though the anomalies may be different in character.
I think the answers you receive will improve if people have a better of idea of the improvement you're seeking.