Is it safe to A/B 2 different speakers using my int. amp's balance so I can compare?


Just got a pair of Rega RS1s and own some Focal 714s.  I have a SS integrated amp with mono that pumps 100/channel.

I'm bad with listening retention where I play a song using one pair of speakers, switch them out with the new pair, and recall differences between the 2.  Will I get a good representation of from each speaker if I connected the Rega to the LEFT and the Focal to the RIGHT channel and just toggle L-R between the two during a song?  I do realize I will lose the soundstage & imaging, but am interesting in hearing the musicality and tone of each.  The next question, and more important one, is this safe?  Thanks.
comedyzen
Unless the speakers have exactly the same sensitivity at all frequencies, there will be differences in frequency response.  Also the speaker with the overall higher sensitivity will have more output.  Supposedly, psycho-acoustic studies show most people will prefer the louder of two speakers. 
Listen to one pair for a while (hours, over a few days, which ever you can get away with), and then do the same with the other pair…this is basically what pro reviewers do. If need be, take notes…one pair will likely make you feel better than the other.
Rega is 90 db
Focal is 91 db

I did A/B as posted and do prefer the Rega though, yet it was louder.  I did NOT have it in Mono though.  I think I just need to train my ears and do as the wolf-man suggests.  Thanks for the replies.
..just the placement in the room makes a huge difference.....this is probably not a sound idea.