What is your opinion of single driver speakers

Single driver speakers can sound amazing.  For example filed coils to me are exceptional. Matching to the right amp also helps.  845, 45, tubes amps and some 1 watt amps make such speakers sound amazing.  Uping the price the horning speakers are also a consideration if you got the scratch.

Happy Listening.

What are you thinking of driving the Pearls with?

I am not familiar with PA but have used the Audience 1+1 for years. Single driver speakers eliminate one of the most vexing problem that designers encounter when putting a system together: the crossover network. Passive network are almost impossible to get right on a budget. Without the crossover and with the right driver, the midrange purity can be addicting in a single driver system. But like everything else in life, you can’t get it all.  The bass might need help depending on your music preference. Your might need to add subs if you want it all. 

some are top notch, some are good, and i imagine some are no good. theyre as good as you wish to purchase. lotta folks buy tannoy cox and never buy another speaker. ive got a really good pair of halford margaritas (halfordloudspeakers.com) using some small fostex drivers. 

i dont know pearl acoustics

I have been using Pearl Acoustics Sibelius speakers for the past year and a half. Room size, 20x20'x9' ceilings. System,  Audio note Oto SE signature, TUBADOUR III SE Nonoversampling Tube DAC, Zestos Andros 1.2 phono preamp, VPI classic 3 with Koetsu Black cartridge. Using Morrow rsa cables and Silversmith Fidelium speaker cables. I would consider my system to be mid Highfi at around $15k not including speakers. I have been a big fan of Fritz's speakers Rev 7 SE and Carrera speakers for their authentic and natural sound.  There are numerous reviews on his Bookshelf Speakers.  I also had REL subwoofers to compensate for the 50Hz and below sounds. But I was tired of the space required for speakers and lack of seamless coherent sound stage. I did my research on a speaker that was authentic in design and neutral in sound, also no crossovers but still gave me a full range loudspeaker. I am extremely pleased with the sound,  more impressed with the best customer service.  Just Google or utube the reviews. Oh and I am happy to demonstrate the sound qualities if you are in the northern NJ area. These speakers can easily and realistically go down below 50 Hz.

Not sure I will be going back to multi drivers as there are just too many components and why do you think some audiophile purist still lean towards SET systems?? Because sometimes simplicity in design translates into listening to the music in the format it was recorded in.  I hope this helps.