Newbie with a question on speakers

[LFC Pete]

Hi everyone.
I'm new to this forum and was wondering if anyone out there could help me please.
I have a pair of EV Stage series S80 speakers that were given to me the other day and was wondering if anyone could tell me exactly what their use was when they were around, they seem quite old, about 15 to 20 years I'd estimate but they are in pretty good condition, Not sure if they are PA speakers or monitor's or what.
Any info would be greatly appreciated.
Thanks in advance.
Pete

 

[Massive Master]

The Big Black Blocks? Just typical PA use. Small rooms, side fills --

 

[Springtex]

I have the EV Sx80 speakers also--for about a dozen+ years, never a problem. I have them in my home studio, with a Kawai MP9000 stage piano, a Mackie 1202 mixer and an EV 7100 amp comprising the system--never a problem. But I just added a new Kawai MP6 to the system and I'm having problems with a loud crackling noise, almost like small firecrackers popping, only when I play the MP6. This is not happening when I play the MP9000. And I don't think it's a "flaw" in the MP6, because I have used it in another room for about six months with another Mackie mixer and some smaller Yamaha powered speakers and did not experience this noise at all. Troubleshooting I have tried without avail: switching out the cables from the MP6 to the mixer: changing channels for input on the mixer; cutting the volume down on the amp; shutting down the wireless computer network in the house--none of that solved the problem. All of my cables are top quality Mogabe or Monster. I'm now wondering if, due to the vintage of these fine speakers, they may not be able to handle the signal now coming out of this new Kawai MP6? Or what? The sound is excellent except when this intermittent breakup noise come out. Any ideas?