Infinity Bookshelf speaker SM-65

[mresistor]

I've had a pair of these Infinity SM-65s hooked up to a legacy JVC receiver from the mid 80s for a few years. They are good sounding little speakers however the other night the amp started shutting down intermittently, on and off.  So I connected a set of JBL monitors to the amp where the SM65s were connected.  The amp works fine with the 8 ohm JBLs. So I wonder what could be causing the problem with the SM65s.
So I read their specifications and it says they are suitable for 4 to 8 ohms.  What the heck does that mean?  I check the resistance and they read 3.5 ohms..  I don't think my JVC receiver is rated for 4 ohm operation so all this time I was probably stressing the power amp out?  I think they were advertised to me to be 8 ohm speakers. I bought them used.
Does this sound logical?  Why would they say these were suitable for a solid state receiver requiring an 8 ohm load?   

[mresistor]

I'm pretty sure I saw suitable for 4 to 8 ohm operation somewhere but now I find this so there might be a problem with the speakers as they read 3.5 ohms. Guess I'll have to pull some woofers and see what is going on.

[mresistor]

Here are specs straight from the owners manual.  look at impedance    I've never seen that kind of rating before

[shooter]

"compatible with", ideally 4ohms, we're 23 years into a century that doesn't know "audio systems" ever existed.
so marketing to the gazing glass folk is probably a good bet.

[mresistor]

Receivers with 4 ohm speaker load rating are far and few between. 

[shooter]

   receivers with any speakers are far n few between, now iTunes n earpads are a dime a dozen

[mresistor]

yesterday I was looking at B&K receivers  - they seem to be plentiful..

[shooter]

oh, they're plentiful, just virtually nobody under 40 has one or will buy one.  I get hit up once a month "Hey can you fix my......70's amp"  I turn them all down.  I send them to the web to buy for $100's less than repairing their broke one.


I'm a systems guy, but after the last 70's Yamaha I had died, i built a kit-amp, one chip, handful of parts, better S/N than anything from the 'ol days.
I have 5 speakers, 4 driven by the Mono-kit, 2 Klipsch bookshelves, 2 3-way Jensen's, with Tang 97spl 3", 2" and 1" pizo.  the 5th speaker being used n driven by my last tube amp converted to Audio.  It drives a 4.5" Mid-Bass 98 spl bookshelf, formally a full range Advent.  all in a 12 X14 room.  The speakers are all "tuned" to my chair 


bottom line, systems have been relegated to buggy whip status. now you just buy a box of "surround sound", Bluetooth it to the master wall sized monitor, no cable, no EQ tweek'n each song, just plop on the couch n let the system handle the mundane

[mresistor]

So last evening the JVC started shutting down a couple of times, then it did fine. I'm tending to think this receiver has a problem, heck it's only 40 years old.