Alan, i would venture to say if he is driving the amp into the clipping region with his current vp-150, the same will happen with a new 150 with the same result... 3 blown drivers... The best most realistic solution is a vp-180. All joking aside, the 180 will play much louder with less power required. The HK amps can handle a 4ohm load quite well from what i have read. To pressurize a huge room of the size you are talking about hawk, the 150/22's seem quite small.. you might be able to just upgrade the center and leave the 22's alone. The number one thing that kills drivers is "bad power" or an amp being driven beyond is capabilities.
Hawk, could you venture to guess what the total volume of the great room+ associated adjacent rooms would be, a total volume number would help determine if what you have is realistic or not, a 150 with all of it's drivers working may in fact be just fine.
Since a speaker is basically a coil of wire, it is pretty hard to make a piece of wire fail. As Alan said " drivers don't wear out". In the 70's/80's when woofers were were paper and foam, the foam/glue would deteriorate over time. However, with the new materials used today this is not the problem it was 30 to 40 years ago...
