Don't compare the SPL charts too closely, they were taken at different times with different calibrations, and they're not even on the same scale. The idea there was to compare the relative sensitivity of the HF sections, and also the phase response.chris_c_ wrote: The piezo frequency response looks amazingly flat and extends up to 20k easily - but the phase response is terrible. The ribbon is flat only 3k-10k , but with close to perfect phase response.
The subjective difference is that the ribbons just sound better, and becasue the phase response is smoother, they are far more feedback resistant, which means less EQ is needed. The piezo response looks flat, but in reality it required a lot of EQ to get right, and lots of feedback notching. Further, I had one cab with three bad piezo drivers, and the response on that one was all out of whack.... the constructive and destructive interference between units in the array is what is creating the flat measured response... but the price is consistency. One bad unit can create problems. These types of problems are minimized with ribbons... they're series wired so if one unit in a cab fails, the whole cab's HF section will go, and replacement is very easy, compared to removing an array and replacing a piezo diaphragm.
No, but I've never had any problems with the ribbons keeping up with the woofer section. HF just isn't as demanding. I'm also thoroughly convinced that they can take more power than they're rated for, and they are far more forgiving of distortion than the melded array.Peak SPL for 2 ribbons is about 117 dB. Any idea what the peak SPL for the melded piezo array is ??