Nelson Bass Messages: 39 Registered: November 2012
Baron
Hi Johnny,
The spider isn't replaceable and it's function is primarly to center the voice coil.
I rely on my amplifiers to control drivers and their excursion.
Yes, I switched from 4Pi's to 7Pi's. With the 7Pi's I have better bass integration in my listnening room and better midrange.
If you're used to be sitting close to the 4Pi's and are enjoying their chest pumping effect you should not upgrade to 7Pi's as you will loose that effect.
I don't use my 3Pi subs with the 7Pi's. I've plenty of bass without and prefer the cleaner setup.