I've connected my 25's to a Sony ES receiver that will do a 4 OHM load then connected the speakers to a new NILES 2125 amp that will do 2.66ohms and in each case, the speakers shut down and trip the receiver or amp at about 3/4 up on the volume level. Other set of INFINITYs don't have this problem. Any Ideas. Thanx.

I've connected my 25's to a Sony ES receiver that will do a 4 OHM load then connected the speakers to a new NILES 2125 amp that will do 2.66ohms and in each case, the speakers shut down and trip the receiver or amp at about 3/4 up on the volume level. Other set of INFINITYs don't have this problem. Any Ideas. Thanx.

You have a pair of speakers that really NEED a beefy amp. What is the power rating on that niles amp? It looks like you like to listen to your LSi25 at loud levels so I wouldn't recommend anything less than 200W with a beefy power supply to handle the continuous 4ohm and lower load. It looks like the power supply on your amp and receiver are crapping out before the speakers even get enough wattage.

You have a pair of speakers that really NEED a beefy amp. What is the power rating on that niles amp? It looks like you like to listen to your LSi25 at loud levels so I wouldn't recommend anything less than 200W with a beefy power supply to handle the continuous 4ohm and lower load. It looks like the power supply on your amp and receiver are crapping out before the speakers even get enough wattage.

+1. Your Niles amp is probably running out of juice to power the LSi25s.

The LSi25s also probably represent a complex load... not just constant 4ohm across the frequency spectrum, but likely with dips down into the 2-3ohm range at certain frequencies. The entire LSi series is tough to drive, so solid amplification that can handle a complex load dipping into the 2-3ohm range is a must.