One other thing about bridging is that you Seldom Hear that it sounds even as good as the Unbridged Amp. Usually the sound goes downhill in some audible fashion.
If you don't believe me, check out hi-fi sites for bridging reports. Few report any improvement. Most are not favorable.
The other thing? A good rule of thumb is that while the amp SHOULD quadruple the power, they NEVER do. I've seen 'em be rated at 2x the 4 ohm power.
My old RB1070 from Rotel is a good example. Something like 130x2@8ohms. And 330 MONO @4ohms.......'bridged'.
To me? That imples 165x2 @4ohms.
My panels ate the amp alive and I sold it 3 months later. My BIGGEST single hi-fi mistake. It just NEVER delivered the goods.
Magnepan MG1.6qr HSU Research VTF-2 MK3 2x Parasound A23 Parasound P5 Cambridge Audio DACMagic Plus Sony PS3 x4 @3foot runs of 10ga Belden speaker wire. GRADO SR80e on-ear headphones iMac as music server (2009) Panamax 5510 w/) ISO transformer LG 65" B6 OLED display