Quote Originally Posted by kexodusc
I'm with you on this - all depends how they're wired, of course, but I assume it was parallel? When you wire an identical driver in parallel you get the +6dB boost, in series you get 0 dB effectively.
The best way for doubling Advents is to run them parallel where most SS amps also put out more power at the nominal 4 ohm load (which falls to 2.3 in two ranges - so not all amps are happy here) and to use separate speaker cable runs. You definitely get +6db when run that way. All Advents take a bit of space between them and the listener for the drivers to blend optimally, but stacking them in a quasi D'Apolito arrangement noticeably improves their apparent image size.

I run a Threshold Stasis 3 amp (400 watts/4 ohms) with my double New Advents and find that I rarely run higher than -20 db (about 4 watts) which is LOUD. Because of their Scream Machine Roller Coaster impedance curve, they really need a bit more DF than the 6400's 40 to sound their best IMHO.

rw