As a curiosity, here are some projections comparing the current H1 noise with SRM T = 20% (nominal aLIGO design) and no SRM (power recycling only). The SRM T=20% and no SRM curves are obtained simply by replacing the modeled H1 quantum noise in the present configuration (SRM T equivalent = 39%) with the quantum noise calculated for these alternative configurations, assuming the rest of the noise the same.

We would have detected GW150914 no matter what; the SNR could have been 30% worse. 


GWINC output for corresponding theoretical curves:

Current H1

BNS Inspiral Range:      159.65 Mpc
BBH Inspiral Range:        3.04 Gpc (z = 1.0)

SRM T = 20%

BNS Inspiral Range:      131.75 Mpc
BBH Inspiral Range:        2.35 Gpc (z = 0.8)

NO SRM

BNS Inspiral Range:      155.89 Mpc
BBH Inspiral Range:        2.95 Gpc (z = 1.0)