Characteristic amplitude h_c of the first harmonics of the quadruple gravitational radiation emitted during the inspiral of the IMRI. The numbers show the first four of the harmonics. The orbital evolution is calculated in the Peters (1964) approximation and the amplitudes as in Peters & Mathews (1963). We assume the source is at a distance D = 1 Gpc. We indicate with a solid curve the noise curve for the ALIA detector with an armlength of 3 × 10⁹ m, a telescope diameter of 0.58 m, and a 1-way position noise of pm, i.e. the 3H configuration of Gong et al. (2011). We also add the noise curve for a LISA-like detector (in grey, Larson et al. 2000), with the Galactic binary white dwarf confusion background (Bender & Hils 1997). Note that the SNR is not given by the height above the curve, but by the area below it. For each panel we show the ratio , the initial periapsis distance over the Schwarzschild radius of the system. We indicate the moments in the evolution for which the time to coalescence is 5, 1 yr, 1 h, 10 min, and 1 s.