The use of sine sweeps is a robust method to measure room impulse responses. One particular advantage is that the frequency spectrum of the excitation signal can be controlled in the time domain—by changing the rate of frequency change—while keeping the amplitude of the signal virtually constant over time. The sine sweep approach is adopted in the measurement tool of the ODEON software. In this paper, a method to optimize the measurements is introduced. The spectrum of the sweep signal is modified, making use of a previously measured impulse response and its resulting Schroeder decay curve. The maximum dynamic range of the Schroeder curve is defined as the decay range. This decay range is calculated in octave bands, and its deviation from a broadband average is subtracted from the sweep spectrum magnitude. The goal of this approach is to redistribute the power across frequency bands in order to ensure a more uniform signal-to-noise ratio (SNR). The method is evaluated through experimental measurements. The proposed optimization leads to a more constant decay range across octave bands, with an improved SNR in bands with poor decay. Practical aspects, including repeatability and sweep duration, are discussed.