Does anyone have tips for optimizing the hardware decimation

[MaxHolloway]

Does anyone have tips for optimizing the hardware decimation filters and sample rate parameters when processing wideband signals on a dual-channel SDR platform to avoid severe alias folding in the lower frequency bands? I am trying to build a clean GNU Radio flowgraph for long-term spectrum monitoring, but whenever the digital downconverter drops the decimation rate below a certain threshold, the baseline noise floor rises dramatically and masks the weaker narrow signals.