The nature and origin of the two Large Low Velocity Provinces in the lowest part of the mantle remain controversial. They have been interpreted as a purely thermal feature, accumulation of subducted oceanic lithosphere or a primordial zone of iron enrichment. Information regarding the density of the LLVPs would help to constrain a possible explanation. In this work, we perform a density inversion for the entire mantle, by constraining the geometry of potential density anomalies using tomographic vote maps. Vote maps describe the geometry of potential density anomalies according to their agreement of multiple seismic tomographies, hence not depending on a single representation. Therefore, the geometries used for inversion are features observed in most tomographies. We use linear inversion and determine the regularization parameters using cross-validation. Two different input fields are used to study the sensitivity of the mantle density results to the treatment of the lithosphere. We find the best data fit is achieved if we assume that the lithosphere is in isostatic balance. The estimated densities obtained for the LLVPs are systematically positive density anomalies for the LLVPs in the lower 800-1000km of the mantle, which would indicate a chemical component for the origin of the LLVPs. Both iron-enrichment and a MORB contribution are in accordance with our data, but the required super-adiabatic temperature anomalies for MORB would be close to 1000K. [ABSTRACT FROM AUTHOR]