Combined NOEMA+IRAM 30 m observations of H¹³CO⁺ 1-0 (background), and C¹⁸O 2-1 (contours, convolved to the resolution of the H¹³CO⁺) envelope emission toward three protostars: NGC 1333-IRAS4A (left), L1157 (center), and L1448-C (right). Contours start at 3σ and have 6σ spacing for IRAS4A and 3σ spacing for the other sources. The gray dashed lines are perpendicular to the small scale outflows. The gray ellipse in the bottom left corner of each panel show the synthesized beam of the H¹³CO⁺ 1-0.