The Doppelflöte is a wooden stop with two mouths, located on opposite sides of the pipe. It is nearly always found at 8' pitch. Authorities disagree on whether it is open or stopped, and Grove reports that it sometimes has bored stoppers (Doppelrohrflöte). The stopped construction seems to be the more common, particularly in the 1800's. It was mentioned by Praetorius as early as 1619, and according to Williams was frequently found in Silesia (southwest Poland and northern Czechoslovakia) from the 1600's through the 1800's. It was never popular in England, but in America was a favorite of Roosevelt. Its tone has been described as full, strong, pure, round, and liquid. Some sources criticize it as being hooting. It is chiefly a solo stop; Audsley considers it a good blender, but Skinner disagrees. Because of its two mouths, the Doppelflöte requires more than the usual amount of space on the wind chest.
The double-mouth construction is usually abandoned in the 8' octave in favor of a normal single-mouth construction.