According to some members of Doom9's forum, the DCA streams generated by ffdcaenc are decoded incorrectly
(i.e., with audible distortion) by the hardware DTS decoders. Until proven otherwise,
the problem is the result of a design flaw in the firmware, since the same elementary streams
are decoded without audible distortion by the software DTS decoders on a PC. For what it's worth,
let's keep in mind the following points:

1) quoting the author of the original source-code of dcaenc:

«this encoder uses only the most basic compression techniques defined in the DTS specification,
and thus cannot win any comparison with commercial DTS encoders.» 

2) quoting myself at Doom9's forum [http://forum.doom9.org/showthread.php?p=1754796#post1754796]:

«it's not impossible that the hardware-based DTS decoders are "crippled" somehow,
much in the same way the official /certified DTS encoders do not go beyond a
tiny subset of the full DTS-audio specifications.»

3) all the .dts files generated by dcaenc and ffdcaenc have been validated by the program DTS-HD Stream Tools,
regardless of bitrate and sampling frequency.