Sound Quality of Direct TV audio

I recently put a 1/3 octave spectrum analyzer on my Direct TV audio outputs and was shocked to find that they are brick wall filtering all low frequencies below about 150 Hz. Not a gentle roll off mind you, everything from 150 Hz down is gone.

I thought they were supposed to be delivery "high quality" audio. Anyone else discover this or am I getting something unusual?
"11-03-15: Philjolet
Zd542 I presumed he had an older unit"

It doesn't matter. They still put analog outputs on current model receivers. I don't know if they do it with every one, but you can still get them.
OK. My DTV receiver/DVR is a "whole home" type recently replaced (due to the previous unit having hard drive issues). It does come with a full compliment of analog outputs (single ended) as well as composite video and HDMI. I am using a conventional two channel audio system for the audio, and did originally run RCAs to my preamp.

I put the 1/3 octave analyzer in the loop so I could EQ some of the news/voice programming (the analyzer is a Phonic i7600 that is also a 1/3 octave EQ).

Interesting what some are suggesting that only the analog is BW limited, and not the HDMI. Unfortunately, I have no way of analyzing the HDMI audio, as I use only the video portion at my Sony LEDTV.

I would wonder why the only the analog is limited because my suspicion is the signal from the sat is limited due to bandwidth considerations. I think this is recent, but cannot be sure when this started.
As a follow up to test the HDMI/digital theory, I fed a toslink optical output from the DTV receiver to my Bryston BDA-1 DA converter on another system. I also have a Phonic i7600 on the power amps of this system.

Guess what. Full range audio. So it must be in the analog outputs on this box.

Thanks very much guys, for helping me solve this mystery.