LFE channel 10db higher?

[Sitron_NO]

I am new to REW and measuring, but I followed the "Getting Started with REW"-guide. I did the test measurements, and all looked good and according to the guide.

But I have one question:
When measuring using "Speaker 4" in REW, which is the LFE channel, I get a graph showing the frequency response of the sub (10-160Hz), as expected.
But when I measure using "Speaker 1" in REW, which is my Front Left, I assumed I would get a similary graph, except that the Front Left would "take over" at the crossover-frequency, and "continue" in the same dB-range. But, for frequences below the crossover (60Hz), the graph shows 10-20dB lower for Front Left than for the Sub.
Is this normal, or have I done something wrong? See attached graph and .mdat-file.

My setup: I have a Denon AVR-X4100W which I did a factory reset on before these measurments. I preformed a Audyssey measurement as part of the (new) setup. Between my AVR and Sub, I have a Antimode Cinema which was calibrated and enabled when I ran the Audyssey setup. The measurments (attached) was taken using my laptop with a HDMI cable to my Denon AVR, and using a UMIK-1 mic (with calibration file loaded). My noisefloor was 40dB, so when using the SPL-meter and pink noise, I had to set my AVR to -5dB to get 85dB on the SPL.

 

[John Mulcahy]

The LFE channels gets an extra 10 dB gain in the AVR.

 

[friedmud]

But are they supposed to? Like - is that something that's done because most subs suck? Or is it REALLY supposed to be there - like DD mixes are -10db on the LFE channel and the AVR +10db is to bring it back up?

I ask because my receiver allows me to remove that - and then REW looks great... BUT movies certainly are lacking that "big boom"...

 

[John Mulcahy]

Yes, they are supposed to, DD is mastered that way. It provides more dynamic range for the LFE channel.

 

[IWC Doppel]

Yes, they are supposed to, DD is mastered that way. It provides more dynamic range for the LFE channel.

Is this to allow the AVR to add any bass sent from the other channels and not clip in the AVR at higher volumes ? so the processor will reduce the output when mixing/adding the low frequencies from the other channels ? I guess the 10b gain is added through the sub amp ?