No sound from subwoofer?

I have neither that sub nor that receiver, so others will probably have better ideas.

Try a different RCA cable, maybe a white or red one meant for line audio. It should work even if its not the exact impedance you want.

When the sub is supposed to be sounding, rest your fingers against the sub's grill to detect vibrations that may be inaudible.

Play with the sub's volume knob -- maybe it needs to be turned up.

See if the receiver has a manual procedure for setting the volume or distance of the sub that sounds noises through the sub.

Check the sub is getting power -- does it have a power light?

Check that the receiver understands that you do have a sub. There should be a menu of some sort that displays what speakers you have connected. As you went through the calibration procedure, if the receiver couldn't hear your sub, it should have complained.

That suggests that everything is working. Maybe the music you're playing has less low bass than you're assuming. Maybe try some jazz with strong plucked bass rhythm?

Music (as in CDs) doesn't have a .1 LEF channel. What format of movies did you try?

With speakers set to large, no bass management is taking place.

On the back of the sub, how is the volume set? Also, how is the low pass filter set?

You are connected from the Denon into the "LFE" input of the sub, correct?

What make/model speakers do you have for right, left and center?

What is the crossover setting for the sub in the Denon?

Try turning up the volume for the sub in the AVR.
There is no setting for "0" on the sub (except phase). There's only 50, 80, 120, 160 or LFE.

In my experience, Audyssey sets the sub level too low. Based on scientific research, most people tend to prefer a higher bass response than Audyssey will give you. Try bumping up the sub level in the AVR's speaker level settings a few db (3-6db) to see if you prefer it.

Couple other questions:

How large is your room and where do you have the sub placed? You could be sitting in a null - does the bass sound stronger in other parts of the room?

Change the filter/crossover setting on the sub to 80Hz. Make sure the crossover for L/R/C in the AVR is set to 80Hz also.

Negative dB is lower volume, Positive dB is louder.

"Fairly large" tells me nothing...we need measurements. The performance of your sub is directly related to the the cubic footage of your room - the larger the space, the more sub you'll need to pressurize the entire room. The shag carpet will have little to no effect on subwoofer frequencies.

If you want you're sub to play louder than calibrated, you would set the level in the AVR to a higher number.

I think you may have mis-read my previous question - when I asked if the bass sounded stronger elsewhere in the room, I meant that when you move around the room are there any places that have nice, strong bass? Or, does the whole room sound as you are describing?

Have you done the SUB CRAWL?

I respectfully disagree with this - you should either defeat the subs crossover or set it as high as it will go so the AVR can handle the crossover duties. If you set both to the same (or close to the same number) you will get some weird audio artifacts from the two crossovers fighting each other.

Just to be sure: you currently have all speakers set to "small", the crossover on the sub either defeated or maxed out, and the crossover for all speakers in the AVR set to 80hz, correct? If you do, and your still not getting any bass from the sub we'll have to try some other stuff.

From what I can gather, the OP has no (or very little) sub output. Just trying to make suggestions to determine where the issue may be (not suggesting the "optimal" solution). It could be the sub's settings, the AVR's settings, a combination of both or perhaps........ a bad subwoofer.

It seems no matter the source material (music or movie), no matter the changes made and no matter how close he sits to the sub, the output volume is not changing.

IMO, that sub should be capable of producing noticable output even if the placement is not optimal at the current location.

Perhaps the OP can:
1) post his questions in a Denon thread for receiver settings
2) post his questions in a subwoofer forum
3) contact SVS and seek help from their technical support