Mojo- so you have your mains set to small i guess?

Yes, I do. All of my speakers are set to small. Only God knows how many hundreds of hours I've spent tweaking.

If you have a DSP-based Axiom sub, set it to 40Hz and then set your pre-pro to 40Hz as well and see how you like it. One of the most memorable differences was the apartment shooting scene in LFODH. At 80Hz, the rat-tat-tats were thick, slow and rattled the whole house. At 40Hz, they were sharp, fast and we all felt them in the left butt cheek right through the leather couch.

And music's a completely different experience at 40Hz. The sub takes over right where the 80s leave off. Just make sure that you adjust the sub level to match the 80s at 40Hz (using a test tone CD). And if that doesn't sound quite right, don't be afraid to nudge the LFE channel gain up or down.

I just received DVE but haven't really looked through it yet. Do you know if that has the test tones you are talking about?

Interesting. Most people would suggest not having cascading filters like you have ie. both in the processor and at the sub. The recommendation is to use one or the other. The argument is that it causes too steep a slope at the crossover point to blend well and introduces intermodulation distortion, but at 40hz it likely doesn't matter and any artifacts would be inaudible. If its better in your room that way, that is all that matters.

I think one of the recent axiom articles discussed some benefits to applying crossovers both on the receiver and the sub.... There was some explanation for it but I don't recall what it was.

I don't know if DVE has test tones. I've been using the RealTraps tests tones that Randy suggested.

For the longest time I reasoned to myself that cascading filters are "bad" so why try? And then I decided to go for it and was surprised at how much better it sounded. I'm sure this has a a lot to do with my bright room. Bass just hangs around in that room even when it's time is supposed to be up.

DVE has test tones.

And, if anyone could come up with a link to that post/article/thread where the benefits/problems of using both crossovers at the same time was discussed, I'm sure John would be interested is perusing it. I can't even remember what was finally concluded, let alone when or where it was brought up.

When you apply a filter phase becomes an issue because it introduces phase delay (a type of distortion). But its hard to figure out what's happening without knowing what kind of filter is in the receiver. Or maybe there is something unique about the subs DSP which makes it worthwhile. Very interesting indeed.

If I recall correctly, some filters like the Butterworth ones emphasise even frequency response but introduce big phase shifts while others do the opposite. I guess I've been brainwashed into thinking just use one but it sounds like you may have found that using both solves some unique acoustical issues in your room. Always pays to experiment.

Yes I would like to read that article Jack. Thanks.

OK, so I thought I had all the speaker/sub settings straight on my Denon but after reading all this something was bugging me. Being a visual guy, a did a really quick diagram and I now have questions. Please keep in mind, I already know my diagram must be wrong, so my question is all about correcting it. I'm not presenting it as correct. I will correct and repost if I can get it straight and it proves useful to other visual style thinkers.

OK, with the assumption that we keep our sub set to "on"
Question 1
When speakers are sent to Large. I'm assuming the crossover for that speaker(s) is totally ignored and nothing is shared with the sub, as in example #2 and #3. Correct?

Question 2
What am I missing in the scenarios #1 and #4 ? I am missing something as they are producing the same results.

EDITED: fixed an error and shrank more. You still may need scroll down to horizontal scroll bars.

Good visual.

According to the article from HomeTheatherHIFI, the LFE is not always entire channel. Since the entire channel for each speaker is set to small and summed with the LFE, the crossover for the mains is also applied to the LFE.

So, in 1 and 4, the LFE is only 60 down. This is what confuses me so much.

Also, and you probably know this, but crossovers are not a step at 60, 80, or 100, but a gradual slope. You probably just showed it as a slope for ease of use.