I regularly read comments similar to your above which constantly begs the question, how much is enough and how much is excess?
I too have my subs dialed down as everything is meticulously balanced and EQ'd with sound meter, Anti-Mode and Audyssey, MultEQ XT but I too want to unleash the beast in our subs (Klipsch, not SubMersives) and let them roar.
I keep struggling with the above as logic says it's too much and emotion says, who cares because it's about the smile factor.
That's because you're screwing up the calibration:
When Audyssey has been run, go into the AVR's main menu, to the Audio section, bring up the subwoofer slider and adjust the subwoofer channel, all subs running, at main listening position, to 73dB. Yes, that's an odd number which is purposefully intended to split the difference between 70dB and 75dB; the two reining standards. Now the subs are balanced and what you hear is up to how your subs interact with the geometry of the room; acoustics. If you want better, you'll need to add the likes of a product known as "DSPeaker, Anti-Mode, 8033" to deal with modes and room treatments to deal with nulls.
Hope the above is found helpful.
You are missing a couple of significant details. First, when you use the receiver's internal test tones to set the levels, you are *bypassing* the Audyssey EQ. That's right... the Audyssey filters are out of the circuit when the test tones are played. So, none of the room correction provided by Audyssey is accounted for in the level setting process doing it the way you propose above. Also, the Audyssey level setting calculations take into account all the measurement locations you've measured at, and it looks at a broad range of frequencies. That is a much more "representative" calculation than a single point measurement taken by an SPL meter using a band-limited test tone. Why do you feel it is necessary to "re-level" the level settings set by Audyssey anyway? Nonetheless, if you really want to verify Audyssey level settings, it would be much more useful to use external test tones, such as the tones on test discs such as Avia, DVE, or The 5.1 Audio Toolkit. At least that way you can set things up so the test tones go through the Audyssey filters. Then measure the levels at all the positions you used for your Audyssey measurements and average them.
Second, you've set the sub too low. Why would you use 73 dB? If you set the speakers to 75, (which is what you're supposed to do if you use the internal test tones of the receiver), then the sub (s) should also be set to 75 or the sub(s) are not calibrated the same as the speakers. (This assumes the SPL meter is accurate at the subwoofer frequencies.)
You would be much better off running Audyssey and just leaving things alone than performing your incorrect and ill-advised procedure.