denon 2112 audy...question

You'll want to connect the "Y" splitter to the sub preout and then to each of the subs prior to running AUTO SETUP with the volume on both subs set to 12 o'clock.

Also, please review the Audyssey 101 guide linked in my sig as well as the Denon AVR-XX12 Owner's thread linked in my sig as well.

12 o'clock is probably too high. try setting them at 10 o'clock instead. On both my systems paired with Denon receivers I ended up having the sub set at 10 o'clock.

Obviously this depends on your room size too but I'd think with dual subs the volume would probably need to be lower.

Experiment a little and you'll find the best setting.

With two subs, the sub trim will normally be at least 3-5db hotter, so although 12 o'clock is likely too high, it's the recommended setting to start AUTO SETUP using as it can always be adjusted down as necessary.

I recommend connecting (just) one and adjusting its level until it's -3 (or so). Then disconnect that sub and connect the other. Run Audyssey again and adjust until the second sub's level matches the first. Finally connect both and go from there... you want minus numbers as when both are firing you'll be increasing the level.

This is the way to do it if you don't have an SPL meter. You can still do it this way if you have an SPL meter and check the results but for me it was not as accurate as using a spl meter. I plugged in 1 sub and measured its volume with the spl meter. Then I plugged in the second sub by itself and adjusted it till it was at the same volume as the first. When I say adjusted the sub I am talking about the volume control on the back of the sub. Once both subs are level matched I ran audyssey with both subs plugged in. Just make sure you set the subs pretty low because I ended up with audyssey setting the sub channel to -9. There is not much I can do because one sub is set to 2 out of 10 and the other is set to 2.5 out of 10 so they really can’t go much lower.

^^
Whether you place them on either side of the TV or one front/one back .... ideally you'll want to place them equidistant from the main listening position (ie. mic #1).

I believe I used to use the SPL meter but since the receiver is going to be EQing the subs I figured why not trust them in the first place. In my dedicated room I have used a dozen or so receivers over the years and I can tell you the level (differences) every receiver will come up with virtually every time. It doesn't seem like much of a challenge.. and probably much more accurate than me being involved. Does the EQ process use different test tones versus manually... any clue which would be more accurate for all frequencies...

The Audyssey Eq system uses the chirps where manually you would use the pink noise from the channel level menu. I also tried using a bass disc but it gets a lot more complicated that way. I even tried using individual frequencies but there was too much of a variation. The two subs could be matched at 40 hz and be off at 60 hz so I just went back to using the pink noise. I don't know which one would really be more accurate but the bass didn’t seem right after just using audyssey which is why I checked it manually. I think XT32 with subeq ht would do a better job with 2 subs than XT did running one at a time. It also could have been an error on my part but I was pretty sure I matched both to the same level. Either way works but for me the matching with the spl meter and then running audyssey gave me better sound than just using Audyssey.