I pretty much see ARC2 as a 'set and forget' kind of plugin and rarely open it up to look at the meters, but I just did this and noticed from toggling the meters from Post to Pre that it seems to be adding between 3-4dB of gain. So I'm looking at my "before and after" curves in the display and I can see that, although it does add a little in the mid-range, most of the correction happens in the bass - it looks to be correcting two modes at around 60Hz and 150Hz (quite dramatically). I would have thought that, if anything, a removal of so much energy in this part of the spectrum would result in either less gain in the output, or at least balance out the relatively small mid range boost that it's doing. 
 
Or is this just not worth worrying about at all? I guess I'm curious though. 

I find this too when using my Edirol MA-5A's, but almost not at all on my Behringer Truth 2030A's.
 
I guess since it's making up for deficiencies in the speakers/room, it will no doubt have an effect on the sound level (or at least perception of the sound level).
 
If you switch to the Monitor tab, you can set the overall gain so it matches your perception of the output without ARC running, which solves the issue for me.
 
I had to do that a lot on my old PC, as ARC added about 1 sec latency making it impossible to record with it on.
 
M.

Actually it's not that I'm perceiving higher gain, it's that the meters in ARC2 are telling me there has been a gain boost. 

use the trim.
 

Yeah dealing with the extra gain isn't a problem. I just wondered why it was happening.

It’s an EQ, it cuts and boosts.
When you boost you increase signal level. I set the “monitor’ to -9.
I notice no increase in latency.
T

DeeringAmps
It’s an EQ, it cuts and boosts.
When you boost you increase signal level. I set the “monitor’ to -9.
I notice no increase in latency.
T

Yes I know EQ's cut and boost and that they can add or remove energy (read my OP). What's confusing me is that from my ARC2 curve it would see that it's removing more than it's adding, yet the end result has a quite dramatic increase in gain. 

sharke
Yes I know EQ's cut and boost and that they can add or remove energy (read my OP). What's confusing me is that from my ARC2 curve it would see that it's removing more than it's adding, yet the end result has a quite dramatic increase in gain. 

I had a similar mystery quite some time ago.  The right speaker curve display showed a boost in volume but when ARC was enabled it was the left speaker that got a bit louder (or maybe vice versa, but that's not important).  Someone pointed out that the displayed curve did not tell the whole story.  Phase shifting is also involved in a consequential way and there's no visible clue as to what's going on with that.
 
While the displayed curves may be good for user moral (or just customer confidence that money was not squandered on snake-oil solution), the displayed information may actually be doing a disservice to the user who should just be listening and not looking at any visuals.

DeeringAmps
It’s an EQ, it cuts and boosts.
When you boost you increase signal level. I set the “monitor’ to -9.
I notice no increase in latency.
T

I've get no latency since I upgraded my machine a couple of years ago, but on my old dual core 2Ghz Athlon I had to constantly switch it off before recording, then back on afterwards to hear it "properly". My Intel i5 @ 3.5Ghz is SO much better.
 

dmbaer
I had a similar mystery quite some time ago.  The right speaker curve display showed a boost in volume but when ARC was enabled it was the left speaker that got a bit louder (or maybe vice versa, but that's not important).  Someone pointed out that the displayed curve did not tell the whole story.  Phase shifting is also involved in a consequential way and there's no visible clue as to what's going on with that.

 
My Edirol MA5-A's have some wierd signal boost in one speaker. I first I thought I must be going slightly deaf in one ear, as it noticably moves the center over to the right. I've re-positioned the speakers so they're both at exactly the same angle and I'm sitting on the edge of what is in effect an equilateral triangle... still the same result.
 
The thing is they sound absolutely fine balance-wise without ARC 2, but obviously with ARC 2 enabled the sound is more level.
 
In my studio I get perfect results with no noticable change in the stereo image, so it must be ARC 2 messing around with the phase on my "bedroom" setup.
 
M.
 

The correction curve display is a “pretty picture”.
It’s not “Span”.
@ M
Rerun your test measurements in the bedroom.
T