If I lower the max bitrate from 1800 to 1600, will I be able to squeeze in more time or CQ that would be noticeable?

Plus, can you really hear the difference between doing the audio at 224, 192, 160 or 128?

Yes you will, but most likely on action movies. On dramas, where the bit rate barely reaches 1,600, the final file size will be about the same. Yes, you can hear the difference between 128 to 160 (little), 128 to 192 much more, and 128 to 224 even more
I do almost all my encodings with HeadAC3he at 112Kbps (+Surround 2) and it just sounds awesome on a Prologic II receiver

-kwag

Hey kwag, just curious....when you use 112Kbps in Surround 2 mode, do you normally downsample to 44.1kHz, or do you leave your audio @48kHz? If I'm not mistaken, I seem to recall Sansgrip mentioning somewhere that leaving the audio @48kHz rather than 41kHz while using 112Kbps in Surround 2 mode would likely be starving the bitrate too much and would probably lead to some nasty noise artifacts or something like that. Thanks.
-d&c

I have to downsample to 44.1Khz because only one of my players supports 48Khz playback from VCDs. But at 44.1Khz, all my players work fine.

-kwag

I have two strands of opinion on this:

At 44.1k I feel I'm saving bit space for video but then using 48k sampling throughout and 192kbps I'm preserving an exact multiple of the original signal.

On the subject of non-standard vertical resolution, I was under the impression that all players decoded the output to 240 (x2) NTSC or 288 (x2) PAL regardless of the original encoding?

Likewise, I thought players were pretty much indifferent to horizontal pixel rate? The trouble is that the officila figure of 352 doesn't relate to any particular format. So-called 'square' resolution is obtained at 320x240 at 4:3 ratio and (approx) 432x240 for 16:9 ratio in NTSC. Neither horizontal figure is really high enough to mask aliasing - the vertical grid-iron effect.

PAL users have it easier. 384x288 (for 4:3) or 512x288 (the standard used for 16x9 digital broadcasts are a lot easier on the eye (if not the bit rate). I've tried converting NTSC material to PAL using TMPGEnc but the results were rather jerky so I'll stick with the grid-iron for the time being.