military academy, Brandenburg Gate don't work???

When I build a barracks I get +15xp for new units, then when I build an armory I get a total of +30xp. When I add a military academy and/or Brandenburg Gate, nothing seems to happen...new units still get +30xp. Is this a bug or am I misunderstanding something?

Thanks in advance for any help.

The difference should be obvious only in the city with both military academy and BG.
15xp -> Level 1
30xp -> Level 2
45xp -> still level 2
60xp -> Level 3

Thanks...if I understand, I think you're indicating that a new unit doesn't get 3 upgrades until 'level 3'?

Yes, I am equating upgrades to levels, I think that is correct. The first couple upgrades only take 15xp each. The 3rd and subsequent upgrades take 60xp each. At least, I think it is all there is to it. There may be another step increase. Also, look at the blue experience bar. You should see that as more full on new units built with military academy but no BG (as compared to Armory-only units).

Yes, the first three promotion levels are 15 XP, 30 XP and 60 XP, so a newly trained unit will only spawn with 60 XP if you have barracks (15), armory (15), military academy (15) and Brandenburg (15) in that city. Some other wonders give a specific free promotion (e.g., Alhambra gives Drill I), and some unique units (e.g., Longbowmen) start with a free promotion (range, in that case), but there is no XP associated with those promotions.

You can always check the current XP level of a unit by mouse hovering over the blue XP progress bar on the unit.

Browd, there is a tool-tip for unit levels. Do the free promotions count as “levels”? I have never been able to figure that out for sure, but I don't think so. If that is the case, one end up with low level units with a fair amount of promotions.

Also, are promotions earned every 30xp (after the 3rd) indefinitely? Or are there other tiers?

The free promotions don't count as levels for promotion purposes (just like Oracle's free social policy doesn't count for purposes of computing future social policy costs).

The XP promotion tiers do increase as you go up, and my recollection is that they increase by 10 XP per tier -- i.e., level 4 is at 100 XP (+40 XP) and level 5 is at 150 XP (+50 XP), but I'm at work and can't confirm in-game right now. I'll try to check tonight -- unless someone beats me to it (hint, hint).

EDIT: From GlobalDefines.xml:

<!--Experience & Promotion Defines-->
<Row Name="EXPERIENCE_PER_LEVEL">
<Value>10</Value>
</Row>