In the pa700 manual there is no mention of the Global Eq and Limiter.
I've used some global eq setting that someone submitted and makes the overall sound better. I've seen some YouTube videos on limiters but am a little unsure of what parameters do what to the overal sound on the limiter.

Page 497 in your manual.

Reposting from Korg Forums

The Limiter in the PA700 is pretty useful. I use it on everything but have different settings based on what mode I am in on the PA700. I mostly use it to protect the internal speakers, since I do not always bring a PA system to the homes I play at.

For regular playing at the nursing homes, using the styles in the unit (like anything big band, etc..), I have a setting for that. I have found that some of the acoustic bass sounds tend to push the speakers a bit more than other bass sounds, especially in the key of 'G' where the acoustic bass produces a bass sound on the G2 note...that particular chord/bass note combination seems to flex the speakers a bit more physically than any other combination of chords or sounds on the PA700 for me.

I use the Limiter to minimize this because the Limiter is basically 'squashing' the signal at a certain threshold (or reducing) so that these peaks on that chord are minimized. I have sent my settings on that before, I believe. It should work.

The only problem is that when the overall output reaches that threshold, it squashes everything, not just the bass note. While it is not a problem for me, it is certainly something to think about when setting up the Limiter settings.

A Limiter and Compressor kind of do the same thing, but they go about it a little differently.

When I am in sequencer mode, I have another setting eabled so that more sound comes through the speakers without as much Limiting going on. I have found that when I use my Limiter settings designed for the Style Play in Sequencer mode, it sounds REALLY compressed (or limited) and it almost sounds unnatural. Think of compression/limiting used in radio stations versus listening to the actual CD containing the song that you are listening to on the radio; there is a marked difference.

When I am using the PA700 with an external PA and not using the volume settings/internal speakers above for monitor use (because I have external monitors or IEM's instead of using the internal speakers), I usually turn the Limiter off. This allows for the full range of sound from the PA700 to go to the PA system - unhindered.

In the manual, specifically starting on Page 488, it talks about the Master EQ/Limiter settings.

Basically:

The In/Out indicators are telling you what the signal looks like as it goes into the Limiter and as it comes out of the Limiter. If you are indeed limiting, then oftentimes (not using the Gain Adjust at all) the output signal will appear to be lower - this is because the Limiter is 'limiting' - like it is supposed to.

The Ratio is the amount of 'limiting' that you are doing. Increase the ratio, and the amount of limiting is increased. Limiting at 1:1 is not going to produce anything, because there is nothing being limited at a 1:1 ratio.

The Threshold is the setting that the limiting would take place. If you set the threshold at -10db, then any signal that tries to go above that will be limited. Anything under that threshold would not be affected.

The Attack is the speed of which the Limiter activates. If the Attack is set with a lower number, then the Limiter will activate more quickly. If the number is set higher, then it will activate more slowly.

The Release is the speed in which the Limiter will release the signal. The lower the number, the faster the Release would happen.

The Gain Adjust is basically like a 'make up' gain because limiting the signal will often reduce the output volume. This allows you to make the volume louder after it has been limited. What you are doing is turning up the 'Limited' volume so that it is louder, even though the 'limiting' has been in place. This Gain Adjust setting is similar to the output knob on a compressor.

My recommendation is to play with the settings and find one that works the best for you. I basically use the Limiter to protect the internal speakers.