The Flex FX option is there to be able to send the audio to an external effect processor that would plugged in and out of the Flex FX in/outs on the back of the mixer or you can use it to use Scratch Live's internal effects post fader.
If your not using an external effects processor and want to use the software effects post fader you will need to first go into the Plugins Tab in the Setup screen of Scratch Live, click on the DJ FX, and 'enable' the DJ FX send'.

From there, simply turn on the USB insert button, turn on an effect in the software, and send the audio from either channel 1, 2, or Aux to the effect by pressing the blue Flex FX buttons.

There is nothing you need to map on the mixer.
You can midi map some of the controls, such as the mic section, to anything in SSL you want. For more info on midi mapping read this article --> serato.com

zach nailed it perfectly! while I've been waiting for my 62z, the gf got her 61 a few weeks back and i have been playing around with it... love it!

Thanks for the help Zach! I got to playing around with it a lil bit last night and I finally figured out how to get the internal fx working together with the sixty one's Flex Fx buttons. The main effect I'm trying to utilize is the echo out. So far all my attempts at making it work have failed. any ideas or is it possible without a external effects controller?

Also wondering why it is rane made the flex fx a slider and not a regular knob? the stiffness of the slider is kind of limiting the capabilities I feel :( or maybe I'm missing the reason for this???

The wet/dry knob for the echo out, within SSL, should be turned up all the way.
From there, you need to turn the effect on, while audio is playing into the channel on the 61, the USB insert button is turned on, and the Flex FX button is turned on for the channel your wanting to use the echo out on.
As soon as you turn ON the effect in the software you should hear the echo out.
I would suggest midi mapping the on/off of the effect to a midi controller and turning it on/off from there vs. having to use the mouse to press the on/off button in the software.

Know that, since the 61 can use the internal effect post fader, you could use a regular echo in SSL and bring the fader down on your mixer to get the same echo'ed out effect.

The only reason why Serato added the echo out effect was to mimic how a post fader echo would work.
With the 61 you can use the echo post fader which renders the echo out in SSL somewhat useless.

The Flex FX slider is not something your going to be using much which is why its a slider and not a knob.
When using the internal software effects I would suggest putting the wet/dry slider all the way to Wet.

I did exactly what you said. mapped the dicer to the echo and it performed flawlessly! this mixer is awesome... so much capability... Thank you for all your help Zach and the quick responses as well!

We're happy your as stoked on the mixer as we are:)
Have fun!

I notice when I have FlexFX on, the sound quality is higher and seems a litter better. Is there a reason for this and is it okay to leave it on although I'm not using any external processor?

I'm guessing you're using a 61?
The sound quality won't be any better but the audio will get louder if the wet/dry slider is turned up.
If you're not using an external effects processor I would suggest setting the wet/dry slider all the way to dry and not engaging the Flex FX buttons.
If you want more gain turn up the gain knobs.

yes that's correct, I am using a 61. I will set it all the way to dry and give it a try.

If you don't mind me asking whats the difference btw dry and wet in regards to using and not using an external FX? (note: I'm not using one)

When nothing is plugged into the Flex INs/OUTs and the Wet/Dry slider is set wet the signal is getting fed back into itself which is why the volume boosts.
You don't want to do that though. Just leave it on Dry if you aren't using an effects processor.

Nicely said Zach!

Zach,

Thanks a bunch. Sounds much better. I just have one other issue which is the mic. The mic is clear over no music for the rane 61 but ppl are hard to hear over music. This is even when the music is lowered. Is there something special required for the 61? I am using a shure mic so I don't think it is the mic. I have the wireless mic plugged into the mixer. Any recommendations would be great.

Its just a volume thing.
If you aren't getting enough volume with the mic level turned up/all the way up (which you should?) than you'll need to turn the music down and the master volume up to compensate.

ahhhh that could very well be it. I have done all which you stated except for turning up the master volume. I will give that a try b/c it is not loud enough with the mic up. But I don't max out the mic level either. I have gone bout 75%. I can try to max out the mic first assuming that is okay?

Its fine to max out the mic level but you shouldn't need to if you're input levels for your channels aren't clipping. Turning up the master level will turn up everything.
If the mic still isn't coming through enough turn down the separate channel gains.

I keep my input level at about one notch over half way. Where it is just blinking in the red. Is that okay? I personally do not think its loud enough and I feel like I should not have to go about 75% on the master to get the sound I want. Let me know if my philosophy is incorrect.

Thanks for your helping me thus far....

do u have the switch on line or mic ?

Its on line.

You want to avoid hitting the red as that is an indication that your running the signal too hot into the mixer.
As for the master gain... Think of this as an attenuator like the one on the back of the DJM 600-900.
There is no issue with turning the master gain knob all the way up. If you do you will be getting the maximum output out of the mixer.
From there, if the output is too loud, turn down your speakers/amp.
This will give you a better signal to noise ratio anyways. This will result in the best sound possible.
Read more on this topic here --> rane.com

If you can't get the volume needed by turning up the mic all the way (which is perfectly fine if you need to do this) than turn down the separate input gains so that the music is quieter thus your mic comes through.

Sounds good. Thanks for your help. I will try all the above.