I don't have a problem. Just a question. I have a behringer pmp3000. Where is the best place to connect two mackie active speakers for maximum results.

Connect one each to the main left and main right outputs.

You can download Service Manual of Behringer PMP3000 free of cost on below link:
https://www.electronica-pt.com/esquema/audio/behringer-audio/behringer-pmp3000-16040/ Behringer PMP3000

Absolute maximum is two of these per side. The speakers are 8 ohm and two on each of the outputs would be 4 ohms which is the minimum allowed for the amplifier. You will get about 400 Watts RMS per side doing this. Please note that the stated 1200 watts for the amp is the PEAK (fakey) values put forth in all the ads we get now. With 4 total B212XL's you should be able to fill an indoor venue of about 10000 square feet with sound at the OSHA limit.

Get an "insert snake" which splits each of two TRS plugs into TWO TS plugs.
Plug the TRS ends into the MAIN INSERT jacks and each of the "TIP" plugs at the other end into inpout jacks of the destroyer. Plug the "RING" plugs into the output jacks of the destroyer. You will need a snake with at least two sets of splits. I use a Behringer PROCOM compressor. For those the TRS plugs go into the channel insert jacks and the tips and ring plugs go to the in and out of each channel of the compressor respectively.

The answer is NO... These jacks need to float driving speakers that are NOT grounded in any way. Connection to channel A with a grounded cable will destroy the channel A amp. Use the 1/4 inch MAIN L & R jacks with balanced lines to active speakers. You can drive several active speakers from each of these jacks.

Di you mean this one? -> http://www.behringer.com/EN/downloads/pdf/PMP1000_P0566_M_EN.pdf

Run your speakers cables to your stereo "outs" (L/R) then run your sub off of one of your aux "outs" or sub group "outs" (make sure you assign channels to sub group out).

Thought I answered this. Using balanced TRS cables, connect the powered speakers to the Main L and R 1/4 inch jacks on the top of the unit.

The passive speakers connect to the main outputs using Speakon connectors on the back.

You will use Balanced connections (TRS) to the main L and R connections on top to the active speakers. Daisy chain 3 active on each of the L and R top connectors.

You can download a user manual if you don't have one.

http://www.behringer.com/EN/downloads/pdf/PMP1000_P0566_M_EN.pdf

ALSO PLEASE read my tip regarding a hazard when using Speakon to 1/4 inch speaker cables on channel "A" in the FIXYA tips for PMP mixers. The barrel of the channel A 1/4 inch is the HOT side of the signal to the speaker instead of the tip.

Assuming they are ALL mains and not for monitors connect this way:

Connect the passive to the A and B powered outputs. Please read my tip on Fixya regarding hazard of grounding speaker leads on channel A of PMP mixers.

Connect each pair of active speakers to the Main L and R 1/4 inch jacks using TRS balanced cables. Power these speakers from the SAME receptacle or source, even if it means running an extension cord to your mixer from where the actives are plugged in. FAILURE to do this creates a hazard of ground loops and ground bounce that can damage equipment. The Main L and R 1/4 inch jackls can drive more than one active speaker... these are line level signals. Make sure to use TRS balanced cables for this.