How Do I Connect A passive PA System's Amplifier To A Mixer

Not that the loss of two inputs on the pa/amp mixer would matter as i would basically be using the pa/amp mixer to power the speakers and the separate Behringer mixer for all the inputs.

@coolrekz -

     Close to the left of your PDA's EQ, there is an 1/8" Line In and (slightly further over) a 1/4" Line In.

     The unit's manual is not very comprehensive and doesn't mention whether either are a stereo input and there are no controls (that I can see) for their levels, balance, etc, so: no indication if they are stereo inputs.      

      If the 1/4" Line In is a stereo outlet*: make or buy a two 1/4" Mono to one 1/4" stereo plug cable and connect the Behringer's 1/4" Outs to that Line In.

      *If not: most 1/8" Line Ins are stereo, to facilitate the playing of portable tapes, CDs, etc and you could follow the above idea, but with an 1/8" stereo plug or 1/4" to 1/8" stereo plug adapter.     

      If neither of the PDA's Line Ins are stereo: go from the Behringer's L/R 1/4"  Outputs to both the 1/4" and 1/8" Line Ins with mono cables.

                            Mickey Mouse, but: it should get you there.

https://www.amazon.com/JOLGOO-Stereo-Breakout-6-35mm-Splitter/dp/B082X6618T?th=1

https://www.amazon.com/NANYI-Female-Headphone-Adapter-Upgrade/dp/B07QLGYW3H/ref=sr_1_4?crid=3DYPFTUO7P7D2&keywords=1%2F4+to+1%2F8+stereo+plug&qid=1651240072&s=electronics&sprefix=1%2F4+to+1%2F8+stereo+plug%2Celectronics%2C89&sr=1-4

There are many ways to connect the Behringer X2222USB to The Power Dynamics PDM-805A.

You can use a pair of RCA to 1/4" TS adapters plug into the X2222USB rear panel L and R "MAIN OUTPUTS" and connect it to PDM-805A rear panel "TAPE IN" via RCA cable.

OR

Connect the RCA cable to the PDM-805A front panel "CHANNEL 8" line inputs so you can utilize its control for level, tone and effects.

RCA to 1/4" TS adapters

@rodman99999 Many thanks for the reply.

@imhififan Many thanks for your answer. Is any of your options the better choice and if so why?

Many thanks all.

@coolrekz -

                                 You're welcome.

                            Go make some music!