PMP4000 MON 1 / Mono Issue

[Mike Frymyer]

I have the EUROPOWER PMP4000 (sn: N1005776A8N Date Code: 1007). I am trying to connect mains and monitors using the MON 1 / MONO setting to 2 Behringer B1520 PRO (SN: S1102901286 and S1102902286 Date Code: 11 07) main speakers using 2 conductor Speakon to Speakon (output B) daisy chained and 2 various monitors using 2 conductor Speakon to 1/4" (output A) daisy chained. When I do this I get no sound out of the mains, but the monitors produce sound. My cables are 2 conductor. I can reverse the cables running the Speakon to Speakon mains from output A and the monitors using Speakon to 1/4" in output B and everything works, but I have to adjust the mains using the monitor controls and the monitors with the channel sliders.

What am I doing wrong?

[James Burns]

Hi Mike!

Thanks for joining the forum. I am going to ping one of our product specialists to get you a response within the next business day.

Also, I am going to move this thread to the Live Sound forum where it will be slightly more on-topic.

Cheers!
James

[Chris Painter]

I have the EUROPOWER PMP4000 (sn: N1005776A8N Date Code: 1007). I am trying to connect mains and monitors using the MON 1 / MONO setting to 2 Behringer B1520 PRO (SN: S1102901286 and S1102902286 Date Code: 11 07) main speakers using 2 conductor Speakon to Speakon (output B) daisy chained and 2 various monitors using 2 conductor Speakon to 1/4" (output A) daisy chained. When I do this I get no sound out of the mains, but the monitors produce sound. My cables are 2 conductor. I can reverse the cables running the Speakon to Speakon mains from output A and the monitors using Speakon to 1/4" in output B and everything works, but I have to adjust the mains using the monitor controls and the monitors with the channel sliders.

What am I doing wrong?

Dear Mike,

We would recommend checking a few things, such as how you have your gain staging set up, what mode you have the PMP4000's internal power amps set to, and the impedance of your speaker setup, to ensure that you are setting things up correctly with your powered mixer.

On microphone inputs, make sure that you are using microphones that have 'lo-z' outputs with standard, balanced, 3-pin XLR cables. Using 'hi-z' mics with 1/4" cables will not provide optimum performance or gain structuring with modern mixers. For most vocal mics or instrument sources other than bass, kick drum, or floor tom, you will want to engage the 'low cut' switch on each channel to reduce low frequency rumble (using the 'lo cut' switch whenever possible also helps reduce the liklihood of feedback). While speaking, playing, or singing into a microphone, turn up the white TRIM (aka input gain) knob on that channel, until the LEVEL SET light comes on when you speak, sing, or play your instrument into the mic. As stated in section 2.1 of your owner's manual, "The LEVEL SET LED illuminates when an optimum operating level has been adjusted," so make sure you have adjusted your TRIM knob(s) on each of your input channels so that your LEVEL SET light(s) are coming on, otherwise you have not set a hot enough input level.

Next, check the INSERT jack on the channel you are setting a level for - if you have an external device, such as an outboard compressor or EQ, inserted here, you are affecting the channel level; for example a compressor connected via an INSERT jack can greatly reduce the volume level (which is why many compressor limiters include a 'makeup gain' control).

Now move on to the three EQ knobs for the channel you are setting up. To start out with, you should have all three (high, mid, low) EQ knobs in their 12 o'clock 'center detent' position. If you have any of your EQ knobs 'cut' (set lower than 12 o'clock) you are reducing the volume at this stage.

Start with the channel's PAN knob in the center (12 o'clock) for now.

Make sure the channel's fader is set to the "0" (about 80% of the way up) position to start out with, and move your MAIN 1 (and MONO, if you're running in MAIN 1/MONO mode) faders up while speaking, singing, or playing, to set your overall output volume.

If you still require additional gain from individual channels, try increasing the input TRIM control knob on that channel to get your additional gain at the input stage of the signal path, before adding additional gain by turning the channel or main out faders higher than "0". This will help ensure that you are setting up proper gain staging as the signal travels through the mixer.

Check how you have set the AMP MODE switch in the upper right hand section of the front panel. If you are using both internal power amp channels for 'main' speakers in stereo, make sure you have the switch in the top MAIN L/MAIN R position. If you are using one speaker output for your 'mains' and one for 'monitors', make sure you have the switch in the center MON 1/MONO position, and that you have read your owner's manual and understand how to set up a monitor mix using the MON 1 knobs on each channel to create a 'monitor mix' from each channel, the "FX to MON 1" knob to add effects to your monitor mix if desired, and the grey MON 1 fader to control your overall MON 1 monitor mix output level.

Use the bottom BRIDGE position of the AMP MODE switch only if you are running the internal amp and your speaker(s) in BRIDGED mono. Please note that you must only connect a load of not lower than 8 ohms to the OUTPUT B jack when in 'bridge' mode, in accordance with your owner's manual (see section 2.5 of your manual for more information).

Check to see what kind of speaker load you are connecting to your PMP4000. First (this may sound silly, but we get this one a lot), make sure you're connecting to the SPEAKON speaker outputs on the rear - any outputs on the top/front panel of the powered mixer are line level outputs, the only 'power amp' outputs are the SPEAKON ones on the back of the unit.

As with any power amp/speaker setup, the output level will vary with the speaker load (in 'ohms') that the amp is being asked to 'drive'. Volume/output power/current draw will increase as the resistance (load in 'ohms') is reduced. In MAINS L/MAINS R or MON 1/MONO power amp modes, the PMP4000 can be run with a load of as low as 4 ohms connected to each SPEAKON speaker output jack (remember, do not connect a load lower than 8 ohms to the 'B' output only, if running in bridged mode). Connecting a speaker load of 8 ohms will result in reduced output compared to a speaker load of 4 ohms, and similarly, connecting a speaker load of 16 ohms will result in an even further reduced output volume (about 1/4 of the 'wattage' output compared to a 4 ohm load). Make sure you know what the ohm load ratings of your speakers are, and how the ohm load changes when you connect your speakers in different ways:

As an example, when you 'daisy chain' two 8-ohm speakers (for example, amplifier output to the 'in' of one PA cabinet, then from the 'thru' of that cabinet to another 8-ohm PA cabinet) you are creating a 4-ohm load.
http://www.sweetwater.com/shop/live-...ng-guide.php#3
http://colomar.com/Shavano/spkr_wiring_many.html
http://www.ptme.com/et/audio/referen...rs/speaker.htm

Also check out the following article from OnStage magazine, which has some great tips on optimizing the output from a PA system.
http://onstagemag.com/ar/performance_limit_push_pa/

Once you've spent some time learning to set up your gain staging, headroom, and speaker connections/impedance considerations correctly with the PMP4000, we're confident you'll be impressed with its performance and features.