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Queries on the Nexo PS10 controller and sense inputs...

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  • Queries on the Nexo PS10 controller and sense inputs...

    Hi guys,

    I have a couple of queries in relation to the PS10 controller and loudspeaker system, if there are any Nexo users who could help me out with any of my questions I'd greatly appreciate it. 

    I recently purchased 4 x PS10 tops, 4 x LS500 subs and the PS10 controller. I started wiring the rack and making the leads etc today, by the time I was finished I had sound clearly coming through all the right speakers from all the right places. The thing that concerns me though is the sense inputs on the back of the PS10 controller. Up until today I had only heard of sense inputs, never laid eyes on them and to be honest I do not know a whole lot about them...if much at all!

    Here's what I've got from the last 30 minutes with Google and I'm still not sure....

    -Sense Inputs are fed from the left +/- of the poweramp to the respective sense inputs? (Previously, the notion of sending the output of the poweramp to anywhere but the loudspeakers was something I thought would be a bad thing to do.)

    -Sense Inputs act as an analyser of the signal the Nexos will be receiving and adjust the controller accordingly, protecting the loudspeakers essentially?

    -They are not vital for the systems performance, just its optimum performance/protection?

    Ideally, I would like to use them if to protect the loudspeakers alone, but the poweramps I'm currently using (1 for highs, 1 for sub) are non-Nexo and only have a Left and Right speakon output on the rear of each one. No live, XLR, link or otherwise. 

    If anyone could shed some light on any of the above it should send me in the right direction, thanks guys.

  • #2

    They are critical for the limiting functions to operate properly. The processor samples the output of the amps post everything (including other processing) and performs calculations to extrapolate true power versus frequency levels in real time. This eliminates any gain compensation that would otherwise need to be entered manually (and often incorrectly).

    Generally, these inputs are fully differential floating (sometimes transformer isolated), scaled and low passed, to protect the processing sense amps from bridged topologies and class D residual carrier.


    • #3

      Phenomenal loudspeakers,,, I was looking at some PS10's, and the Nexo LS600 subs earlier this year,,,, mind you, that was with the 4-channel Nexo NXAMP4x4,,, not the separate processor. These speakers are very linear, even at very high output, and as Andy states, they have a very advanced protection scheme, such as voice-coil temperature-sensing, to precisely get the maximun output, without the danger of break-up or over-heating.

      If you're using the PS10 processor, you need a "sensing" capability in the amp from what I understand. What amp are you using to drive those boxes?

      Veni, Vidi, Velcro;

      (I came, I saw, I stuck around)


      • agedhorse
        agedhorse commented
        Editing a comment

        Note that the voice coil temperature sensing is really a model based (most likely, I don't know how they do it) based on integrating power-impedance versus time - the thermal losses versus time and you "extract" a rolling "average" of power that undergoes calculations to model temp. This value may be used to adjust limiting variables, high pass filter variables, etc.

    • #4
      Pretty much standard operating procedure in high end controlled speakers. The reason for sense lines is to eliminate the need to calibrate system gains to the control elements.

      I've been doing elements of this for 20 years in processing models for products that I have designed.