Possible f/w update to use DSP30 below 20 Hz?

Moderators: Cameron Shoffner, Christian Cook, Kirk Fyvie, Martin Barbour, Fred Thomke, Gary Evans_QSC


  • I have two different subs that I want to HP (4th-order BW) at 10 and 20 Hz.

    I have a DSP30 that I've not really used yet, but in the config s/w I see that the lowest I can set it is 20.8 Hz.

    Is it possible for a firmware update to make this settable to 10 Hz?

    Thanks
    noah katz
    Rookie
     
    Posts: 22
    Joined: Sat Jul 28, 2007 1:01 am
    Location: Mountain View, CA


  • Hi Noah,

    No, Signal Manager V4.75 is what it is.

    The DSP-30’s hardware though will go down to 6Hz (-3db referenced from 1kHz).
    Brad Sambrano
    Systems Support Engineer
    QSC Audio Products, LLC
    Image
    Brad Sambrano
    QSC Audio Products
     
    Posts: 198
    Joined: Thu Mar 06, 2003 2:01 am
    Location: Costa Mesa, CA


  • Hi Brad,

    So no plans for Signal Manager V5? :)

    "The DSP-30’s hardware though will go down to 6Hz"

    That's good; what's the rolloff below that?

    Just had another thought - what about a hardware mod?

    Like are there some caps/resistors whose values could be doubled or halved that would halve the HP filter frequencies set in the s/w?

    Thanks
    noah katz
    Rookie
     
    Posts: 22
    Joined: Sat Jul 28, 2007 1:01 am
    Location: Mountain View, CA


  • Nothing at the DSP hardware level concerning the mod.

    A hardware mod would be better served in the amplifier’s circuitry. Is the amplifier capable of full output at 10Hz?

    As for a below 6Hz roll off spec, I wouldn’t be to concerned. I guess I can measure it.
    Brad Sambrano
    Systems Support Engineer
    QSC Audio Products, LLC
    Image
    Brad Sambrano
    QSC Audio Products
     
    Posts: 198
    Joined: Thu Mar 06, 2003 2:01 am
    Location: Costa Mesa, CA


  • It's down a couple of dB at 10 Hz.

    "I guess I can measure it."

    Actually, don't bother. That's almost an octave below where I want to HP, so not relevant.

    Thanks, Brad
    noah katz
    Rookie
     
    Posts: 22
    Joined: Sat Jul 28, 2007 1:01 am
    Location: Mountain View, CA


  • Yeah, that’s what I was going over in my mind as being something to even worry about concerning how far down in Hz the DSP-30 can pass signal.

    The possible roll off of the amp at 10Hz plus your added (somehow) 4-pole 10 Hz filter, at 5 Hz (which we can slide over to the 6 Hz spec of the DSP safely for this discussion) you are at an octave down from 10Hz. So the amp’s output will be attenuated by: amp’s roll off if any + your added 10 Hz filter of some roll off (6db, 12db, 24db, etc. per octave) which makes what the DSP-30 can pass below 6 Hz something to ignore.
    Brad Sambrano
    Systems Support Engineer
    QSC Audio Products, LLC
    Image
    Brad Sambrano
    QSC Audio Products
     
    Posts: 198
    Joined: Thu Mar 06, 2003 2:01 am
    Location: Costa Mesa, CA



Return to DSP Support




Information
  • Users browsing this forum: No registered users and 1 guest