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Crossover not working - what am I missing?

rfielderrfielder Posts: 8
edited January 2007 in PA General Discussion
My apologies to all if this situation has been discussed before. I just found out about this forum and joined today. I did do a couple of searches, and could not find anything that seemed directly related.

I am setting up a dbx DRPA with a Yorkville system, and it seems like the crossover is not working.

The system:
Laptop as sound source
Numark PPD9000 mixer
DRPA
Tops: Yorkville AP4040 amp and two E12 speakers
Sub: one Yorkville LS700p powered sub.

Went through the setup wizard, Custom for all, custom mono for sub, ended up with a 2x3 system, which seems right.

Checked the xover, and set it to 45hz 24db slope 0 db gain high pass, 150hz 24db slope 0 db gain low pass for the sub, 150hz 24db slope 0 db gain highpass for the highs.

All cables attached as expected - XLR from PPD9000 to DRPA, XLR from DRPA to AP4040, XLR to TRS for sub. Sub is plugged into LEFT LOW.

Something didn't sound right with the music, so I ran a frequency sweep from my laptop.

Now, my understanding of this sort of crossover is this - if I have a piece of music that has NO sub (no notes below the crossover), and I turn of the tops, I should get silence.

In the same way, if I have a piece of music with only sub (bass solo, for example), and I turn off the sub, I should get silence.

Harmonics excepted, of course.

What I get - turn off the sub, run a frequency sweep from 50hz to 1kz, and the tops play EVERYTHING.

Turn off the tops, turn on the sub, run the same sweep, and the sub plays EVERYTHING. Or at least it tries to, subs don't sound real good when playing stuff over 150 - 200hz.

The sub has a variable cutoff on the back. That is set to 150hz. When I say \"turn off\", I am actually killing the power to the sub, or to the AP4040 used for the top, not just turning down levels.

As far as I can tell, the reason my music does not sound good is because the sub and the tops are playing the same music. They are overlapping.

What am I doing wrong?

Thanks in advance!!

Comments

  • GadgetGadget Posts: 4,915
    Ive been thinking about this.. What happens if you use program #1.. stereo 3 way? do you get crossover action then?

    you are using the Hi outs and left mono out? not the mids outs...

    when you decrease the gain of the sub at the crossover does the volume go down, and the same for the tops?

    even in a 24 db slope there will be some overlap

    are you sure the program is actually loaded? the one you are using...?

    Let me know..
    Gadget
  • Gadget wrote:
    Ive been thinking about this.. What happens if you use program #1.. stereo 3 way? do you get crossover action then?
    Thanks for the advice!

    Strange thing happened. The unit worked great at the dance!

    Strange things happened when using a tone generator, as detailed in my original message. However, when playing music, it worked fine, and it worked as one would have expected it to work.

    No idea why the DRPA got so weird with the output from a tone generator. No idea why it tried to send 1KHz tone to a sub or a 50Hz tone to the tops.

    I did use the three way, two high and one mono sub. Didn't have the cables, but wanted to try stereo subs, since the LS700p has inputs for both left and right, and sums them internally. Would have been interesting to see if that sounded any different.

    The only issue with the DRPA was the feedback killer - in testing, it was too slow. Other than that, I am sold on getting one.

    Or rather, sold on trying a DR260, and then deciding. Maybe trying the Behringer units as well, although it will take two or three devices to equal the DR 260. I don't think the Behringer unit would be directly comparible, but if one wishes to make an informed deicsion, one should at least investigate the alternatives.

    One issue for the area I am in - nobody has a DR 260 for rental. Long & McQuade have the DRPA for rental at a great rate, but they have never sold a DR 260.....
  • GadgetGadget Posts: 4,915
    The 260 is simply head over heals above the DRPA.. no comparrison. The thing is with the Beh unit, any problems means its junk, they cannot fix them... thats been the problem with all theur stuff.. Don'r get me wrong, I have several BEH mixers and have had phenominal luck.. I'm not bringing my $20,000 soundcraft into a bar where fights occur and beer and drinks fly! no sir!

    The feedback killer.. what settings were you using.. it should have been live loud music I think.. I use 6 fixed and 6 roaming.. and set the filters to fall off after 10 sec. I have never had any feedback and I have idiots running around right in front of the speakers with wireless mics and screaming into them!

    Gadget
  • fgaborfgabor Posts: 4
    [The feedback killer.. what settings were you using.. it should have been live loud music I think.. I use 6 fixed and 6 roaming.. and set the filters to fall off after 10 sec. I have never had any feedback and I have idiots running around right in front of the speakers with wireless mics and screaming into them!

    Gadget[/quote]

    Hi Gadget,

    Is that you are speaking about the DRPA? I mean the device you never had any feedback problems with? Or is it the 260?

    Gabor
  • DraDra Posts: 3,844
    rfielder,
    I have the DRPA / E12 set-up you have but use SW800's for subs and power all with AP3000's or CE2000's. I also have a 260 for live mix situations. The 260 is, as Gadget always says, head over heals better than the PA. More post PEQ filters for speaker tuning. Brick Wall Limiters. Not to mention the GUI (you're already using the computer).

    As far as the FBX not catching fast, the more narrow the filter, the longer it will take to pinpoint.
    Also, have you done the gain structure? The FBX can only find what it hears. That may sound weird, but if the mixer or DRPA levels are down and the amp levels are up there can still be feedback. The signal is then mostly in the amp so the FBX doesn't hear it well enough to filter it.

    If you would like the tunings that I came up with for the E12's full range and crossed with subs, let me know. I would like to see what you did and compare.

    Best price I found for a 260 is Full Compass. Web pricing is more than phone sales, so be sure to call.

    DRA
  • DraDra Posts: 3,844
    Just checked pricing at Full compass website. $1300 list, $1000 reg sale price. I payed $720(+/-), 1 year ago. So definately call.

    DRA
  • Dra wrote:
    rfielder,
    I have the DRPA / E12 set-up you have but use SW800's for subs and power all with AP3000's or CE2000's.
    I ended up buying two NX55P speakers (12", 550W, active) and an LS200P (10", 200W active) sub. Used it once, and took the LS200P back to the store, traded it for a Mackie 1402-VLZ Pro, Gator 10x6 slant top, and some other stuff.

    Will be renting either an NX720S or LS700P as needed for now.

    I used a pair of E210's after the E12, and would have bought them on the spot, but the final cost worked out to over twice the NX55P price after factoring in the amp and a required DSP of some sort (DRPA or Yorkville). Far more than twice the price if I went for a larger amp. They are worth the $$$, they were that much better, but that was beyond the cash I had to invest at this time.

    May be looking at a DRPA in the future, but for now, will be using the HPF and LPF built into the speakers. Not ideal, but need to get this equipment working and paying for itself before investing further.
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