Home› dbx User Forum› dbx Archive Threads› dbx Archive General› Configuration Wizard

AFS224 Feedback Unit - Please help!

guitarblokeguitarbloke Posts: 6
edited January 2009 in Configuration Wizard
Hi there,

My lovely wife bought me one of these babies for Christmas and I got round to trying it today at rehearsal, however I can't seem to get it working and was hoping some kind soul could help me out a little please :)

I've followed the instructions to the letter, and it all looks to be connected correctly (just vocal 2 mics going into the unit which then feeds out to the mixer) - however when I get to the following 'ringing out' instructions in the manual :

\"The AFS 224 will detect and remove feedback by placing notch filters at the feedback frequency. Continue to slowly raise the gain until all feedback has been eliminated or all fixed filters have been used, this will be
indicated by the flashing <MODE> button.\"

- This doesn't happen - The feedback is not eliminated - even slightly - and none of the filter LEDs light up whilst this is taking place, I increase the gain and the feedback starts and continues!

The unit doesn't seem to be doing anything whatsoever. Although all the power lights etc are on.

I'm a bit of a techno-newbie but this sounds straightforward enough in the manual.

Can anyone please help point me in the right direction?

Thanks in advance!

Sean

Comments

  • DraDra Posts: 3,777
    What mics?
    What mixer?
    So you are plugging the mics into the 224 and then the 224 into the mic channels?
    The best way is to \"INSERT\" the 224 into the channel insert (assuming).
    Make sure the \"BYPASS\" is not on.
    Make sure the 224 has been properly set up (number of total and fixed filters, etc)
    A really easy thing to mess up is to have it in fixed mode while being live (cuz lives won't work) or visa versa. If all filters are assigned (not neccessarily full) as LIVE, then you push the button to go to FIXED... nothing will happenen because there are no LIVES available. The same thing for the reverse.

    DRA
  • guitarblokeguitarbloke Posts: 6
    Hi DRA,

    Thanks for the fast reply!

    Yes we are plugging the 2 vocal mics (1 a Shure SLX wireless condenser mic and 1 a bog standard cheap Shure) into the back of the 224 (the condenser into the Input for Channel 1 and the other mic into the input of channel 2).

    This then goes into our mixer (usually it's a Soundcraft Spirit mixer, but today we tested using our backup mixer - a Tapco 4 channel).

    Bypass was definitely off - the unit did not seem to be assigning any filters - well, not that I could see at least - none of the LEDs illuminated during the ringing out phase.

    I wonder if I did as you say and have it in fixed mode whilst being live... I will try and check this out this week and see what I come up with.

    Thanks again for your advice! I'll let you know how I get on and will no doubt be back if I have any further questions! :)

    All the best

    Sean
  • GadgetGadget Posts: 4,915
    Dude... that's a LINE LEVEL DEVICE...NOT a mic level one.. further, condenser mics (true condensers) require phantom power, and WILL NOT utter a sound unless powered, and NO the power would not back up through the AFS...Insert it as Dra suggested using the 1/4\" jacks or out of the mixer into the AFS then out to the amps/speakers...

    Remember, the AFS requires that you EXCEED the normal level you would EVER end up going, the higher the volume the more filters will hit...

    If you leave a few open (as in your already stupid loud) you can catch spurious signals...

    Remember, the FBX is only as good as the system is tuned...if your speakers have hotspots, you will have a hell-of-a-time getting the feedback eliminated.

    Gadget
  • guitarblokeguitarbloke Posts: 6
    Gadget wrote:
    Dude... that's a LINE LEVEL DEVICE...NOT a mic level one.. further, condenser mics (true condensers) require phantom power, and WILL NOT utter a sound unless powered, and NO the power would not back up through the AFS...Insert it as Dra suggested using the 1/4" jacks or out of the mixer into the AFS then out to the amps/speakers...

    Remember, the AFS requires that you EXCEED the normal level you would EVER end up going, the higher the volume the more filters will hit...

    If you leave a few open (as in your already stupid loud) you can catch spurious signals...

    Remember, the FBX is only as good as the system is tuned...if your speakers have hotspots, you will have a hell-of-a-time getting the feedback eliminated.

    Gadget

    Hi Gadget - thanks for the info there man! :D

    You're right - the mic does need phantom power - The mic capsule itself is battery powered. We were getting sound from the mics - in fact they seemed to be working as normal, however when we cranked up the volume to ridiculous levels, all we got was feedback city! the AFS seemed to be doing nothing. However if as you say, it is not designed to have the mics run direct into the AFS, then I've been going about this the wrong way from the beginning!

    I think it might be worth trying as you suggest - from the mixer to the AFS and then to the (powered) speakers.

    I'm afraid I'm not too sure what you mean by speaker hotspots - is this something I need to read up on and take into account?

    Cheers

    Sean
  • GadgetGadget Posts: 4,915
    Depending on the quality of the speaker it may or may not be a very flat frequency response from the speaker, that is why we EQ them...if say for instance the speaker has a boost in the 1K area of say 3 db the 1K would be prone to feed back..that is what I meant...
    Gadget
  • DraDra Posts: 3,777
    I would not use the 224 on the whole system. The 224 can see a guitar or keyboard sustain as feedback. Unless of coarse, you don't have channel inserts. That way you can sweeten the music and keep the mics nice and sqeal free.

    DRA
  • guitarblokeguitarbloke Posts: 6
    Gadget wrote:
    Depending on the quality of the speaker it may or may not be a very flat frequency response from the speaker, that is why we EQ them...if say for instance the speaker has a boost in the 1K area of say 3 db the 1K would be prone to feed back..that is what I meant...
    Gadget

    Thanks Gadget - that makes sense to me :) Sorry for the basic questions (I'm kinda new to all this!)

    All the best

    Sean
  • guitarblokeguitarbloke Posts: 6
    Dra wrote:
    I would not use the 224 on the whole system. The 224 can see a guitar or keyboard sustain as feedback. Unless of coarse, you don't have channel inserts. That way you can sweeten the music and keep the mics nice and sqeal free.

    DRA

    Thanks DRA, we have channel inserts so will give that a shot at next band rehearsal :D
Sign In or Register to comment.