Members WynnD Posted August 17, 2011 Members Share Posted August 17, 2011 I figured out that trying to set the DRPX/A filters while the jukebox is playing is an exercise in futility. Got to shut down the jukebox and band members noodling to get the fixed filters a chance of being right. My bandmates get it now. Link to comment Share on other sites More sharing options...
Members WynnD Posted August 17, 2011 Members Share Posted August 17, 2011 If it gives you 9dB of additional GBF, something is very wrong with your basis system set-up. I'm trying to figure out if you think the number is too high or too low. (And I honestly don't know how much I got after adding this equipment a few years ago. My band plays too close to the edge indoors to get by without it.) Link to comment Share on other sites More sharing options...
Members twostone Posted August 17, 2011 Members Share Posted August 17, 2011 Our band is having an ongoing discussion about getting a feedback eliminator/killer to help/simplify/speedup with the PA setup and feedback (or getting rid of it/preventing it, we've already got the feedback LOL!)..Wondering if anyone on here uses them or has opinions on them. Thanks Turn down problem solved and you saved yourself some money.If your dead set on one I would highly recommend a Sabine FBX unit. Link to comment Share on other sites More sharing options...
Members jwlussow Posted August 17, 2011 Members Share Posted August 17, 2011 I've heard them mess up intended guitar feedback. That I can understand. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted August 17, 2011 Members Share Posted August 17, 2011 I figured out that trying to set the DRPX/A filters while the jukebox is playing is an exercise in futility. Got to shut down the jukebox and band members noodling to get the fixed filters a chance of being right. My bandmates get it now.Yep, that's one of the "secrets" to getting them to function correctly . Also you need to "ring out" one monitor feed at a time with the others muted. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted August 17, 2011 Members Share Posted August 17, 2011 This is just my experience. I had the dbx AFS 224. I would try to set the first 12 filters and leave the next 12 for live use. Occasionally, there would be feedback and the unit would not pick it up. I would experiment and try to get it to notch it out. It would be an anguishing time period and it just wouldn't find it. Not sure of exactly why it didn't do anything about the feedback though.They have to be driven HARD inserted and NOT inline. If you have to use them inline to yor monitor amps you have to turn down the gain on the monitor amps so you can feed them a 0 db signal OR set the sensitivity switch on the back of them to the more sensitive position even though that's technically wrong. I also have a 'ringer DSP1124P that I use on my "B" rig that has a menu option to increase the sensitivity - set that to the maximum sensitivity (still not as good as the DBX or Sabine units but better than nothing). The Sabine unit has a "turbo" mode that temporarily increases the sensitivity for setting the fixed filters and also reduces the volume of any feedback while dong so. Initial fixed filter setting with the Sabine is least obnoxious if there are people in the venue, the DBX isn't too bad if you have the gain structure set as above, and the 'ringer is the worst. Oh, and the AFS (and maybe newer Sabine's ?) have filters that are too narrow to be useful as fixed filters - as the room heats up or whatever the feedback frequencies will move off the notches . Make sure you set them to 1/20th octave before you set them ! I suppose you can set the width back to 1/60th for new live filters after you finish setting the fixed ones but I don't bother. Link to comment Share on other sites More sharing options...
Members WynnD Posted August 17, 2011 Members Share Posted August 17, 2011 Yep, that's one of the "secrets" to getting them to function correctly . Also you need to "ring out" one monitor feed at a time with the others muted. I haven't been doing that. If I get you right, set one monitor channel's fixed filters at a time. I'm only running one DRPX on a two channel monitor system. Will try that. Thanks Link to comment Share on other sites More sharing options...
Members Vito Corleone Posted August 17, 2011 Members Share Posted August 17, 2011 I thought it sounded weird that someone would claim a feedback suppressor would detect keyboard or guitar and eliminate those notes. I am not a keyboard band so I couldn't dispute the claim. We use our DR260's AFS at every gig. I haven't heard feedback in years so either it is working great or we are just careful about mic/speaker placement. You also use IEMs, right? No doubt a BIG factor in the elimination of feedback. Link to comment Share on other sites More sharing options...
Members twostone Posted August 17, 2011 Members Share Posted August 17, 2011 You also use IEMs, right? No doubt a BIG factor in the elimination of feedback. He's probably referring to the FOH FB. Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 17, 2011 Members Share Posted August 17, 2011 I'm trying to figure out if you think the number is too high or too low. (And I honestly don't know how much I got after adding this equipment a few years ago. My band plays too close to the edge indoors to get by without it.) Way too high. That's 8x power. Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 17, 2011 Members Share Posted August 17, 2011 I have seen guitar notes, some bass notes and keyboard notes trigger the filters. It depends on the what the nhote's harmonic and tonal structure are made up of, and their level relative to the program. Link to comment Share on other sites More sharing options...
Members stangconv Posted August 17, 2011 Members Share Posted August 17, 2011 Not gonna lie, I am super curious to try one. Do you have to set them every gig? Or can they be a set and forget thing? I would be using them just on monitors... Link to comment Share on other sites More sharing options...
Members twostone Posted August 17, 2011 Members Share Posted August 17, 2011 Not gonna lie, I am super curious to try one. Do you have to set them every gig? Or can they be a set and forget thing? I would be using them just on monitors... Yes you have to set it for every room and keep in mind it's not cure all. Link to comment Share on other sites More sharing options...
Members stangconv Posted August 18, 2011 Members Share Posted August 18, 2011 Well that sucks. Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 18, 2011 Members Share Posted August 18, 2011 Well that sucks. Nope, that's reality. Link to comment Share on other sites More sharing options...
Members jwlussow Posted August 18, 2011 Members Share Posted August 18, 2011 You also use IEMs, right? No doubt a BIG factor in the elimination of feedback. Yep. Talking FOH. Monitors are just fine... Since we are all IEM, FOH feedback has a chance to take hold before we really notice it is happening. We do rely on the Driverack 260's AFS to keep us in check... maybe more then we should. We also have years of experience with our system. That does help a bit too. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted August 18, 2011 Members Share Posted August 18, 2011 FYI feedback doesn't have harmonics (unless something's clipping) so the feedback suppressors try to distinguish music from feedback by looking to see if it has harmonics or not. Unfortunately guitar feedback is just that and hard to distinguish from other feedback. Bass with the mids cut and some keyboard sounds are also hard to distinguish . Link to comment Share on other sites More sharing options...
Members agedhorse Posted August 18, 2011 Members Share Posted August 18, 2011 Feedback certainly can have harmonics and they can be "unrelated" too because of the multitude of pathlengths and reflections. If you look at typical feedback, it's full of "junk" and also buried within program or "noise" which is why most do a terrible job with any music playing or much background "clutter". A good feedback eliminator is not a trivial design, and in fact is very hard to do. Link to comment Share on other sites More sharing options...
Members Zeromus-X Posted August 18, 2011 Members Share Posted August 18, 2011 We run sound for a band locally who has their monitors turned up so loud that, upon hearing feedback, I'm never sure if it's in one of the monitor mixes or in the mains. I've been thinking about some kind of feedback suppression on the monitors just for situations like that. If they lose part of the sound of their mix... maybe they'll be okay with turning down. Link to comment Share on other sites More sharing options...
Members RoadRanger Posted August 18, 2011 Members Share Posted August 18, 2011 FYI feedback doesn't have harmonics (unless something's clipping) so the feedback suppressors try to distinguish music from feedback by looking to see if it has harmonics or not. Unfortunately guitar feedback is just that and hard to distinguish from other feedback. Bass with the mids cut and some keyboard sounds are also hard to distinguish . I should have mentioned that I saw this explanation in the literature from one of the manufacturers. IME they all catch "pure tone" feedback fairly well. As AH said catching feedback where there is lots of other stuff going on is difficult. It seems they generally require the feedback to get louder than the music before they catch it. Link to comment Share on other sites More sharing options...
Members JohnnyGraphic Posted August 18, 2011 Members Share Posted August 18, 2011 They have to be driven HARD inserted and NOT inline. If you have to use them inline to yor monitor amps you have to turn down the gain on the monitor amps so you can feed them a 0 db signal OR set the sensitivity switch on the back of them to the more sensitive position even though that's technically wrong. I also have a 'ringer DSP1124P that I use on my "B" rig that has a menu option to increase the sensitivity - set that to the maximum sensitivity (still not as good as the DBX or Sabine units but better than nothing). The Sabine unit has a "turbo" mode that temporarily increases the sensitivity for setting the fixed filters and also reduces the volume of any feedback while dong so. Initial fixed filter setting with the Sabine is least obnoxious if there are people in the venue, the DBX isn't too bad if you have the gain structure set as above, and the 'ringer is the worst. Oh, and the AFS (and maybe newer Sabine's ?) have filters that are too narrow to be useful as fixed filters - as the room heats up or whatever the feedback frequencies will move off the notches . Make sure you set them to 1/20th octave before you set them ! I suppose you can set the width back to 1/60th for new live filters after you finish setting the fixed ones but I don't bother. Maybe that was my problem. I was using it inline and trying to get it to 'hear' the feedback when the levels were way below 0. It didn't seem to matter how wide I set the filters though. At least I don't have to worry about it anymore since my PA has been sold. Johnny Link to comment Share on other sites More sharing options...
Members twostone Posted August 18, 2011 Members Share Posted August 18, 2011 Well that sucks. It's really easy with the Sabine FBX. It just a matter of a few button pushes and knobs turning and your done. Takes maybe a whole 2-3 minutes to set it up and your good to go. Link to comment Share on other sites More sharing options...
Members Flogger59 Posted August 18, 2011 Members Share Posted August 18, 2011 Really? An FBS will mistake a keyboard for feedback? I've never heard of that (or experienced it). That would definitely not be a good thing. I was at a Rane demo of their feedback filter algorithm in the RPM88 (I'm not spamming, you can't get one separately from an RPM88, and no one will part with $3k just for that) where they lined up all the competitor's units, then cued Jimi at Woodstock playing The Star Spangled Banner. The results were eye opening. Link to comment Share on other sites More sharing options...
Members stangconv Posted August 18, 2011 Members Share Posted August 18, 2011 Nope, that's reality. Sometimes reality sucks... Link to comment Share on other sites More sharing options...
Members RoadRanger Posted August 18, 2011 Members Share Posted August 18, 2011 I was at a Rane demo of their feedback filter algorithm in the RPM88 (I'm not spamming, you can't get one separately from an RPM88, and no one will part with $3k just for that) where they lined up all the competitor's units, then cued Jimi at Woodstock playing The Star Spangled Banner. The results were eye opening.Do you happen to remember which units worked the best and worst? Link to comment Share on other sites More sharing options...
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