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feedback / dsp units
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PhilG
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Joined: 29/07/2010 01:46:55
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Location: Brisbane Australia
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Im looking for some gear to eliminate feedback, I know it can mess with the sound and give another whole set of issues but im stuck at a couple of venues I mix at where sound check is not allowed and the singer likes to crowd surf infront of the PA =/

I know the DBX Driverack will do the job but IT is too expensive for what I want to throw at it

basically I want a safety net for the times I can't ring out the system

What gear do you recommend on a budget? - Im prob looking to spend around $1000 all up if I can get it lower even better

I only know of the DBX and behringer gear, - I saw someone post up a Sure DFR11EQ5 half rack unit in the SL forums but could not find any current info on it.

I dont need any fancy RTA or DSP / para eq functions its sole use would be for feedback elimination

would need to be able to cover 2x wedge channels and 1x mono FOH send - if it can do stereo even better ( I know I will have to proberbly get multiple units)

can anyone recommend a good piece of kit? im looking at 2x units of the DBX AFS224 as it does dual mono and stereo but I cant find anything to compare it with - there is the behringer DSP1124P that is super cheap that some people say is the best piece of kit they make and others say its a piece of crap - another weird one I found was the proel predator dual mono rack unit, I have never heard of these can anyone shed some light?

This message was edited 4 times. Last update was at 11/05/2011 00:08:55


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RicB
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Joined: 29/07/2010 17:39:58
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I recommend the Sabine stuff.
I have the Navigator 360 which is more of a Driverack competitor but gives me far more for less money.

Try here;
http://www.sabine.com/Pro_FBX2410_index.htm
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Jerryd
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Joined: 28/07/2010 16:01:24
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Phil -- I have 3 Driveracks and they were all under a $1,000. If you only plan on using the AFS part of it then it would be an expensive unit just for that.

I used to use the AFS and run it a the venue but I quit doing it because it would notch out so much and after 6 fixed filter runs -- it would change the tone of the system a bunch. It would do the same thing for monitors.

I do still use the AFS BUT only use "Live" filters and not half fixed and half live. The live filters grab when a singer lowers the mic at the monitor OR darts out right in front of the tops. It is much faster than I am.

I think the Sabine unit would be good for that.
hsfinlayson
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Joined: 20/04/2009 10:02:12
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Location: Boston area
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Dumb question by a non-user of AFS gear:

Can the unit be channel-based, not system-based...? where it ONLY messes with the offending input source and does not affect the entire system...?
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Jerryd
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Joined: 28/07/2010 16:01:24
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hsfinlayson wrote:Dumb question by a non-user of AFS gear:

Can the unit be channel-based, not system-based...? where it ONLY messes with the offending input source and does not affect the entire system...?


The Sabine -- Yes. You can stick it on one channel input if you like or even on a subgroup like vocals. It has balanced and unbalanced outputs on it.
mamerica
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Joined: 22/10/2010 22:23:56
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I use a DBX AFS-224 inserted on a single channel. Some of the bands use a single large diaphragm mic and this does the trick. It is the same circuit used in the Drive Rack and their digital graphic eq's. The nice thing about the AFS is that you can select how many filters to use so you don't squash the sound unnecessarily. The other nice thing is that it has an extremely high Q, 1/80 octave according to the specs.

Both the AFS and Driverack cost about $200.00 used.

We've used the Beringer with limited success. It tended to be too aggressive and we would have to reset it often.

This message was edited 1 time. Last update was at 14/05/2011 17:45:56

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twostone
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Joined: 19/12/2010 08:33:04
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I use a Sabine FXB2400 and works great for keeping the screech bugs out of my speakers.
TimmyP1955
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Joined: 29/07/2010 08:42:15
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Location: Indianapolis
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I formerly used AFS, and could use it now if I wanted, but I don't. What all the units have in common is that they all take too long to lock onto feedback and create the notch. I do what it takes to induce the feedback (face, hand, or open mouth in front of the mic, hat brim above it, etc.), let the FFT app in my iPhone tell me what the frequency is, and dial it up. Once that's done, I determine whether to leave the notches be, or to make changes (I had five feedback frequencies between 900Hz and 1400 Hz - I replaced those five notch filters with a single wide filter at 1240 IIRC - and got a better sound with better stability over the long haul.)
http://www.padrick.net/TP_Audio.htm
kibo
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Joined: 28/07/2010 23:08:13
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Location: Toronto, Canada
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@TimmyP1955,

what app do you use on the iphone to tell you the frequency... would really love to have the dbx driverack 260...

tnx,

kibo
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TimmyP1955
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http://www.studiosixdigital.com/fft.html

The response measurement is surprisingly accurate even with the iPhone mic (it just can't handle much volume without clipping - and the program tells you when the mic is clipping). The frequency readout is highly accurate.

Demos: http://www.studiosixdigital.com/fft-demo-videos/
http://www.padrick.net/TP_Audio.htm
robare99
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Joined: 16/05/2011 18:25:55
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What about riding the fader, keeping an eye on the singer, and bringing it down when he's not singing.

These guys have terrible technique, they go out in front of FOH as well. I do 2 things:

They have a reasonable stage volume, so it's less prone to feeding back

And again, I'm on the ball with the mix, riding the faders, bringing them down a bit when they aren't singing, just keeping on too of things...

mstorch
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Joined: 07/01/2011 20:26:51
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In that situation I would say "Don't leave the stage or your set will be instrumental the rest of the night" but that's just me. I don't deal with stupid people. You want to cup the mic and point it in my monitors, you better have money for a couple replacement diaphragms (and a good set of legs because I'm not happy).

I don't intend on being the typical asshole sound engineer, but you do stuff like that and you're asking for it.

The technique you described can work, but it's not very practical with more than 2 vocalists. Just my opinion.
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robare99
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This is true. Generally, there's 3 mics across the front, on stands, that stay on stands, as it's usually a 4 or 5 piece band, with the singers usually playing an instrument as well.

BOClark
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Just a few notes:
The picture above...if the guitar player on the right puts his foot up on my monitor like that...he would not have a monitor in front of him by the end of the song.
Secondly...the stage volume would come down if I got feedback! Sorry, but the band won't pay for diaphrames or blown woofers. They will simply just go home and not think twice about it. Or maybe they would...thinking how the soundman sucked!

I have a DBX Driverack and I am about to stop using it. I use it for the crossover feature and the eq function only. To me...I am loosing the sound I am used to hearing. Lately, my sound has been muddy and I am not liking it. Nothing wrong with the speakers, just the sound from how I got the DBX setup.

Feedback from the Stage comes from eq'ing the monitors. Doing a good "ringing" out of the monitors is the most effective method. Sometimes, you can over eq the monitors and the monitors sound like crud! Done this many times. For the money, I would actually buy several good dual 15 or 31 band eq's and use your own ears for the feedback eliminating. I wouldn't put a DBX on the monitors unless you are running more than a 1000 watts into them.
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PhilG
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like I already said I like to ring out when I can but I have several gigs where I turn up 3 hours before the show because that's the earliest I can get in. There is already 400 people in the club with DJ playing and Im setting up at 7pm ready for band to go on at 10pm, there is no ringing out the monitors and usually no sound check all being mixed from side of stage - its all done on the fly so I am in need of a backup solution.

The DJ has usually horribly compressed then gained the 8 x 18" subs under the stage to a earth shattering 125-130db where the flown tops are putting out around 105-110db so I have to counteract that with some weird EQ graphs from the SL


If you have a look at these photos you can see the SL on the right - the subs basically line the whole underside of the stage then there is the 4x flown speakers ( I have no idea what these even are ) - im standing usually about where the photo was taken with the ipad but I have limited time there before the venue totally packs out then I go and sit side of stage controlling lights and doing small tweaks from there





This is why I need a feedback eliminator

This message was edited 1 time. Last update was at 31/05/2011 07:25:31


2 x SL16.4.2's
Audiobox USB
Studio One V2 Pro
/ Rack System
AMD FX-4170 / 16GB DDR3 / Win7x64 / Via 6308FW Onboard
/Mobile System
Toshiba Satellite P200 / 8GB DDR2 / Win7x64 / Ti FW & i7 13" MBP
/Wireless
Ipad v1 16gb - Samsung Galaxy Tab - Asus Black Diamond router

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