Feedback elianators

[banjoman]

Hello everyone, I am looking into buying a feedback eliminator to cover my whole PA. I know there is one from Peavy, DBX, Sabine, and Beringer. Which one do you think is the best anf why. Thanks for your help.

[Audiodude]

Since your post is not a review of gear, it doesn't belong in the Gear Reviews forum. Please read the "Read This First" thread.

[GZsound]

This must have been moved.. since it's now in the FOH forum.

I bought a Behringer FB destroyer for use in my live sound rack. I run sound for bluegrass bands at festivals three or times a year.

The Behringer unit works great and gives me quite a bit more headroom. Especially when the band insists on using a Large Diaphragm condenser on state, which happens frequently. Many times they will also insist on monitors.. Yeech.

I set up an LD mic and start "tuning" the system, turning up the LD fader until I can hear the Behringer unit clamp it, then I keep turning the system up until pretty much all the filters are locked.

Then I store that setting. Next I leave the LD condenser hot and turn up the monitors until they start hollering. The Behringer unit takes out a lot of feedback and allows me to get the monitors pretty hot even though they are pointed back at a LD mic..

I then store that setting with the other. I defeat the Behringer unit for most bands, but as soon as the band wants to use an LD mic, I bring up my stored settings and everything works great.

The biggest thing to remember with all the FB units is that they are not "set and forget".. depending on what preset you use. If you leave any filters in "roaming" mode, the unit will eventually squeeze the life out of your sound.

I always change back to a default preset and then go back to my custom preset between sets to keep the unit from clamping down over several hours.

[Audiodude]

I've used elimators from Sabine and dbx. I know I'm really going to make a couple of manufacturers mad when I say this, but both units worked about the same. With a little tweaking, I was able to get both units (a Sabine FBX1200 and a dbx DriveRack PA with built-in feedback suppression) working about as well with about the same amount of fiddling...

I'm happiest when I don't have to use them, but in both situations we got some extra gain before feedback out of the system, and I was more comfortable turning over the reigns to the customers I had designed the systems for.

[GZsound]

I agree that it is better to not have to use them. And I also agree with your comments about there not being much difference in the units..

I have fellow sound contractors that use the Sabine units and have heard my inexpensive Behringer unit and could find no real difference.

I think the key is to use them sparingly. In my show band PA system, I have never used or needed any feedback supression. Proper mic placement, proper monitor placement and proper gain staging, etc. has "eliminated" the need for an "eliminator"..

[130dB]

I think the key is to use them sparingly. In my show band PA system, I have never used or needed any feedback supression. Proper mic placement, proper monitor placement and proper gain staging, etc. has "eliminated" the need for an "eliminator"..

Geez, I could have used one of these in the "hole" I used to work in. Having said that, I agree, technique before technology will get you a long way.

[sabianq]

yea, i don't use them either.
but i do have a selection of sabine workstations to choose from

if you set up your system correctly, and ring out your room, you really never need one.

besides, they are all destructive to the wave form.

[GZsound]

yea, i don't use them either.
but i do have a selection of sabine workstations to choose from

if you set up your system correctly, and ring out your room, you really never need one.

besides, they are all destructive to the wave form.

Well....that may be true, but until you have run an outdoor bluegrass festival sound system with one or two large diaphragm condensers on stage and the band demanding monitors.. you have no idea how nice a feedback eliminator can be. That is asking for disaster and all the ringing out in the world won't help.

But since that is a very rare occurance with most live music, I agree that proper PA setup is the better idea.

[sabianq]

An outdoor bluegrass festival sound system with one or two large diaphragm condensers on stage and the band demanding monitors..


well, In your case, then some processing would be needed, those condenser microphones can be a bear to work with.

I feel for you man.

I just cheat and use dynamic microphones.

plus, if you ever get a chance, you absolutely have to work with the Mackie active PA systems like the SRM450. the electronics in the system almost totally eliminate all feedback. you can almost rub a dynamic mic right on the grill at full level.

but back to the original question,

When i do use a "feedback" eliminator for those special occasions, i use the Sabine ADF1201 workstation or the FBX series.

those processors IMHO seem to be the easiest on the signal.

the other option is to use a gate/compressor/ limiter in the insert on the microphone line.

this can help if it is set up properly.

[GZsound]

well, In your case, then some processing would be needed, those condenser microphones can be a bear to work with.

I feel for you man.

I just cheat and use dynamic microphones.

plus, if you ever get a chance, you absolutely have to work with the Mackie active PA systems like the SRM450. the electronics in the system almost totally eliminate all feedback. you can almost rub a dynamic mic right on the grill at full level.

but back to the original question,

When i do use a "feedback" eliminator for those special occasions, i use the Sabine ADF1201 workstation or the FBX series.

those processors IMHO seem to be the easiest on the signal.

the other option is to use a gate/compressor/ limiter in the insert on the microphone line.

this can help if it is set up properly.


There is another sound contractor that does a lot of bluegrass and uses the Mackie SRM450's. Several problems arrise when using those boxes. First off, you need a bunch of them to get any projection, and second, he frequently has major feedback problems when he uses them in a less than acoustically pleasant room, like a gym or an armory.

The other issue is the cost of the Mackie speakers. My system has been paid for a long time ago and works perfectly for festivals with up to fifteen hundred people. The Mackies, although great speakers, would be way to expensive.. Much easier to simply buy a $125 Behringer feedback destroyer for the two or three times I need feedback supression over a given weekend sound gig..

The Mackies are also seriously lacking in projecting the low end of an upright bass. He eventually had to buy the Mackie's with two fifteens in each box and use the SRM450's for side fills and delayed room speakers.

I have compression/gating available in my rack, and you are right, a small amount of compression can give me more headroom and a smoother sound. You cannot gate an LD mic when it is used to pick up all the instruments..all the time.

But until you actually have a five piece acoustic band on a concrete stage with two LD mics and an upright bass (normally with a mic, sometimes a pickup) that plays right into the LD mics along with four other instruments and five vocalists... You haven't lived a full life..

Give me a rock band with individual 58's on everything any day...

[130dB]

Give me a rock band with individual 58's on everything any day...

Amen, brother. I've worked with a bluegrass band and an LDC mic, once and even though the show went well, I'd rather not work like that. :cool:

[87PRS]

Bluegrass Music is an awesome challenge, I ran sound for a BG Festival this September and used a LD (at first) then took it down, and replaced with a BlueBall (its a condenser/dynamic) and got more control (no feedback suppression) on my system. Upright bass is always challenging, and I mike them under bridge position w/SM57 in a foam cradle. But...having all the vocals mixed and all those sweet harmonies is very rewarding. Rock bands are way more easy, then a simple clean acoustic sound where nuances are important.

I got turned off by Mackie seven years ago, when right in the middle of a (rock) concert the mains power amp smoked on me. I've got five power amps and a boat anchor. Also, a good friend of mine had his Mackie mixer go out on the job...so I am not easily impressed with Mackie or the price tag. I am not saying that Mackie doesn't make some decent gear, this is just my experience... I've got cheapo Carvin gear that has lasted fifteen years and no problems, I just don't get it. And, honestly I am one of those who kid alot about Berry gear, but I do own some, and again I've never had a problem with it working. Sometimes we get lemons, and can't make lemonade.

Back to thread...hummm, I've never used a feedback eliminator, always rang out system, guess it comes from habit. So, i am absolutely no help on this topic :)

[GZsound]

Bluegrass Music is an awesome challenge, I ran sound for a BG Festival this September and used a LD (at first) then took it down, and replaced with a BlueBall (its a condenser/dynamic) and got more control (no feedback suppression) on my system. Upright bass is always challenging, and I mike them under bridge position w/SM57 in a foam cradle. But...having all the vocals mixed and all those sweet harmonies is very rewarding. Rock bands are way more easy, then a simple clean acoustic sound where nuances are important.

I got turned off by Mackie seven years ago, when right in the middle of a (rock) concert the mains power amp smoked on me. I've got five power amps and a boat anchor. Also, a good friend of mine had his Mackie mixer go out on the job...so I am not easily impressed with Mackie or the price tag. I am not saying that Mackie doesn't make some decent gear, this is just my experience... I've got cheapo Carvin gear that has lasted fifteen years and no problems, I just don't get it. And, honestly I am one of those who kid alot about Berry gear, but I do own some, and again I've never had a problem with it working. Sometimes we get lemons, and can't make lemonade.

Back to thread...hummm, I've never used a feedback eliminator, always rang out system, guess it comes from habit. So, i am absolutely no help on this topic :)

I also use the "stuff" mic technique with upright bass..although I normally use an SM58 because of the bigger head than the 57 which gives less chance of the mic sliding down the foam surround.

However, I have had bands insist I mic the upright bass with an LD set about a foot in front of the "F" hole and that has created massive feedback problems..especially when the bass player and the band insist on lots of bass in the monitors.

Try it yourself sometime. Point an LD at a shiny piece of metal, put a monitor three feet away, turn up the LD, turn up the monitor and then move the metal sheet around...like the upright bass moves, during performance.

In that instance alone, the Behringer feedback destroyer was priceless.

And I agree with the sentiments about Mackie. I use Soundcraft mixers, Yamaha and QSC amps..and NEVER had a failure. knock wood.

And I carry my Behringer PMX powered mixer/amp with me to every gig. $300, 27 pounds, ten low Z mic inputs, 250 watts per side and the best emergency PA system made for the money. It's my "if struck by lightning" backup.