Another question on signal

[gonzobassman]

Do feedback eliminators eliminate the need for graphic eqs,or do the two work hand in hand?I'm thinking for monitors as FOH rarely presents a real problem/challenge on this issue.

[agedhorse]

Used properly, I think both is ideal but if only one is available I will choose a 1/3 octave graphic every time.

[gonzobassman]

Understood from the perspective of FOH engineer,but as a musician trying to do it from stage?I mean if I get a squeal in the middle of a song its gonna be tough to find that frequency,and notch it out on the fly.Not disagreeing with you,just saying.

[tlbonehead]

As a guitarist/singer/person in charge of our sound area as well, I'd easily go with a graphic EQ, especially a Peavey FLS model. But if you dial your monitors in a little initially and leave yourself a little room, feedback should be a rarity.

[gonzobassman]

Yea.Without an eq you really have no tone shaping available to you if you are using aux sends for monitor feeds.And this one singer I work with has to have her signal so hot it's been right on the verge every show.I have an almost entirely new system so we should be able to get her waht she thinks she needs ok now,but I do intend to draw the line at effects in the monitors!!!Lol

[SpaceNorman]

That's why gawd invented the DBX Driverack .... EQ and automatic feedback supression ... AND an EQ "wizard" that does a pretty good job of putting a baseline EQ setting.

 

I've been using one on our monitors for several years and love it.

 

With the recent price drop (GC's hawking 'em for $350 these days...), it's hard to beat.

[gonzobassman]

Don't you need one for every monitor send/mix? I was thinking with 4 monitor sends I would need 2 stereo 31 band eqs just on monitors,so I would need 4 of these driverack"wonder gadgets"just on monitors?Even at the price of $350.00 per thats a little tough just getting this thing going.

[dboomer]

 

Do feedback eliminators eliminate the need for graphic eqs,or do the two work hand in hand?

 

 

It all depends. Do you need to tone shape the speaker or just eliminate feedback ... or both. Eqs are best suited to tone shaping and feedback eliminators because of their very narrow filters feedback. If you need to deal with both, you could use both. The do work very well together when properly set up.

 

Most people use GEQs only to try and combat feedback while shaping tone. It really depends on your skill level. Most that I see actually end up making their system worse than nothing at all. The nice thing about feedback elminators is they are under computer control and require no skill to operate

[xmlguy]

So I'm talking to the Manager at my local Guitar Center when a buddy of his comes up and says he's still having a major feedback problem on the PA system he's testing at home for use with some choir gigs. The GC manager had sold him a Behringer Feedback Destroyer Pro and $1000 worth of new condenser mics, which he told his buddy were essential to get rid of the feedback. As a favor I volunteered to look at the setup since I wasn't doing anything that evening.

 

Sure enough, when I got there he could barely turn up the volume before LF feedback occurred. The Feedback Destroyer, new mics, and all were hooked up. I observed that the PA speakers were about 10feet in front of the mics, but the mics were located in an enclosed patio with an open awning, underwhich the PA speakers sat on pole mounts. I moved the speakers a few feet out from under the awning. The feedback instantly disappeared.

 

The stunned look on their faces was priceless. I was the feedback eliminator. It cost nothing. Later when I looked at the feedback destroyer, I noticed that it wasn't even engaged by default. They just assumed it would do something. I read the manual (which was in the sealed plastic).

[agedhorse]

Being smarter than a computer is not all that difficult IMO.

[xmlguy]

 

Being smarter than a computer is not all that difficult IMO.

 

 

True, not difficult for me. But it helps to learn how engage the computer. My point was to agree with you that the used properly part may be a problem for the people who think buying a feedback eliminator is all that's necessary to eliminate feedback. Automatic parametric EQs may be more difficult to learn and use than the more obvious function of a graphic EQ, since all the functionality is hidden inside.

[gonzobassman]

Thats just wild.Manual was never even looked at.Checking out the manual before doing anything is just one of my guilty pleasures.No matter what I buy!!! Lol

[dboomer]

 

Automatic parametric EQs may be more difficult to learn and use than the more obvious function of a graphic EQ, since all the functionality is hidden inside.

 

 

I have to strongly disagree here. I don't exactly know what you mean when you say "learn and use" ... but if you are not using (properly) a high end measuring system to let you know how to adjust your GEQ ... you are pissing into the wind.

 

Feedback eliminators only know how to attack feedback. There seems to be some disagreement as to whether they cause some loss of tone but I can't imagine that when the choice is loss of tone or raging feedback one could ever chose feedback. Feedback eliminators do nothing to correct for tone ... but hopefully you have a monitor that was voiced by the manufacturer.

 

The most common problem with GEQs is they are mis-adjusted and actually carve out useful frequencies. Users often think they have more loudness but what they really get is less effective monitor signal and end up total net negative.

 

So in response to the post above I would also add that most user's systems would also benefit from pressing the bypass button on their GEQs. As with the example above a better and balanced system should be the first choice before adding the band-aid of GEQ.

[SpaceNorman]

 

Don't you need one for every monitor send/mix? I was thinking with 4 monitor sends I would need 2 stereo 31 band eqs just on monitors,so I would need 4 of these driverack"wonder gadgets"just on monitors?Even at the price of $350.00 per thats a little tough just getting this thing going.

 

 

The DriveRack PA is a two channel (stereo) unit - so at a minimum you'd need two to hand 4 channels of monitors. There is a caveat to the DriveRack PA's "stereo" setup however - and that is that it's "linked" - meaning that you can't EQ each channel separately. The EQ settings are applied to both channels. IF you're using a monitor rig in which all the speakers are of the same make (in our case we're using 4 Yamaha Club 5 wedges) - this isn't a big deal (at least we haven't found it to be).

 

If you're running 4 separate monitors mixes - you'll need 4 channels of signal processing (i.e., EQ) no matter what you do. Using the dBX 231 dual 31 band graphic EQ which appears run $200 (MAP) - you're looking at $400 as a cost baseline since you'll need 2 of 'em to run 4 mixes. For an additional $150 per 2 channels - the DriveRack PA adds automatic feedback supression and the "EQ Wizard" that automagically configures the EQ via real time analysis.

 

I suspect that the real pros on the forum will likely discount the value of the DriveRack EQ wizard - and rightfully so. However as a "mix from stage", weekend warrior kind of band without a pro sound guy at our disposal - we've found that the EQ Wizard consistently provides us with a VERY functional EQ baseline in just a couple of minutes. Tuning the monitor rig is a 4 minute exercise ... plug in the RTA mic ... run the wizard, engage the Automatic Feedback Suppression system - and we're done.

[twostone]

I just use a Sabine FBX2400 for 2 monitor sends and that's it. I'm really not concerned about having perfect tone shapes on the wedges because we're pretty loud on stage. All I need is something that kills the FB at high volumes and the Sabine FBX 2400 works great for us. FWIW, it really doesn't alter the tone that much. Sometimes you can actually hear the FBX working. You can hear a faint FB ring during performing and then zap it gone.

I never was worth a {censored} ringing out with a 31 band eq by time I was done my wedges sounded like {censored} but.mind you they didn't have FB in them just maybe I cut to much and every body complained how bad the wedges sound. Then Dboomer turn me on to the Sabine FBX2400 and it's made things sound better and set up time way faster.

Just my 2 cents worth on the topic.

[Special J]

 

I have to strongly disagree here. I don't exactly know what you mean when you say "learn and use" ... but if you are not using (properly) a high end measuring system to let you know how to adjust your GEQ ... you are pissing into the wind.

 

 

LOL! A high end measuring system? You mean like my ears? That tends to be my go-to tool for adjusting EQ's. I've been pissing into the wind this whole time, and I didn't even know it!

[Coaster]

you have to consider that dboomer is usually on bigger rigs than a lot of us use and on those larger rigs what he says is true. for the smallish rigs we can use our ears just fine for eq.

[Special J]

I'm not questioning the usefulness of RTA's, SMAART or other measurement programs, but they are just another tool, and should never be a replacement for your own ears and good judgement. Same with feedback eliminators. They can be a useful tool, but they aren't a replacement for knowing how to properly ring out a monitor system. Remember, we did sound before the computers came to do it for us. I've worked on some rather large rigs myself. It's just more/better/bigger stuff. The theories don't change.

[Coaster]

no the theories don't change but my ability to walk a small room with only a floor level seating is a lot easier than a very large venue with multiple levels and stadium seating where even the floor is so huge it takes literally minutes to walk from one side to the other. thats when the measurment systems really shine imho.

 

small bar? forget it - i can walk the entire area in seconds.

[dboomer]

I don't expect anyone to not use their ears ... but using only your ears will only get you so far. There are a number of problems that you can measure that your ears will never figure out. Measurement systems are frequently misused too. They are only as good as your measurement position.

 

In the end ears must be the final arbiter ... but there are way too many users that think they can benefit from ears and EQs. There are only so many things that an EQ can fix, and a number of things that your ears hear as wrong but that EQ cannot fix. Having a measurement tool can let you know the difference.

 

Like I say ... when people pay me to come adjust their systems 9 times out of 10 the EQ is all screwed up. YMMV:thu:

[Coaster]

 

and a number of things that your ears hear as wrong but that EQ cannot fix

 

 

like time?

[agedhorse]

 

I don't expect anyone to not use their ears ... but using only your ears will only get you so far. There are a number of problems that you can measure that your ears will never figure out. Measurement systems are frequently misused too. They are only as good as your measurement position. In the end ears must be the final arbiter ... but there are way too many users that think they can benefit from ears and EQs. There are only so many things that an EQ can fix, and a number of things that your ears hear as wrong but that EQ cannot fix. Having a measurement tool can let you know the difference. Like I say ... when people pay me to come adjust their systems 9 times out of 10 the EQ is all screwed up. YMMV:thu:

 

 

Yes, my experience as well.

[dboomer]

 

There are only so many things that an EQ can fix, and a number of things that your ears hear as wrong but that EQ cannot fix.

 

 

Equalizers cannot perform room correction, reflections, absorption, room modes etc. They generally cannot correct any phase related issues.

[xmlguy]

 

I have to strongly disagree here. I don't exactly know what you mean when you say "learn and use" ... but if you are not using (properly) a high end measuring system to let you know how to adjust your GEQ ... you are pissing into the wind. Feedback eliminators only know how to attack feedback. There seems to be some disagreement as to whether they cause some loss of tone but I can't imagine that when the choice is loss of tone or raging feedback one could ever chose feedback. Feedback eliminators do nothing to correct for tone ... but hopefully you have a monitor that was voiced by the manufacturer. The most common problem with GEQs is they are mis-adjusted and actually carve out useful frequencies. Users often think they have more loudness but what they really get is less effective monitor signal and end up total net negative. So in response to the post above I would also add that most user's systems would also benefit from pressing the bypass button on their GEQs. As with the example above a better and balanced system should be the first choice before adding the band-aid of GEQ.

 

 

Actually, I don't agree with anything you're saying here, but perhaps I didn't explain what I meant well enough. I was referring to the use of more sophisticated EQ and feedback detection systems by novices, not by pro soundmen. I like to use 1/3 octave graphics, parametrics, and whatever else I can get my hands on. I also enjoy reading manuals and getting the most out of the gear. But I also appreciate that a lot of people aren't like me, like the amateur soundman I helped with his feedback problem.

 

The simplicity of a 1/3 octave is easier to explain and use, at least initially, to get someone from the no EQ or bad EQ phase of learning to the first step of ringing out a room, notching out the problems, and then helping to flatten out the PA (which is often crap). In the specific example I gave, I wasn't about to give the guy a free lesson in how his feedback destroyer worked, since I was only helping as a favor to get him through a gig. Due to a strange set of circumstances, I actually ended up running the gig, which went great for both the audience and performers. They would've been complete hosed if I happened to not be there, so I didn't mind rescuing the event. I enjoyed the music, and I didn't have to haul/teardown the gear, so it was no real effort for me.

[dboomer]

Let's first differentiate between using a device and using it correctly for net benefit.

 

Feedback eliminators require no skill to use to reduce feedback .. only the ability to patch it correctly into the system. They do not require the user to make any judgements. I see 1/3rd/oct GEQs as very sophisticated devices that require nothing but raw skill (especially when not used with measuring systems). Everything is a judgement call.

 

"Ringing a room" is better than nothing but is rarely a better solution to preventing/removing feedback than the narrow filters of a feedback eliminator can perform on a net advantage. This is because GEQs filters are typically a whole octave wide compared to the typical 1/10/oct of a feedback eliminator. You have to allow that there are some crap fbx's out there and I'm not counting those.

 

The preferable system would use GEQ/PEQ for tone correction including some flattening of the frequency response and then allowing a feedback eliminator (preferably inserted to the most possible mic offenders per channel or bussing them together and processing the buss).

 

Bottom line to me is that it is totally possible to do a great show with less than great tone from the system ... but feedback is a show stopper any time it happens. If you are pushing close to the max these devices can find and fix feedback before you can even look up. It's cheap insurance and if their processing isn't needed they usually just let the filters go.