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feedback exterminator


ThE bAsS MeKaNiK
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Guest DustyDeviada

Are you talking about the plastic things that go over the soundhole of an electro?

If so then Emma Forman has one. Don't know about the results though.

I have an Epiphone Chet Atkins SST, which is a solid body acoustic - no feedback!

Sorry if you're talking about electrics, not really clear from your post.

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Yeh, if your talking about the actualy Feedback ELimator units ie the Rackmount ones then don't bother!

THe only types of feedback you will get and regular and microphonic - you only get regular if you're standing infront of ur amp and this is easy to control by moving around and facing away from the amp!

As for microphonic feedback this is a pickup problem only so there's no need for a unit to combat this - just get ur pickups potted!

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The best way to get rid of feedback issues is to take a 31 band eq (or a parametric with a few channels, the 15 band graphics aren't as good as the 31 band ones), find the frequency that you're feedbacking at (the peavey FLS EQs are handy for this if you're not good at identifying frequency) and reduce it till you get more volume(gain) before feedback occurs, until you get as much volume as you deisre.

Feedback destroyers just atttempt to do this automatically and digitally, but often there is a delay before they operate.

The better quality of equipment (esp monitors) you are using the less of an issue feedback will be and the less you will need to tweak with an EQ. Proper mic placement is essential too, use a different placement of monitors for cardioid and hypercardioid mics.

I wouldn't spend my money on a feedback destroyer.

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Doc, I absolutely agree.

Heres an explanation on how to use an EQ to reduce feedback:

http://acapella.harmony-central.com/forums/showthread.php?s=&postid=7286019post7286019

and here it is again, worded differently:

http://acapella.harmony-central.com/forums/showthread.php?s=&postid=8262668post8262668

if you note in that last thread, theres a link to a nice little piece of software called the 'Neihoff Feedback Trainer', its a simple and effective way to help you identify feedback frequencies, recommended :)

On a side note - there are far too many djs in aberdeen who take one look at an EQ unit and say "Ooh! Ooh! Smiley face smiley face!" and turn the sound to mince. I hear it all the time when I'm out, exodus is quite bad for it.

Again if you've set your mix up properly, you won't need one.

Although this may be true in a number of cases...

1. I'd rather have and not want, than need and not have.

2. If you have no other low pass filters in your system, a lot of EQs will have this feature. A low pass filter around 30 - 50hz will help protect the (sub)woofers, let the system run efficiently and in certain cases a system will have more punch or clarity with such a filter engaged.

3. How many SERIOUS systems have you seen without an EQ or DSP?

Some food for thought...

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The poormans guide to ringing out....

1. Set the EQ to flat (use the detents)

2. Very slowly increase the gain of your first mic channel until you hit feedback, not loads of feedback, but just one frequency ringing out. Too much and you've gone too far. Find the corresponding frequency on the graphic and roll it off just until it cuts off.

3. After removing the first "ring" , increase the gain again, the next time it feedbacks you will hear a much more prominent frequency, which will most likely be your culprit. Roll it off the EQ slowly again.

4. Repeat one more time if desired

5. By this time when you increase the gain you're likely to hear 3 feedback notes, this indicates that your gain is too loud!

You should rarely have to pull out more than 3 frequencies, leaving the EQ flat could even be the best answer. Use your ears as judgement. Every room/scenario is going to be different obviously, so theres no golden rule. Once you've brought up all mics, ring out the whole mix and check levels again.

A tip: patch in a compressor and set the ratio to infinite with a low threshold, this means you won't kill your speakers (or more importantly, your ears) when ringing out.

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The poormans guide to ringing out....

1. Set the EQ to flat (use the detents)

2. Very slowly increase the gain of your first mic channel until you hit feedback' date=' not loads of feedback, but just one frequency ringing out. Too much and you've gone too far. Find the corresponding frequency on the graphic and roll it off just until it cuts off.

3. After removing the first "ring" , increase the gain again, the next time it feedbacks you will hear a much more prominent frequency, which will most likely be your culprit. Roll it off the EQ slowly again.

4. Repeat one more time if desired

5. By this time when you increase the gain you're likely to hear 3 feedback notes, this indicates that your gain is too loud!

You should rarely have to pull out more than 3 frequencies, leaving the EQ flat could even be the best answer. Use your ears as judgement. Every room/scenario is going to be different obviously, so theres no golden rule. Once you've brought up all mics, ring out the whole mix and check levels again.

A tip: patch in a compressor and set the ratio to infinite with a low threshold, this means you won't kill your speakers (or more importantly, your ears) when ringing out.[/quote']

If that's all too much for you, buy a behringer ultra curve pro and a reference mike and it'll do it all automatically.

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Doc' date=' I absolutely agree.

Heres an explanation on how to use an EQ to reduce feedback:

[url']http://acapella.harmony-central.com/forums/showthread.php?s=&postid=7286019post7286019

and here it is again, worded differently:

http://acapella.harmony-central.com/forums/showthread.php?s=&postid=8262668post8262668

if you note in that last thread, theres a link to a nice little piece of software called the 'Neihoff Feedback Trainer', its a simple and effective way to help you identify feedback frequencies, recommended :)

On a side note - there are far too many djs in aberdeen who take one look at an EQ unit and say "Ooh! Ooh! Smiley face smiley face!" and turn the sound to mince. I hear it all the time when I'm out, exodus is quite bad for it.

Although this may be true in a number of cases...

1. I'd rather have and not want, than need and not have.

2. If you have no other low pass filters in your system, a lot of EQs will have this feature. A low pass filter around 30 - 50hz will help protect the (sub)woofers, let the system run efficiently and in certain cases a system will have more punch or clarity with such a filter engaged.

3. How many SERIOUS systems have you seen without an EQ or DSP?

Some food for thought...

Serious systems have serious eq units costing 2000 plus-the only ones with enough definition to be worth having. You don't really need one if you know what you're doing with mobile systems under 5000 watts, providing, as you rightly say, your desk is good enough to have low pass filters.

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Serious systems have serious eq units costing 2000 plus-the only ones with enough definition to be worth having. You don't really need one if you know what you're doing with mobile systems under 5000 watts' date=' providing, as you rightly say, your desk is good enough to have low pass filters.[/quote']

Ok, ok, I see what you're saying. I've seen a number of cheaper systems being run without an EQ and there not being too much of a problem, but to say that only 2000 plus EQs are worth having (after suggesting a BEHRINGER eq unit??? I'll let that slide since you were making a point ;) I would have recommended a driverack myself but they're quite pricey.)? I recommend you take a look at Michael Knowles graphic EQ shootout . For monitors particularly its my firm opinion that the more gain before feedback available the better, and an EQ unit can give you that, especially if you find yourself in a strange shaped room with a lot of reflections. I've managed to reduce feedback and other reflections using just a peavey CEQ unit and the system sounds all the better for it. I've even been able to squeeze more usable volume out of a powered mixer just by tweaking its 7-band eq.

You are right, you dont NEED and EQ unit, and you can get off without one but a carpenter doesn't really NEED a hammer if he can just bash nails with a large file. He still carries a hammer.

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Ok' date=' ok, I see what you're saying. I've seen a number of cheaper systems being run without an EQ and there not being too much of a problem, but to say that only 2000 plus EQs are worth having (after suggesting a BEHRINGER eq unit??? I'll let that slide since you were making a point ;) I would have recommended a driverack myself but they're quite pricey.)? I recommend you take a look at Michael Knowles graphic EQ shootout . For monitors particularly its my firm opinion that the more gain before feedback available the better, and an EQ unit can give you that, especially if you find yourself in a strange shaped room with a lot of reflections. I've managed to reduce feedback and other reflections using just a peavey CEQ unit and the system sounds all the better for it. I've even been able to squeeze more usable volume out of a powered mixer just by tweaking its 7-band eq.

You are right, you dont NEED and EQ unit, and you can get off without one but a carpenter doesn't really NEED a hammer if he can just bash nails with a large file. He still carries a hammer.

I agree. They're very useful if you're using wedge monitors, which seriously limit your gain structure if you don't have one. However, now that in ear systems are getting cheaper, many bands opt for this instead of wedges and have much less feedback issues.

The behringer, while cheap, works very well, but the drive rack is a superb piece of kit, well worth the price tag. Fast and easy to use. You can also set up a room then save it and recall it next time you play there.

With the latest noise police regulations, it won't be long before you won't be able to turn a PA up loud enough to get feedback. 85 dB indeed!

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Just out of curiosity, are you actually having any problems with feedback right now or is this a 'rather take it and not use it, than need it and not take it' thing (like a spare guitar cable) ?

By your last post it looked like you were pricing them up, maybe theres a cheaper solution (like wedge placement or microphone type).

Or were you just asking out of curiosity? :)

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85dB? You're joking! That could never take off, there has to be some exceptions to this, like, a noise licence or something. Concerts just wouldn't be worth going to.

Then again...it might be nice to actually have a conversation in moshulu from time to time :)[/quote

It's not for the punters, it's for the staff!! Latest proposals are that staff can be exposed to 85dB for no more than 1 hour without hearing protection!!!!

They haven't even got around to protecting the punters yet. I've heard levels of 90 dB being bandied about.

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Just out of curiosity' date=' are you actually having any problems with feedback right now or is this a 'rather take it and not use it, than need it and not take it' thing (like a spare guitar cable) ?

By your last post it looked like you were pricing them up, maybe theres a cheaper solution (like wedge placement or microphone type).

Or were you just asking out of curiosity? :)[/quote']

was just a curiosity thing. i play bass and dont sing so i dont really have any probs with feedback - unless tis on purpose :D if i was too spend that kinda cash on something a 31band EQ would be top of the list i reckon but then would i really need that either.......

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85dB? You're joking! That could never take off' date=' there has to be some exceptions to this, like, a noise licence or something. Concerts just wouldn't be worth going to.

Then again...it might be nice to actually have a conversation in moshulu from time to time :)[/quote

It's not for the punters, it's for the staff!! Latest proposals are that staff can be exposed to 85dB for no more than 1 hour without hearing protection!!!!

They haven't even got around to protecting the punters yet. I've heard levels of 90 dB being bandied about.[/quote']

Hehe interestingly enough, I had this crazy idea once that bar staff could wear ear protectors, and punters would use touch screens at the bar to key in what they want rather than scream "THREE PINTS!! THREE PINTS!!! CAN'T YOU F@&KING HEAR ME!!!"

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Hehe interestingly enough' date=' I had this crazy idea once that bar staff could wear ear protectors, and punters would use touch screens at the bar to key in what they want rather than scream "THREE PINTS!! THREE PINTS!!! CAN'T YOU F@&KING HEAR ME!!!"[/quote']

Don't laugh it could happen.

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The poormans guide to ringing out....

1. Set the EQ to flat (use the detents)

2. Very slowly increase the gain of your first mic channel until you hit feedback' date=' not loads of feedback, but just one frequency ringing out. Too much and you've gone too far. Find the corresponding frequency on the graphic and roll it off just until it cuts off.

3. After removing the first "ring" , increase the gain again, the next time it feedbacks you will hear a much more prominent frequency, which will most likely be your culprit. Roll it off the EQ slowly again.

4. Repeat one more time if desired

5. By this time when you increase the gain you're likely to hear 3 feedback notes, this indicates that your gain is too loud!

You should rarely have to pull out more than 3 frequencies, leaving the EQ flat could even be the best answer. Use your ears as judgement. Every room/scenario is going to be different obviously, so theres no golden rule. Once you've brought up all mics, ring out the whole mix and check levels again.

A tip: patch in a compressor and set the ratio to infinite with a low threshold, this means you won't kill your speakers (or more importantly, your ears) when ringing out.[/quote']

That sounds familiar, is it not a BSS guide to EQ?

Unfortunately it leaves out the fact that if the speakers/room aren't that good you've got to do a lot more than 3 frequencies before you can START worrying about feedback.

Personally I wouldn't bother with feedback suppressors: if you need one you've either already fucked it up, your speakers are mince or you're out of your depth and should get in a pro. I've never seen (heard) one faster than a competent human.

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