# Recording lecturns



## Harpmaker (Oct 28, 2007)

I'm hoping to get some advice from folks who have experience with such things. 

The situation is I have an old Zoom MRS-4 digital recorder (uses SmartMedia cards fer cryin' out loud!) and I need to record people speaking at a lectern, but they don't know how to use a mic (meaning they hold the thing at waist level). If I was just recording then I could simply boost the sound volume in post-production (I love digital audio!), but the signal is also going to a cheap Squire PA system.

My current setup is using a Shure SM-58 mic going into the PA and then sending the output to the recorder. From what little I know about microphones, the SM-58 is designed for singing, or talking with the mic close to the mouth. It worked okay the first time I used it, but I knew the sound volume should have been louder. As it is, I have to have the PA gain/volume controls set so they are on the verge of feedback.

Do I need a different mic, a mic pre-amp, or what?

Cost is an issue  since it's a non-paying gig (church group).


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## Wayne A. Pflughaupt (Apr 13, 2006)

*Re: Recording lectures.*


Since it's a lectern, how 'bout a screw-down mount with a gooseneck attached? That would work as long as they're staying put behind the lectern...

Lacking that, a parametric EQ could notch the feedback frequency and allow you to push the gain higher. You have a BFD in your home system, right? 

Regards,
Wayne


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## Harpmaker (Oct 28, 2007)

*Re: Recording lectures.*



Wayne A. Pflughaupt said:


> Since it's a lectern, how 'bout a screw-down mount with a gooseneck attached? That would work as long as they're staying put behind the lectern...


Thanks Wayne.
I tried the whole stationary mic thing, but they want to either move around while behind the lectern (sometimes even standing beside it ), so that won't work too well. If it was just a single speaker I would think about going to a lavalier mic, but there are multiple speakers.



> Lacking that, a parametric EQ could notch the feedback frequency and allow you to push the gain higher. You have a BFD in your home system, right?
> 
> Regards,
> Wayne


Sorry, I haven't gotten a Behringer Feedback Destroyer yet, although from looking at what this thing is supposed to do it might work for the purpose. Does it cut down a little or a lot on feedback? It almost sounds too good to be true.


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## tenzip (May 4, 2007)

*Re: Recording lectures.*

Maybe you can pick up a wireless lapel mic somewhere for not too much, that would solve most of your problems, as they wouldn't have to hold it, just talk. I know we rented one locally for a function at work, don't remember how much it was. No idea how much they cost, either. I know it had a wireless lapel mic, and a standard hand-held wireless mic, both feeding one receiver/mixer unit.


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## tonyvdb (Sep 5, 2007)

*Re: Recording lectures.*

Wireless lap is definatly the way to go. You can even get not only the transmitter battery operated but the receiver as well and they work well. I have a Telex Pro that has a 9v battery on each end and it lasts about 4 hrs on one battery has gain and level adjustments for ideal volume control.


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## tenzip (May 4, 2007)

*Re: Recording lectures.*

Sorry Don, for some reason I didn't make the connection between lavalier and lapel mic, but the system I'm thinking of would at least give you the flexibility of having a second hand held mic for other speakers, particularly if they are just speaking briefly.

Speaking from very little experience, it's quick to change from one person to another with the lapel mic, as long as you're not trying to run the wires inside shirts/blouses. The easiest way I found was to have the person wearing the mic take it off their shirt, hook it to the incoming speaker's shirt, remove the transmitter from their belt/waistband, and route the cord for the incoming speaker. Much faster and easier than having a person try to hook it to themselves.
Of course, the transmitter should be turned off or muted during this process, as it tends to be kind of loud if you leave it on.

If you are sitting somewhere that the speakers can see you while tending to the equipment, I suggest making a large sign saying MUTE, and hold it up to remind them when they are approaching the switch from one to another.

As for folks not holding the mic up to their mouth, there's really no cure besides standing behind them with a rolled-up piece of newspaper, and giving them a sharp whap in the back of the head when they let it drop. After a few whaps, the issue should be corrected.

Is the mic hooked up to a PA, or is it just for the recording?


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## Harpmaker (Oct 28, 2007)

*Re: Recording lectures.*



tenzip said:


> Sorry Don, for some reason I didn't make the connection between lavalier and lapel mic, but the system I'm thinking of would at least give you the flexibility of having a second hand held mic for other speakers, particularly if they are just speaking briefly.


No sweat, the common term is lapel mic; but I guess lavalier is more correct.:dontknow:



> If you are sitting somewhere that the speakers can see you while tending to the equipment, I suggest making a large sign saying MUTE, and hold it up to remind them when they are approaching the switch from one to another.


The problem is that besides their being multiple speakers, sometimes I don't even know who is going to be speaking since it's kind of a "whoever feels like saying a few words" thing. Changing lapel mics from user to user would be a real hassle; that's why I'm hoping to find another answer.



> As for folks not holding the mic up to their mouth, there's really no cure besides standing behind them with a rolled-up piece of newspaper, and *giving them a sharp whap in the back of the head when they let it drop*. After a few whaps, the issue should be corrected.


Oh man, don't tempt me! :bigsmile:



> Is the mic hooked up to a PA, or is it just for the recording?


The mic is hooked to the PA.


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## tonyvdb (Sep 5, 2007)

*Re: Recording lectures.*

Its sounding like you must go with a podium mounted mic, there are many manufacturers of microphones out there that would do the job. Sure still makes one of the best the SM58 Another option is to get a good condenser microphone like the Sure SM81 as it being a condenser it will have a greater range and thus will pick up spoken word from a fair distance away. The drawback is that they can not be held and are poor if spoken into or blown into from less than 2" away.


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## Wayne A. Pflughaupt (Apr 13, 2006)

*Re: Recording lectures.*




Harpmaker said:


> Sorry, I haven't gotten a Behringer Feedback Destroyer yet, although from looking at what this thing is supposed to do it might work for the purpose. Does it cut down a little or a lot on feedback? It almost sounds too good to be true.


I only suggested the BFD on the chance you might have one, so it wouldn't cost a dime to take it out and use it. Ordinarily I prefer a more traditional equalizer.

Reading the other suggestions and your replies, it looks like podium mounting and lavs are out. Since it looks like you'll have to spend some money, I suggest a Rane PE15 parametric EQ. They're pretty cheap on eBay. I sold one a few years ago in pristine condition and got only $30-40 for it, IIR.

Basically, there's nothing like a parametric EQ for eliminating feedback. It's pretty easy, too. You can set it up before the show starts for a quiet, worry-free performance.

All you do is set the mic on a stand at the location you know will be the closest that the (human) speaker will ever get to the (PA) speaker. Slowly push the volume slider on the mixer up until feedback starts, then reduce the slider to stop it. Make a mental determination as to the general frequency range where the feedback is occurring. Typically it is the midrange and higher. As an audiophile you can tell a midrange feedback frequency from a high frequency one, right ? 

Each filter on the Rane has a frequency operating range (say, 200Hz - 4000Hz, for instance). Select a filter that covers the range of the feedback you heard. Turn the bandwidth knob to the left for a tight setting, something like 1/6 to 1/10-octave. Also turn the gain knob to the left for a negative value, say -4 to -6 dB. Turn the frequency knob all the way to the top or bottom of the range - your choice.

Now, run the slider on the mixer up again to cause the feedback, only this time ride gain up and down to keep the offending frequency at a steady level (one that's non-damaging to both the system and your ears!). Then, sweep the frequency knob, "fishing" for the offending frequency. When you hit it, it will suck the feedback right out.

You will notice immediately that you will now be able to turn the volume slider on the mixer to a higher setting than you could before, before feedback starts. 

If you think you need even more headroom, push the slider up some more to find the next ringing frequency, and repeat the exercise and eliminate that one, too. If instead you find that the first frequency starts feeding back again, all you have to do is increase the amount of cut a few more dB via the gain knob. Occasionally you'll find the second ringing frequency is right next to the first. In that case, just open up the bandwidth a bit, and you can catch both offending frequencies with the same filter.

I've use this technique to great success over the years. I used to do "kiddie theater" sound for the my kid's school - i.e., the Christmas, Easter programs, graduations, etc. It was murder getting some of the littlest kids to speak up - kindergartners, 1st, 2nd grade etc. Using my PE15 and the Shure SM 58 mics Tony mentioned, I could push the level of those mics to insane levels with no feedback, enough for the parents to hear their little darling's mumblings. 

As far as the speakers not holding the mic correctly, the usual response from the sound man in this situation is (naturally) to turn the volume up to compensate for the drop in sound level, right? You might instead try a "reverse psychology" or "Pavlov's dogs" approach. As the speaker moves the mic away from his mouth, turn the volume _down_. When the audience starts complaining "we can't hear you," admonish the speaker to hold the mic closer to his mouth. When he does, "reward" him with audible sound. Of course, you will have to ride gain on the slider, turning it up and down with his hand movement to make it appear that he is indeed the cause of the problem. Repeat as needed. When the speaker gets tired of the audience complaining and/or interrupting him, he'll come around.

Regards,
Wayne


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## ludwignew (Nov 14, 2008)

*Re: Recording lectures.*

Why don't you try with a SM89. It has a hypercardioid pattern and could be useful to control distance and gain in mixer.


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## tenzip (May 4, 2007)

*Re: Recording lectures.*

Well, I haven't given up, here's some more suggestions for you. I see Wayne posted while I was typing, his suggestions sound pretty good to me.


 First, do the speakers have any investment in having the lecture recorded? If not, you're fighting an uphill battle, I fear. If they do, get them together and explain the issues. Run down the options, and explain that the easiest/cheapest/quickest solution is for them to hold the mic up to their face. (Including the newspaper training option may or not be indicated, depending on the group, but could be used to get the point across.)
 Cut the hook off of a clothes hanger, and bend the ends around the top and bottom of the mic, so that you have a triangle sticking out perpendicular to the axis of the mic, and tell the speakers to keep the point of the triangle on their breastbone. This will be a physical reminder of correct placement. Adjust the length of the wire to position correctly. Some electrical tape under and over the wires will keep them in place on the body of the mic.


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## tenzip (May 4, 2007)

*Re: Recording lectures.*



Wayne A. Pflughaupt said:


> As far as the speakers not holding the mic correctly, the usual response from the sound man in this situation is (naturally) to turn the volume up to compensate for the drop in sound level, right? You might instead try a "reverse psychology" or "Pavlov's dogs" approach. As the speaker moves the mic away from his mouth, turn the volume _down_. When the audience starts complaining "we can't hear you," admonish the speaker to hold the mic closer to his mouth. When he does, "reward" him with audible sound. Of course, you will have to ride gain on the slider, turning it up and down with his hand movement to make it appear that he is indeed the cause of the problem. Repeat as needed. When the speaker gets tired of the audience complaining and/or interrupting him, he'll come around.


I still like the newspaper. :devil:


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## tonyvdb (Sep 5, 2007)

*Re: Recording lectures.*

Wayne, would it not be cheaper to just get a 1/3 octave EQ and simply cut the frequencies that cause the issue? A parametric EQ has only a certain number of filters available to the user.


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## Wayne A. Pflughaupt (Apr 13, 2006)

*Re: Recording lectures.*


Cheaper than $50-60? :scratch: It's not hard to get a PE15 for that (okay, they seem to be getting a bit higher prices on eBay than when I sold mine :hissyfit: ).

In my experience, a 1/3 octave EQ is not nearly as good for feedback control because it cuts too wide a path. To start, it can't precisely nail the offending frequency, only get close to it (unless perchance it is a perfect ISO frequency)! This means a more severe cut will be needed than if a parametric was used. 

And remember, it's cutting 1/3-octave on _both sides_ of the center frequency - 2/3 octaves total. That's introducing a pretty big hole just to hit a ringing note that can be nailed with a 1/10-octave or tighter filter. Multiply that wide path by the number of cuts you may have to make for additional feedback frequencies, and you're having a pretty devastating effect on overall frequency response, affecting far more than just the offending frequencies. With a parametric, you can notch offending frequencies with surgical precision, so much so that you can switch the filter in and out and hardly hear its effect at all. No way will a 1/3 EQ do that...

Sure, the parametric only has a few filters, but usually that's more than enough. Typically there will be only two or maybe three offending frequencies to get under control. If need be, the mixer itself can be used to "buy more mileage" from the parametric. Engaging its low pass filter and severly turning down the bass knob will take care of the entire bottom end, leaving more filters avalible. For voice, nothing below ~200 Hz is needed anyway. If there are other considerations in the system, like if music is played, the EQ can be inserted in the mic channel's signal chain and leave the rest of the system unequalized.

Regards,
Wayne


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## tonyvdb (Sep 5, 2007)

*Re: Recording lectures.*

Fully understand :T


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## Harpmaker (Oct 28, 2007)

*Re: Recording lectures.*

Thanks for all the feedback (pun intentional ) so far guys. So far the solutions seem to be around the $100 mark, which is doable, but close to the top end of my budget spectrum.

I would really like to stay with a hand-held mic if possible. The quality shotgun mics are just too expensive for me.

To reiterate, I am currently using a Shure SM58. I love the sound I get from the mic, I just wish it picked up sound at a farther distance from the person speaking than it does, but I guess it's designed not to.

Of the solutions so far (please keep them coming!), the Rane PE15 sounds like the one I would go with.

The room I'm recording in is beside the kitchen in a medium sized restaurant. Before we started using my PA system, I tried using a Radio Shack PZM/Boundary Layer mic, but it recorded EVERYTHING! Even the low bass thrum of the air conditioner system that was almost inaudible until it was recorded! Come to think of it, I bet the PE15 could help with that as well.

I'm not currently using a mixer, should I be? I've been looking at some, like the Behringer Eurorack UBB1002. Would this be a help or a hinderence in the long run?

The rest of this post will be quite boring, so I won't be offended if you stop reading now. 

I got into this whole recording mess by accident. I wanted to record lectures without having to flip a cassette tape over every 30 or 45 minutes so I got my little Zoom MRS4 digital recorder. I started taking it to our church services because it was battery powered and I could hook it into the churches sound system with no trouble. The professional musician who was recording the services was having troubles with his equipment and several messages were lost from these hardware failures, I used my recorder as a backup. The guy showed me show to work the sound equipment (nothing fancy, just a portable Peavy PA system) just in case he couldn't be there. After about a year, the musician started his own music ministry and the church recording job fell to me kind of by default.

For reasons I won't go into, the church ending up folding and was no more, but about half the people still get together 4 or 5 times a year for fellowship and Bible study. These meetings are what I'm currently recording.


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## Wayne A. Pflughaupt (Apr 13, 2006)

*Re: Recording lectures.*




> I'm not currently using a mixer, should I be? I've been looking at some, like the Behringer Eurorack UBB1002.


Unless you have a powered speaker like a JBL Eon that will accept a direct mic input, you're using a mixer. Sounds like it's your portable Peavy system... :T

Regards,
Wayne


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## Harpmaker (Oct 28, 2007)

*Re: Recording lectures.*



Wayne A. Pflughaupt said:


> Unless you have a powered speaker like a JBL Eon that will accept a direct mic input, you're using a mixer. Sounds like it's your portable Peavy system... :T
> 
> Regards,
> Wayne


OK, gotcha. :T

I wish I was using that Peavey system (a 150 watt Peavey Escort 2000), it worked great and was very portable. I'm now using a 'Squier by Fender 4-Channel PA System' (shown below) that is only 80 watts and it is barely cutting the mustard.


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## Wayne A. Pflughaupt (Apr 13, 2006)

*Re: Recording lectures.*


Hmm... You'd think it would be enough for just vocal support, even in that restaurant. If you're running out of headroom, you might try reducing the bass control. As I mentioned, you don't need anything below ~200 Hz for voices. Excessive bass on voices not only makes them sound boomy and unnatural, it also wastes power.

Regards,
Wayne


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## Harpmaker (Oct 28, 2007)

*Re: Recording lectures.*



Wayne A. Pflughaupt said:


> Hmm... You'd think it would be enough for just vocal support, even in that restaurant. If you're running out of headroom, you might try reducing the bass control. As I mentioned, you don't need anything below ~200 Hz for voices. Excessive bass on voices not only makes them sound boomy and unnatural, it also wastes power.
> 
> Regards,
> Wayne


I would be enough if they would just talk into the mic.  I'll try again to get that point across.

Maybe I'm misremembering, but I think I cut down on the treble to decrease the feedback problem.

And you are correct, there is no music involved; just voice.


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## drf (Oct 22, 2006)

*Re: Recording lectures.*

Heres a thought I'd like to throw into the mix, Have you considered a shotgun video mic? I have seen them used effectively for highschool theatre, where the students can't stand still or know how to use a mic.


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## Guest (Dec 1, 2008)

*Re: Recording lectures.*

Sorry, I only read about half the posts so if I repeat something, I apologize.

You could try making sure the speaker is far behind the amp. Push the speaker (podium) back a little and/or pull the amp front a bit.
The further from the amp, the less sound is fed back.

Also, make sure your amp is set as clean as possible. Turn main volume all the way up and the gain all the way down and then start bringing the gain up until it's loud enough.

Have any built in EQ set to 0 boost/cut, unless you're using a feedback cut.

I record lectures full time for AM and FM radio and I am a film/video sound recording mixer/boom operator so I have run into just about every problem you can imagine trying to get good dialog.

For my recordings I use an SM81 but a condenser like that will exacerbate your feedback issue when fed through an amp. A lapel can be the best bet if they are an animated speaker.

Sometimes you just have to talk to the speakers and let them know that unless they use good mic technique, the sound will suffer and the audience may not hear them. If they are speaking in front of an audience, they most likely want to be heard so they will probably work with you.


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## Guest (Dec 1, 2008)

*Re: Recording lectures.*

I see that your amp is a PA system. I thought you were using a Squire guitar amp! Sorry, the gain vs master comment is not applicable then.

I've had lots of folks trying to use guitar amps as PA amps (bad idea) but it can at least be maximized for the best sound, but then again, so could a tin can!


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## Harpmaker (Oct 28, 2007)

*Re: Recording lectures.*

drf,
Interestingly enough, I purchased a Audio-Technica ATR 55 Uni-Directional Condenser Shotgun Microphone (see photo below) about a year ago. It does double-duty on by my old Sony Digital8 camcorder and as a recording mic when hooked to my Zoom MRS4 voice recorder. Back when we were using the restaurants built-in wireless PA (the sound was truly horrible, and then they started charging for it's use) I got great recordings using the ATR-55 directly into the Zoom; it honestly sounded like a good lapel mic (at least to my ears). I positioned it about 6 feet from the lectern. The problem is I can't get enough volume out of it when hooked to the PA system; that may be associated with it being an unbalanced input.:dontknow:











Matt,
Thanks for the tips. Yep, it's a cheap PA not a cheap guitar amp.:bigsmile:

Something I'm really having a problem with is understanding microphones. I get the difference (I think) between directional mics vs handheld mics; but then I get lost. How do you know if a mic is designed to be used with the lips almost in contact with the mic and one designed to pick up a group of singers? Dynamic vs condenser; large diaphragm vs small diamphram? Sorry to be so dumb about this stuff, but I am trying to learn.:bigsmile:

You are the second person to recommend a SM81, but Tony said they can't be handheld (I assume because they pick up handling noise). In case anyone missed it, I'm currently using a SM58.

Another issue that I don't understand is that when I hooked my SM58 up to my PA using an XLR-1/4" adapter the volume level dropped significantly and I got hum (I did this just as a test since the PA has both kinds of inputs, an adapter cable came with the amp). Would I get better performance from a mic such as the ATR55 above if I used an adapter to plug it into an XLR input?

Sorry for the long posts and dumb questions. I seriously appreciate the help!


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## tonyvdb (Sep 5, 2007)

*Re: Recording lectures.*



Harpmaker said:


> Something I'm really having a problem with is understanding microphones. I get the difference (I think) between directional mics vs handheld mics; but then I get lost. How do you know if a mic is designed to be used with the lips almost in contact with the mic and one designed to pick up a group of singers? Dynamic vs condenser; large diaphragm vs small diamphram? Sorry to be so dumb about this stuff, but I am trying to learn.:bigsmile:


Here is some of the microphones you will find, 
Cardioid (hand held microphone like the SM58)
Omni-directional (Picks up sound from all around the micorphone)
Super Cardioid
Hyper Cardioid (both the Super and Hyper mics are more sensitive and good for insterment pickup or choir)
Figure 8 (not a common one but picks up sound from in front and befind the mic but not from the sides)

An even more detailed look can be found here



> You are the second person to recommend a SM81, but Tony said they can't be handheld (I assume because they pick up handling noise). In case anyone missed it, I'm currently using a SM58.


Yes that is correct, they would pick up the handling noise unless held very carefully. But they have a gain control as well as a three position High Pass filter built in.



> Another issue that I don't understand is that when I hooked my SM58 up to my PA using an XLR-1/4" adapter the volume level dropped significantly and I got hum (I did this just as a test since the PA has both kinds of inputs, an adapter cable came with the amp). Would I get better performance from a mic such as the ATR55 above if I used an adapter to plug it into an XLR input?


If your not using a proper transformer box known as a direct box or DI Box to convert the XLR to 1/4" you will loose gain and pick up allot of noise.


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## Guest (Dec 1, 2008)

*Re: Recording lectures.*

Good questions.

All mics are directional. It's just a matter of which direction.

Cardiod - supercardiod, - hyercardiod: Picks up from just the front and rejects from the sides and back in varying degrees. 

Omni directional = picks up from all directions

figure 8: picks up from the front and back but not the sides.

Then independent of polar (pickup) pattern, there is dynamic and condenser family.

The design of a dynamic allows it to be handled without as much handling noise but it's also less sensitive and often less natural sounding. But your PA and room are going to make a MUCH larger difference on the sound than any mic ever could, so don't fret that.

reducing handling noise and the great sound of the SM58 make it superb for what you're doing.
I do not recommend the SM81 for amplification. It's just what I use to record many dialog events. I do not run it through a PA system and unless under good circumstances, I would not.

A condenser's design is much more delicate and allows it to be more sensitive but also has more handling noise.
Another reason they aren't always top choice for sound reenforcement (PA) is they are more susceptible to feedback because they are so sensitive.

You might hear someone say a shotgun mic is very directional because it rejects side noise very well and thus has an almost telescoping way of pinpointing sound from a distance with pin point accuracy.

Most Shotgun mics are condensers and will also have extreme handling noise and sound best at least 2 or 3 feet from the mouth. (at least)

Every mic is different and each of them has their place.

For running through a PA system, your best bet is a dynamic like the SM58 you already have. The SM57 is also a great choice for speech. Both are similar. Little handling noise, cardiod pattern rejects rear and side sound, great gain before feedback with PA systems, great frequency response for dialog, and rugged as can be! These are the mics you see punk rockers swing around and slam on the ground and then start singing though it again.
That would never happen with any condenser I've ever used.


I'm thinking that the reason your mic sounded quieter and buzzy was you unbalanced it.
An XLR type connector is a balanced system type. A TRS (Tip, Ring, Sleeve) is as well. However a TS(Tip, Sleeve) is not.

Suffice it to say that a balanced system affords you 6dB more level and can often be much quieter by resisting hu,mm and noise.

Again, your best bet is to separate the mic and speakers so that as little sound as possible gets from the speakers into your SM58 and tell the talent most commonly heard phrase heard in a radio booth,.." Speak into the mic".

Also, if the room is very "live" or has a lot of echo (as most untreated rooms do) that will not help matters.
You might consider a better PA, acoustic treatment of some sort if it's the same room all the time, and the above.

Good luck!


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## Harpmaker (Oct 28, 2007)

*Re: Recording lectures.*

I want to sincerely thank everyone that helped me in this thread. It's MUCH appreciated!:hail:

On a similar, but slightly different, note; one of the problems I have with live recording is people either not 'speaking into the mic' at a constant distance, or changing the volume they speak at. This brings up a new question on how to use dynamic compression to limit those volume differences. Is this something that is better done live or in post-production (at the computer with software)? Any input welcome!


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## tonyvdb (Sep 5, 2007)

*Re: Recording lectures.*



Harpmaker said:


> one of the problems I have with live recording is people either not 'speaking into the mic' at a constant distance, or changing the volume they speak at. This brings up a new question on how to use dynamic compression to limit those volume differences. Is this something that is better done live or in post-production (at the computer with software)? Any input welcome!


Its always best to do it live rather than post production as once you clip the input or distort the incoming signal you can not repair it. Compression can be your friend or your worst enemy if you don't use it right. You don't want to start compression to early or you will have problems with getting the gain you want nor do you want to have it snap on at the last second either.


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## HaleStorm (Oct 7, 2009)

Hi Harpmaker,

Is there a mixer involved? Could you send the input signal from the mic to a separate output buss
for the recorder? This way you could control the gain going to the speakers and the recorder separately.

In my humble opinion, the SM58 should be fine.

Bill


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## planetnine (Mar 3, 2009)

Just a bit of advice about EQ. Graphics EQs have their uses and are an easier learning curve than parametric EQs as by their name they are "graphic". They were called Broadband Equalisers when they first appeared as they were intended to roughly shape an EQ by broad "brushstrokes". They were usu used in balancing cinema sound.

Third octave graphic EQs are a more recent introduction and have become the standard EQ for uses such as live reinforcement and stage monitors -the visual aspect helps with speed of response and the centre frequencies have been standardised by international agreement. Third-octave do only take a third of an octave cut (not 2/3), usually measured to the -3dB (half-power) point either side of each frequency, but there are variations to the design, some being constant width and some constant-Q, etc. They are good tools for eliminating acoustic feedback, but they are not perfect and there are better EQs.

Parametric EQs are where all parameters of each EQ filter are available to adjust, they are the most powerful and controllable type of EQ where anything from broad sweetening to surgical precision cuts can be made -but can be daunting to the inexperienced, especially if not familiar with the audio frequencies. Narrow cuts of 1/20 to 1/5 of an octave can effectively cut feedback without gouging-out large swathes of the wanted audio spaectrum too.

Feedback eliminators/destroyers are a type of automatic parametric EQ. They listen for and recognise feedback and then apply narrow EQ cuts at those frequencies to (hopefully) quickly remove the feedback loop. Their difficulty in "live mode" is recognising feedback from any other wanted sound and they can be fooled by some musical instruments (eg, flute, synths) "Ringing out" mode is different, and where the sound system (PA, monitor rig, install, etc) is purposely cranked up with mics open until feedback occurs and the eliminator's filters then cut in. Here all loud frequencies are treated as feedback as it is a non-live test, and after ringing-out those filters are locked.

Feedback eliminators are a good tool for many situations, especially if used in combination with another EQ (eg GEQ or PEQ), but they have their limitations and should not be considered a cure-all. For a lecturn mic where high gain and room/mic colourations will become apparent as acoustic resurgence is approached, a graphic or parametric EQ can deal with those issues, with sweetening and some particularly "hot" frequencies, and then the eliminator can take any further notches out as required by the expected mic gain needed.

If buying these units I would urge anyone to buy a good one if their budget allowed, I use several channels of Sabine FBX on some jobs where we know gain and feedback will be an issue (eg lecturn mics, childrens choirs thru PA against instrumentation, theater lavaliers, narration, etc).

There are dedicated lecturn mics, usu hypercardoid condensers, and sometimes these are used in pairs for redundancy and better coverage of "wandering speakers" (levels can be ridden). A cheaper, quite useable alternative is the supercardoid Shure beta57, I have used this successfully in televised press conferences where multiple sets of mics have been required at short notice. Another thing to bear in mind is that the US President always uses a pair of winshielded cardoid SM57s for public appearances and briefings -if it's good enough for him...

The SM58 is not the perfect mic some people think, but it is likely perfectly adequate for this application; the SM57 would probably be a little better as it does not have the bass roll-off of the 58, required to compensate for the proximity effect of close vocal miking.


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## Equilibrium8 (Sep 11, 2008)

It looks like most of the possisble solutions have been discussed. The idea of speaking to them about it would be the most cost effective and you'd still get to use the SM-58. A simple "if you want people to hear you, hold it here...or if you don't want anybody to hear you, hold it here.." should appeal to their ego's. 

One more suggestion I can think of is using a PZM style boundary mic. These are used on conference table so it can pick up everybody talking around the table, so it should be fine for picking up anywhere around the lectern and a bit away from it. It may also pick up a bit of crowd noise, so setting the gain levels properly would be essential.


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## Equilibrium8 (Sep 11, 2008)

I almost forgot, side note to the OP. Camera shops are a great place to get SmartMedia cards cheap.


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## leviset (Nov 27, 2008)

Have just recorded something similar at a Symposium at The Thackray Museum in Leeds. I sat at the front and used my Zoom H4 recorder and what I also had was a line out from the actual lectern podium setup. I was involved with the conference and had access to their equipment but you should check that if someone is speaking from a lectern that the amplification equipment they have will have a dedicated line out just for what you need. Leeds University were also recording from the lectern straight into Audacity on the Sony Vio that was being used for the Powerpoint presentations and they also gave me copies of those recordings as well.
Denny


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## fractile (Mar 15, 2009)

BTW, Rane also made a 4-band parametric with all bands adjustable from 20-20kHz


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## jaddie (Jan 16, 2008)

Wayne's solutions are great, give them a try. There is, however, no substitute for good mic technique. I've used the reverse Pavlov idea many times, it works quite well! Also, a bit of coaching can go a long way. I tell hand-holders to think of the mic as an icecream cone. Hold it away from the chin, and more vertical than horizontal. 

For fixed podiums, I most often use a cardioid on a stand with a boom extending over the podium, but not touching it. That gets you away from hands-on-the-podium vibrations, etc. and out of the sight lines of the talker's notes. I also have an assistant adjust the mic for each and every talker. The "magic" position, with the talker facing forward and not down at his notes, is 4" to 6", mic pointed at the chin. That way, if a talker looks down, he's on mic, if he looks up, he's still on mic. 4" to 6" keeps him from getting too punchy by moving around, and keeps good voice level straight into the mic. 

Having EQ'ed a good many systems, I'd add that notching feedback is really good, but flattening off the overall system response first is essential. Smooth response is more important than flat, especially if you use a house curve too. Get the bumps big bumps out, then smooth it off. Then, if you have time, take a look at the actual system response measured at the mic you are using at the podium. You'll actually be looking at the shape of the audio that will be feeding back to the mic. Wow, will a lot of issues show up there! Again, if big peaks in the response are there, deal with them.

On notching for feedback, don't get too obsessive with tight notches unless you have a fixed mic position. If it's fixed, go nuts. But, moving it around, or hand-holding it will make those tiny 1/10 octave notches pointless as the feedback frequencies will move outside of them when the mic is repositioned. There again, smooth system response first, it helps feedback EQ work. 

Related to that, pick a cardioid mic with smooth off-axis response. It just makes the EQ thing so much easier. Hyper-cardioids are sort of a mixed blessing - improves back rejection, but off axis is anything but similar to on-axis, and usually anything but flat or smooth. More expensive too, usually. 

Auto feedback controllers sort of work, but the only one that works universally and without regard for mic position (it does it without notches!) is the Polyfusion Audio 755, which basically uses a pitch-bender, so you can't really use it on music, but it's deadly on speech. It's likely outside of your budget, but you should know anyway.

Get this part right, and your recordings will sound fantastic!

Jim


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## RobAnderson (May 12, 2010)

Hi all

One suggestion I have not seen is doing a transformer split between the mixer and the recorder.

Boxes like these can be had from Whirlwind for about $75

This will enable you to have completely independent gain structures for recording and live sound.



> the SM57 would probably be a little better as it does not have the bass roll-off of the 58, required to compensate for the proximity effect of close vocal miking.


This is not really correct - the two mic's are identical in design except that the 58 has the signature ball-type grill - both have the same frequency response with the exception of the artifacts caused in the high to high-mids of the 58 by said ball-type grill with built-in two-stage pop-filter (I think that is the most hyphens I have ever used in a single sentence :R )

The SM58 is just fine for the application described by the OP - the President of the United States, the Mayor of New York and may others use SM57's for their press conferences and such.


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## Kirill (Apr 14, 2010)

Harpmaker said:


> I need to record people speaking at a lectern, but they don't know how to use a mic (meaning they hold the thing at waist level).


Question. Why don't you explain speakers how to use a mic before the beginning of the lecture?

I'd use a wireless Lavalier (Lapel) mic right on the clothing without hiding it. Would give you a great result in case if speaker doesn't know how to use a mic. Also you would have to have a huge amount of gain with lavs, thus not causing a feedbacks in to a PA system. 

Or you could use a Shotgun mic in that situation I guess too, it has a narrow polar pattern, cuts many unwanted noises, has a way longer reach ability compare to SM57. Might have to play around with EQs to resist the feedback, since most of shotgun mics that I've used are condenser (Phantom 48 Volts or other type of power will be required) or back-electret (internal battery power)...

I'd say Lavlier would work the best for your situation. Just play around with placement to avoid cloth russtling. Which is unwanted noise.

Good luck,
Kirill 

Hope that helps.


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