Lectern Microphone

[Charc]

I don't know sound, so I figured I'd ask a question here that has been on my mind. Our lectern microphone (correct name?) seems to be lacking in the pickup department. I feel like our speakers half to hover over the mic to be heard well, maybe closer to 8". It seems to me like the normal distance would be closer to 18", though that's just for lecterns I've seen on TV, and it's hard to see depth from a straight on view. Is this poor pickup have to do with the quality of the microphone, the placement, or the pickup pattern? Sadly I don't have any of that information readily available. I do know that our audio line on the lectern is on the S.R. side, and not in the center of the lectern, so we have to bend the neck of the microphone in, hence lower, or use a not straight on shot, which what usually happens. It just seems, from the booth at least, that they have such a narrow pickup range and often end up talking off mic. I'd consider trying different pickup patterns, (I mean if we are using cardiod, trying omni, but our speakers just sorta clip the stage, and feedback can be a problem. (Our speakers need to be about 6-8 feet forward from their present position, unfortunately they are dead-hung from the ceiling.) Or is this the normal situation, and I should just explain how to talk into a microphone to every speaker? (For instance, don't turn your head 100º degrees away... )

 

[stantonsound]

That is always a problem. The TV press conferences don't have that problem b/c they usually are using condensers but with no speakers there is no feedback problem. They just limit the signal down, so the level stays the same even if the person turns their head.

If you can't buy any new mics, you can try using 2 mics in an x/y configuration (it is what is commonly used), just don't forget to change the phase on one of the mics. Personally, if feedback is a problem, I use two Shure SM57's, with a windscreen if outdoors. Most of the presidential speeches for the last few decades have been with the SM57's and they really are an industry standard.

If feedback is not a problem, I prefer a good vocal condenser. There are several out there that are made for just that application. Shure, AT, AKG, Sennheiser, etc.... all make podium mics.

One hint, put it on a good compressor/limiter/gate. It will take the harshness out of things like someone moving/repositioning the mic, turning their head away, hitting the mic and saying "is this thing on", and other things that infuriate me.

 

[CJM2341]

Hey HS technician.
Just so you know there are many factors that effect how far a presenter can stand from a mic and be heard. Most Dynamic mics have what’s called proximity effect. This translates into the sound getting thinner as the mouth gets further away from the mic.
We use slim line condenser mics as our lectern mics. I work for a company the produces meetings. Our audiences vary from fifty through five thousand audience members. We also double mic. There is a cool trick where you switch one mic out of phase to help cancel feedback. For this to work the capsules need to be very close. This will also create a ‘thinner’ sound that may need to have some of the low mids or bottom put back in. Sometimes the canceling that results from two mics being out of phase on the subject are just what’s needed to clean up a tubby or boinky sound. I was doing this for a while and then read an article by the guy who mixs a lot of the big name awards shows you see on TV. He always puts the lectern mics out of phase and eqs them completely differently so that one mic is his mid range mic and the other has the top and bottom for instance. He also experiments with putting a very shot delay on one of the mics. This is pretty esoteric stuff but I wanted to get your mind thinking about how many factors there are in sound reinforcement. And some of the experimentation that you can try.
I realize that in a HS theater you are generally limited to use what you have. What is the model of the mic you are using? What others are available? Also Eq is a big factor. If you have access to parametric EQ, that can increase the gain before feedback ratio. Another thing to consider is the reflected sound from the speakers getting back into the mic. Try orienting the lectern so that the mic is not pointing at a hard surface that will reflect sound back into the mic.
I’m a TD now but as you can tell I’ve spent a lot of time mixing live sound. If you let me know more specifics of all your equipment for example I would be happy to make more recommendations.
And yes you are going to have to continue to educate presenter to not do the big head turn. Why are they turning their heads? Do they have slides? If you can give them a confidence monitor that keeps the facing forward it will sound and look better.
Chris

 

[wolf825]

I don't know sound, so I figured I'd ask a question here that has been on my mind. Our lectern microphone (correct name?) seems to be lacking in the pickup department. I feel like our speakers half to hover over the mic to be heard well, maybe closer to 8". It seems to me like the normal distance would be closer to 18", though that's just for lecterns I've seen on TV, and it's hard to see depth from a straight on view. Is this poor pickup have to do with the quality of the microphone, the placement, or the pickup pattern? Sadly I don't have any of that information readily available. I do know that our audio line on the lectern is on the S.R. side, and not in the center of the lectern, so we have to bend the neck of the microphone in, hence lower, or use a not straight on shot, which what usually happens. It just seems, from the booth at least, that they have such a narrow pickup range and often end up talking off mic. I'd consider trying different pickup patterns, (I mean if we are using cardiod, trying omni, but our speakers just sorta clip the stage, and feedback can be a problem. (Our speakers need to be about 6-8 feet forward from their present position, unfortunately they are dead-hung from the ceiling.) Or is this the normal situation, and I should just explain how to talk into a microphone to every speaker? (For instance, don't turn your head 100º degrees away... )

Could be many things as you stated--poor pick up pattern or placement etc...or more likely its low to inadequate gain structure or bad EQ. Unless its a total piece of junk, a poor mic can also be factor..but even most places have some decent stuff to work with. Can you provide more info as to what you have, how its set up and so on??

Its been my experience that a lot of sound issues has to do with the operator and placement, more than the equipment itself. If your system is a turnkey system--it may have been preset for general level by a company or installer--and needs adjustment only to remedy the problem. But also remember--if folks don't speak INTO the Mic or they tend to stand off to the side and not talk towards the mic--then you don't get any magical sound coming out of it--it can only pick up what is aimed at it. If someone whispers or stands 5 feet away--then that is what it will sound like...

A good engineer knows how and can get the most out of even the crappiest gear if you think its the gear...a bad engineer can make the best most expensive gear sound like butt..so try to figure out which is your problem.. Not sayin you are a bad engineer--you said yourself you don't know sound and thats OK--everyone starts somewhere and it IS a learning process and practice....but what I am saying is a lot of folks who run into problems tend to look at the gear as being fault, and not at how it is or is not being used properly... Before you go spending money hoping for a solution--determine the real issue or problem or it will stay the same problem but you will have spent money just to find that out...

-w

 

[Peter]

Hey Chris, welcome aboard! Thanks for a great first post.

If we knew what microphone you were trying to use it may be helpful. I think everyone else here is already pointing you in the correct direction of experimentation and methodical tweaks to find what works best for your microphone.

The one other thing that comes to mind is if you are using a condenser microphone without knowing it (and without giving it phantom power). Many condensers will work without phantom power, but their output will be significantly reduced. Again, knowing what kind of microphone it is would help determine this.

 

[BillESC]

We install a lot of these:

The 18.94" version of the U857Q, the U857QL cardioid condenser quick-mount gooseneck microphone is designed to plug directly into a panel- or desk-mounted XLRF-type connector. The microphone offers unsurpassed immunity from radio frequency interference thanks to UniGuard™ innovations. It features an ultra-flexible small-diameter gooseneck and accepts interchangeable elements, available in cardioid, hypercardioid, omnidirectional and UniLine™ line cardioid polar patterns. Equipped with self-contained electronics, the phantom-powered microphone also offers an 80 Hz low-cut UniSteep® filter that reduces pickup of low-frequency ambient noise.

It comes with a shock mount that eliminates noise from tapping fingers or closing books, etc.

They are not cheap, but they do the job very well.

 

[gafftaper]

Hey Charc,

I'm not really a "noise boy" but I play one once and a while. First off you are right, you need to get the EQ properly set. Once it is set, make a spreadsheet or chart of some sort and right down every setting so when an idiot comes along and messes with it, you can easily set it back correctly.

Secondly you need a decent microphone. The old school industry standard is a good old Shure SM57. A lot of high schools don't know better or can't afford a variety and so they just have a bunch of Shure SM58's... which are more for singing than spoken word but they work. If you are using some funky low budget mic, step one would be to spend $100 and buy an SM57... you can get them for a little less if you get a good deal. MANY places just use a 57 or 58.

The negative to the SM57 approach is that it isn't a condenser microphone. A condenser microphone is actively powered by Phantom power. This means they are a lot "hotter" and pick up all kinds of things that a 57 wouldn't. So a step up is something like Bill posted. The negative is that condensers are more expensive and require phantom power in the line... something you may not have if it's an old system.

 

[soundlight]

What's on the podium of the president of the United States? A pair of SM57's. And they pick up great. I've used the SM57 as a lectern mic alot, and it's great. You do need to have a nice gooseneck with a good-looking mic cable (not old and covered in tape residue) to do this, but if that's the case, this system works great. It is recommended, however, that you get isolation mounts and windscreens for any SM57's used on a lectern/podium. Shure actually sells a dual SM-57 package, with mounts, cables, preamps, etc:

http://shure.com/ProAudio/Products/WiredMicrophones/us_pro_SM57VIP_content

 

[gafftaper]

We have phantom power, and keep it on as a default. I thought the SM57 were for instruments? Anyways, I think the aesthetics of a lectern mic will overrule the use of an sm57.

To get VERY general, you won't go wrong with:
-SM57 for spoken word and instruments
-SM58 for singing
I bet half the high schools and churches in America either use 58's for both speaking and singing and 57's for instruments only, OR they use 58's for everything. There's nothing horribly wrong with that, since both mics are great workhorses, it's just not their best strengths.

 

[soundlight]

I know a rental company that uses 57's for everything. They don't deal with many of the rock show types, so they don't have to worry about people getting all up in the grille of the mic.

 

[avkid]

I think the aesthetics of a lectern mic will overrule the use of an sm57.

Umm....I don't think so!!

 

[gafftaper]

It's been a commonly known fact that the president uses SM57's... now that may in the future. But the 57 has been the standard for MANY presidents for many years. If it's good enough for 20+ years of presidents it's good enough for your school.

 

[BenFranske]

The SM57 may not be the best choice, or even a good choice in this situation. What people are failing to consider is that in the always talked about presidential use the mic is being used for recording/broadcast and NOT for local sound reinforcement. While it might be acceptable to record/broadcast speech with a dynamic microphone quite a distance from the person speaking it is not so acceptable when you want to amplify the speaker in the same room. I am not the first to mention that either, read back in the thread.

For reinforcement purposes you're much better going with a small podium style microphone (probably a condenser) which is much closer to the person's mouth. You'll get a lot more gain before feedback (something recordings and broadcasts don't need to think about) with a microphone much closer to the speaker. Remember the inverse square law applies to sound reaching a microphone as well as your ear!

 

[gafftaper]

Yeah Charc, Ben has a point in that in order to pick up all those people who aren't projecting, too tall, too short, or just not standing where they are supposed to you would be much better off getting the school to drop a couple hundred bucks on a good condenser podium mic. Plus they look cool (again back to something like Bill posted the picture of).