Hey guys. Last year around this time I was considering a rather extensive (and expensive) miking setup for an adult education classroom and I got some helpful feedback from some of you. (http://www.dvinfo.net/forum/all-things-audio/517476-proposing-2k-fix-boss-distance-learning-solution-new-post.html)

After much thought, I put the idea aside. But our little "gig" has been expanding and we're looking to partnering with a rather large publisher soon so I'm revisiting the idea. My end goal is to capture great audio from the students in-class that I can pipe via XLR to our camera and ultimately to our video feed (where the other half of our students participate live distance-learning).

I think I may have figured out a microphone configuration for a classroom setting, but I need your input.

To preface, here are some important details:

1. This is a traditional classroom set. Two banks of five or six long tables (two chairs per) on each side extending front to back.

2. The students are finance and accounting professionals. Average age is 35. They typically bring their own laptops to class and sit two per table, aforementioned.

3. The audio equipment I'm proposing to my boss is below. It will be used to pipe audio into a camera via XLR which is then ultimately fed into Ustream Producer for a live webcast. The point of miking the students in class is so that the distance-learning participants can hear their questions/comments, etc.

Proposed Equipment:

1. (8) Shure SM48-LC Microphones
2. Peavey PV14 Mixer
3. (2) 8 channel audio snakes
4. Sony MDR 7506 Headphones
5. Behringer EuroLive B205D PA
6. A host of mic cables, desktop stands, a rackcase, etc.

One microphone will be placed on the center of each of four tables to pick up speech from the student sitting on either side of the it. The snakes run on each side of the classroom to the back where I am with the mixer. The PA is there is to provide a moderate reinforcement to students near the back of the room.

I'm open to place two mics on each table (meaning one per student) if need be. The microphones are not that expensive anyway.

My question: Do you think this modest ($1,500) setup will work for the purposes I outlined above?

How is the teacher mic'd?

Who is operating the audio set up or are you just opening ALL the mics and hopeing for the best?

Does that operator understand Eq, compression, limiting, and are those tools avalable to them? (needed for the limited bandwidth of webcasting)

My suggestion is hire a 'professionsl' location sound person (who will have all the gear you need), set up the room, operate the mix, and deliver a 'pro' level product to the camera / webcast for probably about half your allocated budget.

Personally, the SM48 would not be my choice at all. Somebody swapped one of my 58s for a 48 last year and compared to the 58 it's a bit dull. I'd look into condensers without a doubt. Small diaphragm imports are crisp, bright and cheap, but there are some nice goosenecks used by the conference people that would be quite nice, come with a built in stand and get the mic closer to people's mouths. I have ten small cheap condensers I use for conferences and would not swap them for SM48s .

In the conference setup I use the table is a single long one, and the biggest operational problem is catching peoples first words. The mixer we use at the moment is an x32 Behringer. I appreciate your budget problem of course, but the key feature for us is that it lets us gate the mics that are fader open, but not in use. Somebody speaks and the gate opens. Nice and clean. Before we had this mixer, the only working solution was to have all faders half open, and then when somebody started to speak unexpectedly, we'd have to find which one quickly. A nightmare in practice. I'd really suggest having the mixer at the side where you can see their mouths. The back of their heads doesn't help at all.

I would not consider sharing mics, because it works, but needs increased distance, and while maybe ok for the video it's not helpful for PA.

IMHO those hand-held "rock star" microphones are a very poor choice for this application.
I still think the On-Stage DJM618 DJ Gooseneck Microphone (or equivalent) would be a FAR better choice.

A lot is going to depend on the competency of the console operator. If all the mics are 'open', the recording is gonna be a freak'n mess no matter what mics you have. I have done 'similar' projects and used prefader sends for the house PA and used the linear faders for the recording / webcast.
I would also suggest a wireless headset or lav mic for the instructor as well as shock mounts for the table mics, (especially for the budget variety mics, the capsules are hard mounted.. (folks who tap on the table top sound like Godzilla walking)

I agree with a few of the points raised above.

Mixing this is going to be a headache. You will need a good operator.

You definitely need good shock mounts on the mics, because each mic is on a table with two people typing at their computers. Without good shock mounts, the typing noise will be more than annoying, and might be enough to open the mic channels if you use an automated mixer. Even with shock mounts this might be a problem, which takes me back to the need for a good audio operator.

Is the situation where you have to break down all the equipment, and then set it all up again for the next session? Or can you leave it all set up for days at a time? Are you recording at all, or only the live webcast? And does the webcast have live long-distance participants from elsewhere interacting with your students?
I wonder if headsets for each student would be better for live interactivity.

I agree with what other people are saying. That's an awful lot of open mics and a dynamic mic like that needs to be spoken into from inches away to pick up anything. That many open condenser mics would just give you mud. Have you thought about going with a single boundary mic up high or even a pair of them on facing side walls? It wouldn't sound pretty but you could probably hear everyone well enough to understand what they are saying. Another option would be to pass around a handheld wireless mic and insist that no-one can comment unless they use it, kind of like a talking stick. This would sound the best. The instructor would need their own mic, of course. Make it a wireless lav.

I fear most customers like this won't understand the difficulties without spending a big pile of money and failing. That is the only consultant/expert some people understand.

IMHO, there is NO situation where boundary microphones will give you anything superior to just using the mics built into the camcorders (which will be terrible). Complete waste of time and money, IMHO.

If the presenter can't remember to repeat the question, then appoint an "MC" or "moderator" or "host" or whatever you want to call them and whose primary job is to ensure that comments and questions are adequately captured. There is no effective "budget" solution to this scenario.

I am still having a hard time even understanding what numbers we're talking about.

Two banks of five or six long tables (two chairs per) on each side extending front to back.

I interpret this to mean one bank of tables on each side (a total of two banks) with either five or six tables per bank. Is that right?

If the above is correct then you are talking a total of ten to twelve tables. And you're talking about one mic per table, so that would mean ten to twelve mics.

But then later you talk about having eight mics. As far as I know, eight is not the same as ten or twelve. Please explain how you will deal with the two to four tables that seemingly have no mics.

I interpret this to mean one bank of tables on each side (a total of two banks) with either five or six tables per bank. Is that right?

If the above is correct then you are talking a total of ten to twelve tables. And you're talking about one mic per table, so that would mean ten to twelve mics.

But then later you talk about having eight mics. As far as I know, eight is not the same as ten or twelve. Please explain how you will deal with the two to four tables that seemingly have no mics.


Sorry. I should have been more clear. Not all the tables are occupied by students; some are used for other reasons. So actually we have 3-4 tables in total being used.

If I have to increase the microphone count to 12, then that's fine and negligible.

Personally, the SM48 would not be my choice at all. Somebody swapped one of my 58s for a 48 last year and compared to the 58 it's a bit dull. I'd look into condensers without a doubt. Small diaphragm imports are crisp, bright and cheap, but there are some nice goosenecks used by the conference people that would be quite nice, come with a built in stand and get the mic closer to people's mouths. I have ten small cheap condensers I use for conferences and would not swap them for SM48s .

In the conference setup I use the table is a single long one, and the biggest operational problem is catching peoples first words. The mixer we use at the moment is an x32 Behringer. I appreciate your budget problem of course, but the key feature for us is that it lets us gate the mics that are fader open, but not in use. Somebody speaks and the gate opens. Nice and clean. Before we had this mixer, the only working solution was to have all faders half open, and then when somebody started to speak unexpectedly, we'd have to find which one quickly. A nightmare in practice. I'd really suggest having the mixer at the side where you can see their mouths. The back of their heads doesn't help at all.

I would not consider sharing mics, because it works, but needs increased distance, and while maybe ok for the video it's not helpful for PA.

I'll review the goosenecks again, but they are so darn expensive. I originally (last year) posted about the use of an automatic mixer, but I became a bit more open to *not* using one because a recent panel discussion we had used convention handhelds and a rather generic mixer and we got great results. Video below.

The mics are strictly for patching in audio to the camera. The PA will be used primarily for other functions.

Here's a video of a recent panel discussion where we experimented with convention hand held microphones. (http://www.ustream.tv/recorded/42791568)

Ignoring the audio sync issue (that was later corrected), I think the audio portion came out just fine. That's what I was attempting to replicate per this scenario I posted.

I'll review the goosenecks again, but they are so darn expensive

Huh? Your rock-musician microphones are shown in your citation at $37.04 each.
The On-Stage gooseneck mics are selling for $29.95 at every place I look.
What does "so darn expensive" mean here?

Ref: On-Stage DJM618 DJ Gooseneck Microphone at zZounds (http://www.zzounds.com/item--MUPDJM618)
On-Stage Stands DJM618 18" L Gooseneck Microphone with XLR-M Connector, DJM-618 | Full Compass (http://www.fullcompass.com/product/437991.html)
On-Stage DJM618 | Performance Audio (http://www.performanceaudio.com/item/on-stage-djm618/33887/)
Amazon.com: Audio Spectrum DJM618 Professional XLR Gooseneck Microphone: Musical Instruments (http://www.amazon.com/Spectrum-DJM618-Professional-Gooseneck-Microphone/dp/B0075DS728)

A condenser microphone is inherently more sensitive. Your application needs all the sensitivity you can get.
The gooseneck gets the microphone up closer to the subjects' mouths. You desperately need proximity in your scenario.

Here's a video of a recent panel discussion where we experimented with convention hand held microphones. (http://www.ustream.tv/recorded/42791568)

Ignoring the audio sync issue (that was later corrected), I think the audio portion came out just fine. That's what I was attempting to replicate per this scenario I posted.

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A condenser microphone is inherently more sensitive. Your application needs all the sensitivity you can get.
The specs state that those gooseneck mics are dynamic.

However, if you can provide one mic per person, and can get the people to talk directly into their mics, this would probably be satisfactory. Don't forget the isolation mounts!

The On-Stage DJM618 DJ Gooseneck ic specs state a sensitivity of -76dB, so it is probably dynamic. -76dB is also a very low output, so it may not be a good choice for Cornelius' application. Omni directional table mics may be a good choice... On omni does not have to be right in the speaker's face and is free of the proximity effect bass boost (or lack therof) ... however feedback could be problem if it's going through a PA..

The specs state that those gooseneck mics are dynamic.
However, if you can provide one mic per person, and can get the people to talk directly into their mics, this would probably be satisfactory. Don't forget the isolation mounts!

Doh! I should have checked that. An electret equivalent would appear to be something like this....

Superlux E321SC Black Supercardioid Condenser Capsule For E321 Series Microphone SPLX-E321SC - Professional Broadcast Supply (http://www.probroadcastsupply.com/superlux-e321sc-black-supercardioid-condenser-capsule-for-e321-series-microphone-splx-e321sc/)

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Sorry Richard. Use this link instead.

As I mentioned previously, I was pleasantly surprised with how well this little panel discussion experiment went. The audio was not bad, in my opinion. Also keep in mind that we are not using the PA for this, just piping the audio feed to a camera via XLR.

Huh? Your rock-musician microphones are shown in your citation at $37.04 each.
The On-Stage gooseneck mics are selling for $29.95 at every place I look.
What does "so darn expensive" mean here?

Ref: On-Stage DJM618 DJ Gooseneck Microphone at zZounds (http://www.zzounds.com/item--MUPDJM618)
On-Stage Stands DJM618 18" L Gooseneck Microphone with XLR-M Connector, DJM-618 | Full Compass (http://www.fullcompass.com/product/437991.html)
On-Stage DJM618 | Performance Audio (http://www.performanceaudio.com/item/on-stage-djm618/33887/)
Amazon.com: Audio Spectrum DJM618 Professional XLR Gooseneck Microphone: Musical Instruments (http://www.amazon.com/Spectrum-DJM618-Professional-Gooseneck-Microphone/dp/B0075DS728)

A condenser microphone is inherently more sensitive. Your application needs all the sensitivity you can get.
The gooseneck gets the microphone up closer to the subjects' mouths. You desperately need proximity in your scenario.

I actually meant that using gooseneck microphones would be more expensive because the base units tend to be 2-3X more expensive (http://www.bhphotovideo.com/c/search?sts=ma&ci=8732&N=4294254546&Ntt=gooseneck+base) than that entry-level gooseneck microphone itself.

You could simply use the same stand that you planned to use with your original mics. Equip the stand with an XLR-diameter mic clip (instead of a fat one to fit the "rock star" mics), and clamp the goosneck's connector in that clip.

Actually, Mr. Crowley suggested this last July, in your original thread, in case you had forgotten.

I actually meant that using gooseneck microphones would be more expensive because the base units tend to be 2-3X more expensive (http://www.bhphotovideo.com/c/search?sts=ma&ci=8732&N=4294254546&Ntt=gooseneck+base) than that entry-level gooseneck microphone itself.

Everything is 2-3x more expensive when you buy at retail at a vendor like B&H, et.al.
But this is the 21st century and AlGore has given us the interweb.
And we can buy stuff directly from China and bypass the retailers.

You can use the same desk/"banquet" mic stands you would have used with the rock-star mic, so that is a wash either way.
Unless you were planning on laying the mics on the table and expecting the participants to remember to pick up the mic and hold it properly. That seems like a pipe-dream IME.

As I mentioned previously, I was pleasantly surprised with how well this little panel discussion experiment went. The audio was not bad, in my opinion. Also keep in mind that we are not using the PA for this, just piping the audio feed to a camera via XLR.

For a low-sensitivity dynamic "rock music" vocal mic on a stand between each two people, that is about what we expect, although there is ample room for improvement in mixing and levels, and getting rid of that (completely preventable) hum in the audio track. This is what I would call "minimum document-quality" audio. It is adequate for internal review of the event, but I would be embarrassed to release this for public consumption, especially if I were charging money for it.

But if that is what you can get away with in your industry/location, then go for it. But you could greatly benefit from somebody setting up the equipment who can get rid of that annoying hum, and someone who can actively mix the audio to achieve better results with what you have to work with. Having to deal with local PA systems will greatly complicate things on several levels.

For a low-sensitivity dynamic "rock music" vocal mic on a stand between each two people, that is about what we expect, although there is ample room for improvement in mixing and levels, and getting rid of that (completely preventable) hum in the audio track. This is what I would call "minimum document-quality" audio. It is adequate for internal review of the event, but I would be embarrassed to release this for public consumption, especially if I were charging money for it.

But if that is what you can get away with in your industry/location, then go for it. But you could greatly benefit from somebody setting up the equipment who can get rid of that annoying hum, and someone who can actively mix the audio to achieve better results with what you have to work with. Having to deal with local PA systems will greatly complicate things on several levels.

Richard, I completely understand your point of view. If money were no object, yes, I would have an experienced audio tech onsite to produce the highest quality audio accompaniment to the video feed that we use for our livestreaming. Unfortunately we have a budget and are not able to take on additional personnel. However, I think your commentary brings to light the need for a local consultant who can assist from time to time in a non-dedicated manner.

Secondly, please know that the audio we capture is not being used for "public" purposes. It's used for a closed livestream of class sessions (a group of no more than 20-25 people). I think the criticism citing how the video clip's audio above is not of the quality of a blockbuster movie is a little edgy considering the audience that will be consuming it. However, even as an amateur, I do want the best quality that our funds can wisely afford.

So to summarize: What was ultimately suggested was this:

Condenser gooseneck microphones like these (http://www.probroadcastsupply.com/superlux-e321sc-black-supercardioid-condenser-capsule-for-e321-series-microphone-splx-e321sc/), right?

I still don't know what to do about bases/stands. Or would the (condenser) "rock star" mics work?

Maybe its just not clear what the objective is here? Are we recording the students to make them feel better? Or are we trying to capture their comments and questions for the benefit of people watching the video (whether live or after the fact)? Do the students make long speeches, recount anecdotes, etc? Or are they just brief questions or comments?

I just don't understand the tradeoff decision for sub-par audio vs. a sure-fire (and cheaper, as well) solution: having the presenter repeat the question. Do you have a camera to get audience shots? Is it more important to SEE the students or to HEAR them? I think I know what my priorities would be. But I don't understand the producer's priorities.

In any case, you should never have to put up with that kind of background hum. It is completely preventable and really makes the audio track sound shoddy and second-rate. Just say no. Do some test setups with your gear and work out what is causing the hum and get it fixed before your next production.

IMHO the prime factors in mic selection are SENSITIVITY and PROXIMITY. A low-sensitivity rock vocal microphone far away from the subjects just seems like a poor choice.

With all due respect, I get the impression that the same questions are being asked over and over, and essentially the same answers have been given (frequently by multiple people) over and over. I've seen good suggestions about the mics and mic stands.

My understanding is that this is some sort of teleconference, where mediocre audio is acceptable. It's not ideal, but if the person paying the bill doesn't care, and your personal pride doesn't care, that's your choice. (But bear in mind that many people in this forum are sound professionals, and as such they probably will not wholeheartedly endorse that approach.) There will be 3 to 4 tables, with 6 to 8 people. You will use one mic per table. A reasonable mic has been suggested. The question of stands (with shock mounts) has been addressed. An 8 input mixer will suffice. You need an operator wearing headphones, in the front of the room so he can see who is speaking and react quickly. Unless you have not accurately defined the situation, or have omitted something, that seems to be how it will play out.

(signed)
Department of Redundancy Department

With all due respect, I get the impression that the same questions are being asked over and over, and essentially the same answers have been given (frequently by multiple people) over and over.

My understanding is that this is some sort of teleconference, where mediocre audio is acceptable. It's not ideal, but if the person paying the bill doesn't care, and your personal pride doesn't care, that's your choice.


Greg:

I disagree with your characterization of the issue. I am aware (now) that you think of this thread as largely redundant, but my goal in posting this topic was to simply gain some insight that I have little to no experience in.

Yes, you are correct that this is a closed webcast or similar to a teleconference but with HD video output as well. That alone should tell you that the audio does not have to be perfect, but to dismiss my view that we can't spend unlimited funds on perfecting audio in equipment and/or specialized personnel is offensive. I *do* care about the level of quality. I do not wish for "mediocre" quality as you put it. Instead I have stated that I want the best bang for the buck. I think what has been redundant is the insistence by you and others that I don't care about the quality of audio. That's simply not true.

Maybe its just not clear what the objective is here? Are we recording the students to make them feel better? Or are we trying to capture their comments and questions for the benefit of people watching the video (whether live or after the fact)? Do the students make long speeches, recount anecdotes, etc? Or are they just brief questions or comments?

I just don't understand the tradeoff decision for sub-par audio vs. a sure-fire (and cheaper, as well) solution: having the presenter repeat the question. Do you have a camera to get audience shots? Is it more important to SEE the students or to HEAR them? I think I know what my priorities would be. But I don't understand the producer's priorities.

IMHO the prime factors in mic selection are SENSITIVITY and PROXIMITY. A low-sensitivity rock vocal microphone far away from the subjects just seems like a poor choice.

This audio is for a closed video webcast of 20-25 distance-learning participants. It is not public. The audio comes from microphones picking up short questions and comments made from students in a traditional classroom environment that is piped to a camera via XLR and broadcast (along with video of the lecturer) to the aforementioned distance-learning participants.

We currently do the "repeat the question" method you suggested above. It works except it gets tiring to repeat questions and comments over and over again. We would rather our distance-learning participants hear them from the students' own mouths. Hence the reason for asking advice with this thread. It is more important to *hear* the students than see them (only the lecturer is presented in video).

So, based on the feedback I have gotten in this otherwise productive thread:

1. It looks as though I can propose we purchase these Shure Gooseneck Condenser microphones (http://amzn.com/B00A361VAY) (with the seperate base units).
2. We hire a consultant specializing in audio production to do some training for the person who will be dedicated towards producing the media (which happens to be *me*)

Why do people really believe that quality sound can be achieved with set and forget kit, and nobody with any skill to work it. Why do we send overpaid and troublesome football players to the world cup, when we could just pick 11 men from any local park? Why do outdoor festivals not just make do with the Fender compact PA system advertised as suitable for outdoor events? Why don't the broadcasters give cheap cameras to people who have no clue how to use them (well, actually they do and we've all seen the results).

Everyone has suggested better ways to do this project, and being very blunt - consensus is we think the budget and the plan seriously flawed. Most of us would walk away, because the chances of doing a good job are very slim.

We have explained in quite detail what you need to do. We appreciate that you don't have the budget for even low price kit, and don't have anyone skilled to mix it - what do you expect us to say? Sure - turn all the mics on, leave them up, and don't worry - the sound will be excellent.

It's lottery number stuff - the chances of success, and if it does work, then it was luck, not planning.

Everyone has suggested better ways to do this project...

And I have conceded on a number of suggestions such as using a gooseneck microphone, using a condenser microphone, exploring the option to hire a consultant for training, not using the PA for sound reinforcement, acquiring an automatic mixer in the absence of an "experienced" sound tech, etc.

Seriously. I think a fair bit of your post above is just residual criticism because it's the "in" thing to do for a rookie like me. I *HAVE* taken note of many of the suggestions made in this thread and said that I would explore them further.

What more do I have to say?

It boils down to this: how much money and effort are you spending on getting the video versus how much are you willing to spend on audio? I'll wager your video budget is several times that of your audio. Yet as a trainer who is often called upon to deliver distance learning courses I can attest that high-quality audio is far more critical than is video for the learning experience. Get your audio as good as you can get it then if there's any money left in the budget think about adding video. An exception to this might be when teaching a mechanical action, like how to cut a diamond, where sight is a crucial part of the skill set being communicated. But if it's a talking head of a presenter, the video is mere frosting, wow-factor; you could completely lose picture and the presentation will still work. But weak or difficult to understand sound will reduce the effectiveness of your presentation to nearly zero.

"a freak'n mess"

Rick, I love it when you talk like that! :)

and, you're right!

Regards,

Ty Ford

"a freak'n mess"

I also agree. I just watched two demonstration videos showing how a panel discussion audio setup benefited. The first video showed of the use of auto mixer turned off compared with the second video showed the auto mixer turned on. Huge difference in audio quality. I don't want subpar results.

So, I have decided it's best if we hold off on a cheap audio "solution" until we can afford a much superior (and expensive) one. That means that we'll have the lavaliere-miked lecturer repeat questions from those inside the classroom.

I thought about expanding our future "wishlist" to three Shure SCM410 automatic mixers (http://amzn.com/B0002JEV0E) (since we will never have a dedicated person for audio) to accommodate 12 condenser mics, like the Shure CVG12-B/C Gooseneck (http://amzn.com/B00A361VAY) along with their separate desktop base with built in foot-long XLR cable (http://amzn.com/B00AEYUZ98)

The only question I have is how am I going to reconcile the "Last Mic Lock-On" feature if the only mic we want "locked on" is the lecturer's? Some kind of daisy-chaining or something? And it appears that since three of those mixers will have to be purchased, then I'll have to get another mixer to take the feed from all three of these.

Cost of this superior setup: ~$4,020

The is also an 8 channel version of the Shure auto mixer and they do have a cascade function so multiple units work as one.....no need for a summing mixer.
The last mic open function is fine, when the lecturer starts it will switch to that mic.

Auto mixers are fine (well almost), if everyone is close mic'd.. but I don't think that would work in the OP's case.

Auto mixers are fine (well almost), if everyone is close mic'd.. but I don't think that would work in the OP's case.

Actually I've modified the plans to have everyone mic'd. All the students in the classroom will have a dedicated microphone. I've axed the original plan to have one mic per two students.


The is also an 8 channel version of the Shure auto mixer and they do have a cascade function so multiple units work as one.....no need for a summing mixer.
The last mic open function is fine, when the lecturer starts it will switch to that mic.

I've been looking for those, but they all have euro/phoenix block connections which is unusable for me. I take it that is for a fixed installation, whereas my setup is mobile so I need XLR or 1/4" connections, which the 8-channel versions of those mixers do not offer.

With that said, if I have to opt for three 4-channel SCM410 mixers, what am I going to do about the the "last on, locked" feature that will essentially leave one mic open per mixer. I only want one to be open (the lecturer's).

I share Rick's reservations about this setup... All the students should be miced as closely as possible.

I also think it's very important that all the desktop mics have very good isolation mounts, otherwise the thumping of the desks, when people type, might confuse the gated mixer. Using a fairly steep HPF on all the student mics might help with this, too.

It would be ideal if you could somehow get the equipment on a trial basis, to be sure it will do what you want in this particular situation, before making a final and irrevocable purchase. Again, a trustworthy local dealer is worth a million bucks in a situation like this.

they all have euro/phoenix block connections which is unusable for me. I take it that is for a fixed installation, whereas my setup is mobile so I need XLR or 1/4" connections, which the 8-channel versions of those mixers do not offer.

If this is for a portable setup, have the mixer(s) installed in a road rack/case. Also, mount a panel with the XLR connectors you need, and permanently wire the connectors to the mixer with short pigtails.

I share Rick's reservations about this setup... All the students should be miced as closely as possible.

I also think it's very important that all the desktop mics have very good isolation mounts, otherwise the thumping of the desks, when people type, might confuse the gated mixer. Using a fairly steep HPF on all the student mics might help with this, too.

It would be ideal if you could somehow get the equipment on a trial basis, to be sure it will do what you want in this particular situation, before making a final and irrevocable purchase. Again, a trustworthy local dealer is worth a million bucks in a situation like this.

Do you know where I could get "isolation mounts"?

I think the trial basis purchase is a good idea. Thanks for that.

If this is for a portable setup, have the mixer(s) installed in a road rack/case. Also, mount a panel with the XLR connectors you need, and permanently wire the connectors to the mixer with short pigtails.

I am aware of the portable rack case, but I'm not sure about the XLR connector panel. How is that done?

I am aware of the portable rack case, but I'm not sure about the XLR connector panel. How is that done?
Visit an online pro-audio retailer such as Full Compass and search the site for XLR audio patchbay.

Sort of like a patch bay w/ XLRs.
TecNec TecNec XLR To XLR Patch Bays Patchbays & Panels Accessories at Markertek.com (http://www.markertek.com/Patchbays-Wallplates/Patchbays-Panels-Accessories/TecNec/PBXLR-1.xhtml)

I'm not sure about the 410 auto-mixer, but some have a priority channel mode, which is locked on.
Depending on the mics, shock mounts are plentiful.. I don't think there are that many options for goose neck mics, some come with a shock mount base.. others must be 'permanently' installed.. using a hole saw..
<rant> My problem with goose-neck mics was they're very susceptibility to plosives.. folks 'eating' the mic. to the point of bottoming-out the diaphragm.. major distortion.. and not easily repairable after the fact. </rant> If the speaker is eight or so inches away, they're OK. So again, the auto-mixer may or may not work good.. even in best environment, they're not fool-proof and must be set-up properly.. so an experienced audio tech should still be enlisted.

You don't exactly want a patch bay, though. You want a panel with eight (or more) XLRs mounted in the panel, and pigtails soldered on the back end of the XLRs. They you connect the bare end of those pigtails to the screw terminals on the mixer. Again, a local retailer should be able to source these for you, and, in fact, should be able to mount the mixer and panel, and wire everything so you're ready to "plug and pray."

Does anyone have a better (priced) suggestion than those wildly expensive Shure gooseneck condensers (http://amzn.com/B00A361VAY) I sourced? With mic and base, those are costing ~$160 per unit, which I think is unnecessary given that we are only capturing brief, intermittent speech.

PyleHome - PDMIKC5*-*DJ Equipment*-*Microphones (http://www.pyleaudio.com/sku/PDMIKC5/Professional-Table-Top-Condenser-Microphone)
Street price appears to be ~$30 and widely available.

There ya go. Sensitivity ain't too bad. (-40dB)
Don't expect top shelf performance for $30 though.
Probably very susceptible to plosives and table noise. Likely unbalanced and a 1/8" plug as well.

With mic and base, those are costing ~$160 per unit, which I think is unnecessary given that we are only capturing brief, intermittent speech.

I can give you a good deal on a couple of intermittent microphones.

There ya go. Sensitivity ain't too bad. (-40dB)
Don't expect top shelf performance for $30 though.
"Top-shelf performance" seems like overkill for occasional comments from the audience.

Probably very susceptible to plosives
It comes with a windscreen according to the instructions PDF.
And replacements are available likely for a few bucks per dozen.

and table noise.
A piece of recycled foam glued to the bottom would eliminate most of that.

Likely unbalanced and a 1/8" plug as well.
Since the cord plugs into a receptacle on the back, it is an ideal candidate to make balanced XLR cords for these.

Sorry guys about all the back-and-forth here, but I have another proposal:

What if, instead of close miking everyone in the classroom, I hang highly-sensitive, long tube condenser microphones above every two desks or so?

For example, I could use four Audio-Technica ATM10As (two on each side of the room or "bank" of seats) mounted on long arm boom stands suspended overhead ("http://www.bhphotovideo.com/c/product/407080-REG/On_Stage_SB9600_SB9600_Studio_Tripod_Boom.html') and routed to a four-channel Shure SCM410 automatic mixer ("http://www.bhphotovideo.com/c/product/188356-REG/Shure_SCM410_SCM410_4_Channel_Automatic.html').

I ask this scenario because it would reduce cost and make setup faster and easier (since we are a mobile operation), without reducing quality because it would still be used in conjunction with the automatic mixer (gating the mics and mitigating unfavorable ambient noise).

If you have a better microphone suggestion, please let me know. Or, if this scenario is less preferable than the idea of close miking all the students individually with gooseneck condensers, let me know.

By the way, here is a picture that I took earlier today of my work environment that you can refer to -- you'll notice my little station there in the back with the camera and PC:

Sorry to say Cornelius, but neither the "long tube condenser" (shotgun I assume) nor the AT omni mic would work very good with an auto mixer. Manually mixed yes, but as before requires an experienced audio mixer.
In my experience with this type of scenario, I used two cardioid or shotgun mics in the front of the room for audience questions, applause. ect. in much larger rooms than pictured. In most cases, I could pick up the question.. not 'in-your-face quality', but certainly understandable and also requested (both verbally and written) the speakers or moderator to repeat the question.
example:
http://www.dvinfo.net/forum/members/rick-reineke-albums-alblum-picture744-nyb-notice.jpg
http://www.dvinfo.net/forum/members/rick-reineke-albums-alblum-picture744-nyb-notice.jpg

Sorry guys about all the back-and-forth here, but I have another proposal:
I'll check back in 2017 to see if you've made a final decision yet.

What if, instead of close miking everyone in the classroom, I hang highly-sensitive, long tube condenser microphones above every two desks or so? it would reduce cost and make setup faster and easier (since we are a mobile operation)
For a mobile operation? Are you kidding? Do you mean you'd rather take along a ladder, and hang mics from the ceilings at every location, string the wires along the ceilings, do the shoot, then take down the wiring and mics ... and repeat this at each new location? How is this cheaper? Is the cost of time/labor zero, or less?

mitigating unfavorable ambient noise
There is no way a directional mic located many feet from the "talent" will have less ambient noise than a desk mic a few inches away from the "talent." That's absurd. As Rick indicates, "in most cases" the audio might be "understandable." But it will never be as good as with a properly located close mic.

I think many experienced members here, with great patience and a lot of repetition, have already evolved the best possible solution given your constraints and budget. Maybe it's just me, but IMHO this is starting to get silly.

(By the way, your stand light is really washing out the screen. I hope the presenter isn't trying to use any projections! And I thought you said the participants were all using laptops ... I don't see any in your photo.)

What if, instead of close miking everyone in the classroom, I hang highly-sensitive, long tube condenser microphones above every two desks or so?
If you are going to use non-standard terms (like "long tube condenser microphone") you will need to define them. If we presume that you mean a "shotgun" or other highly-directional microphone, that is quite possibly your WORST idea yet.

Those ultra-directional microphones rely critically on the angle of incidence, and when you interfere with that by using them near reflective surfaces (i.e. ceiling or walls), it circumvents most of the directional functionality. And if you don't have somebody actively aiming the microphones right at the mouth of the subject, they are worse than no mics at all. And even in ideal conditions their quality usable range rarely extends to 3ft/1m

For example, I could use four Audio-Technica ATM10As (two on each side of the room or "bank" of seats) mounted on long arm boom stands suspended overhead.

No, maybe I made a mistake in the previous paragraph. Maybe a couple of OMNIDIRECTIONAL mics mounted far away is the WORST idea yet. You seem to have completely missed the point about PROXIMITY.

It is not clear how either of these will "reduce cost and make setup faster and easier". And there is no quality to reduce because it will be too awful to worry about preservation.

We warned you going in that this is among the most difficult of things to mic properly, and there are not shortcuts.