The No.1 Website for Pro Audio
 All  This Thread  Reviews  Gear Database  Gear for sale     Latest  Trending
Recording Board Meetings
Old 2 weeks ago
  #1
Gear Maniac
 

Recording Board Meetings

Fellow Slutz,

I'm needing to help some schools get set up to audio record their regular Board meetings.
Trying to figure out what the best lower-budget mic solution might be.

These are typically in rooms that have no acoustic treatment and a lot of ambient noise from HVAC and people shuffling around so I'm thinking that might rule out a simple Omni condenser in the middle of the table?
Most of the boards have 7-9 members.

We've tried capturing it by repurposing some of those large plexiglass piezo mics you see hanging from the ceiling in teleconferencing rooms but those picked up more noise than speech (my guess is that is mostly because in their original design they relied heavily on noise cancelling algorithms that happened within the video conferencing hardware codec they originally connected to.) It's older Tandberg gear if that matters, but the codecs are long gone.

The little hand-held interview-type recorders don't seem to do very well either.

Ideally, a table-top push-to-talk for each member would be good, but these are all very small schools in very rural areas so budget for this type of unplanned expense is very small (actually non-existent, so we want to do as much as possible for as little as possible.)

Wireless would be nice to reduce setup time and clutter (these meetings are typically in multi-purpose rooms, so everything has to be set up and then torn down to get out of the way for the next day/use.

We just need to record/capture. We don't have to worry about feedback since we don't route any of this to a sound system/PA in the room (at least not currently.) That being said, we do have one school that streams their meetings that might be nice to route this to once we get the mics figured out... but I think we can handle that with an iPad and an iRig on a tripod.

I know this isn't as fun as trying to figure out what is the best Kick Drum mic for a given application, or listening for the best spot to put the ribbon in conjunction with the 57 on the guitar cab... but it's a necessary evil and still lets me work with audio.

Any suggestions?

Thanks!
Tim
Old 2 weeks ago
  #2
Gear Guru
 

Quote:
Originally Posted by tvent View Post
...
I'm needing to help some schools get set up to audio record their regular Board meetings.
Trying to figure out what the best lower-budget mic solution might be.

These are typically in rooms that have no acoustic treatment and a lot of ambient noise from HVAC and people shuffling around so I'm thinking that might rule out a simple Omni condenser in the middle of the table?
I would suggest a PZM (boundary) mic in the middle of the table. Or attached to the ceiling above. If not the exact middle, maybe you want to favor The Boss, just a little.

The nice thing about boundary mics is that they have a quality called "reach" which is defined as "the ability to reproduce quieter, more distant sounds ". The idea behind a boundary mic is that it eliminates phasing between direct and reflected sound. It does it by using only reflected sound.

A voice from the far end of the table will not be made 'louder' but it will be more coherent than the pickup from a regular mic. Greater clarity and intelligibility. Placing it right on the table is very common. The entire table couples with the mic's plate and that can help the pickup. But you may not want it on the table if people are drumming with their fingers or constantly banging their coffee cups down. Many people mount them on ceilings.

This page on B&H has a little blurb on these kinds of mics and links to a number of models that they sell.

I own a pair of Crown PZM-30's. While I use them for kick drum, percussion, room mics, and even piano, the conference room is often the top application listed for these mics.

In my experience, few people ever end up actually listening to these recordings, but they are needed as a public record. If you have to go back to the recording, you just want it to be clear what someone said or did not say. This also reminds me of another point. Are you going to attend ALL these conferences as the "soundman"? Travel around with mics and recorder, and set up all the mics, start the recordings, download and archive them? Or are they going to be self recording - each board with their own gear? If the latter, not only should the setup be KISS, the recording device itself should be dead simple. No matter how many mics you end up with, set it up to record all down to one stereo file onto an SD card - so that it is very easy to grab the files and store them somewhere on a computer. Something like the zoom h4 would take only a short while to learn how to operate.

Things like HVAC noise are easy to get out with software like Izotope. On those rare occasions where someone actually wants to listen to the board meeting.

Quote:
Most of the boards have 7-9 members. ....Ideally, a table-top push-to-talk for each member would be good,
The seven people sitting at that same table can hear each other just fine, so you must mean "push to be recorded"? I would think at a conference, people should be just able to talk. Without needing to think about the recording system, much less need to push a button before saying something. You said there is no 'audience', no PA. So no one even gets a feeling for their mics being "on" or not. They will forget to push the button and then you have silence.

At the college where I teach, the board has individual mics for each member. Instead of push-to-talk, they are set up with a gate system where the mics are muted by default and then it automatically unmutes the mic when someone is speaking in front of it . It even has a feature so that the Board Chair's mic overrides the other mics! Guess who asked for that?

But that is an installed system, it is not very portable. The automatic mixer is a 19" rack-mount unit. And it is hooked up to a PA so that the public can attend the meetings. IMO this may be overkill for what you need.

Quote:
Wireless would be nice to reduce setup time and clutter (these meetings are typically in multi-purpose rooms, so everything has to be set up and then torn down to get out of the way for the next day/use.
Wireless introduces a host of new problems, especially if you are mobile. Batteries can go dead. Signals can cut out. Walls with metal stuff inside them may prevent you from putting your recorder where you would like. Interference: maybe one town has a fire department using your frequency? Unless there is a party going on in the same room, I think you can cover a 7 person conference with one or two mics.

One or two PZMs sitting on the table, and a recorder with XLRs and phantom. Like a Zoom H4.
Old 2 weeks ago
  #3
Gear Nut
 
ventil's Avatar
 

I would definitely avoid wireless, if at all possible. In addition to the problems JoeEQ mentions, the RF "landscape" in the US is prone to change, as the FCC tries to cram more use - especially big mobile providers - into the same RF spectrum. There were major changes several years ago with the switch to all DTV and we have just completed another one with the TV repack. I've had to abandon a few wireless systems and send others back for expensive modifications. But then I'm in D/FW.

JoeEQ mentions a PZM which is a type of mic called a boundary mic. That is a good suggestion, but the PZM specifically has one drawback. It is a hemispherical polar pattern - essentially half an omnidirectional. The PZM will pick up all the board members and might work quite well if the table is round. However, if it is a long table, the guys on the ends might be more difficult to understand. With ambient and HVAC noise you described (which I can well imagine), intelligibility could be compromised, especially for those farther away from the mic. The mic will pick up a substantial amount of that room noise, relative to the voices.

I would recommend directional boundary mics, such as the Crown PCC-160 or the cardioid version of the Shure MX391 or MX393. Some other manufacturers make similar mics.

These are essentially half cardioid (or super cardioid) pattern. Depending on the configuration of the table, 2 mics would probably do it, but be willing to go to 4, if necessary. Place them in the center of the table, back to back and about 1 to 2 feet apart, depending on the size of the table. The board members at the end may still be a little lower in level but those in the middle will be off-axis, so attenuated. Most importantly, the cardioid pattern will reduce the HVAC and other distant room noises. The PCC-160 also has a low frequency roll-off switch to help attenuate LF noises such as HVAC rumble or low frequency table born noise. I thought the Shure models had that, too, but , having checked mine just now, I can't find it. So maybe not.
Old 1 week ago
  #4
Gear Maniac
 

Joeq and Ventil thank you both very much for the very thoughtful and helpful responses.

Yep, that's it- the boundary mic is the one i hadn't thought of (which is ironic since the plexiglass Tandberg mic I did use is basically a Crown PZM stuck to a formed piece of plexi... but I think my poor results might have been because it was simply to far away from the table.

I actually use those Crown PCC160's in the local theater here for shows all the time. We keep them simply taped across the front of the stage. I've actually been planning on adding a couple to my personal collection for a while now... but now that I see the PZM-30d, it has my attention.

I might try moving that Tandberg mic closer to the table for our own meetings, but it is in a drywall-ceiling so I'll probably take it down and test it before permanently moving it. Drop-tile ceiling would have made this one a no-brainer.
Other than that, I'm thinking two of either of the Crown mics mentioned above at the center of the table facing opposite directions a couple feet apart like Ventil mentioned will be best.

Regarding the other meetings - No, I won't be able to be at the meetings to run things so yes, yes, yes: KISS is the soup du jour.
Excellent point on the push-to-talk for these scenarios. Spot-on - it would be "push-to-record" in which you are exactly correct: we would not be able to trust the board members to remember to push when they speak. (of note, we actually have some of those in a particular location and we jumper them (well, technically we "dip-switch" them) to stay on all the time for that very reason - but those DO go to a PA rather than just to record.

Slightly off topic: In the theater we place foam under the PCC160's to try to isolate them from foot noise. That's just what has always been done so I've never questioned it. Seemed right enough.
Now that I realize they are an actual boundary mic, is this wrong? Would we get better pick up if we taped them right to the floor? Knowing what I now know after reading the link Joeq offered above, it seems like we should and then we can just low-cut to taste to keep the stomps out of the FOH? Hmm... Gonna have to experiment with that.

Thanks again! This is MOST helpful.
Old 1 week ago
  #5
Gear Guru
 

Quote:
Originally Posted by tvent View Post
Now that I realize they are an actual boundary mic, is this wrong? Would we get better pick up if we taped them right to the floor? Knowing what I now know after reading the link Joeq offered above, it seems like we should and then we can just low-cut to taste to keep the stomps out of the FOH? Hmm... Gonna have to experiment with that.
Coupling the boundary mic to a large surface is usually a plus. I would often tape mine to plexiglass to record an orchestra. Acoustically, plywood would be about the same, but conductors object less to a rectangle of clear plastic in front of the stage.

but you are correct that there is a trade off from direct vibrations of footfalls or coffee cups through the material. You will have to experiment to see if it is "worth it".
Old 1 week ago
  #6
Gear Maniac
 

Quote:
Originally Posted by joeq View Post
Acoustically, plywood would be about the same, but conductors object less to a rectangle of clear plastic in front of the stage.
Sorry, that literally made me Laugh Out Loud right now.
So glad i didn't have a mouth full of coffee or beer.
Old 1 week ago
  #7
Gear Nut
 
ventil's Avatar
 

Quote:
Originally Posted by tvent View Post
Slightly off topic: In the theater we place foam under the PCC160's to try to isolate them from foot noise. That's just what has always been done so I've never questioned it. Seemed right enough.
Now that I realize they are an actual boundary mic, is this wrong? Would we get better pick up if we taped them right to the floor?
The whole point for the invention of the boundary mic, was to pick up the sound in the (then newly-discovered) pressure zone that exists at a boundary. The major advantages, IIRC, being phase coherency and uniform frequency response. (It's been many years since I looked at the literature.)

I don't remember how far above the boundary the pressure zone extends (if I ever knew), but it is not very thick. So if you raise the boundary mic off the surface, the capsule may not be in the pressure zone, so you no longer have a boundary mic. It's just some sort of weird, who-knows-what-kind-of-mic.

Also, the LF extension of the boundary mic is directly related to the size of the surface on which it is mounted - up to some theoretical point. So by raising the mic off the floor or table you could be compromising the LF response of the mic. That may or may not be a problem - or could even be an advantage - depending on your application.

In years past, I have used PCC-160's on stage edges as you mentioned, except I mounted them directly onto the stage floor. I don't recall structure-borne noise being a problem, but stages have pretty heavy construction. It did pick up footfalls acoustically, but this was for a state-level pageant where a number of the contestants were tap dancers. So picking up footstep was the whole point.

Structure-borne vibration might be more of a concern on a table. But - and I'm trying to remember this - doesn't the PCC-160 have internal shock mounting of the capsule?

So in short, if ypu raise a boundary mic off the boundary surface, then you are using it in a manner different than what it was designed for. But if it gets you what you need... whose to say it's wrong?
Post Reply

Welcome to the Gearslutz Pro Audio Community!

Registration benefits include:
  • The ability to reply to and create new discussions
  • Access to members-only giveaways & competitions
  • Interact with VIP industry experts in our guest Q&As
  • Access to members-only sub forum discussions
  • Access to members-only Chat Room
  • Get INSTANT ACCESS to the world's best private pro audio Classifieds for only USD $20/year
  • Promote your eBay auctions and Reverb.com listings for free
  • Remove this message!
You need an account to post a reply. Create a username and password below and an account will be created and your post entered.


 
 
Slide to join now Processing…
Thread Tools
Search this Thread
Search this Thread:

Advanced Search
Forum Jump
Forum Jump