Microphone for recording a round table discussion

[Greg Miller]

Originally Posted by Richard Crowley

You can see in many shots in this video the little audio gadgets that he hacked. They are clipped on to the shirts/pockets/lapels/collars of the subjects. To my ear, the audio from this very ad-hoc documentary is quite above average in quality despite the "cheap as chips" (BrEnglish) or "dirt-cheap" (AmEnglish) audio solution.

That's a Sansa Clip. I love them and have used them on and off for several years. I'm pretty sure I've recommended them on this forum, and have recommended them to other folks as well. You can literally clip one on the mic wire of a podium mic, for example. You can clip one inside a shirt or suit-coat pocket, and it will be barely visible; yet the mic is on top, peeking out of the pocket, so you get good audio.

I'm not sure what mod would have been done (or how) unless he installed the Rockbox third-party firmware which does make some improvements. Out of the box, they record mono, WAV, 16bits/sample, 24kHz sampling rate. There's no recording level metering, but they're pretty hard to overload with normal conversational voice levels. You would not want to use one at a sporting event with a shouting crowd.

Unfortunately the original Clip (internal memory only), and the Clip+ (which accepted a microSD card) have been discontinued. I got a handful at great price from the local RatShack when they closed. I wouldn't mind having a few more. Some later versions of the Clip (e.g. the Clip Zip, Clip Sport, etc.) are in current production.

BTW I never saw this video before, and I've followed this forum regularly for several years, so I suspect you originally found it elsewhere, rather than here. It's a great find ... thanks for sharing!

[John Nantz]

For a temporary relief with a non-permanent installation, reasonably easy to deploy and demob, here are some thoughts for any surfaces that are out of shot:

Glass area: one could use re-useable suction cups with hooks:
Mudder 45mm Bathroom Kitchen Suction Cup Wall Hooks Hangers, 12 Pack for $7.98
Find some used curtains, maybe shears to let some light through if necessary.

Walls: If smooth, one could use more suction cups, if textured then use a backdrop system.
Neewer Pro 10x12 feet/3x3.6 meters Heavy Duty Adjustable Backdrop Support System Photography Studio Video Stand with Carrying Bag for $69.99
A backdrop system is very portable and reasonably easy to set up.

Floors: spread out some old blankets where they don’t walk because they could be slippery. Blankets would be easy to move and take up minimal storage.

For shots that inadvertently get a bit of the sound treatment in view then use the Ken Burns effect.

[Kathy Smith]

the room is 40'-20'
I'm interested in hearing more about the curtains Richard mentioned. Richard do you have any specific info?

[Greg Miller]

Yikes, that's bigger (therefore worse) than I had guessed. I'll bet the reverb time in there is several seconds.

[Richard Crowley]

It is quite literally a trade-off between what the owners of the space will allow (aesthetically), what the decorator can provide, and how much acoustic absorbance you can squeeze out of it.

I had in mind something like this "Austrian balloon curtain". In a sheer colorless fabric, it would still let in a lot of light and not "block" the open feeling of the window wall. But all that semi transparent fabric is also semi-transparent to sound, and the spaces created by the folds would absorb some of the ambient sounds both traveling on their way to bounce against the glass, and as they reflect off the glass and back into the room (and your microphones). The rounded, uneven patterns would make an interesting contrast to the stark design/decor of the rest of the room. I am not a decorator, nor do I play one on TV, but I know what I like. :-)

And I would lobby hard for hanging some kind of fabric feature (even if it is all white) anywhere on the opposite wall that isn't being use for protection. And for some of those big thick shaggy faux-fir carpets.

[Greg Miller]

Richard, that's a very interesting curtain. I've never seen anything like that. Of course I don't get out much. ;-) It does appear fairly transparent, especially at the top where it's just one layer. Actually a rather nice effect: it lets you see the sky, yet somewhat blocks out the view of "man-made stuff" at the lower part of the curtain, especially if it hangs all the way to the floor.

I doubt that it would do much at the low end of the spectrum (which makes the room boomy), but it might help a tiny bit with the higher frequencies, and those are the ones that affect intelligibility. Still, the fabric looks very light in weight. Do you have any published acoustical specs for that kind of hanging?

[John Nantz]

Richard,
These Austrian sheers are very nice and an nearly every home uses them. The help to reduce the amount of stark daylight while still allowing for a view out the window.

Originally Posted by Richard Crowley

I had in mind something like this "Austrian balloon curtain". In a sheer colorless fabric, it would still let in a lot of light and not "block" the open feeling of the window wall. But all that semi transparent fabric is also semi-transparent to sound, and the spaces created by the folds would absorb some of the ambient sounds both traveling on their way to bounce against the glass, and as they reflect off the glass and back into the room (and your microphones). The rounded, uneven patterns would make an interesting contrast to the stark design/decor of the rest of the room. I am not a decorator, nor do I play one on TV, but I know what I like. :-)

I don't know why homes in the US don't use them more. Here is a listing of shears on an Austrian web site similar to Craigs List in the US: https://www.willhaben.at/iad/kaufen-...ne+wei%DFer%2C

Don't know if just clicking on the URL will or if it has to be cut-'n'-paste.

[Kathy Smith]

Thanks Richard for showing the curtain. Unfortunately this design doesn't go with the original design of the house.
What a bout something like this?
curtain

[Greg Miller]

Kathy, those are very nice looking, and would certainly look appropriate in that room. Based on the graphs shown in the .pdf file, they are surprisingly good acoustically, especially the Formoza fabric. If your client would be willing to cover the entire window area with Formoza, that would certainly be an improvement over bare glass.

Of course they could cover the long wall with the same fabric, and get twice the improvement. The look would then be consistent. And if they needed some projection area, they could just open the wall drapery in the middle.

[Rick Reineke]

That would likely help the lighting as well by defusing the harsh outside light. Though I'm not a lighting or camera person but I usually work with some really good folks.

[Paul R Johnson]

Is this just one of those situations where the solution is a lav mic on everybody, and multitrack the audio to edit later? I can't see even that expensive solution being more than treating the room and using distant techniques. Close in or nothing, I guess?

[Greg Miller]

I agree that the absolute best sounding solution is probably separate lav on separate tracks. But the OP has explained in detail (last paragraph in post #59) why that is not an option in this situation.

Besides, it would come down to a choice between the client spending some money to improve their own problematic room, vs. the recordist spending money to solve the problems created by the client's room. The client has asked the OP (post #45) for suggestions on improving the room. If the client is willing to improve their room, by all means take that approach first!

So yes, "in the best of all possible worlds" (as Candide would say) go with separate lavs on separate tracks ... but in reality, from what the OP has said, that ain't gonna happen.

[Kathy Smith]

Here are 2 audio samples from the recorded conversation. The first one is someone who was sitting a bit closer to the mic than the person in the second recording.

https://www.dropbox.com/s/t1gfiwb0oc...o%201.wav?dl=0
https://www.dropbox.com/s/jlt55ew5wf...o%202.wav?dl=0

[Kathy Smith]

Also, I came across interesting looking acoustic panels, what's your take on these:
Snowsound USA Acoustic Panels |

[Richard Crowley]

Originally Posted by Kathy Smith

Also, I came across interesting looking acoustic panels, what's your take on these:

The "Oversize" product looks most appropriate for soaking up sound and minimizing reflections in your echo-chamber room. The other products that BLOCK sound from one cubicle or area to another are not really as effective in your space.

Many people have made simple "shadow box" open frames, covered them with one of dozens of colors of double-knit polyester (solids, patterns, etc.) and put loose-fill absorbent material (fiberglass, polyester, etc.) inside. By choosing a fabric color the matches the wall color, the visual impact is minimized and only adds a subtle geometric feature to the otherwise big blank wall.

But it could make a huge difference in acoustics. Note that it will not only improve acoustics for recording, but it will also increase the intelligibility of speech in the room for all the participants.