Capping MOBS 2008 with a Sony PCM-D50

Here are some of the MOBS 2008 recordings I captured. If you're interested in details about the recorder or the process for capturing, read on below. Note that these recording attempts, as well as redistribution using this hosting provider is considered experimental. In an upcoming post, I may discuss the content of the talks at MOBS 2008.

Recordings

Flac format is lossless, so the files are bigger. Flac files are posted here in addition to the mp3 files in order to provide samples that approach original quality.

Update: I noticed that the file hosting provider, Dropbox, is adding album art to these files as a form of advertising when you download them (I did not add the "RedMonk" album covers).

John Quinn "Stewards of Money and Material" 49:30
Background fan noise, low 2s rumble at 31:43 - i think a fly walked on the mics!
full mp3 -OR- 1 minute flac sample

Al Diestelkamp "Stewards of Body and Family" 41:38
At several points that fly buzzed by quite loudly. I've filtered some of that out. Good cap otherwise.
full mp3 -OR- 1 minute flac sample

Singing #1, 5 songs, 14:21
Unfortunately the big fan was very audible for all but the last 30 seconds of the 5th song.
full mp3

Singing #2, 5 songs, 14:41
Better this time. Calibrated levels after start of song #1 and turned the fan off right after that.
full mp3

"Sing On Ye Joyful Pilgrims" 3:53
A good sample.
full mp3 @160K -OR- full flac

"What Will It Be?" 1:51
A good example of the recorder driving to clipping, causing it to engage its digital limiter. Limiter was set to 150ms recovery.
full mp3 @192K -OR- full flac


Unfortunately due to operator error, the recording of 1 full hour of singing on Friday night was not successfully captured. Also regrettably, I was unable to capture all of the talks that were given.



Sony PCM-D50 Recorder


I have played audio engineer for as long as I can remember. The recording equipment side of my studio was in need of something better than a laptop for a digital recorder, and so I've been keeping an eye out on the various offerings in that space as they are released. Last week, I finally bit the bullet and picked up a Sony PCM-D50 linear PCM recorder. This portable device records good quality audio to solid state memory. It supplies its own attached pair of mics, but can also receive input signal from line in or SP/DIF digital IO devices if the situation calls for it. If you are interested, these links tell way more about the hardware than I will cover: brochure official page review review sound samples

After just a few quick recording tests around my home, I gave this piece of gear its first test at MOBS 2008. The venue is challenging and not very audio friendly: the room has several loud fans which could all be turned on, a refrigerator that cycles and many open windows that invite in the sounds of nature as well as noise from occasional yard maintenance vehicles. Close miking was out of the question, since the speakers vary so often and they tend to move around during speeches. A Capella singing tends to be impromptu and levels can vary widely. I had no idea what this would turn out like - I just wanted to see what this device was capable of with little preparation and experience. My intent was to spend as little time as possible distracted with recording and instead be focused on the teaching being done. Unfortunately, my lack of sleep the night before pretty much botched my focus for the next day.

The recorder has threading for a standard camera tripod on its back. So for capturing the lectures, I just used a mini-telescoping camera tripod I had on hand. This seemed to work fine on the table in front of the speaker, about 4 feet from their mouth set on the lowest height possible. For the singings, I simply combined one of my microphone boom stands with an OnStage CM01 tripod adapter. This was a perfect combination, allowing me to place the Sony at a height of 9 or 10 feet. Using the ball joint of the CM01 adapter, I could aim the Sony's mics back down at the audience to capture the group without any hot spots.

This recorder has an elaborate digital limiter. Fortunately, it was exercised and demonstrated well by these recordings. You can hear the limiter at work on the singing track "What Will It Be?" It works like this: a simultaneous recording of a second mirror track is made at a lower level (-20 db below your setting, I believe). This mirror track is stored briefly as the recorder checks to make sure there's no clipping going on. If a signal peak causing overload is detected, the -20db backup audio is normalized (brought to 0 db) and is "stitched into place of" the clipped signal. This feature alone compensates for one of the most difficult problems relating to digital recording and its a huge selling point. It's one of those features that once you've had it, you'll never want to go without it.

Recordings were all made at 44.1kHz 24bit. That 24bit part was fortunate, since the captured levels were often lower than intended (only about 15% of 0db). Converting those low levels into 16bit for redistribution here definitely was a breeze - that 24bit original provided more than enough bits of sample resolution to compensate for the low levels without dropping bit-precision in the final file (15% of 0db on 24bits is still far more than 0db on 16bit samples).

Some virtues the Sony has that swayed me in its direction:

• amazing battery life. Over 24 hours straight on 4 AAs
• top notch lossless recording quality ranging between 22kHz/16bit and 96kHz/24bit
• very solidly built
• digital input and output
• a unique and highly practical digital limiter

and there are as always, a few drawbacks:

• wind and handling noise
• no mono recording (yet)
• no facility for copying files from internal memory to a removable card is provided within the device itself (yet)

I say "yet" in the cons section because the device is firmware updatable and the hope is that Sony will add these features in an upcoming release.

Since the wind noise issue is so prominent, I was fortunate that B&H threw in the official Sony (and normally expensive, $50!) "dead cat" style windscreen for free. I was pleasantly surprised to find the windscreen package also included a soft carry bag for the recorder. I certainly didn't expect I would need to actually use the windscreen to avoid capturing any thunderous sounds from flybys by small insects!

I think that this will be a nice tool to have on hand for recording singing at lectures or at places like RJ Stevens' singing school.

Do you have experience trying to cap good quality audio in venues like this? What have you found that has worked for you?

So MOBS 2008 is over, and I am now mostly recovered from the experience and the weekend in Chicago I spent immediately afterward. I was glad to be there, but felt challenged about my participation. I have been having trouble sleeping lately and the shared quarters and constant rain (among other things, ... a big "shout out" to my neighbors at Motel 6 here!) made rest rather elusive. Operating on less than 2 hours of sleep is not great preparation for a Saturday full of bible study, but there was good in it nonetheless.

I appreciated Steve's talk entitled "Stewards of Time, Ability, and Opportunity" which very directly challenged us men on dozens of characteristics of the spirit, many of which we are still no doubt busy working on in our lives. I appreciated the singing together and the camaraderie with the men there. Several good discussions were enjoyed by this camper on Friday night. I only wish I had been more rested and that we had more time to enjoy the weekend together. The rain made it a little uncomfortable, even indoors due to the very high humidity.

I have another post I'll put up very soon that will talk about the recordings I attempted to make at MOBS using my new PCM recorder. I intend to post some of these tracks for download, a few of which include decent captures of the singing sessions.