Tuesday, February 14, 2017

Valentine's Day microphone comparison

It's Valentine's Day, which means that spring has sprung here in Ireland. I know my Canadian friends will find that hard to believe! But the crocus are out, the trees are budding, and birds are starting their courtship and territory marking.

So I did what every field recording mammal does on a day like today... I went out for a walk with two different recorders and three sets of stereo microphones. I thought I'd share with you some sounds, since every now and then it's fun to compare gear. Well, in truth I have been in more of a philosophical than technical mindset lately, so this was a nice change of pace.

What follows is a microphone comparison that developed over three updates. I think it's done now!

You can download the sound files in a ZIP archive from Dropbox. I will keep this available for as long as is practical.

Microphones
I won't (yet) tell you which microphone is which, but these are your choices:

Microphone A is a pair of EM 172 caps recorded on an Olympus LS-11.

Microphone B is a pair of AT 3022 recorded by a Zoom F8.

Microphone C is the popular DPA 4060, again recorded by the Zoom F8.

For each recording site I have kept the correspondence consistent between tracks 1 to 3 and microphones A to C.

Details
The configuration was spaced omni. All microphones had fuzzy windsocks of differing efficacy; none were in a blimp or other enclosure. I tried to get the capsules aligned as closely as possible, by clipping the smaller mics to the larger.

I've tried to match signal levels, but as each microphone records different timbres that is never entirely possible. But it does mean that some signals have been boosted from their original level.

This is especially true of the Olympus LS-11. It has the best signal-to-noise ratio operating at low sensitivity. This means that significant amplification is required for quiet signals. But this nonetheless works out better.

Site A
Site A was along the park Canal in Corbally, Limerick. In front of the microphones is the view pictured. There is a row of trees, still without leaves at this time of year. Beyond are grazing grounds, used for horses. To the left distance you can see a suburban housing estate. Birds are in the trees and on the pylons and power wire.

The persistent drone is from behind the microphones, across the canal, and even further past housing, 600m distant. Most of this is from the traffic on Dublin Rd., the main arterial access to this side of Limerick.

For those who downloaded this set initially, note that the files have been updated. They have been properly tagged and shortened in length to 30s.

This is a good test of real-world usage when field recording.

Site B
This recording was made at Studio Ubiquity AKA my living room. The time was 3:30am and it's extraordinarily quiet... likely quieter than some recording studios! (Though, unlike a proper studio, this sound level is inconsistent and likely to be disturbed.) The photo shows a close-up of the triple microphone cluster.

This is a good test of the microphone's noise characteristics. I ensured that the levels were equal across the mics, using a simple method. The full recording includes some quiet but distinct sounds. These were matched in all three tracks, for both timing (across the two recorders) and peak amplitude. Then the files were trimmed to the silent portions, removing the key sounds.

I ensured the segment was undisturbed by low frequency sounds from local traffic.

This is the first time I have performed this test... the results are illuminating! Hopefully you too will find them useful.

Site C and D
These are not actually different locations, but I have retained the terminology. In order to test a full-spectrum source I played back music over my KRK VXT4 speakers. (While not ideal, they are far from poor.) I close miked each speaker.

Site C is a 20s excerpt from "Watershed" by Mark Hollis, taken from the album "Mark Hollis" (Polydor 1998), engineered by Phill Brown. If you don't own this you are missing out on some wonderfully expressive music, recorded with heart and precision.

Site D is a 16s excerpt from "Rush Minute" by Massive Attack, taken from the album "Heligoland" (Virgin 2010), produced by Neil Davidge and Robert Del Naja.

Naturally I can say that these excerpts are for educational purposes, etc., but the truth is the publishing companies don't care about fair use. So grab them while you can.

Update history
Feb 14 2017: Site A recordings posted.
Feb 16 2017: Site B recordings posted. Site A recordings edited.
Feb 17 2017: Site C and D recordings posted and all files provided in ZIP.

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