Name: Noise Reduction Test by Douglas Langley in Microphone/Audio Recorder Tests
Duration: 1 min 42 s
Description: First clip is RX8 Spectral De-Noise just using the hiss control preset at 4db of reduction. Second clip is using EQ to reduce the hiss (5db band reduction around 8khz).

Microphone/Audio Recorder Tests

The European fire-bellied toad is, in fact, a frog. (No fire, either.) However, this is more than compensated by its satisfyingly fun-to-say Latin name: Bombina bombina. They also produce antimicrobial peptides in their skin secretions – the even more fun-to-say ‘bombinins’. 

Native to eastern mainland Europe – recorded here in the protected land of Poland’s Barycz Valley Landscape Park – they use their internal vocal sacs to produce their “whoop” call: the mournful, slow-motion honk immortalized here. Imagine the sound that clowns might make when they cry and you won’t be far off.

Bombina bombina mysterious call

Recorded on the land of the Peramangk people.
Deep, slow, careful listening required.
Read the Playlist description for more information: https://soundcloud.com/hearingbeings/sets/2023-iron-curtain-autumn-and-summer

2023.03.16 Iron Curtain. Early Autumn.

An hour before sunrise in a secluded valley mire in Dartmoor National Park. Snipe (Gallinago gallinago) are performing their "winnowing" courtship display, flying up and diving downwards so their tail feathers vibrate with a distinctive thrumming sound. Tawny Owls and Cuckoo call across the valley.

Recorded on 1st May 2023 with 2 x AT4022 microphones in an Olson stereo array (www.trackseventeen.com/mic_rigs.html) and a Sound Devices 722 recorder.

May Day Snipe

This is a very high-gain recording, the forests are so quiet in this part of Sweden, I like the idea of really opening up the gain.  MixPre3 the gain set to 74db, with a pair of Lewitt 440's.  Recording 4000.

Stream (1) -  12 May 23 - 11am - Dalsvallen

At the crossroads of day and night, diurnal birds meet nocturnal animals for a precious hour. Thus the black-crowned night herons, doves, ducks meet the roar of the deer, the fleeting bats and the tawny owl, in a unique and precious soundscape in the heart of the forest of Orléans, the biggest forest in France

Crépuscule Automnal À L'étang Du Ravoir (Automn Nightfall At Ravoir's Pound)

Recording I made while waiting in a parking lot to get out until the rain shower was over.

Rain on the roof of a car - interior

PodCast

Rain on the roof of my car - interior (September 21st, 2023)

ST_amb_usineVallorbe

A Days Walking in the Hills North of Innerleithen Scottish Borders Summer 2024

A lone Golden Plover vocalises near the southwestern top of Windlestraw Law. 

 7th July 2024. 

EM272 pair + Sony A10

Windlestraw Law

amb_st_reveil_naples_2

There's two old empty oil storage tanks beside Tahkoluoto harbor. The tanks are closed, but have one open maintenance hatch through I put the microphones inside. I waited for a stormy day to do that, and so it sounds. Headphones recommended! 

http://www.rupuranta.net/weblog/filet/180922/

(MKH8020 ab50cm, SD702, nothing done in edit, 24/48 flac)

Jan Eerala Finland

The Black Hole - 22/9/2018 - Tahkoluoto Finland

2 x Clippy microphones in a cupboard recording to an Olympus LS-P4. Same source recorded at 7 different gain settings (1, 5, 10, 15, 20, 25, 30) and normalised in post (adding 70db to the lowest gain setting, 5db to the highest). Recorded at 24/48.

This shows a very clear linear progression in the reduction of noise. I often record at level 15 in quiet ambiences but this shows there's something to be gained (in terms of HF noise reduction) by cranking it up to 20 so long as there's no likely to be any loud sound sources that will clip the recorder.

Olympus LS - P4 Self - Noise Test

Test of the baffled omni array I have been working on with two Primo EM172 capsules (FEL Clippy). Microphones were pointing out from a first floor window up towards the sky (at some birds clattering about in the gutters).

Baffled Omni Array Test

This test is comparing the self-noise of the Sony PCM-A10 and the Olympus LS-P4 at various gain settings using external microphones (Clippy EM172). Both recorders allow gain settings from 1-30. I recorded the same sound source (quiet ticking clock) at levels 1, 5, 10, 15, 20, 25 and then 30 simultaneously on both recorders and then normalised the levels in Reaper. I then had to do quite a bit of manual correction of the levels because there were some low frequency sounds that were louder than the ticking clock and which were messing with the normalisation process. Recordings were made at 24/48 WAV.

In this recording you first hear the Sony at gain level 1, followed by the Olympus at gain level 1 and so on up to level 30.

As shown in an earlier test the Olympus exhibits much higher levels of self noise at lower gain settings, with a noticeable improvement coming at level 20. This means that when recording quiet scenes, it is worth taking the risk of setting the gain high to minimise the recorder self noise.

The Sony behaves quite differently. At gain level 1 the noise is quite terrible  but at level 5 there is a sudden improvement and in fact there is almost no difference between the noise at level 5 and level 30. This seems to suggest that you can be much more conservative with setting the gain on the Sony to avoid clipping, and increase the levels later in post with no apparent self-noise penalty.

Sony PCM - A10 VS Olympus LS - P4

Another test of the Sony PCM-A10 at different gain settings using external microphones (Clippy EM172 stereo pair). Recordings of two different subjects at low and high gain to compare the recorder self-noise. Tracks normalised in post afterwards. Recorded at 24/48.

Clip 1: Indoors with windows shut. Birds audible through the windows. Recorded at input level 5.
Clip 2: Same as above recorded at input level 25
Clip 3: Outdoor ambience recorded at input level 5.
Clip 4: Same as above at input level 20 (highest I could go without the sparrows clipping the recording!) 

A gain setting of 5 on the PCM-A10 is very, very low in case it isn't clear. There was virtually nothing registering on the meters while I was recording.

I hear zero difference in noise for the recordings at very low and very high gain settings. This is incredible as it means you can set your levels very conservatively to avoid clipping and increase levels in post later with no fear of losing the signal in the noise.

Sony PCM - A10 Gain Test

More tests of the Sony PCM-A10 at extremely low gain levels. I recorded a few seconds of test tone followed by 20+ seconds of a quiet room at gain levels 1, 2, 3, 4 and 5, and then level 25 as a high gain level for comparison (highest gain should have the best noise performance).  The recordings were then normalised in Reaper, resulting in gain being added to each clip of: +40.8dB, +39.1dB, +37.7dB, +35.7dB, +34.6dB and finally +2.87dB (gain level 25).   

Hopefully what you can hear in this is that levels 1 and 2 have a high level of noise, but then it suddenly drops off at level 3, and levels 3, 4, 5 and 25 all have nearly identical levels of audible noise.

My conclusion is that when recording a dynamic source such as a thunderstorm, I can safely go all the way down to gain level 3 to minimise the chance of clipping, while not adding significant noise when I later raise the levels in post.

Sony PCM - A10 Gain Test (Extremely Low Levels)

First clip is RX8 Spectral De-Noise just using the hiss control preset at 4db of reduction. Second clip is using EQ to reduce the hiss (5db band reduction around 8khz).

Noise Reduction Test

Stereo soundscape recordings. Sometime nature, sometimes people, sometimes machinery. Sometimes quiet things like a single branch creaking in the wind on Dartmoor, sometimes odd moments in the city. Mostly local, but sometimes travelling. 

Noise Reduction Test

Douglas Langley

Related tracks