Tutti gli articoli di fab

Rain in car

Yesterday was raining in Rome. It’s not a big scoop usually but considering that the average temperature was not under 28 C. and this was going on since the last days of June, you can understand why this has been so refreshing.

I had with me my Tascam while driving home from workplace so I decided to stop in some low-traffic roads and try to record the sound of the rain on the car’s roof and windscreen. The result is this:

Sorry no pictures for that but nothing interesting also…

The first track has a very low volume but I decided to not edit at all because it could be used for another project.

Recorder: Tascam DR100 MKII
Microphones: Tascam onboard ones (directional)
Editing: none

Quickly generate spectrograph

Just as reminder: the sndfile-tools package in the Debian repositories contains some useful utilities to work on audio files, for example to generate a PNG image with the spectrograph from CLI.

Having a list of audio (flac) files in one folder and want to generate the spectrographs with matching names:

for f in $(ls .); do sndfile-spectrogram $f 1000 480 /tmp/${f/flac/png}; done

Here more info (man pages) on the sndfile-tools


Le rupi – a first contact mic experiment

Some times ago I bought a couple of cheap contact microphones, mainly intended for acoustic instruments.

Today is the first day here in Italy without too much blizzard (the weather is very very fine, nearly spring indeed) so I decided to test them.

The location is a very nice spot on the lake, quite high and calm, without wind or too much anthropic noise except some random cars passing on the streets around the lake shore that projects their sound very far. Occasionally birds and children voices.

I’ve tried to apply the microphones to a wire mesh with simple clamps, using a common pattern I’ve seen dozen of times in these kind of field recording.
Suddenly I’ve discovered a whole world of hiss and bangs and rings induced by the low wind stream, birds (the mesh captures the higher frequencies too) and the unshielded mic cables.

This first recording is at medium gain. I’ve amplified with Audacity so the cheap microphone noise is very perceptible.

The second time I’ve set the gain on my Tascam on “High”. The difference is plain:

Recorder: Tascam DR100 MKII
Microphones: cheap unbranded contact mic
Editing: minimal (increased gain with audacity)

FiiO Olympus 2E10K

I’ve recently bought a new headphones preamp, the FiiO Olympus 2-E10K.


Is a very very small (about 2cm x 8 cmx x 2cm h) DAC that uses the PCM5101 chip (seems that the old WM8740 used in previous version of this box was suffering by delays in hi-res reproduction start).  The amplifier chip is the quite common LMH6643.

The specifications on the site above claims for very low noise (S/N Ratio >= 105dB) and I have to say that the general circuit noise is very low indeed. A very trivial trial: with my ATH-M50 headphones, nothing in reproduction, all volumes set to max, no noise at all.

The claims to drive from 16 to 150 Ohm should be enough for my AKG K601 (120 Ohm) that are currently my best open headphones.

The setup under Debian Sid has been straightforward: plug it and select it as main ALSA output. I avoid using pulseaudio as possible as software mixing is not what I’ve choosing the external card for, but sometimes I will need to.

I’m very pleased also for the very small dimensions and the metal case, seems very robust. The gain and bass switch probably will never be used, unless some esoteric try: I lke the sound as clean as possible.

Now I only need a cable at least 4 m long to connect it to the Marantz vintage amplifier…

Caldera (Manziana, RM, Italy)

Yesterday I went to the “Caldara di Manziana”, a reserved area near Rome famous for it’s volcanic feature. The area is in a very nice wood with a small group of birches, quite uncommon for this kind of climate.

While I wait for the windshields I take advantage of the nice sunny evening, with practically no wind at all to use only the Tascam DR100 MKII with only the small foam protection to record some unique sound from this area.

Surrounded by this very enchanting wood, the actual caldera is a small lowland where a sulphureous smell dominates the air. Small and bigger puddles creates an unique view and sound, from the tiny bubbling to the large water boiling and spiffs. In the distance animal calls , birds and crickets.

2014-08-10 19.25.55
Small mud pools


No water from this hole in the ground, only sounds from the hollow underground...
No water from this hole in the ground, only sounds from the hollow underground…


The biggest spurt in the background produces a lot of whiffs and splashes. Close to the recorder the mud produces a lot of tiny bubbles.
The biggest spurt in the background produces a lot of whiffs and splashes. Close to the recorder the mud produces a lot of tiny bubbles.



All audio files has been minimally cropped to eliminate the planes noise that reflects on the ground. Recorded at 48kHz 24bit and converted to FLAC.