Insects time stretched

This patch of unpromising looking waste ground next to a main road hosted a number of crickets – probably bush crickets by the sound through the bat detector compared with some on the web, but heck, what do I know, they could be something else.
Anyway, lots of these guys, and they sound a lot better to me reconverted and time-stretched

6x time stretched 5.3Mb mp3

than the original recording which sounds like mush to me

Original Heterodyne recording 2Mb mp3

Once again, detail seems clearer in the time stretched recording. The tone colour and character of the time stretched recording is much more recognisable as related to the audible sound, recorded with a standard MKE300 microphone (with traffic noise and people – this was a busy road)

Audible sound of the crickets heard in the bat detector 0.5Mb mp3

Electret paralleling experiment

Rapid Electronics’ 35-0190 electret mic insert is cheap enough to muck around with. Rumour has it paralleling these guys up is worth doing for extra sensitivity and noise reduction, so it seemed worth a go.

Schematic

Listen to the results, test signal provided by a bunch of gormless teens playing in the rec and some friendly sparrows. The right-hand channel is the paralleled set

Bunch of gormless teenagers and friendly sparrows 240kb mp3

Rightmark shows a 2.5dB improvement in signal level from the doubled up pair
It doesn’t pay to pull this trick directly off plug-in-power on a Sony MZ-NH700

friendly sparrows 240kb mp3

as the PIP hasn’t got enough grunt to power the paralleled pair. I measured 1.1V across the singleton and 0.24V across the pair, which isn’t enough to power the capsules, operating voltage range 1.5V to 10V. In fact the singleton wasn’t really in spec on PIP.
With the 6k8 resistors the corresponding voltages were 6.9V, 4.9V from an 8.2V onload battery voltage

Rightmark shows the corresponding drop in output