If you like our work, please donate through Paypal link below any amount that you consider. We have expenses, like energy cost, software licenses, hardware maintenance and upgrade, travel to remote location to record video and audio, time, s.o. Thank you!
https://www.paypal.com/cgi-bin/webscr?cmd=_s-xclick&hosted_button_id=GLE6SS9BYBAH4&source=url
.

Video 4K – Test du son par les haut-parleurs (10-20000 Hz) – 60 minutes (une heure) d’amplitude linéaire, gamme complète, graves, moyennes et aiguës – spectre vidéo 4K et audio de haute qualité.

For more great videos, please subscribe to this YouTube channel or our Facebook page: Relaxing and useful sounds, noises and videos (https://www.facebook.com/relaxingsoundsandvideos).