Headfonia made a review for Sendy Audio Aiva
"The body from bass to treble is good and it’s a full sounding headphone. The tonality is a little warmer and the delivery is smooth. What impresses most is the spaciousness and airy presentation but it at the same time isn’t the best regarding separation, sound stage width, depth and layering. The Aiva is extremely relaxed sounding and it really makes you enjoy your music not looking at technicalities.
The bass body and impact is slightly above neutral, the mids a little recessed/more to the back and the treble more forward because of those mids. Does the Aiva always sound the same? No it doesn’t. Hook it up to a DAP without an amplifier and you won’t get the best sound possible. Maybe leaving you underwhelmed. Hook it up however to a nice amp such as the Mojo or Niimbus US4+ and you get a much better, impressive sound. And when the Aiva has enough power, it’s a headphone you can use and enjoy all day long. At the end of the day your troath will probably hurt from singing along so much."
Read more: https://www.headfonia.com/picture-sunday-sendy-audio-aiva/