Only alternative for a true bookshelf speaker with no rear port:
https://www.youtube.com/watch?v=QA8_1PFUAaU&ab_channel=CharlesKeng
https://www.youtube.com/watch?v=cwpIYFWDfQ8&ab_channel=MyHifiNews
https://www.youtube.com/watch?v=up6ZpOGt66E&ab_channel=CharlesKeng
https://www.youtube.com/watch?v=aQYP2Qm2pAw&ab_channel=MinhHoanVu
https://www.youtube.com/watch?v=xFRAoSSsv8g&ab_channel=MyHifiNews
https://www.youtube.com/watch?v=IDYgTI-czog&t=51s&ab_channel=TMRAudio
With a rear port / passive radiator:
https://www.youtube.com/watch?v=2DgNqgVGrTo&ab_channel=HiFiFan
https://www.youtube.com/watch?v=Apn-LzZEBdY&ab_channel=StereoChannel
But may need a sub(s) with either to warm it up a bit...