Conflicting results with helmholtz calculators-Acoustics Forum-Acoustic Fields Forum

Hello.
First post here. I have searched the net for a reliable helmholtz calculator
but for some strange reason the ones I have found do come up with two
different results. Example for all calculations where:

Box volume:1000L
Port diameter: 30cm
Port length:10cm

Results where either 25hz or 46hz. If someone could point out what the
answer should be that would be most helpful.

Here is the list of the ones I have found so far.

I guess it’s copy/paste if you want to try them out.

https://boomspeaker.com/helmho…..alculator/

http://www.vk2zay.net/calculat…..mholtz.php

https://www.omnicalculator.com…..-resonator

http://www.mh-audio.nl/Acousti…..HReso.html

https://www.lautsprechershop.d…..ltz_en.htm

Best regards. Bengt Dahlberg