Can too low of a frequency damage my speakers?

[417 - Alnico]

If you are driving a ported speaker at high power below its box tuning frequency it becomes "unloaded" and you can quite easily exceed mechanical limits and potentially damage the woofer.

Your avatar shows a 604E. Is this what you are using? If so, what is your box alignment/tuning frequency?

Does this apply to a 614 cab? Because I could not find a spec sheet on the frequency range for it.. The tuning for the enclosure.
It seemed to indicate..to go with the speaker's specs...That is, if using a 414 go by its range...417 etc...
Being a heathen and mainly a MI guy, I am more than ignorant on the physics of sound and spl etc... ... I know by reading JBL lit, that their enclosures, purportedly can attenuate or vice versa, the low end of a specific driver...of course, they have over, under hung Voice Coil drivers etc..

http://www.voiceofthetheatre.com/images/614D.1.jpg

http://www.voiceofthetheatre.com/images/614D.2.jpg

http://www.voiceofthetheatre.com/utility.cabs.2.jpg