40hz ratings/speaker response


Hi, as a neophyte to the technical end of this wonderful addiction, I am curious. If a speaker's frequency response capability is rated to say 40hz or above, what happens to that sound that was recorder that falls below that range? Say for instance the lower octaves on an accoustic piano, or a cello, electric bass etc? And again, what happens to a speaker, with the same rating, if the volume is "pushed" to hear and feel music that has a lower range?
Curious
joeb
Thanks for the info folks. You have to be careful about jumping to conclusions based on that spec.

I would much rather have a speaker rated 40hz or so that handled that really well than most speakers sold today rated below that number. Northcreek is a good example.

Cheers,
Sean, I believe I understand you correctly when I assume you favor non-vented designs. I am not clear on some of the basic design concepts of transmission line and infinite baffle (are these vented or sealed box types) while I believe the acoustic suspension aspect of the sealed cabinet seems relatively straight forward. Forgive me, but could you elaborate?

Also, Clueless, do you mean that the NorthCreek ratings are conservative, and that their designs subjectively go lower than their rated output?

Thanks for the information gentlemen.
Mike
As Scott Campbell (and others) said in the first post your number was the frequency where your sound is down three decibals(-3db). This does not say much about the quality of any speaker despite the fact that it is used that way sometime. Lots of speakers with really low specs sound horrible. One the other hand, you look at a North Creek, I think their Rhythm has a rolloff/F3/-3db point (what ever you want to call it) that is not that deep by today's standards. Maybe 44hz. And it has a tuning frequency (Fb) of 39hz or so. Sean pointed out that vented designs progressively lose damping below that point.

However, the design of the speaker does a great job reproducing sound in the high 30hz and they sound very musical. The www.northcreekmusic.com site is worth a look. You can listen to this speaker in the right room without feeling you have lost the last octave of music. At least I can.

I remain,
Well, looks like I'm back in business. I had my electronics tested. The tech said there were no spikes, square waves etc. In fact, he said it had one of the "flatest" frequency response deviations he'd ever seen. so I can trust my Classe gear. BW has sent me a brand new replacement speaker so I'm back to music nirvana.
Thanks to those of you who shared your knowledge.
joeb
My problem is with the speakers rated at 25HZ, but i cannot hear much under 40Hz?! Except, when i turn volume up, up high, then i can hear window panes rattling? I own Wilson Watt/Puppy 3/2 and Conrad Johnson CAV 50 integrated with very low gain. Is my amp too weak? Thanks! Ursula