# How many hertz is a low B?

Discussion in 'Miscellaneous [BG]' started by Sonorous, Mar 16, 2005.

Oct 1, 2003
Denton, TX
Eh? Anybody?

2. ### Mike MoneyBanned

Mar 18, 2003
Bakersfield California
Avatar Speakers Endorsing Hooligan
31

3. ### Sonorous

Oct 1, 2003
Denton, TX
Thanks.

I decided to look it up after I posted this (Priorities?) and found it was 30.9 but hey, 31 works for me.

4. ### Sonorous

Oct 1, 2003
Denton, TX
So my Avatar 4x10 Delta is rated at 65 HZ...

What is a low B at 31 hertz going to do to it? And for that matter, an E at 41? And for that matter, whatever an A is?

EDIT: Yes, I'm derailing my own thread.

5. ### Jaye

Jan 30, 2004
Portland, OR
You will be fine, for the most part you hear the first and second harmonics of the B insted of the fundamental anyways. What you will lack is the kick you in the chest punch that you would get from a cab that is rated to a lower Hz.

6. ### ThorModeratorStaff MemberGold Supporting Member

Save this chart someplace handy ...

Physics of Music - Notes

When you said the Delta was rated at 65 Hertz, I confess to being a bit confused.

Did you mean that the Fs ( Resonant Frequency) was 65? The Eminence website lists the Fs of that driver at 41 hz, so pardon me if I seem confused.

To address your other question, the human brain is a wonderful thing. When your ear hears the harmonics of a LF
note, the brain assumes the note is being sounded. Your particular speaker may not reproduce 41 hertz well, but you will hear it regardless. Actually, many bass speakers have F3 values quite a bit higher than 41 Hertz. F3 is the point on the left shoulder of the SPL vs Frequency curve where the response decreases by 50% (3db). Other speaker and cabinet parameters such as box volume, vents and ports can affect these values.

( I know the description is over simplifed ...)

I hope that helps.

There is a very good FAQ by Joris on the site on speaker and electronics design you may find quite helpful in exploring speaker questions and other related issues. here.

Oct 1, 2003
Denton, TX
8. ### ThorModeratorStaff MemberGold Supporting Member

It would seem that they are.

However, once you mount them in a vented enclosure,
you change their bass response. Those measurements
are done in a 2700 cu ft chamber under standardized conditions.

The cab designer takes those measurements and uses them to design a better performing cab by mounting the driver in a vented or unvented enclosure. This changes the resulting bass frequency response curve vs dbSPL indices.

Too big a box can actually decrease response, which is why
you see a recommended cubic volume. Also, the length and diameter of the port, and whether the port is radiused or not changes the response as well.

9. ### Sonorous

Oct 1, 2003
Denton, TX
Ah, ok. I guess I never understood how much thought goes into a cabinet.