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low B frequency

Discussion in 'Strings [BG]' started by bizzaro, Feb 22, 2001.


  1. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Could someone please tell me the frequency that an open low B string produces?
     
  2. I believe it's 28Hz, but don't quote me on that.
     
  3. Oysterman

    Oysterman

    Mar 30, 2000
    Sweden
    30.9 Hz (with regular 440 Hz tuning).
     
  4. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    I can't seem to find a 15 inch bass speaker that will reproduce that frequency,(30.9hz). Do you have to get an eighteen?? And even the eighteens barley go down to that frequency. Are the frequency specs for speakers conservative?? Usually manufacturers expand their specs. Will the speaker still produce that frequency even though it's rated for say 40 HZ? It just won't sound as good or clean?? How about what is the frequency of the note above low B,C. What is that frequency??
    Thanks
     
  5. notduane

    notduane

    Nov 24, 2000
    Location
    There's a relatively simple way to figure out the frequency of various notes.

    1) Start at "A" in any octave: 110.0, 55.0, 27.5, etc.

    2) Get a calculator with a "y\x" and "INV" key.
    (the built-in one with Windows OS will work in "scientific" mode)

    * The difference between notes of a standard chromatic scale is based on
    the 12th root of 2. To get this number, key the following into your calculator -

    2 INV y\x 12 . You should get something like 1.05946 .

    3) Therefore, to calculate G# from A=55.0, substract 1.05946 from 55.0 (53.9405).

    4) Make yourself a little chart (or write a Perl loop :p ) to keep track of things.

    When I had a Conk GT7, I got a SWR Big Ben. It has a fast BagEnd 18"
    spec'd at -3dB at 25Hz. I was gonna' tune the Conk with the low F# (around 23Hz).
    `Course it didn't occur to me to get an AMP spec'd to ~23Hz :rolleyes: . Got rid of the Conk,
    still got the Big Ben (it's a gut buster! :D ).
     
  6. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Thanks for the formula. But I am a little confused. Did I miss something along the way in my bass tuning 101? I thought that in concert tuning "A" was 440 Hz. And then you multiply or divide by two for higher or lower octaves. Is a bass guitar intentionally tuned a little sharp or something that I haven't heard about for some reason??
     
  7. Oysterman

    Oysterman

    Mar 30, 2000
    Sweden
    No sweat, bizarro, even a cab isn't spec'ed down to the very fundamental of a note, it doesn't mean it would not come through cleanly. The two 10"'s I have in my combo go down to 70 Hz, but the B is loud and proud, and actually more balanced with the other strings than it would be with a 18" sub. On the other hand, it's no room-shaker - to achieve that you'd need a sub.

    IMO: On the whole, people worry too much about reproducing fundamentals. If you don't have a great bass, chances are the bass itself won't give the fundamental for the low B anyway, especially if it's a bolt-on.
     
  8. notduane

    notduane

    Nov 24, 2000
    Location
    Hmmmm...As best as I can recollect, it's " divide by 2 per octave"...

    A = 880.0 Hz
    A = 440.0 Hz
    A = 220.0 Hz
    A = 110.0 Hz
    A = 55.0 Hz
    A = 27.5 Hz

    ...and so on. I think the open A on a "bass guitar" is 55.0 Hz.

    Now if'n you'll excuse me, there's a tornad-ey a' brewin' and I gotta' shut down :eek: :p .
     
  9. eli

    eli Mad showoff 7-stringer and Wish lover Supporting Member

    Dec 12, 1999
    NW suburban Chicago
    bizzaro --

    notduane gave one A as 110 Hz. Double that (another A) and you get 220; double it again, and you get 440.

    Soyou're both right, and you actually DO remember correctly.
     
  10. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Of course, it's obvious now. I just briefly glanced at the post and didn't take time to do the math. I had to Race off to a gig. But back to the speaker question. If a speaker is rated for 40 Hz. how does it reproduce Hz's lower that? Or doesn't it? Let me guess that it starts reproducing the first lowest sub- harmonic it can and goes from there??
     
  11. I read that article in BP by Mike Tobias about the fundamental missing (I suspect it's more accurate to say reduced) in bolt-on basses, but I have to ask- if the fundamental isn't there, how can you hear the difference between, say the open B string, and the B an octave above on the E string?:confused:
     
  12. eli

    eli Mad showoff 7-stringer and Wish lover Supporting Member

    Dec 12, 1999
    NW suburban Chicago
    This gets into a complicated area called psychoacoustics.

    Any note produced by an instrument is composed of the note's fundamental plus a bunch of overtones -- multiples of the fundamental frequency -- in certain ratios characterisic of the instrument. Your ear has learned what those sound like. So even if you hear the overtone series without, or with a severely reduced, fundamental, your brain will actually "fill in" the missing fundamental. To answer your question, the overtones of the low B are different from the overtones of the B an octave higher. The series is in the same ratio, but they're ALL an octave lower. So your brain "hears" the low B by calculating the fundamental fron the overtones.

    I'm not clear on the details, but I know that this is a big part of why an SVT 8x10 enclosure works -- it doesn't actually produce the lowest fundamentals, but it does such an accurate job on the overtone series that it makes you THINK you're hearing the fundamentals.

    ::dana carvey johnny carson impersonation::

    Weird, wild stuff.

    ::impersonation off::
     
  13. bizzaro

    bizzaro

    Aug 21, 2000
    Vermont
    Thanks Eli for the informative and really interesting info. I ment overtones when I said sub-harmonics, just didn't know the right term. Yea, weird wild stuff!!! I love it.
     
  14. thanks for the explanation, Eli.

    my theory is that the body of a bolt-on bass is freer to resonate, and more of the fundamental gets converted into overtones- that sort of makes sense anyway.

    however, after thinking about this and other neck width/string spacing/B string clarity issues I've abandoned my idea of getting a 5string.:D

    re. the brain "filling in" the missing fundamental, I've noticed on a couple of recordings I've done that some bass notes (eg. G on the D string) sound exactly as if they were played an octave lower- probably due to the low end on the guitar tracks interfering.
    I seem to have a hard enough time getting my 4stringers represented in the mix (lots of arguing between me and the engineer and singer/guitarist at the last recording session) :( - I don't even want to think about what problems I'd face with a 5.......
     
  15. Munjibunga

    Munjibunga Total Hyper-Elite Member Gold Supporting Member

    May 6, 2000
    San Diego (when not at Groom Lake)
    Independent Contractor to Bass San Diego
    Another aspect of this is that, even though a speaker might be rated down to 40 hz, that just means that it will reproduce that note with less than a specified number of decibels of fall-off. So, while the speaker might be able to produce frequencies down to 40 hz with less than 3 dB of fall-off, it might be able to go down to 31 hz with less than 6 dB of fall-off.

    For example My Eden D-410XLT is rated 50 hz to 13 Khz with less than 2 dB fall-off or gain across that frequency range. It is rated at -6 dB at 31 hz. So it will still produce the 31 hz low B (quite nicely), but at a slightly lower sound pressure.

    Clear as mud, right?
     
  16. Acmes nail the low B fundamental using 10" drivers. So giant drivers aren't necessary. I mean, think about the size of drivers in earphones.

    A cab like the Low B-2 can be 3 dB down at low E and 6 dB down at low B, but because the room acts as an extension of the cab, if you put the cab on the floor, the lows will be boosted to the point where they sound balanced. If you also put it close to a wall, they may sound a little loud (my Low B-4 with twice the lows of the B-2 is a little too loud in the bottom, so I normally cut lows). And if you put it in a corner, you may find yourself cutting the lows.