How much is half an octave of deep bass extension ?

[bob412]

There's a bookshelf kit speaker system sold by Partsexpress.com that goes down to 40hz . A salesman who works there said if I get a better woofer I could get a half octave more deep bass extension . The speaker in question goes down to 40 hz . How much lower would half an octave go ?

 

[sKiZo]

30hz ... do I get a prize? <G>

 

[Will S.]

Four whole notes!

 

[sKiZo]

Yeah ... but ... they're really really important notes! ;-}

 

[Porkloin]

I'd be skeptical. Mathematics tells me that both of my 10 inch woofers in each ported enclosure, get down to 46. And yet I've never had anything else in the living room that did a more visceral low end. Neither of my two "book shelf" (ADS L-780 & Energy C-2) speakers come even close and the home theater towers (Monitor Audio Silver-6) are getting there, but not with the apparent ease that the vintage behemoths do.

Get the better woofer. I'll bet it does several things that will appeal more to your natural human preferences than some magic number that the brochures beat into our heads.

 

[damacman]

OP - an Octave is defined as a doubling or halving in frequency. Half an octave is significant.

 

[Dennis Gardner]

Basically 6 or seven notes on a piano. It doesn't sound like a lot, but info from 40 down to 30 is musically important for bass guitar extension into the lowest notes on its neck. I also notice that each time that I improve the bass extension, those notes at the earlier limit are so much more effortless and consistent with the rest of the musical range. In other words, a speaker that plays down to 30hz well will likely play 40 hz better.

 

[Hobie1dog]

But you can't believe rated frequency response numbers as gospel, especially when it comes to low frequencies and the many box variations there are.

 

[Tom Brennan]

A woofer that goes lower in the same box must do so at the expense of efficiency, thus the tweeter would need more attenuation to keep the voicing the same, a means for this must be provided.

 

[toddalin]

Another way to look at it.

Assuming the numbers are true...,

40 Hz is the low E-string on a bass guitar. 30 Hz is low B, below the 32 Hz low C-pedal on an organ, or the lowest note on some 5-string basses. What kind of music do you like?

 

[bob412]

Another way to look at it.

Assuming the numbers are true...,

40 Hz is the low E-string on a bass guitar. 30 Hz is low B, below the 32 Hz low C-pedal on an organ, or the lowest note on some 5-string basses. What kind of music do you like?

New Age , smooth jazz , any and all things produced by James Newton Howard .

 

[toxcrusadr]

Do they actually have any hard data - such as response curves of this same speaker built with the two woofers in question? Not that I think they're lying, but, y'know, salesmen.

 

[unfairlane]

The question is not if IF plays like 40hz but rather HOW it plays it. A weak amp can play the whole frequense-range just like a big killer-amp but they shure do not do it the same way. Same with speakers

 

[toddalin]

New Age , smooth jazz , any and all things produced by James Newton Howard .

Then look towards the instrumentation of the groups you like to listen to and go from there.

I don't listen to any of those, but would think that New Age would use lots of bass synth and you would want a lower extension. For smooth jazz, maybe it doesn't matter as much.

 

[sKiZo]

I was amazed and astounded when REW told me I'm getting usable SPLs down to 14hz here ...

(can't hear em ... but you can sure as hell feel them).

And that's where the extra bottom comes in. Sub-harmonics can make or break that gut wrench sternum crushing OMG moment some of us live for. It may just kill ya, but you'll die happy.

 

[JoeESP9]

Lowest frequencies of electric bass strings.
Open E = 41.204Hz.
Open B = 30.868Hz

 

[audiotemp]

30hz ... do I get a prize? <G>

Octave is defined as a doubling or halving in frequency. Half an octave is significant.

Basically 6 or seven notes on a piano.

Half an octave below 40 Hz is about 28.2 Hz.

An octave is a factor of 2 in frequency...so half an octave is a factor of square root of 2, which is 1.41 (or so). Unless you can divide by 1.41 in your head, the easy way to proceed from there is to note that half an octave below 40 Hz is also half an octave above 20 Hz. So 20 * 1.41 = 28.2 Hz.

I hope y'all are paying attention because there will be a test...

edit: wink added...for DG

 

[nexus]

30hz is easy to do nowadays. most small subwoofers can do it. the real difficulty is when you want to do 20hz or those fabulous 16hz organ pedals, to say nothing of synthesizer bass tones.

even the old Lrg Advent could do a respectable 30 hz in most rooms in it's day.

that was okay back then because few if any vinyl records had anything but rumble below that frequency.

today so many speakers won't even go smoothly down to 30 hz. that is why there are so many subs that just cover the 30hz range.

also, ime many people who are not actually familiar with experiencing 25hz tones will hear 40hz and say they are hearing 30hz. they hear 30hz and say their speakers are doing 20hz.

most (but not all) movies soundtracks have plenty of explosions etc. that are centered around 30hz and people like my neighbor say "man, did you feel that 15hz!"

 

[I LIKE MUSIC]

In acoustics and electronics an octave is defined as the ratio of two frequencies where the ratio is an even number integer.

It is based on a ratio of 2 not a power of 2.

This can be seen in things such as speaker crossovers.

Take a 1st order crossover. It has as slope of 6 dB per octave (halving of the frequency).

Another example is pink noise. Some may be familiar with it. It is energy that has equal energy per octave (double or halving of the frequency).

So, in terms of the OP's question, it will be 30 Hz. But that by its self does not tell us much. As previously mentioned, what is the slope of this extended response?

 

[kaplang]

Too much math and numbers. The real question is, do your ears hear 1/2 an octave lower.