B string frequency vs. Cab freq. level

[billfitzmaurice]

The only way you're likely to get a pure sine is by generating one on a computer, or a synthesizer.

-Nick

Not even then. While you can generate a pure sine no loudspeaker will reproduce it precisely, as the movement of the driver cone creates harmonics. FWIW, when you see amp distortion figures the quoted value is referenced to THD, Total Harmonic Distortion, which means the percentage of harmonics created by the amp at full rated output that does not appear in the original signal. With amps a THD of 1% is considered horrid, but with loudspeakers a figure of 10% is about average, with only 1% nearly unobtainable.

 

[alexei]

The only way to reproduce frequencies this low is with a high quality sealed subwoofer or a sub that is tuned very low.

True. A sealed cab would most likely be the best bet.

I remember back in 2001 or '02 I had a BOSS (2x300watt) car PA and a Rockford Fosgate 15" subwoofer in a big cab, with something like 80 litres (2,7 cu.feet) of volume space inside. Don't remember exactly the cab's dimensions.
That equip allowed me to get any low frequency I wanted with SoundForge 6.
I was able to "SEE" frequencies of 1 to 10 Hz for example. Speaker cone was moving back and forth at speeds i was able to feel in the chest and even see. Of course, that was impossible to hear.

I remember that 20-30 Hz was a frequency range so hard to identify with ears. Because it gets really confusing: are you actually hearing it or just feeling the air vibrating in the skin? Well... now I recovered a big part of my hearing since I left the last band (have not joined another band for the last 3 years) and I still can't hear those lower freqs.

I will try to test some of the thing we are talking here and I'll post my result. It would be great if some others do that too.

cheers!

 

[Arx]

Not even then. While you can generate a pure sine no loudspeaker will reproduce it precisely, as the movement of the driver cone creates harmonics. FWIW, when you see amp distortion figures the quoted value is referenced to THD, Total Harmonic Distortion, which means the percentage of harmonics created by the amp at full rated output that does not appear in the original signal. With amps a THD of 1% is considered horrid, but with loudspeakers a figure of 10% is about average, with only 1% nearly unobtainable.

Of course THD means very little when you're speaking of a specific frequency.

My headphones, I believe, are producing those low frequencies fairly precisely.

30Hz is quite hard to hear, unless it's quite loud.

If it's very loud they start to distort and it becomes much easier to identify, but it is audible considerably below this point.

-Nick

 

[JimmyM]

Wow, how did people before us create music without knowing all this stuff?

This is all stuff I never would have cared about 6 months ago. But I find this stuff endlessly fascinating all of a sudden. But with all this science going on, my rule is still, "If you hear it, it's real to you."

 

[JAUQO III-X]

"If you hear it, it's real to you."

 

[rockstarbassist]

Wow, how did people before us create music without knowing all this stuff?

This is all stuff I never would have cared about 6 months ago. But I find this stuff endlessly fascinating all of a sudden. But with all this science going on, my rule is still, "If you hear it, it's real to you."

How Mozart composed w/out distinguishing between 22.8hz and 33.205hz is beyond me.

But whew, thank goodness he did.

I wonder who ran FOH for that guy...

 

[billfitzmaurice]

Wow, how did people before us create music without knowing all this stuff?

All this stuff was quantified by the audio engineering community by 1940.

 

[alexclaber]

Wow, how did people before us create music without knowing all this stuff?

Music and audio engineering are two completely different things, just as race car driving and automotive engineering are.

The problem lies where you get musicians with no audio engineering knowledge trying to lay down the law on sound reproduction, like a regular commuter driving an indy car and telling the design engineer that it definitely felt like it was going 200 mph...

Alex

 

[bassbrock]

Music and audio engineering are two completely different things, just as race car driving and automotive engineering are.

The problem lies where you get musicians with no audio engineering knowledge trying to lay down the law on sound reproduction, like a regular commuter driving an indy car and telling the design engineer that it definitely felt like it was going 200 mph...

Alex

+1

Well said Alex!