Transducers?

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awolski
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Transducers?

Post by awolski » Tue Oct 19, 2004 8:40 am

All right, this may display some sort of massive ignorance on my part but it will bug me until I find out...

If small diaphragm condensers can reproduce all the way down to very low frequencies, and some headphones can reproduce low freqeuncies well (though often hyped), why do tiny computer speakers/bookshelf speakers/etc. always seem to be lacking in bass? After all, they are all transducers.

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Re: Transducers?

Post by joel hamilton » Tue Oct 19, 2004 8:48 am

Ocean waves could be measured with a tiny device. Think of the size of a machine that would be required to PRODUCE ocean size waves!>!?

The mass of the ocean water acting on a small little fishing bobber creates measurable motion. That same bobber plunked in the water only makes a tiny ripple. The two act, or are acted upon by completely different forces.

I cannot express this in an equation, but my grandfather worked on EMP, and LFO technology for years. He explained it to me basically the way I did above.

He also made hydraulic 10 foot carbon fiber woofers that blew the windows out of houses at 500 yards away...... For the military, not for Ludacris...

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Re: Transducers?

Post by jajjguy » Tue Oct 19, 2004 8:55 am

i don't know about headphones, but...

microphones with small diaphragms don't have to be able to produce low frequencies, they just have to be able to react to them, which is much easier.

to produce low frequencies, you have to be able to (using just electromagnetism) make something (speaker driver) push a lot of air in one direction for a relatively long period of time before reversing direction.

with higher frequencies, it's easier to generate more sound energy because the drivers are moving very fast. with low frequencies, the driver is moving very slowly, which means it has to move that much more air to create the same amount of energy.

it's not that small speaker drivers can't be made to vibrate slowly enough... it's that they can't be made to push very much air while doing so.

[edit: joel beat me to it, and very elegantly. nice one.]
Last edited by jajjguy on Tue Oct 19, 2004 8:57 am, edited 1 time in total.

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wayne kerr
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Re: Transducers?

Post by wayne kerr » Tue Oct 19, 2004 8:56 am

Joel Hamilton wrote:Ocean waves could be measured with a tiny device. Think of the size of a machine that would be required to PRODUCE ocean size waves!>!?
What an excellent explanation. By the way, I have one of those machines, and you're right, it's HUGE! Almost as big as my widebody A80! :lol:

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awolski
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Re: Transducers?

Post by awolski » Tue Oct 19, 2004 9:02 am

Cool, but what about headphones? I assume since they are so close to the ear they don't need to move as much air in order for the user to hear the lower frequencies? That's why you get this hyped bass response?

Chuckles for the Ludacris wisecrack. :lol:

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Re: Transducers?

Post by xonlocust » Tue Oct 19, 2004 10:40 am

Joel Hamilton wrote:He also made hydraulic 10 foot carbon fiber woofers that blew the windows out of houses at 500 yards away...... For the military, not for Ludacris...
that is so cool!!

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Re: Transducers?

Post by joel hamilton » Wed Oct 20, 2004 12:16 am

Totally. He worked on some amazing stuff in the 50's and 60's, for MIT and Lincoln Labs. Amazing tube research in broadcast and crazy stuff like pulse cannons and EMP, and LFO stuff. Amazing. I guess they made some really amazing broadcast stuff as well. I wish he would have built compressors for more than just his home radio thing. (ham radio).

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Re: Transducers?

Post by @?,*???&? » Wed Oct 20, 2004 7:12 am

The wavelength of a 30Hz tone is 36.7 feet. How close do you sit to your computer?

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Re: Transducers?

Post by @?,*???&? » Wed Oct 20, 2004 7:13 am

Btw wavelength = 1130 (ft per second) divided by frequency.

fyi

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Re: Transducers?

Post by jajjguy » Thu Oct 21, 2004 2:36 pm

Jeff Robinson wrote:The wavelength of a 30Hz tone is 36.7 feet. How close do you sit to your computer?
Are you suggesting that you need to be 36.7 feet away from your speakers to hear a 30Hz tone? That's not true. It is true, however, that most rooms will be too small not to make a mess out of these low frequencies.

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Re: Transducers?

Post by Scodiddly » Thu Oct 21, 2004 3:40 pm

awolski wrote:Cool, but what about headphones? I assume since they are so close to the ear they don't need to move as much air in order for the user to hear the lower frequencies? That's why you get this hyped bass response?
Exactly - the drivers in a pair of headphones are almost as large as the space to which they're coupled. Sort of like having a woofer the size of your entire wall.

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Re: Transducers?

Post by awolski » Fri Oct 22, 2004 9:10 am

Cool, thank you.

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