Physics of (bass) sound

[DigiSUN]

Greetings Pulsarians

I have a few questions and i'd be greatful if you can share your wisdom...

One can often hear bass beats from a distant party. What is heard is mostly the bass.
Why do lower frequencies travel further distance? Do they, or is it an illusion?

Also, why do woofer speakers should be BIGGER than tweeters? I assume we need big woofers to produce longer wavelengths, but i seek a little more detailed explanation...

Links for articles with answers would also be very appreciated.

Thanks

<font size=-1>[ This Message was edited by: DigiSUN on 2004-07-11 10:02 ]</font>

[Ricardo]

It's all to do with wavelength and energy. Hi frequecies have low energy and short wavelengths, hence they are better heard close up. Lo freq have high energy and long wavelength (100Hz=30 metres)I think, could be wrong. So, all the hi freq bounce around a room and absorbed quickly, whereas the Lo penetrate the walls, and also build up inside a closed space (phase addition) such as a room or car. The proximity effect is based on this. Never close mic a bass amp if you want to capture the bottom end freqs.
I haven't done a search, but you should find plenty on this in any sound engineering literature.

[paulrmartin]

http://www.headwize.com/tech/elemnts_tech.htm

Huygen's principle should provide some answers, I think

[Stubbe]

During construction of some speakers years back, I learned the rule of thumb that 70% of the energy from the amp went to the bass, 20% to the mid-range, and 10% to the tweeter, and that I had to dimension the units accordingly.

Stubbe

[DigiSUN]

Thanks guys

[firubbi]

On 2004-07-11 13:46, paulrmartin wrote:
http://www.headwize.com/tech/elemnts_tech.htm

Huygen's principle should provide some answers, I think

Thanks. this will help me to do room acoustic.