tiny amplifier.. big speaker?

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This thread, or a least the first post, is a great illustration of how poorly most people understand speakers. Realflow has good company on this one, the vast majority of the general population! :)

Speakers aren't light bulbs, and they aren't motorcars. They just don't work the same way and are not rated or specified in the same way. Maybe the forum needs a FAQ explaining this.
 
Give it a try, you may be surprised. In fact a good pro speaker can make a lot of sound from the output of a portable transistor radio. Surprise your friends! :D

Anything like an iPod touch has sufficient current drive on the output to drive speakers directly.

Given suitably sensitive speakers (>98dB@1w), the results are rather good - there's no intervening electronics, so the signal chain is about as pure as can be.
 
My friend drove these 16Ω theater speakers with a 3W rated car radio that could put out about 0.75W at 16Ω.

Ubangi1.jpg


Of course the 84" wide RCA are 110dB/W with their dual 15" horn-loaded woofers.

They are now at home in a small community theater and are driven with a Leach amplifier that can drive about 50W~60W into 16Ω.
 
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A typical 4x12" guitar cabinet is around 105dB/W/1M, with (much) higher peaks in the 3Khz region.

Run for cover when driving that 1W amp into producing a 2W square-wave!

One Eminence 12, add 6dB for 4:

http://www.eminence.com/curves/curves.php?model=Legend_GB128&KeepThis=true&TB_iframe=true&height=420&width=580

109dB at 2.4Khz from one driver!

They do have some at 110.8dB at 2.4Khz too:

http://www.eminence.com/curves/curves.php?model=Tonkerlite_16&KeepThis=true&TB_iframe=true&height=420&width=580
 
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"no 1 watt is not extremely loud. "

There must be a language problem here, many of the speakers mentioned here are 100dB/W and higher, and you don't think that is loud?

That's loud in my book.

On popular music 85dB is moderately loud, 95dB is loud, 105dB is very loud, and 115dB is too D*mm loud. Fifteen minutes of 115dB can cause permanent hearing damage (according to OSHA).
 
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"no 1 watt is not extremely loud. "

There must be a language problem here, many of the speakers mentioned here are 100dB/W and higher, and you don't think that is loud?

That's loud in my book.

On popular music 85dB is moderately loud, 95dB is loud, 105dB is very loud, and 115dB is too D*mm loud. Fifteen minutes of 115dB can cause permanent hearing damage (according to OSHA).

115 dB at 40 Hz won't cause hearing damage, and does not sound overly loud to me.

The OSHA permissible noise levels are in dBA, which rolls off below 1000 Hz.
While I certainly agree that sounds above 1000 Hz at 115 dBA sound loud, it would take 155 dB for a 30 Hz noise (about what astronauts experience in the cockpit when launching) to read 115 dBA.

Art
 
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