Power Audio Amplifiers

[Rene]

I am trying to figure out how many watts I need to get out of an audio
amplifier to have enough power to feed a speaker capable of producing enough
volume to sound like some of the kid's toys that have sound such as:

http://www.kbtoys.com/genProduct.html/PID/2421779/ctid/17/INstock/Y/D//ls/default

Someone told me that a 1-watt audio amplifier would be enough but I have my
doubts. Could anyone tell me how much wattage I would need from the
amplifier to accomplish my goal?

Thank you.

 

[John Miles]

I am trying to figure out how many watts I need to get out of an audio
amplifier to have enough power to feed a speaker capable of producing enough
volume to sound like some of the kid's toys that have sound such as:

http://www.kbtoys.com/genProduct.html/PID/2421779/ctid/17/INstock/Y/D//ls/default

Someone told me that a 1-watt audio amplifier would be enough but I have my
doubts. Could anyone tell me how much wattage I would need from the
amplifier to accomplish my goal?

Thank you.

1 watt through a typical small consumer-type loudspeaker will drive you
screaming from the room.

Your kids might be into it, but you won't.

-- jm

 

[Ben Bradley]

I am trying to figure out how many watts I need to get out of an audio
amplifier to have enough power to feed a speaker capable of producing enough
volume to sound like some of the kid's toys that have sound such as:

http://www.kbtoys.com/genProduct.html/PID/2421779/ctid/17/INstock/Y/D//ls/default

Someone told me that a 1-watt audio amplifier would be enough but I have my
doubts. Could anyone tell me how much wattage I would need from the
amplifier to accomplish my goal?

You need to:

1. Measure the dBSPL of the sound from the toy/device (probably from a
fixed distance of 1 meter, because that's how loudspeakers are
measured/rated, as in step 2). Radio Shack sells an inexpensive but
usable SPL meter with an analog meter dial. THey also sell a more
expensive one with a digital dieplay, but analog dials are generally
easier to read for sound level applications.

2. Decide what loudspeaker the amplifier is going to be connected to,
and get its sensitivity rating (specified by the manufacturer, usually
something like 94dBSPL measured at 1 meter with 1 watt input).

3. Calculate how much power into the loudspeaker will give the same
SPL as the toy does. A little googling brings up this page, which
explaina how to calculate the needed amplifier power:
http://www.integratedaudio.com/help/sensitivity.pdf

 

[N. Thornton]

You need to:

1. Measure the dBSPL of the sound from the toy/device (probably from a
fixed distance of 1 meter, because that's how loudspeakers are
measured/rated, as in step 2). Radio Shack sells an inexpensive but
usable SPL meter with an analog meter dial. THey also sell a more
expensive one with a digital dieplay, but analog dials are generally
easier to read for sound level applications.

2. Decide what loudspeaker the amplifier is going to be connected to,
and get its sensitivity rating (specified by the manufacturer, usually
something like 94dBSPL measured at 1 meter with 1 watt input).

3. Calculate how much power into the loudspeaker will give the same
SPL as the toy does. A little googling brings up this page, which
explaina how to calculate the needed amplifier power:
http://www.integratedaudio.com/help/sensitivity.pdf

Thats the thorough answer, but if youre a hobbyist you might not want
to do all that. The simple answer is use an LM386, which produces
enough power for almost any kids toy.

Regards, NT

PS little 2.5" speakers tend to be much less efficient than bigger
ones, and 94dB/1w/1m is at the higher end for speakers.

 

[Norm Dresner]

I am trying to figure out how many watts I need to get out of an audio
amplifier to have enough power to feed a speaker capable of producing enough
volume to sound like some of the kid's toys that have sound such as:

http://www.kbtoys.com/genProduct.html/PID/2421779/ctid/17/INstock/Y/D//ls/de
fault

Someone told me that a 1-watt audio amplifier would be enough but I have my
doubts. Could anyone tell me how much wattage I would need from the
amplifier to accomplish my goal?

Thank you.

The most fundamental consideration in your situation is speaker
efficiency, i.e. how much power into the speaker does it take to create a
given intensity of sound. For typically small speakers used in toys,
speaker efficiency can vary over a range of roughly 5:1, depending on the
bandwidth requirements. Therefore there is no simply answer to your
question. You first have to determine your bandwidth, then choose a speaker
or six and then determine each speaker's efficiency.
BUT ... Typically a watt or so of power through a modestly cheap
speaker will create enough sound to get your neighbors angry. I've seen
good HiFi speakers which produce almost unbearable sound levels with a volt
or two of rms signal. 1v RMS into 8 ohms is 1/8 watt. You can't get 125 ma
out of most OpAmps but there are some easy to use power amps in single IC
packages which will work wonders.

Norm

 

[Boris Mohar]

The most fundamental consideration in your situation is speaker
efficiency, i.e. how much power into the speaker does it take to create a
given intensity of sound. For typically small speakers used in toys,
speaker efficiency can vary over a range of roughly 5:1, depending on the
bandwidth requirements. Therefore there is no simply answer to your
question. You first have to determine your bandwidth, then choose a speaker
or six and then determine each speaker's efficiency.
BUT ... Typically a watt or so of power through a modestly cheap
speaker will create enough sound to get your neighbors angry. I've seen
good HiFi speakers which produce almost unbearable sound levels with a volt
or two of rms signal. 1v RMS into 8 ohms is 1/8 watt. You can't get 125 ma
out of most OpAmps but there are some easy to use power amps in single IC
packages which will work wonders.

Norm

Like this? http://www.royaldevice.com/custom3.htm



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs http://www3.sympatico.ca/borism/

 

[Rich Grise]

Like this? http://www.royaldevice.com/custom3.htm

THis guy definitely has way, way, too much money.

 

[Boris Mohar]

THis guy definitely has way, way, too much money.

Maybe he is also hard of hearing

"Acoustic level at listening position (6 meters from frontal speakers) are
100 dB with 1 Watt."

If not than he will be.



Regards,

Boris Mohar

Got Knock? - see:
Viatrack Printed Circuit Designs http://www3.sympatico.ca/borism/

 

[Jim Thompson]

THis guy definitely has way, way, too much money.

I don't know, in my youth I once considered such an arrangement for a
game room I was building in the back yard (back in those days when I
had an acre lot).

But I consider people, who brag about no feedback or crossovers, to be
village idiots.

...Jim Thompson

 

[Jan Panteltje]

THis guy definitely has way, way, too much money.

He is using a tube amp.....
?????????????????? I like the bass speakers