Which speaker (amplifier) for a "mobile-like" output of rttl (midi) sounds?

 

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I am working on a simple PICAXE (4.5 Volt) project that plays 

a (downloaded ringtone) rtttl sound file

 

... the melody's volume should be loud enough 

for a "doorbell-like" alert whereas the sound quality 

should be as good as an old-school's mobile ringtone output.

 

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how may i improve the sound's output quality?

 

The (ringtone) melody sounds even worse than expected -

it is noisy and the melody not really good 

probably due to my piezo sounder * (?) 

So i might need to use a speaker instead of a piezo-sounder ...

 

- which (budget) speaker* would you recommend ?

May you give me any advice on how many watts, 

which make, additional/integrated amplifiers, condensators, ...

i should use?

 

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* i tried a piezo sounders & transducer

 

... piezo-transducer (www.conrad.de, # 752223 - 62)

... piezo-sounder (www.conrad.de, # 710131 - LN )

 

whereas the latter produced sounds of better quality

 

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... and looked for speakers

& through several entries on forums

some of them recommending ...

 

 

computer speakers

since they are amplified already.

That coukld be the best solution

but i would prefer to build my own, 

not breaking casings, hacking/de-soldering existing pcb's

(eventhough it would help to improve my very bad soldering skills)

 

 

use speakers with 40 or 80 ohm values

... some users about of 40 ohm speakers

mentioned that their output is too silent

for a tune built on wide range of sounds 

 

add capacitors

... 1x 10 uF,  non-polarized capacitor 

    in series with a 40ohm speaker 

   (as recommended & shownin the picaxe manual) 

or

... 2x 10 uF - 1 in series and

   1 in parallel with a 40ohm or 80 ohm speaker 

   (as illustrated the picaxe manual) 

or

... 22 uF

   to prevent speaker from burning 

   since the "sound" command leaves the port "high"

   or,

        alternatively using " low (-- port # --)" to reset the port

        (this being critised since it might cause a too low output)

... 1 uF for best range of several sounds

 

 

- boost speakers

using the lm386 chip to boost the output

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thanks for your reply!

… did it again - posted a comment twice …

sorries, won’t happen again!

As an alternative to the LM386

Here is a link to an example using a stereo amp http://embedded-lab.com/blog/?p=3405

It seems to be rated at 2.4W per channel or 4.7W into a mono load.

If you are set on using the LM386, check http://hackaweek.com/hacks/?p=131 before getting all settled in. :slight_smile:

great sources … thanks!

thanks a lot for your reply & links, birdmun!

good to read  http://hackaweek.com/hacks/?p=131

it adds a lot of important information, especially 

about the capacitors as illustrated within the circuit 

included within the LM 386 N’s datasheet

 

being new to electronics i just start to get a rough

idea that e.g. capacitors with a specific value may come

in quite a lot of different “flavours” …

 

am feeling tempted to “just” buy a cheap set of usb speakers

as recommended to keep chips and components

from being burned and myself from becoming crazy

& to have a already working setup

but i will definitely give http://hackaweek.com/hacks/?p=131 a try