"Fixing" the toy that is too loud
Many toys are WAY too loud with no way to adjust the volume. There are low-tech solutions like removing the batteries or taping cardboard over the speaker, but the solution I present here is better than those.
I've done this with several toys so far: the "infernal car", the candy crane, the toy piano keyboard, and the robot. Surely there have been others that I am forgetting now.
My first attempt was to just install a resistor in-line with the speaker, but with the talking "infernal car", this caused the sound to be very distorted. I found that I needed to match the impedance of the original speaker pretty closely before the voice was both understandable and muted.
For a 16 ohm speaker (such as the robot had), I used a 33 ohm resistor in series with the speaker and a 22 ohm resistor in parallel to the speaker and other resistor. That makes the toy see a 15.18 ohm load, which is close enough to the original 16 ohms to work great. For an 8 ohm speaker, I use a 10 ohm resistor in place of the 22 ohm resistor, and a 33 ohm resistor in series with the speaker, for an almost perfect match.
For those of you that don't speak resistor:
10 ohm = brown black black
22 ohm = red red black
33 ohm = orange orange black
So here's the boy with the toy to be "fixed":
I've found the wires to the little speaker, cut one, and scraped the insulation off the other without breaking it:
Here the resistors are installed. 33 ohm in series with the 16 ohm speaker, and 22 ohm paralleling the speaker-resistor mess. Use a 10 ohm instead of 22 ohm if you are "fixing" a toy with an 8 ohm speaker.
Here's the final result: the boy still loves the toy and the parents are happy. The toy is still plenty loud, but we're not tempted to hide it anymore...
I've done this with several toys so far: the "infernal car", the candy crane, the toy piano keyboard, and the robot. Surely there have been others that I am forgetting now.
My first attempt was to just install a resistor in-line with the speaker, but with the talking "infernal car", this caused the sound to be very distorted. I found that I needed to match the impedance of the original speaker pretty closely before the voice was both understandable and muted.
For a 16 ohm speaker (such as the robot had), I used a 33 ohm resistor in series with the speaker and a 22 ohm resistor in parallel to the speaker and other resistor. That makes the toy see a 15.18 ohm load, which is close enough to the original 16 ohms to work great. For an 8 ohm speaker, I use a 10 ohm resistor in place of the 22 ohm resistor, and a 33 ohm resistor in series with the speaker, for an almost perfect match.
For those of you that don't speak resistor:
10 ohm = brown black black
22 ohm = red red black
33 ohm = orange orange black
So here's the boy with the toy to be "fixed":
I've found the wires to the little speaker, cut one, and scraped the insulation off the other without breaking it:
Here the resistors are installed. 33 ohm in series with the 16 ohm speaker, and 22 ohm paralleling the speaker-resistor mess. Use a 10 ohm instead of 22 ohm if you are "fixing" a toy with an 8 ohm speaker.
Here's the final result: the boy still loves the toy and the parents are happy. The toy is still plenty loud, but we're not tempted to hide it anymore...