DFPlayer MP3 Module - General Question regarding Speaker Power Consumption.

Thread Starter

DaveInNevada

Joined Apr 15, 2021
2
Hi all. I have built a circuit using the DFPlayer Module, Speaker, Buttons, and Independent Power Supply. It works perfect and I love this module. My question has to do with the Speaker Output. It reads on the DataPage that it is up to 3 watts. The speaker I am using is a much larger speaker in Wattage rating, but still is an 8 Ohm speaker. Therefore, I assume that the max power out from the Module will be 3 watts, regardless of the "Size" of the speaker I am using, because it is still the proper resistance/impedance level.
Is this correct?
I don't want to draw too much current through the module and destroy it.
I guess what I am asking is, if I connect a tiny 2" 8-Ohm 3-watt speaker, or a Giant 10" 8-Ohm 50-Watt speaker, the current draw should be the same because they are both 8 Ohm Speakers, even though the quality of sound will be different between the two speaker types. Is this correct?
 

Audioguru again

Joined Oct 21, 2019
2,982
The module into does not say which amplifier IC is used. Maybe it is a mono bridged class-D type.
With a 5V supply, the maximum bridged output will be 9.5V p-p which is 3.4V RMS. Then the maximum output power to an 8 ohm speaker is only (3.4V squared)/8 ohms= 1.5 Watts continuously at low distortion or almost 4 Whats of very distorted peak power.

The size of the speaker does not change the maximum output power, the 8 ohm impedance and the power supply voltage do.
The 2" speaker is tiny and will not be loud. It will sound squeaky. It will not be able to play low frequencies.
The 10" speaker will sound louder and will play all audio frequencies if it is in an enclosure designed for it.
 

Thread Starter

DaveInNevada

Joined Apr 15, 2021
2
The module into does not say which amplifier IC is used. Maybe it is a mono bridged class-D type.
With a 5V supply, the maximum bridged output will be 9.5V p-p which is 3.4V RMS. Then the maximum output power to an 8 ohm speaker is only (3.4V squared)/8 ohms= 1.5 Watts continuously at low distortion or almost 4 Whats of very distorted peak power.

The size of the speaker does not change the maximum output power, the 8 ohm impedance and the power supply voltage do.
The 2" speaker is tiny and will not be loud. It will sound squeaky. It will not be able to play low frequencies.
The 10" speaker will sound louder and will play all audio frequencies if it is in an enclosure designed for it.
That's great news. What prompted my question was that the sound's loudness was impressive. And I wanted to make sure that I wasn't overloading my little module. I was thinking "This is pretty decent for only 3 Watts". But in all honesty I really didn't have a point of reference to compare Wattages too. So, thank you for your reply. I have the module set for a maximum of 25 out of 30 for volume setting, and it is quite nice. Thanks again.
 

KeithWalker

Joined Jul 10, 2017
1,680
The data sheet does not specify the speaker impedance but it does state that the output power is up to 3W. This device has a bridged output circuit so you could use a 4 ohm speaker to get the full 3W out.
 
Top