Distortion in 3 inch speakers with TDA 2822 amp

Thread Starter

Vaibhav Shinde

Joined Jan 4, 2014
8
Dear All,
I have built up a small project of stereo amplifier using TDA 2822M. I am using regulated 5v power supply. And speaker has 4 Ω 10w configuration. I give input to circuit through mobile. Now, when I run circuit at low volumes it runs clean and fantastic. But as I increase volume through 47k POT from mid to high, my speakers starts distorting . And I cant get clear sound. Also bass is not that much good in speaker (Though it has rubber cone ring , just like sub woofer) . When bass effect comes in music, speaker volume goes down... please provide me solution. I want to build custom good bass speaker system for my laptop.Even I used some large 4ohm 10w speakers. But they are also showing same distortion at high volume.
Please find circuit & speakers used by me in attachment.
 

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crutschow

Joined Mar 14, 2008
34,464
According the the data sheet, in the stereo configuration the maximum power with a 5V supply into a 4Ω load is about 0.55W at 10% distortion. That's only enough to give a low volume level and little bass, so it's not surprising you are getting high distortion at higher volume levels.

You could wire the amp as a single-channel with a bridge output connection to increase the maximum output power to about 1W, but that's still pretty low.

The most you can get with a larger amp at 5V would be about 3W such as one of these.
 

THE_RB

Joined Feb 11, 2008
5,438
...
The most you can get with a larger amp at 5V would be about 3W such as one of these.
I agree, Crutschow's link to a stereo 3W class-D digital amp module would be a good solution. It will produce a lot of sound from a +5v USB supply, and with pretty good sound quality.

I used one in a recent project here;
http://forum.allaboutcircuits.com/showthread.php?t=92589
which was also running from a +5v regulated supply and driving stereo 4 ohm speakers.
 

bountyhunter

Joined Sep 7, 2009
2,512
Well, they don't do go down to much below 60Hz
That's my point. That ain't bass. 60 Hz is just transformer hum.

The spec on the Tang thing says 65 Hz is the free air resonance of the speaker.

Thiele-Small Parameters

  • Resonant Frequency (Fs)65 Hz


In an enclosure, the lower 3dB cutoff is significantly higher than the Fs frequency.
 
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