I have 3 audio amplifier modules with me pam8402 ,tda2030 and tda89328 now what i want is build 2.1 home theather system just powered with 12v .First i thought just use low pass and high pass filter .In internet they said to crossover circuit .I found there are 2 types of cross over active and passive . i dont know which one should i use .
Active crossover using op amp
Passing using RCL
i dont know which one is suited for this small thing
the speaker i have currently is 2x4ohm 3watt and 8ohm 20 watt woofer .Can you guys help me building this thing .
If you need any further details feel free to ask
Note: ALso i dont know how to build crossover circuit
With a single woofer, or with a bi-amplified speaker where the woofer & tweeter have their own amplifiers, you need an active crossover.
The signals for left & right bass need to be mixed at line-level. That can be done with a summing amplifier (made from an op-amp) or you can make a passive mixer with a couple of resistors.
Active crossovers work at line-level (before the input to the power amp) and they need a power source.
Passive crossovers work at speaker-level between the amp & speakers and they don't need AC or DC power.
Most hi-fi speakers are passive (they need a separate amplifier) and 2-way or 3-way speakers have a built-in passive crossovers. Except for the optional active (powered) subwoofer.
AVRs (audio video receivers = home theater receivers) have a built-in active crossover ("bass management") and a line level output for an active (powered) subwoofer. There are speaker outputs for the other channels.
There are lots of active (powered) bi-amplified "monitor speakers" and "computer speakers" which have built-in active crossovers.
I currently build the circuit which works but i am facing a noise issue on the amplifier side .Something like ground loop .Using separate power supply for amp introduced some new kind of noise .my one amp works on 12v and other in 5v ( while using single power supply i am using buck converter to lower the voltage to 5v)
for Woofer i am using TDA8932 and for stereo i am using PAM8403
Are these things (source, filter, amplifiers, power supplies) all close together???
Earth loops could indeed be a problem.
A star ground configuration is often recommended. But that will work best if everything is in the same housing...
Post a picture of your setup!
And while drawing schematics: keep the gnd line straight!
I would guess the buck convertor would create noise .
Power supplies for amplifiers are critical for performance - use linear regulators , 12 to
9v followed by 9-5 v.
And think carefully about layout - single point grounding , shielding etc .
I don’t know what your PSU looks like so hard to say , but I wouldn’t use the buck type power supply in an amplifier .
This might be a bit high end for your application , but the top half is my power supply for my phono amp.
The amplifier circuit runs off +- 12v and uses two stage regulation -I/p down to 15v, then 15to 12v using linear regulators . This method gives low noise .
(,the amp is a prototype , the 2nd version uses better caps )
You really need to improve your soldering joints. There is nit enough solder where the black and green are connected.
Same with black and red.
What kind of wires do you use?
Solid aluminium???
Use copper wires!!!
Or use the legs that you cut off from resistors to make them fit...
Did you use flux?
