Upgrade to higher speaker Ohm&Wattage safe?

[123sample]

Hi,

I have another question,
let's just make PSP as an example, it's stated that PSP could handle around 0.25W 8Ohms speakers

1. it that alright if I put e.g. 2W 4Ohms speakers on it?

2. What would happen if I do so? what is affecting it?

3. Does it automatically reduce to default volume even I put higher Wattage speakers?

Thanks a lot!

[FOOKzâ„¢]

is it that alright if I put e.g. 2W 4Ohms speakers on it?

Straight up answer to your question is no.

Well because an amplifier outputs power at a certain rate determined by gain.

Speakers have a thing called Impedance measured in Ohms... so your speakers' impedance in this case is 4 Ohms.

What would happen if I do so? what is affecting it?

Improper impedance matching can lead to excessive power use, distortion, and noise problems.

Think of it like this if you Decrease your resistive impedance You will allow more electrons to pass through the speaker... therefore allowing the amplifier to pump more unnecessary power to the speaker... which will end up bad like a blown fuse or a burnt amplifier.

It is an easy fix however. Capacitors are the total opposite of Inductors. Coils are the same thing as Inductors, you will find coils inside of speakers...

The most probable solution to your problem is LM386 op-amp to match impedance and drive your 2W speaker all the way or put a 4 Ohm resistor is series with your speaker. 

Does it automatically reduce to default volume even I put higher Wattage speakers?

Higher wattage speaker just means it can handle up to that amount of power, yes the volume will sound a bit quieter on a higher wattage speaker. An LM386 op amp will drive a 2W speaker easily.

[123sample]

Thanks for the info mate,

Here I walk around and borrow 1 of my friend's board:




I understand a bit what he did,
my question is:

1. Can I buy each of the components required for making project above?

2. What is the core requirement to build project above? to drive 2w speaker easily..

3. Let say if it's not using PSP's battery as source, but I have separate 3.7w 200mAh battery, how can I do the wiring?

Thanks a lot!!!

[FOOKzâ„¢]

1. yep.

2. Read this: http://www.hobby-hour.com/electronics/lm386-power-audio.php

3. theres quite a few ways to wire this circuit up. Yes you can use another battery; you would just have to connect it directly to the amplifier circuit.


I think we have a tutorial around acidmods for the UMD speaker mod, this has the same chip and the same circuit.

[123sample]

I used lm386n-1 already just now..

The thing that I made is different, although the volume is extremely loud and working good,
but I have unsatisfying result, that is excessive noise from speaker when it goes to lower freq sound (bass)

I'm using:
1. 10k resistor connecting (+) input (feet number 3)
2. and 220uF connecting to speaker

5v input Voltage, and 2w speaker..
What is affecting speaker noise in my project?

Also:
1. What is the different between Capacitor that has same (220uF) but one of them 25v and 6.3v?
   which one is most suitable and correct one?

[hyper999]

the noise at low frequencies may be due to a poor quality speaker, although FOOKz will probably come along in a while and give you some more :P

and for the capacitor that voltage is the maximum operating voltage so if the voltage applied to the cap is 5v either of them will be fine it just needs to be above 5v

[FOOKzâ„¢]

I used lm386n-1 already just now..

The thing that I made is different, although the volume is extremely loud and working good,
but I have unsatisfying result, that is excessive noise from speaker when it goes to lower freq sound (bass)

If it's too loud try a feedback resistor about 100K from pin 5 to pin 2. Remove pin 2 from ground and replace it with a 100 Ohm resistor. See what it does. The 100K resistor will take high gain and feed that back into the negative input which will cancel out the signal coming to the positive input which will give you  a better output signal.

I'm using:
1. 10k resistor connecting (+) input (feet number 3)
2. and 220uF connecting to speaker

Thats good. You can try a bigger capacitor if you want more bass.

5v input Voltage, and 2w speaker..
What is affecting speaker noise in my project?

Also:
1. What is the different between Capacitor that has same (220uF) but one of them 25v and 6.3v?
   which one is most suitable and correct one?

the noise at low frequencies may be due to a poor quality speaker

your 220uF capacitor is probably not big enough to handle heavy bass. Bass sound needs more power to operate therefore you need a bigger capacitor to store more power for the speaker. Your speaker is probably fine.

yep, the difference between a 25v cap and a 6.3v cap is it's maximum voltage rating before it 'dies'. You are supplying 5volts to your circuit so the 6.3v capacitor is OK. Make sure that you do not surpass the voltage rating because they will fail.