09-04-2017, 07:31 PM
What do you mean by "2ah"? That's a battery specification, not a power supply specification. Do you mean 2A?
Don't worry about speaker impedance. Those numbers are very approximate; impedance varies wildly with frequency.
Most likely, you are driving something into clipping. If you have an oscilloscope, it would be easy to verify whether that's the case, and indeed, whether it's the phone or the amplifier. A partial cure to the latter would be to raise the supply voltage (read the datasheet carefully), but actually, you could just be expecting too much from it - especially if the speakers are decent quality hi-fi speakers that tend to be inefficient.
Some care is needed when working with rechargeable batteries. Lithium types are obviously the scariest, but NiMh types also need to be treated with respect.
Don't worry about speaker impedance. Those numbers are very approximate; impedance varies wildly with frequency.
Most likely, you are driving something into clipping. If you have an oscilloscope, it would be easy to verify whether that's the case, and indeed, whether it's the phone or the amplifier. A partial cure to the latter would be to raise the supply voltage (read the datasheet carefully), but actually, you could just be expecting too much from it - especially if the speakers are decent quality hi-fi speakers that tend to be inefficient.
Some care is needed when working with rechargeable batteries. Lithium types are obviously the scariest, but NiMh types also need to be treated with respect.
