amp power

[robbie1982]

Will an amplifier rated at 2x100wpc sound significantly more powerf
ul than say a 2x50wpc amp

 

[mmg]

If rated in the exact same way, it will sound significally more powerful and dynamic. This means:

- Same impedance
- Same THD
- Same frequency range

Of course the difference also depends on your speakers: the more demanding your speakers are, the bigger the improvement will be

 

[davedotco]

We have been through this many times before.

Doubling the amplifier power will double the acoustic output of the speakers (in acoustic watts) giving a +3dB increase in measured sound pressure level.

(In reality speakers tend to compress so there are some losses, so in the real world the difference will probably measure a little less than +3dB.)

Now the human ear is normally believed to be sensitive enough to hear a 1dB change in level, but this is with a test tone under lab conditions. Make that a music signal, in a domestic living room and you will be lucky to hear a change of +2dB.

So, realistically a +3dB change in level, in those conditions, represents the smallest increase in in level that is clearly identifiable as an increase as such.

And to achieve that increase you need twice the amplifier power. It depends how you define significant, but twice the power most definitely does not sound twice as powerful.

For reference, science requires a +10dB increase (10 times) in power to sound twice as loud but, modern subjective analysis suggests that, around +8dB sounds twice as loud to most people. This is hugely subjective so views will and do vary.

 

[lejockey]

One manufacturers 50w is another manufacturers 100w. Whilst this might be a slight exageration, they could well be very similar in power, one company claiming conservatively and another somewhat optimistically! As the previous answer, assuming everything else stays the same, then 3db increase. FYI the old BBC mixing desks, the faders jumped in 2db steps, and sounded like a continuous fade.

 

[Electro]

This is quite a useful tool to calculate the differences .

http://myhometheater.homestead.com/splcalculator.html

 

[andyjm]

If rated in the exact same way, it will sound significally more powerful and dynamic. This means:

- Same impedance
- Same THD
- Same frequency range

There is much misinformation on amp power, mainly for commercial reasons. It got so bad in the US that the consumer association of America put together a testing standard.

http://digisec.co.za/ZUS/SPECIFICATIONS/CEA-490-A%20R-2008%20FINAL%202011.pdf

In simple terms, RMS power into a 8ohm load at 1KHz, with THD less than 1%

The spec goes into further detail about how many channels need to be driven and to what level, and also how long the amp has to be able to sustain max rated power.

I am not sure if this approach is adopted in the EU or if there is an equivalent standard.