Watts! How many do we need?


Got a new amp. Accuphase P-4600. It’s great. I love it. 
150 watts into 8 ohms, 300 watts into 4 ohms and it has meters so I can see wattage. Have them set on freeze so I can see the highest wattage during the session.

My Harbeth speakers are not very efficient. Around 86db. Their impedance is an even 6 ohms dipping no lower than 5.8 ohms. 

Playing HiRes dynamic classical recordings  ( Tchaikovsky , Mahler) at room filling volumes I have yet to exceed 1watt.. 

Amps today offer a lot of watts some going to 600 even 1200 watts. Even if you have inefficient speakers with an impedance that dips down to 2 ohms do we need all this wattage or should we be focusing on current instead? 

jfrmusic

@ghdprentice  I assume it makes a great deal of difference on the individual speaker you are using.  I've always heard there is a difference between "tube" watts and SS watts.  On this very sight I have read that tube watts are roughly 3 times as powerful as SS watts.  To this end I've found this lengthy article penned by Roger Sanders to be quite interesting.  Especially as I am driving a set of SoundLab Majestic 745's.  Cheers.  

https://sanderssoundsystems.com/technical-white-papers/172-tubes-vs-transistors

@bpoletti 

 

That’s the issue I was addressing. The meters in my amp are set to freeze at the highest peak reached. So at the end of the night when I check them they never exceed 1 Watt. And that’s with me listening to full Classical orchestral recordings at  room filling volume that are very dynamic.  So even my large peaks  that are  musically dynamic do not move the meter past 1 watt. 

Maybe those meters do not capture those peaks.  I would not go less than 100 watts.  But that's just me.

It’s a new Accuphase amp and the meters are accurate. The amp is rated at 150 watts per channel into 8 ohms and 300 into 4 ohms. I think we are all using a lot fewer watts than we think even  in peaks. 

I would be curious to know what actual volume you are listening at? A crude app for your phone will tell you peaks at your listening position, and if you are feeling inquisitive, you can measure at 1m from the speakers. 
 

1 watt at 1m will give you 86db from your speakers. It’s math. As was stated above, every 3dB step  above that, will require a double amount of watts.

The other thing, is higher powered amps, have bigger power supplies. They will have more power in reserve at lower watt output.

Provided the transistors, and the topology of the amp is such that it is operating in a linear manner at low output, they will sound “better” at low volumes than a lower powered amp with an inadequate power supply.

Which brings us full circle back to Nelson Pass, and the relevance of the first watt.