Your speakers are not as hard to drive as sensitivity of 85-86 db. You don’t deep under 5-6 ohms. Big speakers like Wilson’s that are dipping into the 1.6-1.5 ohm range need a way more powerful amp even if they have a 91db sensitivity.
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?
- ...
- 110 posts total
Digital metering with a peak hold function is more accurate than physical meters. P=I squared R or V squared/R It is hard to get away from the fact that current and power are extremely closely related. You know an amp has an adequate power supply if it doubles down to 2 ohms. There is no such thing as too much power. How much power is adequate depends on the speaker and listening habits of the individual. Since every 3 dB doubles the power requirement power requirements increase dramatically with volume. To get bass at realistic levels and depth always requires a lot of power especially if room correction is utilized, in the thousands of watts. |
@ghdprentice 'Current' in the way you describe it above has little or no meaning. You might want to read this article which explains why. @jfrmusic If you need over 100 Watts to make your speaker really sing, you have a problem- the speaker might be criminally inefficient unless you are in a very large room. The more power you need, quite often the harder it is for the amplifier to sound like real music. Most higher powered amps I've seen simply don't, although they are pretty good at sounding like electronics. |
Hi @atmasphere, Thanks for your comment, but I am pretty sure I understand current and how it relates to solid state amplifiers performance characteristics. Sorry, but the article you refer to is so poorly written as to escape making any sense to me, hats off to you if you can understand the techno babble, with a bit of some kind of marketing. I am familiar with ohms law.
In the 70’s the power measures of peak watts and then RMS watts were shown to be grossly inadequate. This is when current came into the discussion. This is also when the first high current designed amplifiers were created. The first was the Threshold s series. I purchased the s500 after amp after amp failed to adequately power my speakers. The s500 would produce over 2.5 amps into 8 ohms and much more into lesser resistance. My next amp was a Pass x350 which would develop over 5.5 amps. This I found very amazing as I used an arc welder that produced 6 amps on constructing steel prototypes for work in the mid seventies. Anyway, through these and other high current amps I have used over the decades showed it to be a very positive guide to the solidity and resilience of solid state amplifiers. |
- 110 posts total