{"id":7165,"date":"2023-06-27T16:17:18","date_gmt":"2023-06-27T14:17:18","guid":{"rendered":"https:\/\/audio-2g.com\/?p=7165"},"modified":"2023-06-27T16:35:35","modified_gmt":"2023-06-27T14:35:35","slug":"the-sizing-of-the-speakers-with-respect-to-the-power-output-of-the-amplifier","status":"publish","type":"post","link":"https:\/\/audio-2g.com\/en\/the-sizing-of-the-speakers-with-respect-to-the-power-output-of-the-amplifier\/","title":{"rendered":"The sizing of the speakers with respect to the power output of the amplifier"},"content":{"rendered":"\t\t
\n\t\t\t\t
\n\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

My goal is to clarify what the best sizing of a loudspeaker versus the stated power of an amplifier might be, dispelling some myths and trying to provide some clarity that can help the enthusiast make an informed choice.<\/i><\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t

\n\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t

Let's start with the declared specs<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
\n\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

A common Class AB amplifier has an efficiency around 60%-70%-the rest of the energy is dissipated in various ways. So how is it possible that a modern amplifier-and just to give an example-that claims 350 watts per channel, then draws a maximum of 850 watts from the grid?<\/strong> Let’s do the math. 350 watts for 2 channels is 700 watts, with 60% efficiency is 980 watts drawn, no doubt very dissimilar to the 850 watts claimed. So where is the scam, compounded also by the fact that an amplifier also has numerous circuits, between preamplification and services, that consume additional power? We are certainly not back to the 1980s<\/strong>, when Car Audio was all the rage, and when incredible powers were claimed for apparatuses, not only lilliputian in relation to the claimed powers, but especially powered at 12 volts without any surdevoltage circuitry (step-up of the supply voltage).<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\t\t
\n\t\t\t\t\t\t\t\t\t\t\"\"\t\t\t\t\t\t\t\t\t\t\t
An old booster\/equalizer from the early 1990s that claimed exorbitant powers but could not afford it<\/figcaption>\n\t\t\t\t\t\t\t\t\t\t<\/figure>\n\t\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t
\n\t\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

Actually, each power section of those 2 mentioned in the example are capable of delivering 350 watts, relative to the voltage supplied by the power supply circuit of the syntoampli, but they simply cannot do so in unison<\/strong>. The concept, pass me the expression, is “sound,” in the sense that it is impossible for there to be an identical power demand–for 350 watts–for all 2 channels. What becomes important at these junctures is to have well-sized filter capacitors<\/strong>, which will always act as a ready and available energy reserve under all conditions, so much so as to cope with continuous absorption demands, no doubt more pressing than can be with a normal stereophonic amplifier. Let us try to figure out-academically-what the real continuous power on all 2 channels of the amplifier might be. 850 watts of absorption, take away a 40% of varied dissipation and we are at 510 watts, which, divided by 2, does not reach 255W continuous. This, however, is not the figure to keep in mind when designing the acoustics to be connected to the amplifier. The output stages and power supply are sized-usually-to deliver the stated power, at the specified distortion. This is not “cheating” on the power output, but rather sizing the amplifier much more than amply, which will simultaneously be able to deliver about 255W per channel ! Then if there will be special power demands there are the filter capacitors to come to the rescue of the power supply, being reservoirs that discharge impulsively while still making the machine deliver the maximum declared watts for a few moments. Those who “cheat”-and this is done more in low-cost products or in the home theater world-do so blatantly-declaring power figures on 6 ohms<\/strong>, which is certainly higher than that on 8 ohms commonly used. 100 watts on 6 ohms is plus or minus 70 on 8 ohms at best. All this is to say, that one only has to look at the manufacturer’s stated power for each channel, add it up, and see the maximum power draw of the amplifier to understand the “real” sizing of that machine.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

\n\t\t\t\t
\n\t\t\t\t\t

Some excellent examples<\/h2>\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t
\n\t\t\t\t
\n\t\t\t\t\t\t\t\t\t

The Yamaha A-S3200 claims 100W per channel into 8 ohms, a power consumption of 350W and 700W maximum, with a power transformer of 625VA. So we are dealing with EXTREMELY<\/strong> conservative specifications, which make us realize how very conservative the Japanese engineers have kept themselves, guaranteeing that the power output is indeed 100W per channel, and both channels simultaneously. And this in listening can be felt, which is after all why one of the things that is taken care of most in absolute level products is precisely the power supply. First of all as sizing. Another shining example is Denon’s “old” PMA-SA1, from “only” 50+50 W into 8 ohms, but with a 230W power draw. If you look at the photos of the internals of both products, you will notice the equipment as far as transformers and filter capacitors are concerned, which immediately suggest that the adjective “oversized” is reductive.<\/p>\t\t\t\t\t\t\t\t<\/div>\n\t\t\t\t<\/div>\n\t\t\t\t

\n\t\t\t\t
\n\t\t\t\t\t\t\t
\n\t\t\t