2. amps-preamps
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Determining exact power being sent to your speaker

How does one go about determining the exact amount of power being delivered by the amplifier to the speakers? Let's say the amp delivers 160w/channel at 4ohms (or so the reading materials state anyway) but yet the speaker specs show 120w maximum. My current integrated amp shows the volume
attenuation (dB units) in .5db steps ranging from -100 (min) up to 0.0 (max).

All that said, the concern is when should I be concerned about pushing too much power to the speakers and how I can determine the "Don't turn it up past this number on the display or you will damage the speakers..."
vineman55
erik_squires
16,059 posts
 

The amplifier power is never continuous. It’s 0W at silence and maximum wattage at the loudest.

A speaker’s power rating is based on maximum output. If a speaker is rated for 100W maximum, you can safely use a 300W amplifier with it so long as you don’t play it too loud.

You can calculate "too loud" bu using the power to db conversion. That is, if a speaker is rated for 100W, and 90 dB sensitivity:

dB = log10(100) = 20.

That is, at 100W input the speaker will play it’s rated sensitivity + 20. So, if your speaker is 90 dB at 1 watt, it will be at 110 dB at maximum. Just don’t play your speaker more than 110 dB (at 1 meter or yard) and you’ll be fine with any size amp.

https://www.rapidtables.com/convert/electric/db-converter.html

kijanki's avatar
kijanki
4,428 posts
 

Vrms x Irms = Pavg. This average power is equal 0.5 of peak power for sinewave.. Pavg represents dissipated heat while rms value of power curve would be 0.62 of peak power for sinewave and it does not represent anything.

stuartk
2,782 posts
 

@mlsstl 

"I happen to be in the camp that is more concerned about the sound quality of an amp rather than whether it has a zillion watts"

Just curious -- are you suggesting these two factors are mutually exclusive? 

I happen to enjoy both aspects of my Hegel H390. My speakers have never sounded as good as they do with Hegel (250 watts @ 8 ohms/500 watts @ 4 ohms) and the amps "warm side of neutral" sonics work very well with my other components. 

mlsstl
1,436 posts
 

@stuartk -- I have nothing against lots of power and have owned and heard lots of amps over the years, ranging from not much power to lots of watts.  So, you're putting words in my mouth with the "mutually exclusive" comment.  It's just in my case, my favorite amp is currently a 20 watt/channel class A Aegir, which replaced a VTV Hypex with many times the power. I prefer the Aegir's sound and never had a hint of running out of steam at my preferred listening levels. 

That's the nice thing about this hobby -- people can pursue what works for them. As they, YMMV for others. 

stuartk
2,782 posts
 

@mlsstl 

Your prickly defensiveness is entirely unwarranted. 

As I made no accusations, assertions or assumptions, I find it quite puzzling that you would describe my QUESTION as "putting words in [your] mouth".

All I have to say on this topic...

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