Should You Match Amplifier Power to Your Speakers?

gene

gene

Audioholics Master Chief
Administrator
Do you need to match your amplifier power to your loudspeaker power ratings? Can too much or too little power damage your speakers? In this article clipping, impedance, heat, sensitivity, blown drivers, and other annoying mysteries are discussed from the perspective and real-world experiences of a professional audio guy who for many decades has tried to save people from themselves.

Don't blow a speaker. Read this article!



Read: The Truth About Matching Amplifier Power to Loudspeakers
 
R

rrehart

Enthusiast
I have always been confused about impedance (Ohms). I have Miller-Kriesels as my speakers in the theater. The LCRs (THX-750) can handle 4 Ohms, but the surrounds (550 THX) are rated for 8 Ohms. So which do I set my receiver to (Sony STR-DA5600ES); 8 or 4? :confused:

I do calibrate to THX standards (75 db), but that doesn't account for impedance.

Can you clear things up for me?
 
M

markw

Audioholic Overlord
Good job. I particularly like the part on how to properly use an equalizer. Now, whenever someone asks this question, I'll just post a link to this article.
 
Paul Scarpelli

Paul Scarpelli

Audio Pragmatist
I have always been confused about impedance (Ohms). I have Miller-Kriesels as my speakers in the theater. The LCRs (THX-750) can handle 4 Ohms, but the surrounds (550 THX) are rated for 8 Ohms. So which do I set my receiver to (Sony STR-DA5600ES); 8 or 4? :confused:

I do calibrate to THX standards (75 db), but that doesn't account for impedance.

Can you clear things up for me?
Audioholics has done some great work on explaining how you should always use the 8 ohm speaker setting; never the 4 ohm one, which greatly reduces current/power. And I've mentioned it before, but there's no such thing as an 8 ohm or 4 ohm speaker. The impedance varies with frequency, and a typical speaker that's referred to as "4 ohm" will in reality vary from as low as 2 ohms to as high as 24 ohms, depending upon the frequency. When we who have worked at speaker companies try to determine if we call a speaker 4 or 8 ohms, we generally look at the impedance curve and either take an average or a wild-ass guess. With separate amplifiers, which rarely have any problem with a 2 ohm load, you don't have to worry about impedance. Receivers use "current-limiting" to protect their inadequate power supplies and output stages, and that really cuts back on the fun. BTW, I have always loved M&K for theater applications. Small and potent, and reasonably priced.
 
gene

gene

Audioholics Master Chief
Administrator
AcuDefTechGuy

AcuDefTechGuy

Audioholic Jedi
Great article, Paul! I like it a lot. :)

I never liked Tone Controls and EQs on-the-fly either.

I have never blown a speaker driver in my 26 years of audio hobby. :D

You can definitely damage any speaker or subwoofer if you put your mind to it.

And I think that heeding the recommended power rating by the speaker engineers (usually 50-200W) and using common sense is the best advice. :D

I think using 400-1000WPC amps is a total waste of money and doesn't improve any SQ and only increases your chances of blowing drivers.
 
Paul Scarpelli

Paul Scarpelli

Audio Pragmatist
I think using 400-1000WPC amps is a total waste of money and doesn't improve any SQ and only increases your chances of blowing drivers.
I totally agree, although my last two sets of theater LCRs each did well with 375 watt/channel amps. Anything over 400 watts per channel is usually senseless, other than for boasting. And amps that powerful usually use bridging technologies, which means the signal passes through a lot more components...and that's never good. Sparce signal paths tend to sound better.
 
E

eyleron

Audiophyte
How about showing the user where distortion gets objectionable, or where compression sets in, a la data-bass.com?
 
I

itawad

Audioholic Intern
Thank you for yet another great article at Audioholics.com
imad
 
E

Ernie Schmuntz

Junior Audioholic
Do you need to match your amplifier power to your loudspeaker power ratings? Can too much or too little power damage your speakers? In this article clipping, impedance, heat, sensitivity, blown drivers, and other annoying mysteries are discussed from the perspective and real-world experiences of a professional audio guy who for many decades has tried to save people from themselves.
Don't blow a speaker. Read this article!

Read: The Truth About Matching Amplifier Power to Loudspeakers
I Have always made sure I have far more power on hand than I could ever use. If the wave is fully reproduced then heat buildup in the speaker coil will be minimal. I’m also very picky on my power. I’ve bought a few receivers that boast of 100 + watts, that would never happen unless lightning struck.
 

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