Speaker wattage ratings for newbies

[JoeE SP9]

<font color='#000000'>Could someone please tell me where I can find some onformation (on line information) referring to amplifier output and speakers. It is difficult when neophytes all believe that a &quot;100 Watt speaker&quot; can't be driven by a 200 watt amp. Or that those so called speaker wattage ratings actually mean something.

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[Audioholics]

<font color='#000080'>There's an article comng on this... suffice to say that many manufacturers rate their amplifiers/receivers differently, so you really have to watch for that.

One of the biggest misconceptions is trying to match the amplifier exactly to the speaker. You can have a 200W amp drive a 100W rated speaker. You'll only get 200W at max power and this is WAY better than say, driving a 50W amp to clipping and sending squared off waves to your speakers.

Keep your eyes peeled for a more in-depth article on amplifiers andpower ratings to come very soon.</font>

 

[gene]

<font color='#000000'>Joe;

Very briefly, just because you have an amp that is rated to 200wpc, doesn't mean you will ever reach those power levels in most listening conditions, particularly for any extended amounts of time. &nbsp;Thus if amp #1 is 100wpc and amp#2 is 200wpc, they will play at the same loudness when driven below amp#1's limits, assuming all things being equal other than power. &nbsp;However, amp#2 does have 2X the power translating to 3dB added headroom or potential to play louder without audible distortion.

Clint is correct that it is better to have a more powerful amp then less, all other things being equal, to avoid running out of dynamic range. &nbsp;When an amp cannot produce more power, it runs into clipping which leads to audible distortion and as Clint pointed out. &nbsp; It essentially sends square waves or DC power to your speaker and can damage them if exposed to this clipping for too long.</font>

 

[Yamahaluver]

<font color='#0000FF'>Fully agreed with Gene and hawke, would just like to add that the peak power handling rating is more important than continuous as there would hardly be a situation where you can run 200W for couple of hours, whereas peaks of 200W to 400W are quite common with high power amps.</font>

 

[JoeE SP9]

<font color='#000000'>I must clarify. I am not asking for myself. I need a reasonably concise explanation for friend and neighbors who look to me as an audio guru. When I start talking about RMS and clipping and other factors I can see the glaze slide slowly over their eyes.</font>

 

[Audioholics]

<font color='#000080'>Maybe you could point them to this site and guide them to the audio principles and set up tips sections...
You can do that and still maintain your status as &quot;Audio Guru&quot;... &nbsp; &nbsp;

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[Verdinut]

<font color='#000000'>Joe;

Very briefly, just because you have an amp that is rated to 200wpc, doesn't mean you will ever reach those power levels in most listening conditions, particularly for any extended amounts of time. &nbsp;Thus if amp #1 is 100wpc and amp#2 is 200wpc, they will play at the same loudness when driven below amp#1's limits, assuming all things being equal other than power. &nbsp;However, amp#2 does have 2X the power translating to 3dB added headroom or potential to play louder without audible distortion.

Clint is correct that it is better to have a more powerful amp then less, all other things being equal, to avoid running out of dynamic range. &nbsp;When an amp cannot produce more power, it runs into clipping which leads to audible distortion and as Clint pointed out. &nbsp; It essentially sends square waves or DC power to your speaker and can damage them if exposed to this clipping for too long.</font>

Hi Gene,
But won't you agree with me to the fact that high frequency drivers are the most susceptible to being fried with amplifier clipping which produces mostly awful harmonics, while woofers can take more distorted power for longer periods within their power rating, if their cones don't exceed their excursion limits? Woofers are supposed to handle up to 4 times their power rating with peaks according to JBL. This, obviously, has to occur within their excursion limits.

I doubt that modern solid state amplifiers output DC when clipping as opposed to the situation many years ago when SS amps came on the market.

To tell you frankly, I'm getting addicted to this site.

 

[slipperybidness]

Hi Gene,
But won't you agree with me to the fact that high frequency drivers are the most susceptible to being fried with amplifier clipping which produces mostly awful harmonics, while woofers can take more distorted power for longer periods within their power rating, if their cones don't exceed their excursion limits? Woofers are supposed to handle up to 4 times their power rating with peaks according to JBL. This, obviously, has to occur within their excursion limits.

I doubt that modern solid state amplifiers output DC when clipping as opposed to the situation many years ago when SS amps came on the market.

To tell you frankly, I'm getting addicted to this site.

Yeah, when you hard-clip the crests of the sine curve, it looks pretty much like a DC signal if you hit it with an O-scope. Most amps that I know of will indeed hard-clip if driven too hard.

Now, there are some amps that have a "soft-clipping" feature. For soft-clipping, it will kick in and do its best to try to maintain an unclipped sine wave. For these, it should not look quite as much like a DC wave. But, these type of amps are in the minority in the home.

 

[highfigh]

<font color='#000000'>I must clarify. I am not asking for myself. I need a reasonably concise explanation for friend and neighbors who look to me as an audio guru. When I start talking about RMS and clipping and other factors I can see the glaze slide slowly over their eyes.</font>

You can drive any speaker with any amplifier. The question is "How well will this work?". A low power amplifier will work fine if high power is never needed and the speaker will not be damaged by a low OR high power amplifier if, again, high power is never needed. It's not a matter of a round peg/round hole or square peg/square hole- it's a device outputting voltage into a load and there are no absolutes as far as matching equipment.

Don't say a word about things they don't understand- all of this can be explained simply. You're not putting street tires on a dragster.

 

[highfigh]

Yeah, when you hard-clip the crests of the sine curve, it looks pretty much like a DC signal if you hit it with an O-scope. Most amps that I know of will indeed hard-clip if driven too hard.

Now, there are some amps that have a "soft-clipping" feature. For soft-clipping, it will kick in and do its best to try to maintain an unclipped sine wave. For these, it should not look quite as much like a DC wave. But, these type of amps are in the minority in the home.

Under most normal conditions, an amp shouldn't clip so hard that it looks like nice, crisp square wave, but adding an equalizer or other device that can add gain is where people have had a lot of problems, mostly in the past.

 

[slipperybidness]

Under most normal conditions, an amp shouldn't clip so hard that it looks like nice, crisp square wave, but adding an equalizer or other device that can add gain is where people have had a lot of problems, mostly in the past.

Right, but when you have an amp on the bench and you hook up a dummy load and an O-Scope, the entire point is to drive it to hard clipping, so you can measure the power at just before the clip point. At that point, the signal looks more like DC on the scope than AC, with the catch that it likely has a much longer rise time than a normal square wave DC signal.

 

[highfigh]

Right, but when you have an amp on the bench and you hook up a dummy load and an O-Scope, the entire point is to drive it to hard clipping, so you can measure the power at just before the clip point. At that point, the signal looks more like DC on the scope than AC, with the catch that it likely has a much longer rise time than a normal square wave DC signal.

I know, but under normal use, it usually won't happen unless the input signal is hotter than intended or the user goes WOT.

Is the rise time changing under this load? It would seem that the power supply isn't keeping up if the slope decreases.

 

[Pogre]

Necro post! This thread is almost 14 years old!

Puts it into perspective though. This site has been around for a long time in internet years.