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Topic: Speaker wattage |
Bruce Wutzke
From:
Marion, Iowa
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Posted 20 Mar 2007 6:34 am |
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| When looking at speakers, "RMS wattage" and "peak wattage" should be pretty easy to understand, but when I see "power handling wattage", "program wattage" etc., I don't know where this fits in. Is there a standard wattage that one should look for? |
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Jonathan Cullifer
From:
Gallatin, TN
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Posted 20 Mar 2007 6:56 am
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Speakers have different wattages listed for different duty cycles. Most speakers can handle far more power instantaneously than they can sustain, and the different ratings are for different types of sounds. White noise has just less than a 100% duty cycle, while music typically has a far lower duty cycle. The AES power ratings on speakers refer to the power handling capability for an extended length of time (I've seen 2 hours or 24).
Hope this helps.
Jonathan |
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Tom Mossburg
From:
AZ,
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Posted 20 Mar 2007 7:11 am Power
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Bruce, This subject has been very misunderstood so don't feel all alone. Different manufacturers have different ratings systems, some more conservative than others. This is a subject that can get very technical. Basically power is the dissipation of energy over time. A Speaker's peak handling capacity is the maximum it can handle over a short period of time. The RMS is a more conservative estimate of what it can do in the long haul. Program handling power also measures the ability of the speaker in the long run. An analogy is how much weight can you lift over your head? For short spurts you can lift a lot more than trying to hold it up there continuously. Its also like the difference between a short sprint and a marathon.
Steel guitars are very demanding on systems because of the complexity of the waveforms. They require a system that can handle a lot of dynamic range quickly. That requires a lot of reserve power, fast delivery of that power, and a speaker that can handle it. |
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Bruce Wutzke
From:
Marion, Iowa
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Posted 20 Mar 2007 9:05 am
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Thanks guys and your explanations are understandable. But, for an example, on the Peavey Tour 210, a bass cabinet, it says on the ad page...400 watts program power. Then, open the spec sheet and it says...Power Handling: 800 W program/ 1600W peak. It seems contradictive. I am not picking on Peavey by no means, just using them for an example of my confusion.
Maybe Mike will see this and comment? |
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Lynn Oliver
From:
Redmond, Washington USA * R.I.P.
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Posted 20 Mar 2007 9:21 am
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My understanding is that continuous power (AKA rms power) is what it sounds like: the average power dissipated in the speaker, which represents the maximum heat the speaker can dissipate. Continuous power is usually calculated using a continuous sine wave signal.
Program power is based on the power of a complex waveform that simulates actual program material. There is no standardized program for this rating, so you can't compare ratings from different makers directly.
Peak power is the maximum instantaneous power that the speaker can handle, and is limited by maximum excursion.
There is also a standardized rating called EIA power handling. It provides both an average level that tests thermal capacity and peaks up to 6dB above the average level to test excursion.
A good reference for this stuff is the "Sound Reinforcement Handbook" by Davis & Jones.
_________________
Lynn Oliver
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Tom Mossburg
From:
AZ,
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Posted 20 Mar 2007 12:41 pm
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| That is contradictory. Peavey is really good at answering questions if you call them. I find it hard to believe that two 10" speakers could handle 400 watts program power let alone 800. I'm not knocking Peavey here because I have never had a problem with any of their stuff and it's extremely roadworthy. But you're right about the confusion. The 410 cabinet says it will handle 1600w program! Thats a lot of power handling ability and a ticket to going deaf! |
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Jim Sliff
From:
Lawndale California, USA
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Posted 21 Mar 2007 5:37 am
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| Quote: |
| I find it hard to believe that two 10" speakers could handle 400 watts program power let alone 800. |
You might want to research bass drivers. Bass speakers rated at 200W and up are common.
_________________
No chops, but great tone
1930's/40's Rickenbacher/Rickenbacker 6&8 string lap steels
1921 Weissenborn Style 2; Hilo&Schireson hollownecks
Appalachian, Regal & Dobro squarenecks
1959 Fender 400 9+2 B6;1960's Fender 800 3+3+2; 1948 Fender Dual-8 Professional |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 21 Mar 2007 7:58 am
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"Program power" is normally the lowest rating, since that's the hardest on the speaker, electrically. "RMS" generally comes next, and lastly (the highest rating) is "Peak Power", as that is the least (electrically) demanding.
Power ratings, by themselves, are relatively meaningless. A small 100-watt light bulb will handle 100 watts...it won't sound very good, though.  |
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Lynn Oliver
From:
Redmond, Washington USA * R.I.P.
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Posted 21 Mar 2007 8:13 am
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| Quote: |
| "Program power" is normally the lowest rating, since that's the hardest on the speaker, electrically. |
Continuous power or rms power is the worst case spec and will have the lowest rating. If you look at Peavey's spec sheets you will see something like: continuous power 100W; program power 200W; peak power 400W.
| Quote: |
| Thats a lot of power handling ability and a ticket to going deaf! |
Speaker efficiencies vary so more power handling capability doesn't necessarily translate to higher SPL's. You should look at sensitivity and efficiency ratings as well.
_________________
Lynn Oliver
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 21 Mar 2007 1:17 pm
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You're right Lynn, I had that backwards.  RMS is called "Continuous Power", and "Program Power" ratings are usually about twice that. The "Peak Power" levels are usually about twice that, and that is the figure usually used when rating those cheapie bass speakers that are used in car audio systems. (Their efficiency is often under 90db.)
Where you get into a problem is with certain types of programming (heavy distortion, for instance) that can lead to average power levels that exceed the RMS rating (.707 x peak-to-peak, as I recall). I can also remember Harvey Gerst (of JBL D130-F fame) saying that he could regularly blow them out with an 18-watt Williamson amp driven to distortion! 
So, a 100 watt RMS speaker should handle what comes out of a 100 watt RMS amp - unless there's significant distortion.
In that case, all bets are off...and you'll be buying a replacement quite soon. |
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Lynn Oliver
From:
Redmond, Washington USA * R.I.P.
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Posted 21 Mar 2007 3:17 pm
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| Quote: |
| Where you get into a problem is with certain types of programming (heavy distortion, for instance) that can lead to average power levels that exceed the RMS rating... |
I know that the term "RMS power" is commonly used, and I even referenced it myself earlier. But this usage is actually incorrect. Power is voltage times current, but if you multiply the RMS values of the voltage and the current together you don't get power, because the voltage and power are not in phase unless the load is purely resistive.
For sure distortion can get you into trouble. If you assume an amp with infinite bandwidth, the output signal approaches a square wave, which contains twice the power that is in a sine wave with the same peak value (.707 squared = .4998...). Suddenly your 200W continous power rated amp is trying to deliver 400W continuous power to your 200W continuous power speaker...
_________________
Lynn Oliver
Last edited by Lynn Oliver on 22 Mar 2007 1:49 pm; edited 1 time in total |
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Tom Mossburg
From:
AZ,
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Posted 22 Mar 2007 10:04 am I stand partially corrected
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| Quote: |
| I find it hard to believe that two 10" speakers could handle 400 watts program power let alone 800 |
I find it hard to believe that two 10" speakers could handle 400 watts Continuous power let alone 800
Jim I took your advice and did find some 10" bass drivers that will handle quite a bit of power. I misused the "program power" rating. US Speaker has it listed at double the RMS rating. Here is a good website that may clear some things up for some folks. http://home.comcast.net/~rcrimm/rms.html
This is kind of the point of Bruce's post though. The different ratings can be confusing. This is especially true when the manufacturer has the same thing labled differently in different locations. |
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Bruce Wutzke
From:
Marion, Iowa
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Posted 22 Mar 2007 12:42 pm
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This has helped a lot guys. Reading the wattage claims from some can be deceiving, but I can see now that me playing the "Minuet in G" would not produce the same program power as Joe Wright playing "Taking Care Of Business." As it was said, program power would be hard to define.
I appreciate the help! |
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Lynn Oliver
From:
Redmond, Washington USA * R.I.P.
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Posted 22 Mar 2007 1:59 pm
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| I don't know how many of the speakers that Peavey uses in enclosures are also listed by Peavey as separate items, but the musical instrument speaker I found with the highest power rating has a continuous power rating of 300W. |
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Tom Mossburg
From:
AZ,
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Posted 22 Mar 2007 3:24 pm
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| Good point Lynn and the highest power 10" speaker handles 150w |
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Donny Hinson
From:
Glen Burnie, Md. U.S.A.
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Posted 22 Mar 2007 3:33 pm
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| Quote: |
| ...but the musical instrument speaker I found with the highest power rating has a continuous power rating of 300W. |
Ohh, I think we can do a little better than that, if we really look...
http://www.usspeaker.com/B&C-18nw100-1.htm |
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Bill Creller
From:
Saginaw, Michigan, USA (deceased)
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Posted 22 Mar 2007 9:28 pm
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| On the Weber speaker site, where they have the re-coning info, they say speaker mfgrs are quite optimistic about how much power their speakers will handle, and they (Weber) are inclined not to believe all the advertising. |
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Ken Fox
From:
Nashville GA USA
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