|
Post by Tyler wants bass! on Aug 7, 2010 20:58:52 GMT -5
Hes just saying some companies rate at 12v, and some at 14.4v.
One amp that does 100 watts at 12v ( a cars sitting, non running state ) vs running ( a running vehicle varies a lot by manufactuer ) at 14.4 ....(with unregulated power supplies)
When the amp that does 100watts at 12 volts has 14.4, or 13.8, or 15.6 whatever running into the amp, it can put out a lot more then 100 watts output.
I'm a SPL guy, have been for years. yes one of those "annoying kids"(even at 27) that pound their system hard driving around.
But this whole comparrison rating crap is all bullsh** because a lot of manufactuers test differently, car audio is a big bad one in this.
|
|
RSavage
Emo VIPs
My goal is to live forever. So far, so good.
Posts: 674
|
Post by RSavage on Aug 7, 2010 21:22:17 GMT -5
Hes just saying some companies rate at 12v, and some at 14.4v. But this whole comparrison rating crap is all bullsh** because a lot of manufactuers test differently Oh sorry....my bad. I thought Ohm's law applied here. Stupid me. Clues are obviously optional
|
|
|
Post by Tyler wants bass! on Aug 7, 2010 21:31:20 GMT -5
Hes just saying some companies rate at 12v, and some at 14.4v. But this whole comparrison rating crap is all bullsh** because a lot of manufactuers test differently Oh sorry....my bad. I thought Ohm's law applied here. Stupid me. Clews are obviously optional Search around and read for yourself, read some specs, check out the voltages and ratings. If there was a standard EVERY company that did car audio would be rated at 14.4v ( or whatever voltage they chose ) But, they don't like stated above ranges go from iirc the lowest I've seen was 11.8v rating to 18v rating being the highest for competition amps. Also not every amp will drop to the same low impedence, I've seen amps hit 1/8 (.125) ohm loads, and run fine with ample battery power in reserve and I've seen amps blow up with 4 ohm loads. The closet thing you have to standard that I've seen is home audio, most of its specced at 8 ohms.
|
|
Lonnie
Emo Staff
admin
Pay no attention to the man behind the curtain
Posts: 6,999
|
Post by Lonnie on Aug 7, 2010 22:41:00 GMT -5
I am surprised to no one has pointed out that Emotiva publishes the performance of their amps at the bottom of each Product Page. The PDF file results for both a 4 Ohm and 8 Ohm load are provided for your use. The graphs show the results from a randomly select amplifier from the warehouse stock for each model of amp that Emotiva sells. These files will tell you far more about the performance of the amps than the "static" numbers provided by most other vendors. If you have not already viewed those PDF results, this is where you should concentrate your efforts when attempting to understand how well a particular beand and model performs. It would be great if more vendors provided similar test result for you to use in doing a meaningful comparison between competing products. When you study the published PDF results you will find that Emotiva routinely publishes very conservative specifications. I have viewed these and all but the XPA-1 show broadband sweeps at less than full power. The test that give sweep times are for a few hundred mili seconds. None of these test IMHO show what these amp can do ACD continuously. So if you claim in your marketing literature that these amps can provide these power outputs continuously where is the empirical data to show this? And if it can why not test it long term on the bench to back up you claim? I have seen my share of ..............shall we say unusual request but this one just up pretty high on the list. Lets see where to start? Ok, the transformer has more than enough overload capacity, the secondary caps are rated to 105c so that wouldn't be a problem, the output stages are way over built, so the only limiting factory would be the thermal disapation. To run a class a/b amp at full power for 4 hours would require roughly 4 to 5 times the heatsink size which can be done, but would make the amp around 250 to 300 pounds and would never be needed. As I said before, music is dynamic, not steady state sign waves. I know I don't listen to sign waves at full power and if I did, I don't know of any speakers that could take it. Please show any company that does this, I don't believe you will find one.
|
|
Lonnie
Emo Staff
admin
Pay no attention to the man behind the curtain
Posts: 6,999
|
Post by Lonnie on Aug 7, 2010 22:58:38 GMT -5
I have viewed these and all but the XPA-1 show broadband sweeps at less than full power. The test that give sweep times are for a few hundred mili seconds. None of these test IMHO show what these amp can do ACD continuously. So if you claim in your marketing literature that these amps can provide these power outputs continuously where is the empirical data to show this? And if it can why not test it long term on the bench to back up you claim? The term "continuous power" has a common description as noted below. Feature Feature Description RMS (Continuous) Power The amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds. When choosing an amplifier, the RMS rating is the power rating you should pay most attention to. Also, keep in mind that some manufacturers calculate the RMS power ratings of their amplifiers at different input voltages. For example, an amplifier rated at 100 watts RMS at 12 volts can produce considerably more power than an amp rated at 100 watts RMS at the more typical 14.4 volts. Interesting post which is related to car audio. If the car amps are using a free running power supply then the conclusions are correct. However, if the amp is using a tightly controlled feedback system on the PWM then the power output will not change as the input voltage varies. This brings back memories. ;D ;D ;D In another life I used to design car amps (as well as other gear) for companies. I loved the car audio industry, it was a lot of fun. The one thing I really miss about car audio is that it was all about having a good time. No one was beating me up about things that don't matter. All everyone wanted was to have a good time and enjoy the gear. ;D
|
|
RSavage
Emo VIPs
My goal is to live forever. So far, so good.
Posts: 674
|
Post by RSavage on Aug 7, 2010 23:01:54 GMT -5
Search around and read for yourself, read some specs, check out the voltages and ratings. Yeah.....guess I should have gotten some edumacation before posting about Ohm's law and other such silliness. Sorry....I get all confuzzeled by eagles, indians, and rocks. Time for this old timer to go back to his cats whisker I guess.
|
|
LCSeminole
Global Moderator
Res firma mitescere nescit.
Posts: 20,495
|
Post by LCSeminole on Aug 7, 2010 23:46:17 GMT -5
Interesting post which is related to car audio. If the car amps are using a free running power supply then the conclusions are correct. However, if the amp is using a tightly controlled feedback system on the PWM then the power output will not change as the input voltage varies. This brings back memories. ;D ;D ;D In another life I used to design car amps (as well as other gear) for companies. I loved the car audio industry, it was a lot of fun. The one thing I really miss about car audio is that it was all about having a good time. No one was beating me up about things that don't matter. All everyone wanted was to have a good time and enjoy the gear. ;D That's some really good insight, sometimes I believe the specifications and features get in the way of the real reason most of us got in to home theater to begin with, enjoyment.
|
|
|
Post by johndavidson on Aug 8, 2010 6:22:45 GMT -5
I have viewed these and all but the XPA-1 show broadband sweeps at less than full power. The test that give sweep times are for a few hundred mili seconds. None of these test IMHO show what these amp can do ACD continuously. So if you claim in your marketing literature that these amps can provide these power outputs continuously where is the empirical data to show this? And if it can why not test it long term on the bench to back up you claim? I have seen my share of ..............shall we say unusual request but this one just up pretty high on the list. Lets see where to start? Ok, the transformer has more than enough overload capacity, the secondary caps are rated to 105c so that wouldn't be a problem, the output stages are way over built, so the only limiting factory would be the thermal disapation. To run a class a/b amp at full power for 4 hours would require roughly 4 to 5 times the heatsink size which can be done, but would make the amp around 250 to 300 pounds and would never be needed. As I said before, music is dynamic, not steady state sign waves. I know I don't listen to sign waves at full power and if I did, I don't know of any speakers that could take it. Please show any company that does this, I don't believe you will find one. So my point is these amps cannot run full output continuously and in the Audio world continuous has a different meaning than that of the rest of the world. (defined by Webster's: Continuous- Marked by uninterrupted space , time , or sequence) Since the word continuous means for limited time in the audio world what is that time? I don't think you can tell me becasue this time is not a standard. To expand on this, would it be fair to say that continuous RMS power ratings have become mostly a marketing tool since it implies something that in fact it does not represent. The UPA-5 delivers 125 watts of continuous power with all channels driven. That's the key word. 'Continuous' means...well, just that. Continuous. Not a peak rating. Not the rating the amp achieves while being pushed to its limits, putting out a distorted and muddy sound. Continuous power means the amplifier is in its comfort zone, doing what's its designed to do - giving you an exceptional theater and music experience without breaking a sweat.So can you define what the continuous time is for the measurements on the Emotiva amps that has qualifying data such as THD so as to define your product literature's use of the word continuous?
|
|
DYohn
Emo VIPs
Posts: 18,349
|
Post by DYohn on Aug 8, 2010 9:29:37 GMT -5
Oh sorry....my bad. I thought Ohm's law applied here. Stupid me. Clews are obviously optional Search around and read for yourself, read some specs, check out the voltages and ratings. If there was a standard EVERY company that did car audio would be rated at 14.4v ( or whatever voltage they chose ) But, they don't like stated above ranges go from iirc the lowest I've seen was 11.8v rating to 18v rating being the highest for competition amps. Also not every amp will drop to the same low impedence, I've seen amps hit 1/8 (.125) ohm loads, and run fine with ample battery power in reserve and I've seen amps blow up with 4 ohm loads. The closet thing you have to standard that I've seen is home audio, most of its specced at 8 ohms. Not sure where this is coming from but there is a car audio test standard, CEA-2006-B. although there is no regulatory agency to enforce following it. The best manufacturers follow it and post their specs "per CEA-2006."
|
|
DYohn
Emo VIPs
Posts: 18,349
|
Post by DYohn on Aug 8, 2010 9:43:00 GMT -5
johndavidson, you seem to be an intelligent man with some electronics background, so it amazes me that you cannot find the definition of what "continuous power" means. It means it was measured using a continuous test signal instead of a burst or sweep, usually 1Khz or sometimes full-range signal, into a fixed dummy load and without exceeding stated distortion, not that the amp can sustain that output level forever.
|
|
DYohn
Emo VIPs
Posts: 18,349
|
Post by DYohn on Aug 8, 2010 9:49:35 GMT -5
Feature Feature Description RMS (Continuous) Power The amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds. When choosing an amplifier, the RMS rating is the power rating you should pay most attention to. Also, keep in mind that some manufacturers calculate the RMS power ratings of their amplifiers at different input voltages. For example, an amplifier rated at 100 watts RMS at 12 volts can produce considerably more power than an amp rated at 100 watts RMS at the more typical 14.4 volts. That's a car audio spec and thus the BS marketing language, but amplifiers are amplifiers. Note that there is no such thing as "RMS Power." It is a commonly used term but it has no meaning since "RMS" cannot be applied to power. It is usually derived using the RMS voltage output of the amp which is where it comes from, but the correct term would be "average power."
|
|
|
Post by psbman on Aug 8, 2010 10:17:53 GMT -5
Feature Feature Description RMS (Continuous) Power The amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds. When choosing an amplifier, the RMS rating is the power rating you should pay most attention to. Also, keep in mind that some manufacturers calculate the RMS power ratings of their amplifiers at different input voltages. For example, an amplifier rated at 100 watts RMS at 12 volts can produce considerably more power than an amp rated at 100 watts RMS at the more typical 14.4 volts. That's a car audio spec and thus the BS marketing language, but amplifiers are amplifiers. Note that there is no such thing as "RMS Power." It is a commonly used term but it has no meaning since "RMS" cannot be applied to power. It is usually derived using the RMS voltage output of the amp which is where it comes from, but the correct term would be "average power." Can we take that one more step and call it "Average continuous power" ? I've been guilty of using the "RMS" wording myself.
|
|
DYohn
Emo VIPs
Posts: 18,349
|
Post by DYohn on Aug 8, 2010 10:20:05 GMT -5
That's a car audio spec and thus the BS marketing language, but amplifiers are amplifiers. Note that there is no such thing as "RMS Power." It is a commonly used term but it has no meaning since "RMS" cannot be applied to power. It is usually derived using the RMS voltage output of the amp which is where it comes from, but the correct term would be "average power." Can we take that one more step and call it "Average continuous power" ? I've been guilty of using the "RMS" wording myself. If it's measured with a continuous signal and not a burst, yes.
|
|
|
Post by Tyler wants bass! on Aug 8, 2010 10:30:14 GMT -5
Search around and read for yourself, read some specs, check out the voltages and ratings. If there was a standard EVERY company that did car audio would be rated at 14.4v ( or whatever voltage they chose ) But, they don't like stated above ranges go from iirc the lowest I've seen was 11.8v rating to 18v rating being the highest for competition amps. Also not every amp will drop to the same low impedence, I've seen amps hit 1/8 (.125) ohm loads, and run fine with ample battery power in reserve and I've seen amps blow up with 4 ohm loads. The closet thing you have to standard that I've seen is home audio, most of its specced at 8 ohms. Not sure where this is coming from but there is a car audio test standard, CEA-2006-B. although there is no regulatory agency to enforce following it. The best manufacturers follow it and post their specs "per CEA-2006." I know about CEA, but like I said to Savage look around and see how many manufactuers actually use it. Good ones do, a lot don't.
|
|
|
Post by Tyler wants bass! on Aug 8, 2010 10:32:25 GMT -5
Search around and read for yourself, read some specs, check out the voltages and ratings. Yeah.....guess I should have gotten some edumacation before posting about Ohm's law and other such silliness. Sorry....I get all confuzzeled by eagles, indians, and rocks. Time for this old timer to go back to his cats whisker I guess. Read Lonnie's post, and read mine until you catch I said unregulated power supplies. The point still is NOT to make the same 100 watts, It is that when you are getting 100 watts at 12.6 or whatever at X amps, ( depends on build of the amp for power draw/effecient and ohm load) that you will get more then 100 watts at 14.4 volts pulling the same aperage, which does agree with ohms law, so stop stating that, because you are not getting what is being said. we were NOT saying youd still get 100 watts with an unregulated power supply. Like Lonnie said with a regulated power supply, 12.5 v will draw more current then 14.4 The amps I use have unregulated pwms and I run my electrical at 15v at comps to get a little more out of them. Also I drop my dual 1 ohm speakers which usually sit at 2.5 ohms to just over .6ohm loads for burps which gives gobs of more power.
|
|
DYohn
Emo VIPs
Posts: 18,349
|
Post by DYohn on Aug 8, 2010 10:40:42 GMT -5
Not sure where this is coming from but there is a car audio test standard, CEA-2006-B. although there is no regulatory agency to enforce following it. The best manufacturers follow it and post their specs "per CEA-2006." I know about CEA, but like I said to Savage look around and see how many manufactuers actually use it. Good ones do, a lot don't. People who purchase non-CEA certified car audio gear do so at their own risk.
|
|
DYohn
Emo VIPs
Posts: 18,349
|
Post by DYohn on Aug 8, 2010 10:45:30 GMT -5
Yeah.....guess I should have gotten some edumacation before posting about Ohm's law and other such silliness. Sorry....I get all confuzzeled by eagles, indians, and rocks. Time for this old timer to go back to his cats whisker I guess. Read Lonnie's post, and read mine until you catch I said unregulated power supplies. The point still is NOT to make the same 100 watts, It is that when you are getting 100 watts at 12.6 or whatever at X amps, ( depends on build of the amp for power draw/effecient and ohm load) that you will get more then 100 watts at 14.4 volts pulling the same aperage, which does agree with ohms law, so stop stating that, because you are not getting what is being said. we were NOT saying youd still get 100 watts with an unregulated power supply. Like Lonnie said with a regulated power supply, 12.5 v will draw more current then 14.4 The amps I use have unregulated pwms and I run my electrical at 15v at comps to get a little more out of them. Also I drop my dual 1 ohm speakers which usually sit at 2.5 ohms to just over .6ohm loads for burps which gives gobs of more power. I think you two are arguing apples and oranges here... Power at the output and power drawn on the input side of an amp do have a correlation of course, but it has less to do with whether the power supply is regulated or not and more to do with the efficiency of the amplifier... but in general, just because a car audio amp is fed with 15V does not necessarily mean it will produce more power than it will at 12V, it just means it will produce its power while drawing less current on the supply side...
|
|
topcat
Emo VIPs
A Dream Come True
Posts: 532
|
Post by topcat on Aug 8, 2010 10:45:58 GMT -5
Feature Feature Description RMS (Continuous) Power The amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds. When choosing an amplifier, the RMS rating is the power rating you should pay most attention to. Also, keep in mind that some manufacturers calculate the RMS power ratings of their amplifiers at different input voltages. For example, an amplifier rated at 100 watts RMS at 12 volts can produce considerably more power than an amp rated at 100 watts RMS at the more typical 14.4 volts. That's a car audio spec and thus the BS marketing language, but amplifiers are amplifiers. Note that there is no such thing as "RMS Power." It is a commonly used term but it has no meaning since "RMS" cannot be applied to power. It is usually derived using the RMS voltage output of the amp which is where it comes from, but the correct term would be "average power." Sorry, my intent was only to show that johndavidson's definition for "continuous power" as used in amplified power was not necessarily the only nor correct definition. Below is more to what I meant to show. Thank you DYohn stating what I really meant to say. Posted by DYohn on Today at 9:43am johndavidson, you seem to be an intelligent man with some electronics background, so it amazes me that you cannot find the definition of what "continuous power" means. It means it was measured using a continuous test signal instead of a burst or sweep, usually 1Khz or sometimes full-range signal, into a fixed dummy load and without exceeding stated distortion, not that the amp can sustain that output level forever.
|
|
topcat
Emo VIPs
A Dream Come True
Posts: 532
|
Post by topcat on Aug 8, 2010 10:52:08 GMT -5
The term "continuous power" has a common description as noted below. Feature Feature Description RMS (Continuous) Power The amount of continuous power, measured in watts, that an amplifier produces is called RMS power. The higher the RMS figure, the louder and cleaner your music sounds. When choosing an amplifier, the RMS rating is the power rating you should pay most attention to. Also, keep in mind that some manufacturers calculate the RMS power ratings of their amplifiers at different input voltages. For example, an amplifier rated at 100 watts RMS at 12 volts can produce considerably more power than an amp rated at 100 watts RMS at the more typical 14.4 volts. Where did this come from? Power is a function of voltage times current. You can produce the exact same power at two different voltage levels as long as the current changes. As the examples you give the current would need to be 8.3 amps @ 12 volts or 6.94amps @14.4 volts. Both equal 100 watts. Since power is measured in watts how is one more than the other? This an honest questions. I am not try to be argumentative. I took the quote from here: www.audioallies.com/GetFeatureDesc.asp?...(Continuous)+Power
|
|
|
Post by johndavidson on Aug 8, 2010 11:02:29 GMT -5
johndavidson, you seem to be an intelligent man with some electronics background, so it amazes me that you cannot find the definition of what "continuous power" means. It means it was measured using a continuous test signal instead of a burst or sweep, usually 1Khz or sometimes full-range signal, into a fixed dummy load and without exceeding stated distortion, not that the amp can sustain that output level forever. Then maybe you can answer this question? How long is continuous? To me it is exactly what it states it to be, without interruption. There was a time with 2 channel audio that it did mean exactly that. But what does it mean today and if there is no standard how can it be meaningful when I compare one amp to another? I do distinctively remember have a SAE 200 w/ch amp on a test bench with an audio analyzer in the 70s that I know we run for more than 30 minutes and it showed no signs of stress or overheating. When we started building multi-channel amps it seems that the continuous rating went out the window. Why did it go out the window? Simply for marketing purposes? I am not saying that you amp needs to be able to do this but if you are going to use finite short duration testing there should be a standard time. You should not be able to refer to it as continuous output. Since most amp as a whole in the AB realm are only around 50% efficient how much power can you claim on a amp that has a limited VA rated transformer or only 1800 watt continuous power available to it from a dedicated wall outlet? It seems that there is almost no limit to what can be claimed. As a consumer I want to know are the numbers and the words just all BS? As a consumer I have a right to know does you product do what you claim it can do. To all the rest of the world continuous means ...well continuous. If it really doesn't mean it in the audio world then maybe that needs to be communicated it the product literature. Or better yet a standard developed that puts everyones measurements on the same plane. Of course the FTC has tried to address this as have some manufactures but ultimately the industry refuses.
|
|