Are you measuring built in sub amps or using some sort of external amp for passive sub use? Mostly I wouldn't worry about an amp suited to the powered sub, but would worry more about if you're trying something with a "passive" sub and another amp....
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Power amps: continuous output power measurements
- Thread starter StigErik
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- Thread Starter
- #42
External amps tested with a 4 ohm resistive load. What is your worry regarding this?
Not a worry rather than your specific application
- Thread Starter
- #44
I understand.
My application is not optimal, as I use each ICEpower 2000AS2 module to drive three 4 ohm subwoofers, where one is connected to channel 1, and the other two in parallel on channel 2. It’s an asymmetrical load of 4 and 2 ohms.
My application is not optimal, as I use each ICEpower 2000AS2 module to drive three 4 ohm subwoofers, where one is connected to channel 1, and the other two in parallel on channel 2. It’s an asymmetrical load of 4 and 2 ohms.
Sokel
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When testing 10Hz you have to consider that it will be a small loss in power because of the lowest bandwidth protection limit (3Hz at -3dB)
Just for my personal curiosity, I extracted the audio track from the YouTube video clip;
The video clip is "Interstellar 4K HDR IMAX Into The Black Hole - Gargantua 1 2.mkv" of 778,246,203 Byte file.
Using JRiver MC32, I extracted the audio track into one non-compressed 48 kHz 32 bit PCM (AIFF) file which was automatically named "Interstellar 4K HDR IMAX Into The Black Hole - Gargantua 1 2.aif", 236,154,942 Byte, internally consists of 6 tracks.
I loaded the "Interstellar 4K HDR IMAX Into The Black Hole - Gargantua 1 2.aif" into Adobe Audition 3.0.1 recognizing it as 6-track multi-track (multichannel) audio music; from there in Adobe Audition 3.0.1, I could save each of the 6 tracks separately (52,478,040 Byte each) into a folder for analysis using also MusicScope 2.1.0.
I hope the following six diagrams would be self-explanatory for you.
At least in these audio tracks extracted from the YouTube video clip, the sound gains are saturated in many portions, I believe.
The video clip is "Interstellar 4K HDR IMAX Into The Black Hole - Gargantua 1 2.mkv" of 778,246,203 Byte file.
Using JRiver MC32, I extracted the audio track into one non-compressed 48 kHz 32 bit PCM (AIFF) file which was automatically named "Interstellar 4K HDR IMAX Into The Black Hole - Gargantua 1 2.aif", 236,154,942 Byte, internally consists of 6 tracks.
I loaded the "Interstellar 4K HDR IMAX Into The Black Hole - Gargantua 1 2.aif" into Adobe Audition 3.0.1 recognizing it as 6-track multi-track (multichannel) audio music; from there in Adobe Audition 3.0.1, I could save each of the 6 tracks separately (52,478,040 Byte each) into a folder for analysis using also MusicScope 2.1.0.
I hope the following six diagrams would be self-explanatory for you.
At least in these audio tracks extracted from the YouTube video clip, the sound gains are saturated in many portions, I believe.
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- Thread Starter
- #47
If we assume a 1st order filter, it's only going to be ~0.3 dB loss at 10 Hz, or 7%
There will be some additional loss in the DAC used for measurement as well, but in my case it will not be significant at all.
- Thread Starter
- #49
I've finally conducted a new set of tests of my ICEpower 1200AS2 class-D amplifier. All tests were performed with the module pre-heated, which means it had been powered on long enough for all temperatures to stabilize. After each test pass, the amp was allowed to cool down for 10 minutes.
The sinewave tests are all 60 seconds long followed by a 30 second delay. The "Interstellar Black Hole" test is 50 seconds long, followed by a 40 second delay. This signal has the same RMS value as the sinewave tests.
All in all, this "2 x 1200 W" amp is able to output somewhere around 600-650W when driving a combined load of 4 ohms (8+8 or single 4 ohm load). In 3 ohms, it seems to be current limited in some way, resulting is less output power, but still quite a lot of power!
Although the amp is not as powerful as I want it to be, I have to praise its thermal protection systems.....
"Limiter" means the signal was either clipped or the output level attenuated.
"Shutdown" means the amp turned itself off.
The sinewave tests are all 60 seconds long followed by a 30 second delay. The "Interstellar Black Hole" test is 50 seconds long, followed by a 40 second delay. This signal has the same RMS value as the sinewave tests.
All in all, this "2 x 1200 W" amp is able to output somewhere around 600-650W when driving a combined load of 4 ohms (8+8 or single 4 ohm load). In 3 ohms, it seems to be current limited in some way, resulting is less output power, but still quite a lot of power!
Although the amp is not as powerful as I want it to be, I have to praise its thermal protection systems.....
"Limiter" means the signal was either clipped or the output level attenuated.
"Shutdown" means the amp turned itself off.
Sokel
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To tell the truth I didn't except it to last as long as a minute outputting 600W,despite it's stated specs as for continuous is about half that (the rest for "burst" and "peak" I consider useless) .
Good to know about protections,that's my No1 criterion when buying amps (yep,the good-old paranoid me
)
Good to know about protections,that's my No1 criterion when buying amps (yep,the good-old paranoid me
)- Thread Starter
- #51
I'm currently testing an other amp - the ICEpower 2000AS2. I have to wait with presenting anything, as I'm getting very strange results. It seems to output a lot less power than the smaller 1200AS2, and I'm trying to figure out if I'm doing something wrong or not.
- Thread Starter
- #52
Regarding my previous post - it seems like I have a faulty 2000AS2 module.
Here's measurements done with a module that is working properly. It does have slightly less continuous output power capacity than the smaller sibling 1200AS2. A major difference is that it does not do any limiting of the signal at overload, but rather shuts itself off.
Just for fun, I tested it with a single 12 ohm load as well, where the amp also shut down at around 550 W.
Here's measurements done with a module that is working properly. It does have slightly less continuous output power capacity than the smaller sibling 1200AS2. A major difference is that it does not do any limiting of the signal at overload, but rather shuts itself off.
Just for fun, I tested it with a single 12 ohm load as well, where the amp also shut down at around 550 W.
- Thread Starter
- #53
This is a wrap for now. I've got :
- some interesting results
- one destroyed Hypex NC502MP
- burn scars on my fingers from touching the dummy load, that reached in excess of 150 degrees Celsius at the surface ......
Sokel
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How did the Hypex ended up like that?Didn't the protections kicked in?
Interesting about the rest thought.
Seems like the big brother 2000as is good if someone just needs gigantic transients and that's it.
For continuous 1200as is doing better (?) as my installers said?
- Thread Starter
- #55
I tested it in BTL mode with 4 ohm load. The protection kicked in, but the amp was fatally damaged....
- Thread Starter
- #56
I agree.
这很简单，因为没有音乐信号像正弦波那样。真正的音乐信号，会有非常夸张但同时非常短暂的极端波峰。音乐的连续播放可能只需要几瓦特甚至几十瓦特的输出足以支撑。但对于极端波峰，可能需要几百甚至几千瓦的功率支撑。。这就是HIEND放大器对于低欧姆稳定性的支持。
Translated by Moderator: Please use English going forward.
“This is simple, because no music signal is like a sine wave. A real music signal will have very exaggerated but very short extreme peaks. Continuous playback of music may only require a few watts or even tens of watts of output to support it. But for extreme peaks, hundreds or even thousands of watts of power may be required. This is the support of HIEND amplifiers for low-ohm stability.”
Translated by Moderator: Please use English going forward.
“This is simple, because no music signal is like a sine wave. A real music signal will have very exaggerated but very short extreme peaks. Continuous playback of music may only require a few watts or even tens of watts of output to support it. But for extreme peaks, hundreds or even thousands of watts of power may be required. This is the support of HIEND amplifiers for low-ohm stability.”
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You are writing in Chinese - not many people can read that here. Please use a translator.
The LFE channel doesn't really matter for amplifiers unless you are talking about the amplifiers inside the subwoofers that get fed that signal. Then I can understand wanting to measure this, but then again most subwoofer amplifiers are already very high power and effects almost never last that long as you are posting.
But if you are feeding LFE to your mains I wouldn't worry too much about the amplifiers, but more about not smoking the actual speakers themselves. There are VERY few loudspeakers that can play the LFE channel without issue.
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