500w amp power consumption so low!! |
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tcm
Registered User Joined: 19 September 2012 Status: Offline Points: 10 |
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Posted: 13 July 2015 at 10:07pm |
Hello!
apologies for the newbie talk but I have finally purchased a couple of these digital amps after hearing about them a couple years back. Set one up (sure 500w) with my wharfedale titan 18inch speaker and it all works nicely. What has amazed me is the power consumption, or rather how low it is! I assumed 500w amp and speaker I would be generally using more than the max 15w/1amp that my Watt meter is showing!! And 20w was with it pumped right up! Is this normal? You could build a massive rig which would run for weeks right!? on the 500AH battery I've put in my campervan! I'm amazed.. or is my watt meter broken!?
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lutkeveld
Young Croc Joined: 23 September 2013 Location: The Netherlands Status: Offline Points: 517 |
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Your wattmeter can't keep up with the peaks. Which specific amp do you have? Normally a 500W amp would consume 50-100W on full volume with music.
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tcm
Registered User Joined: 19 September 2012 Status: Offline Points: 10 |
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Ahh that makes sense! are there any cheap watt meters that can keep up?? I use an RC meter that I use on my electric bikes.. 1 x 500 Watt 3 Ohm Class D Audio Amplifier Board Compact - T-AMPhttp://store.sure-electronics.com/aa-ab31511-1451\ and 2 of this http://store.sure-electronics.com/aa-ab31512 - 1 X 500Watt Class D Audio Amplifier Board -IRS2092This audio amplifier board employs IR's High Voltage, high performance class D audio amplifier driver IRS2092SPBF and 200V Single N-Channel HEXFET Power MOSFET IRFB4227. http://store.sure-electronics.com/aa-ab31512 - Learn More The first one I have tested sucessfully but the second one irs2092 I cannot find the manual on the website and I am not sure of the connections.. the board is very different from the other one..
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lutkeveld
Young Croc Joined: 23 September 2013 Location: The Netherlands Status: Offline Points: 517 |
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How much volts do you have on the input?
There are no wattmeters that keep up with the demand realtime. Even if they could, you couldn't. The RC meters should monitor the consumption just fine. Divide the watthours by hours and there you go.
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studio45
Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3864 |
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Well, there are 2 things happening here - firstly, that board only develops 500 watts into 3 ohms. Its maximum output voltage is therefore 38.7 volts RMS. Your Wharfedale sub is probably 8 ohms, meaning the board will develop about 187 watts into that load.
Secondly, what supply voltage are you running the amp from? 38.7v RMS is 54.7 volts peak to peak, meaning the supply would need to be at least 55 volts to get that much power. If you are running at 24 or 36 volts, then your maximum power into 8 ohms will be about 32 or 76 watts respectively. Plus, as people have already pointed out, most power meters average over several seconds so will not register peaks. So, in conclusion, if you up the voltage and lower the impedance, you'll be drawing much more power, and making much more sound. By the way, the 500 watt IRS2092 board requires a split-rail supply, not single-rail like the T-AMP board. So that means +60v, ground, and -60V. You can achieve this with a set of several batteries, but it would always need at least 2 to function. You *might* be able to power it from a pair of the Sure 500 watt boost converters and a single battery, but I'm not sure how they would react to being wired in a split-rail configuration.
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Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA
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tcm
Registered User Joined: 19 September 2012 Status: Offline Points: 10 |
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thanks for all the help and advice! I am a beginner when it comes to audio! Was running it at 48v from the sure supply. I have 2 of the sure supplies so how would I set them up to try and make the split rail supply? I dn't even know what that is, I didn't read the blurb properly when buying these oops! I want to run a sound system from my van which will have a big 12v bank in it but was hoping to just use the dc converters to make the higher voltages...
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tcm
Registered User Joined: 19 September 2012 Status: Offline Points: 10 |
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just read up on slit rail configuration, so you just put the ground in the middle point of the batteries basically Yes i wonder how the sure dc converters would react? will post a pic of the connections on the irs2092 tomorrow hopefully one of you guys can point me in the right direction with the connection as there are quite a few but now I know about this split rail it start to make more sense.. hope I haven't fried it by trying to fire it up with 48v across + / - ground!
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studio45
Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3864 |
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Thinking about it further, you definitely could *not* power the split rail board from a pair of boost converters and 1 battery. The negative side of the battery is basically connected straight through the converter board, so if you just stacked two up running from the same battery, there would be a short circuit from the + output of the "lower" board to battery ground, and everything would blow up.
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Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA
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tcm
Registered User Joined: 19 September 2012 Status: Offline Points: 10 |
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ok good to know, thanks!
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