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I am confused about Ohm loads on Dave Rats video and amp Bridging & Ohm's Law.
- Thread starter iMickey503
- Start date
So I'm listening to me F208s through bridged Rotel RB-976MkII which is a 6 channel amp. I'm using 2 of its amps bridged. Sounds good and doesn't seem to be heating up. Wanted to switch it up- been using the VTV Purifi for several months and wanted to see how the Revels sounded through the Rotel. Am I going to cause damage? I know the Revels dip pretty low.
DanielT
Major Contributor
I pasted a bit from wikipedia for clarification. Well, what you pointed out it was an answer to the question:
Can you get an idea of the power without adding a lot of power resistor and measuring RMS at type 50hz directly on the output?
Edit:
And the answer to that was the paste, what I quoted and you criticized. It may not get better, or more right just for that. Just wanted to show what caused it.
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OP
- Thread Starter
- #24
You may be bad at english, but yea, this makes sense now that he was talking about line losses not power as his main point.
Dave Rat got in contact with me and also sort of explained this. But this makes the most sense so far. Thank you.
And a Big thank you for all of you helping me understand what was going on and clarified my misunderstanding.
So to clarify, if I got this right, He is talking about Power to the speakers not actuall power output of the amp, but to the reactive load itself correct?
I think that is where I was confused.
Thats how i understut. But like i told thats completly out of hifi world. You would never think about cables, where reaistance gets so high that looses come into your mind. Couse this changes also FR. So for a typical hifi run of 10m you use 6mm^2 and never think on cable again, couse you already have overdone. The pros have to fight in a different world.
You just have to ask Rotel, is this amp good engineered? If they say yes, the worst thing that could happen is it goes into protection.
If it blows, they lied to you.
No such thing as RMS power. Current RMS x voltage RMS = Apparent power in VA, which isn't indicative of actual energy delivered to the load. For power amplifiers, the term "RMS power" simply refers to average continues power measured by a pure sine wave test signal (1kHz or few different test across the audible range).
Its the rms voltage ^ 2 / pure resistive load
P=u^2/r
I think its ok like it is. Who the hell likes to fight with cos phi on speakers?
We could add this on speakers to.
And a changing cos phi depending on frequency?
Joking
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Its the rms voltage ^ 2 / pure resistive load
P=u^2/r
I think its ok like it is. Who the hell likes to fight with cos phi on speakers?
We could add this on speakers to.
View attachment 153868
And a changing cos phi depending on frequency?
Joking
A speaker is very complex and nonlinear load. You got the crossover network, the driver, which acts as an AC motor with its own back EMF when the coil moves and oppose the applied current, and you also got the non linearity of the core saturation. The speaker impedance varies with both frequency and the current magnitude due to the back EMF which will increase as the motion range increases due to higher current...
This is why self oscillating modern class D amps have a huge advantage, due to the feedback loop closed at the input terminal of the speakers, which allows the amp to be almost load invariant. The amp controller will vary the current shape and the switching frequency to compensate for the speaker non linear behavior, ensuring the original signal is always applied to the speaker.
A better solution will be a class D based powered speaker with servo control, in which voltage, current and driver movement signals are observed and used as feedback signals to the amp's controller. Also add a DSP with pre calculated filter coefficients, for acoustic compensation, and you got yourself the prefect speaker. I hope Bruno is reading this...
A speaker is very complex and nonlinear load. You got the crossover network, the driver, which acts as an AC motor with its own back EMF when the coil moves and oppose the applied current, and you also got the non linearity of the core saturation. The speaker impedance varies with both frequency and the current magnitude due to the back EMF which will increase as the motion range increases due to higher current...
This is why self oscillating modern class D amps have a huge advantage, due to the feedback loop closed at the input terminal of the speakers, which allows the amp to be almost load invariant. The amp controller will vary the current shape and the switching frequency to compensate for the speaker non linear behavior, ensuring the original signal is always applied to the speaker.
A better solution will be a class D based powered speaker with servo control, in which voltage, current and driver movement signals are observed and used as feedback signals to the amp's controller. Also add a DSP with pre calculated filter coefficients, for acoustic compensation, and you got yourself the prefect speaker. I hope Bruno is reading this...
Lets do this and give it to me cheap!
OP
- Thread Starter
- #32
My life long dream is to perform live in front of an audience doing a cover song by Blink 182 or Green Day.
I have done some EDM shows where I had set up the gear, then ended up being the DJ at one of them, since the dude that was suppose to show up had a bottle of acid break in his pants, and was O.O.C. for the show.
The part that made it fun (Just got invited to help out) was even though I had zero business being a DJ for the start of the show, (Thankfully, no one noticed til the other guy came in 20min later thankfully!) I was damn good at setting up the Speakers and doing some tweaking to the E.Q. so it did not sound like some Muddy mess that I have been use to for these small shows.
Its kind of odd to have a guy that knows how to mix and fade, and then his "house sound" is just some loud mess.
I knew how to hook up all the gear so that they would not burn out speakers during a show. And I had a good idea on how to repair them.
So it was something I did for fun with some people I mes in California while I was going to school there.
I took an elective working with film and stage at City College of San Francisco .Met some people, and I brought in Pizza for the class, and one thing just lead to another.
DMX is still some Black art. But that's what I came for since its about my passion for lighting. So I learned how to set those up.
Then started doing the audio portion of it. Then the Hard wire networking so that the DJ's always had a connection to their laptops/gear (My field of expertise) as wireless seem to be an issue with the shows often.
It was the time of my life man. Go to school, go to work, then get off to set up a show at 6pm or so, and then Jam all night while taking care of any issues that came up.
As far as doing it for a living? Nope. But I often do help out at weddings. I try to stay away from those things as much as possible. But from time to time I get asked to help out one way or another.
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