The Communication Cube


Amplifiers commonly put out their maximum power, but if you're not pumping out the volume they'll just be ticking over more or less. Also your powerbank might be tuned for old and partially knackered cells that don't take a full voltage any more, so it just reports 100% for anything over that.
It works just fine when it's turned on properly, charging a phone or running a raspi the percentage goes down as intended. It's like that part of the circuit isn't powered at all. Hence my fear I might be damaging something.
I'm asking these things because I suspect badly regulated output to be the culprit in damaging the connected amp and exciters. They worked fine for about two hours and then started clipping.
Measuring possible spikes could be the excuse I need to buy a proper DSO...
 
So my recovery training is now on the go: my plan is to drive maybe a half hour every evening whit the Indoor Bike, as I hope this movement will bring my leg back to its movability, as I have to watch Protected Content (Netflix..) on Phone, this is also no loss on time ..
then I just need to put on my ventilator, and the Radio..
 
So my recovery training is now on the go: my plan is to drive maybe a half hour every evening whit the Indoor Bike, as I hope this movement will bring my leg back to its movability, as I have to watch Protected Content (Netflix..) on Phone, this is also no loss on time ..
then I just need to put on my ventilator, and the Radio..
Vorsicht, false friends: englisch "ventilator" ist auf deutsch auch ein Beatmungsgerät. Ich denke, ja hoffe sogar, du meinst "fan".

Gute Besserung!
 
It works just fine when it's turned on properly, charging a phone or running a raspi the percentage goes down as intended. It's like that part of the circuit isn't powered at all. Hence my fear I might be damaging something.
I'm asking these things because I suspect badly regulated output to be the culprit in damaging the connected amp and exciters. They worked fine for about two hours and then started clipping.
Measuring possible spikes could be the excuse I need to buy a proper DSO...
Presumably we're talking about an amplifier that runs off 5V here? I've only ever seen those as part of PC speakers and the likes, so I've little idea what an independent one of those looks like. Normal power banks that put out 5V start at a 3.7V lithium battery and have a boost circuit that boosts that up to 5V. I'm not sure what part of which circuit could really be left unpowered. The amplifier normally has a balanced line level input, boosted up to a level suitable for driving fairly big speakers using transistors of some variety or other (probably mosfets). If it's clipping it possibly means the voltage input to those mosfets is dropping. I think on balance I don't trust that claimed 100% of the battery meter on the power bank and thing it might just be that that's at fault.
 
PAM8403-750x750.png
@levi It's a basic PAM 8403 module. I will give it another go running off 3s NiMh to compare. It can take 2,5 V - 5,5 V.
And I'll stop mistreating the power bank. It's not supposed to be used like this and I'll leave it there. Thanks for thinking it through :)

I put two of those on an old helmet. When it works it makes me dance through the house with that old thing on my noggin. I have to stop myself from dancing on the bike :D
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Just watched the latest two episodes of South Park. Feels to me it's lost something. Anyone better know what I'm talking about than me?
 
Anyone after an inexpensive runabout?

 
 
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I know some people who put a Samsung phone in airplane mode inside a high-grade faraday cage and monitored radio waves. The phone didn't emit anything.
However it can still receive signals, so one could imagine a mechanism where the phone would react to some predefined signal and start transmitting.

As for turning off the phone, some hacks actually fake the power off behaviour to keep the phone running. However, this becomes obvious if you look at battery consumption. I guess a device maker (or anyone with access to some part of the supply chain or to the device's hardware) can have some low-consumption stuff still powered when the phone is supposed to be powered off.

But I remember back when you could remove battery and there were people to tell you that "even if you remove the battery, they can still track down your phone!", so I'm taking these claims with a grain of salt.
 
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But I remember back when you could remove battery and there were people to tell you that "even if you remove the battery, they can still track down your phone!", so I'm taking these claims with a grain of salt.
There might be some truth to that, even if your phone has the battery removed and is put inside a faraday cage. Imagine you are at home a lot, and have a normal routine, suddenly there is this protest at a certain spot. So halfway there, you shutdown your phone. And start it up again when you are back home.
So the data shows you were en-route to somewhere unusual, at a certain speed. So you can extrapolate a little as to the direction where you were going, and by the time you have your phone off, how long you would have been in an area (which gets bigger as time passes and your phone is still off)
Some "off" modes are flightmode, then the cellphone still communicates with towers, it just does not answer back, so if you have a backdoor installed, it could send that data as soon as you go "on" again (or as the link showed, through BLE).

Then there is the second battery inside some phones to keep track of time. To detect if your mobile has that, read this article:

Then there's this too:
 
I like miniatures, this looks like expensive niche fun:
There's one thing off when I look at the screen: the refresh is vertically instead of horizontally. It means the display, just like the Pyra, is for mobile devices with a vertical orientation.
 
Does this parse?
Audio clipping means that the amplitude is too high to be played properly. Along with the harsh sound comes higher (RMS?) power. That might go over what my 3W speaker can dissipate in heat and thus damage it, despite being connected to a 3W max amplifier. Audio files can have clipping in them, thus the wrong file can destroy a speaker.
 
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Does this parse?
Audio clipping means that the amplitude is too high to be played properly. Along with the harsh sound comes higher (RMS?) power. That might go over what my speaker can dissipate in heat and thus damage it, despite being connected to a 3W max amplifier. Audio files can have clipping in them, thus the wrong file can destroy a speaker.

If you mean, "can you understand what it says", then yes. Are you asking for grammar improvements or if we can "get" what it says?

I do not agree with the idea in the sentence though. Even at low volumes, if the "clipping" is in the source already, say, a CD, the sound will be distorted. But at high speaker volume, then yes, the speaker can go in-out many times and rupture its cone, or misalign the cone base.

So if "clipping" is at the speaker level: Bad! You can damage it. If it was at line level, well, some guitars use that to get more metal sounds out of it ("overdrive")

mic-to-amp-sound-system.png



overdrive: emulating a too high gain at low volumes:


I like this graphic with the red part of the soundwave marked as clipped: https://www.researchgate.net/figure...pling-a-Ultra-wide-band-signal_fig1_327805613
But note that this is still digitally, and can be solved by, say, using 24 bits or 32 bits to represent the wave, as music studios do.

Back to the sentences.

Audio clipping means that the amplitude is too high to be played properly.

I assume this is not your first sentence, because if it is you need to add context to it. "played"? As in, play a guitar? Sorry, I can't play this partiture on my guitar, it has audio clippings. Does not make sense, so add:

Audio clipping means that the amplitude of an audio signal is too wide (or loud) to be played back properly on a speaker.

*(but again, my opinion is that it can be amplified and clipped digitally, and played back at low volume and no harm is done to the speaker, yet it still sounds distorted)



Along with the harsh sound comes higher (RMS?) power.


Looking up what RMS is. Sound ok but look at that PEAK RMS. For me, that is the likely cause of speaker rupture, and not just the root mean square. But for overheating, yes RMS (I think).
And the RMS part is confirmed here:

I like PMPO, but in the music world, the term is frowned upon. And I do not what the acronym means.
PMPO: Abbreviation for Peak Music Power Output. A very subjective specification designed to help provide "real world" wattage ratings for power amps and speakers.
Acronym for peak momentary power output. This term refers to the maximum power output achieved for a speaker system under perfect conditions. PMPO is a controversy term, as many feel it is used as a marketing ploy, since the perfect conditions on which PMPO are based are next to impossible to achieve in a home where the speaker system is set up.




That might go over what my speaker can dissipate in heat and thus damage it, despite being connected to a 3W max amplifier.

Dissipate in heat... ok, so you are talking about prolonged sound exposure, and not a quick "pop" that kills the speaker because it was a 1W speaker and I connected it to a 3 Watt amplifier?




Audio files can have clipping in them, thus the wrong file can destroy a speaker.


A clipped soundwave, means that the soundwave goes up to the max, then goes down to the max. Does this kill the speaker? Or if the signal is only on the top, let's say it's a flat horizontal signal, but instead of being in the zero (normal silence), it's actually on the top. Would that also destroy a speaker? (I have no idea - I think we would hear nothing, but the speaker would get hot "playing" that sound)

So I think that clipping contributes to a higher RMS, which is that what kills a speaker by overheating it IF the speakers have a too low wattage for your amplifier over a certain volume, and thus is unable to dissipate the heat produced.

Here is an article that says just what you are saying: https://geekmusician.com/can-speakers-overheat/
it uses words like over-excursion and is well made.

Does this help?
 
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I should have asked "does this make sense?" :)

I've partly destroyed two exciters. The only reason I can think of at this point is that's partly my shoddy files' fault. A few of them look like this.
Prolly drill a few holes in the back of another pair and see if that gives em literal breathing room. And get proper files.
clipping.PNG
 
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