Acoustical feedback energy system

[aleks]

I think the loudspeakers were similar to the currently available SVEN 230 computer speakers (available in Russia). Here's the photo of internals, it's a "barebone" opamp-based amplifier (I suppose) with a built-in transformer. I haven't disassembled speakers I had in 2011, but considering the cost ($10 per pair), it's the only option. Maybe I'm mistaken about power rating, it could have been 10W per pair, but that's not so important I think.

[stivep]

Note that computer speakers have stereo inputs. IIRC I've simply twisted them so instead of stereo they became mono inputs. I do not remember how I twisted them, but cutting and exposing the original wires wasn't hard, what's more important this worked and all speakers reproduced the same sinewave signal.

About stereo vs mono:
stereo  creates a sense of immersion-signal strength (3 dB more doesn't sound a lot louder, but is actually twice as much power!),
our ears  are very sensitive to phase relations. even very far away. This is so even if there is some panning going on and there are actually multiple PA speakers broadcasting the signal.
But it looks like  you have  analog output from the  sound card.( please  provide  sound card  model number and manufacturer  or just a picture of it.)
(in digital output there is No sine wave  nor even a chance to  provide a sine wave)
_{digital to analog converter does the trick by signal sampling process.}

So we assume for now that:
- output from the sound card was analog .
- Right and Left channels  from sound card have common wire - ground and L. R wire that you connected in parallel
-  I means you created  two signals that  had two  sinusoids :
    - not in phase, or in phase.
    - of the same amplitude  or not .
    - slightly differing frequency or not.
      but both were simultaneously present, and you had no chance to know if amplification level of your sound card for both channels was the same
      nor know anything  about that sound  apart of  just listening to that sound and presuming that  generated sound was as you think it was.
    - frequency and amplitude scan was  made by digital to analog converter  in your computer and you were able to change it, scan it.

https://youtu.be/SFBY-vhgUHw?t=21
Each one of the speakers had its own power plug to electrical outlet? or  just one for all of  the speakers ?
Please correct me  if I'm wrong.
Wesley

[aleks]

Each one of the speakers had its own power plug to electrical outlet? or  just one for all of  the speakers ?
Please correct me  if I'm wrong.

I'm talking about 3 speaker-pairs. Each pair has 1 stereo input which I converted to mono by twisting the L/R input leads, so they were receiving the same in-phase signal, obviously at a lower voltage. Then all 3 twisted input stereo pairs were twisted together with the output channel of the soundcard (I can't remember exactly, but I've probably only used 1 output lead as to not cause any interference on the soundcard); ground leads were twisted together, of course. Very loose and lame way to do it I know, but as a result all speakers received the same in-phase signal, from the soundcard which produced a mono sinewave signal output.


Each speaker pair was connected to the electric tee independently, 3 connections overall. Note that the fuse on the tee was blown not due to connection awkwardness, but only after I hit a certain frequency on computer's sinewave generator plugin.


I'll try to do it all again soon, I've just ordered the required parts.


I do not think soundcard chip model is relevant, and I do not know which one it was. Probably, some common Realtek soundcard chip.

[stivep]

reedited quote of aleks:

I'm talking about 3 speaker-pairs.
//having 1 stereo input //receiving the same in-phase signal, //obviously at a lower voltage.
all 3 twisted input stereo pairs were twisted together with the output channel of the soundcard
only used 1 output lead (was possibly used)
ground leads were twisted together,all speakers received the same in-phase signal, from the soundcard which produced a mono sinewave signal output.Each speaker pair was connected to the electric tee independently, 3 connections overall.
Probably, some common Realtek soundcard chip.

Thank you.
So I understand that  e.g right channel from the sound card was not connected at all .
and only left was used ?

Note that the fuse on the tee was blown not due to connection awkwardness, but only after I hit a certain frequency on computer's sinewave generator plugin.

Question  about the tee:
The tee you are talking about- was it the electrical extender  allowing from single wall electrical outlet to  have  3 individual  outlets like a T splitter  connected into the 220V outlet that had its own 15A fuse?
Was your computer than connected to separate outlet but  your apartment  or house  was connected to  only one single  220V phase?
Do you have in your apartment or house  3 phase feed 3x220V?
Do you have in your apartment or house  2 phase feed   means you can have 220V or 380V ( in between the phases?)
If you have  anywhere in your apartment or house  380V is it possible that one of the outlets  on the wall was connected to different phase?
Wesley

[aleks]

So I understand that  e.g right channel from the sound card was not connected at all .
and only left was used ?

Yes, most probably. That's what common sense tells me at the moment. There was no need to twist output leads together as only a single source signal was needed. That was the whole idea in fact - hexagonal geometry and a single signal source. I now think that 6 speakers in a hexagon were a bit overengineered, but I guess otherwise I would not get big enough energy surge to notice anything. Now I do not think distances (108cm) or the number of speaker pairs are important overall, but to myself it was the only way as I'm not an EE.

Question  about the tee:
The tee you are talking about- was it the electrical extender  allowing from one wall electrical outlet to  have  3 individual  outlets like  T splitter  connected into the 220V outlet that had its own 15A fuse?
Wesley

Yes, it was a simple electrical extender with 15A thermal fuse, the simplest one that costs about 5$ at the moment.


The apartment has 360V input, but as I was doing the experiment in the same room I think both the computer and the speakers were connected to the same 220V phase, just different outlets.