I didn't present my question well enough, 🙂 ... with that vertical sheet of sound, which is directly in front of you as you face the centre of the speakers, if you move sideways, still facing the speakers, does the vertical sheet also move sideways - so, if you move, say, 2 feet to the left does the sheet also move 2 feet to the left? IOW, it tracks your lateral position with respect to the speakers.
This is what happens for me, obviously, when the sound works sufficiently well - one of the many subjective tests I use. As regards 3D from mono, yes, there is a very strong spatial effect, I think the brain triggers very easily when there are plenty of clues in the sound.
Also, you need to be sure you really have mono: I've got a very poor CD transfer of Caruso recordings from the library, lots of mid-bass resonance encoded in the recording - why does the left speaker sound different from the right? Well, in Audacity obvious big differences between L and R, a straight transfer from a stereo cartridge was used - so, mix down to pure mono, and now the sound properly balanced.
Wider, taller, deeper imaging absolutely. This I know how to do. "surround" I have never heard. Ambient, enveloping, and what other magazine terms you my apply, but not surround.
I have a nature recording CD of an electrical storm recorded from within a valley.
Lightning (thunder) strikes at the far end (front) of the valley, travels up the valley past the mic (listener), hits the enclosed end of the valley and reflects back from behind the mic (listener).
I have had friends looking behind the couch for rear surround speakers.
This only works when all sound sources (drivers) are in correct absolute phase over the whole frequency range.
Dan.
I didn't present my explanation well enough, 🙂 ...
Ok, with stereo done right I can get 'holographic' sound image.
By that I mean two dimensional sound space occupying the volume behind the two speakers.
Now, like a hologram image, you can move (change the viewing/listening position) and that image remains rooted in space.
Like the hologram image, all the information is there, you are just viewing it (listening) from a different angle, just like the real world.
As you move sideways and closer to one of the loudspeakers, the image remains essentially the same, but you are hearing it from a different angle AND the nearer loudspeaker does not become dominant.
IME, in the case of reversed cable direction, the image 'skews/distorts' toward one side, and the balance control don't fix it.
Maybe that clears things 😉.
Dan.
I could say a whole lot more on the phone, any time you're free, you're welcome to have a yarn. 😉
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Which is probably why I said:
Which part of "based on the impedance of the path" was not clear?
No.
The understanding I have presented is a tad above "basic understanding". You then need to look closer. When discussing NON dc current, it is necessary to include the impedance of the path. If there is sufficient inductance in the lower resistance path, then the higher the frequency is, the less inclined the current will be to take the path with the lower resistance but higher inductance. The inductance has a frequency dependent impedance, and that comes into play. Essentially, the system will have several breakpoints in the current path function. Any path that is NOT the shield destroys the shield's ability to shield against trapped loop dB/dt.
Brian neglected to consider the phrase "Return current will travel based on the impedance of the path". And the subsequent explanation which detailed how the current will SPLIT paths based on the relative impedances of the path.
Is it going to be necessary to start a tutorial on Norton, Kirchoff, Thevenin, and Ohm?
ABSOLUTELY NO.
There are two reasons for the safety bonding conductor.
First and foremost, it is there to force the circuit breaker to clear the line in the event of a fault to chassis. As a consequence, it must be capable of forcing and supporting fault currents which will clear the circuit breaker magnetically within a few line cycles. We are talking high hundreds to kiloamps fault current. An inductor will not force these currents, and in general cannot survive them if it could.
Second, it must keep the chassis voltage to below 50 volts during the fault event, the standard considered lethal. If for example, the inductor had an effective impedance at 60 cycles of 1 ohm, the fault current will limit to 120 amps, and the chassis will go to hot potential. Should it have an impedance of 10 ohms at 60 hz, the breaker will never trip and the chassis will remain at 120 volts. (in the USA)
Never ever, put an impedance in series with the bonding conductor, it is very much against code, and against safety.
Nah, he never gets it...😀
My gallery drawing includes the resistance of the loops, and the inductance. I also stated that the path of audio currents is frequency dependent.
It may be better to ask for clarity if needed, rather than accuse an EE with 35 years experience of missing fundamental basics, eh?
jn
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Couldn't one use a single point ground for the electronics with an impdeance between the electronics and the point where the electronics is connected to chassis.
Of course, this would inturn require isolated connectors for inputs and outputs which in turn impose other potential problems.
Of course, this would inturn require isolated connectors for inputs and outputs which in turn impose other potential problems.
A lot do and this quite often doesn't work, this will also leave you more open to RF interference.
if you get hum one good way of getting rid of it is some nice thick wire between the devices grounds. I often see that the more thought and effort that has gone into a hyper complex star of star ground, the more likely it is to be susceptible to noise.
Tony Waldrens EMC rants do discuss an alternate.
But for a simple home set up where hum is present, firstly try the thick wire trick, then by playing about with the wires you can usually isolate the loop that is causing the problem and solve it. many PCBs often have a nice big PTH hole connected to ground just so this can be done during product development to help identify where the problem is, and often said products will go out with a nice thick wire attached. One area where this was always a problem was when ribbon connectors were used to connect a display PCB to a main PCB.
if you get hum one good way of getting rid of it is some nice thick wire between the devices grounds. I often see that the more thought and effort that has gone into a hyper complex star of star ground, the more likely it is to be susceptible to noise.
Tony Waldrens EMC rants do discuss an alternate.
But for a simple home set up where hum is present, firstly try the thick wire trick, then by playing about with the wires you can usually isolate the loop that is causing the problem and solve it. many PCBs often have a nice big PTH hole connected to ground just so this can be done during product development to help identify where the problem is, and often said products will go out with a nice thick wire attached. One area where this was always a problem was when ribbon connectors were used to connect a display PCB to a main PCB.
That's precisely the phrase he was considering. As I said, taken literally, it could strongly imply that there is but a singular return path and that current will flow only in the path of lowest impedance even if there are other higher impedance paths. He was simply clarifying that it would take all available paths.
Compare:
"Return current will travel based on the impedance of the path."
"Return current will travel based on the impedance(s) of the path(s)."
How did he neglect it when he specifically said he agreed with it?
se
Nice survey of current nano-scale electronics, even useful for the layperson. Note the scales and often the extreme temperatures of the experiments. The notion of 3" long continuous nano-tubes paralleled and terminated to make a device of unusual properties at room temperature is absurd. BTW the interesting properties are usually quantized and/or horribly non-linear.
http://nanotube.msu.edu/nt05/abstracts/NT05tutor-Nygard.pdf
http://nanotube.msu.edu/nt05/abstracts/NT05tutor-Nygard.pdf
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I've had this demoed with the cheap built-in speakers of a Philips LCD TV. The phaser comming from right and behind nearly made you jump out of your seat.
Wow.
I am with Feynman on this, I think.
"If you think you understand Quantum ....."
3" this sounds like a veiled reference to our favourite component for verbal self flagellation.
😀
Sound bars create quite a surprising souroundsound, often much better than multiple speaker set-ups in UK small living rooms, would rather listen to a soundbar than the 5 speaker set up where the speakers are just way out of position.
Yes, immediately after I clarified that it would take the available paths using a numerical example.
I hate you..
nitpicker.
How's it going Steve? Hope all is well that side of the island.
john
In a word, hectic. Have about half a dozen projects all converging at once (not a coincidence, it was intended to be so). On the bright side, when it's all done it will have been worth it. I hope. 😀
se
Nice.
The work widget worked exceedingly well. We are in the process of commissioning it over the next 6 to 8 months.
I'm finally getting around to those line arrays. Designed the mids as ten 4 inchers in a line, and the tweets as twenty 3/4 inch domes in a line (I'm keeping the length under 48 inches). If they sound ok, I'll make 12 of the mid arrays, and 8 of the tweet lines. That'll leave me 12 pieces of 4 inch and 40 domes as spares. (Of course, if they are too darn heavy, I'll just get rid of the whole kitten-caboodle..I'm getting too old for this crap.)
So, now the question.
I'm wiring them so that 6 mid arrays would draw 750 watts from an rmx 1450 channel, and 4 tweet arrays would match impedance.
I assume that any drivers in series need independent back spaces to control xmax. I've seen two drivers in series in a single box before, and marveled at the odd way the drivers float during power.
I noticed that thread talking about transformers to lock series drivers, that really necessary? I was hoping to just create 10 independent back volumes, using the partitions as strengtheners.
jn
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JN, I used to use a sub with 4 x 12" in the same (IB) box, wired series/parallel. I used it like this for about 10 years, and never noted any issues with driver "float"
jp
jp
My thinking is that with them wired in series, with the amp end low z as in on or shorted, if you push one cone inward, the voltage it creates will push the other driver out. In addition, the air in the cab will also try to push the other out. Paralleled, the drivers will try to go the same way even though the air is fighting both.
They were high compliance 15 inchers, I had four boxes with 2 drivers in each. At high power, they really floated big time, far more than the signal excursions.
Paralleled, it stopped.
jn
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