Ed your way of presenting things confuses others here also if you don't realize that maybe you have a problem.
I like your way to accuse the others to be " erroneous" when their points of view differ from your "erroneous" ones.
The room (or theater) sound stage is yet IN the musical message. Everything you add to it from you listening environnement is parasitic.
Reason why, in all the mixing rooms of the recording studios, a great attention and huge work is always been took to dump the reflexions and room's resonances.
But you are free to do what you want, even if it is stupid to water behind you and on the sides a lawn that is only in front of you.
Costly (efficiency), and you get wet with the drops that bounce off the wall behind you.
So obvious...
Like with many things elsewhere, luck of ingenuity in new loudspeaker patents is becoming intellectually insulting.
I should avoid reading new patents when I am alone at home.
Ed you are one of the educated members in acoustics. You missed to apply the proper emoticon at the end of your post.
George
Attachments
I'm not heckling you, I'm trying to figure out what you meant by "non-Ohmic" because it's not a definition I've typically seen, as yours is extremely restrictive.
Any device/material has resistance as a function of anything else is not Ohmic by that verbiage. Any resistor will experience Joule heating and has a temperature coefficient, therefore the R changes with current. Is it Ohmic? Does a wire's bulk resistance changing with skin depth make it "non Ohmic"?
At the same time, any instantaneous snapshot of a diode will show it behaving "Ohmic", even though that apparently violates your definition. See why the language gets confusing? When do we call something Ohmic and when don't we? Which is why if you want to say that power line distortion increases due to complex loads across a diode, then just say that outright. Calling it "non Ohmic" just serves to confuse.
*I characterized the "ohmic contact" metal stacks (Ti/Pt, Ti/Au, Ni, Cr, etc etc under various deposition and annealing conditions) for a semiconductor device being designed some years back; we didn't call the contact non-ohmic because R changed over the sweep's range, although the ones that had diode-like behavior (Schottky) at low voltage were not pursued.
Scott - ironically it's voltage and current as our base units in SI, and not charge itself, although that may change in the coming years.
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I apologize Ed for my tone but please realize why Dan is confused. Drawing the same rms power at very different duty cycles does not make one Ohmic and one not, and if the rms is the same the Joule heating is the same.
Dear friend, I stated that I found the preconception to be erroneous, not any person in particular, but I agree with you on one point: highly directive speakers do need a highly treated room in order to shine. More specifically, either flush (wall) mounting, or heavy padding behind and sideways of the speakers. In control rooms, this can be done. In most rooms, not so much, and that was where I referred to in my post. Omni's (or better, wide dispersion speakers) work better in most rooms. Or let me be more precise: the most recent experience I have is in direct comparison between 1) speakers that are essentially flat over 180 degrees, and 2) narrow speakers such as the Kii.
As Scottjoplin I think remarked, imaging is just better and more precise with omni's. Another great thing is that highly directive speakers create a narrow sweet spot and require constant toe-in alignment if a listening position is changed, whereas omni's can create a credible stereo image in a wide area, and toe-in or toe-out, no difference to be heard.
As to why this should be so: power response of Omni's is much more even, and the Haas effect filters out reflections, so reflections do not impede on stereo image. But, reflections do add up in way that influences timbre. In highly directive speakers, off axis frequency response is horribly out of wack, and this reflected jumble influences timbre in a bad way. This, btw, is the reason highly directive speakers benefit so much from damping on the sides and behind them.
Large office buildings have been setting new rules about PFC only equipment. Can you guess how ugly their power bills got before that? What about all the malfunctioning equipment... Printers can do weird stuff when the power lines are out of whack - inherently driving everyone out of their mind.
They are TC Sounds 18 inch drivers. Maybe not available any more... so expensive to make.... 50 pound magnets each. Model LMS Ultra 5400 dual voice coil.
Probably a compound- isobaric-push-pull 3 chamber-bandpass filter thing.
Not.
Just simple sealed enclosure of suitable size to keep GD low. Since they are low distortion etc, I can use just one driver per side.
THx-RNMarsh
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controlled dispersion meaning constant directivity which gives a flat power response. There are no critical sitting place with constant directivity of 60-90 degrees (-3dB). Maybe for a 30 degree ..... but that is not what I said ... 60-90 degree. Up to maybe 120 degrees if away from adjacent walls.
Note the M2 is spec'ed as 120 degrees but they use the broader -6dB figure. It's 90 degree is more like at -3dB.
THx-RNMarsh
Note the M2 is spec'ed as 120 degrees but they use the broader -6dB figure. It's 90 degree is more like at -3dB.
THx-RNMarsh
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Just for my interest, do you have an idea why they don't use Neodymium Magnets, which would be smaller in size an lots more efficient.
I am aware abouth the tempco making problems 80 deg C and up, but when very efficient there would be significant lower thermal load and i am also aware that Neo's are expensive an on the other hand they can be much smaller compensating the price partially.
Thanks for taking your time to answer if possible.
regards Frank
Scott,
Anyone confused can ask their own questions.
Derfy
Ohmic contact - Wikipedia
Yes no resistor is perfectly ohmic but some come really close. Skin depth is not an issue for DC. Impedance is a different animal.
If you are running a induction motor on an AC power line it really doesn't much care about low distortion waveforms. If using an incandescent lamp true rms voltage and power are the issues. Same for electric heaters. Now if you are using an unregulated DC supply then the line distortion will change your output voltage.
Once AC line distortion goes above 5% you run into issues. I think this is even covered in the National Electric Code.
Problems start creeping in with things like power factor correcting capacitors overheating.
Surprisingly power distribution networks vary a bit in exact implementation around the U.S.
If you are using ohms law to say that at a specific voltage and current the load behaves as a resistance of some value and that changes as voltage or current changes, then why are you bothering to calculate the resistance? It seems what you are trying to get is the voltage drop across the device. Barlow did a lot of great work but electrical resistance wasn't one if the good works.
Ohm got ridiculed for suggesting voltage and current had a linear relationship.
Anyone confused can ask their own questions.
Derfy
Ohmic contact - Wikipedia
Yes no resistor is perfectly ohmic but some come really close. Skin depth is not an issue for DC. Impedance is a different animal.
If you are running a induction motor on an AC power line it really doesn't much care about low distortion waveforms. If using an incandescent lamp true rms voltage and power are the issues. Same for electric heaters. Now if you are using an unregulated DC supply then the line distortion will change your output voltage.
Once AC line distortion goes above 5% you run into issues. I think this is even covered in the National Electric Code.
Problems start creeping in with things like power factor correcting capacitors overheating.
Surprisingly power distribution networks vary a bit in exact implementation around the U.S.
If you are using ohms law to say that at a specific voltage and current the load behaves as a resistance of some value and that changes as voltage or current changes, then why are you bothering to calculate the resistance? It seems what you are trying to get is the voltage drop across the device. Barlow did a lot of great work but electrical resistance wasn't one if the good works.
Ohm got ridiculed for suggesting voltage and current had a linear relationship.
Vacuphile, my answer was ironicous, but not aggressive. This question is, in fact very simple. Please make an effort to understand what I will try to explain despite my poor poor English that make me feel like doted of the QI of an oyster.
We don't know how to build systems with constant directivity all over the bandwidth. So we will will lost more energy outside of our listening places in low frequencies than in high frequencies where the directivity is reduced. In the same time, the room will add its resonnances (or reflexions) in a way that is not universal, because different in all the listening rooms.
That implies two things. First the global subjective linearity of the bandwidth will differ from one room to another. Depending of this situation you cannot take as granted a omnidirectional speaker will be better than a directional one, even if it will sound more linear in your room witch is a specific and particular situation.
YOU have to linearize you systems frequency responses in your rooms before to compare the two solutions.
I can only testify that when people listen to my system, very directive, because horns, the always say a word about how precise and near magical is the localisation. My response curve, in free field, is slowly descending all along the bandwidth, only way to get a near good linearity at the listening point in most of the rooms with a minimum of acoustic treatment.
For me, (and i was designing omnidirectional speakers for the company I was working for, long time ago, just for money), omni is just like a bad bad response to the problem, like make all the population of the world hill of a disease because you you have a climate that is the best to survive with this disease, and pretend you have the best wealth system. The ideal system is a system with a directivity constant all over the bandwidth that reduce the reflexions outside of the listening area to a minimum. An elementary logic.
Well, I just find a way to image my purpose. Omni directional speakers use the same solution than painting in black the walls of a room with a lot of smokers inside, to minimize the speed the walls turn in yellow with white walls.
Or to treat someone with a flame thrower to let-him no longer suffer from mosquito bites.
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It may be easier to just go to here if one isnt familiar with constant directivity designs.
Speaker off axis: constant directivity horn waveguide speakers - Acoustic Frontiers
Gainphile
Constant Directivity - What is it? How does it work? Who does it?
and many others... see Google.
THx-RNMarsh
Speaker off axis: constant directivity horn waveguide speakers - Acoustic Frontiers
Gainphile
Constant Directivity - What is it? How does it work? Who does it?
and many others... see Google.
THx-RNMarsh
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