Perhaps you erred in wording - a day/night cycle is a planetary thing. In space, radioisotope thermoelectric generators make sense for craft in the outer solar system, and beyond: it is always day for them, but the light is very weak, so it may as well not be.
I'd be shocked if they were ubiquitous by 2026.
I can imagine the bugs being worked out best in (literally) low impact systems, like self-driving trolleys moving parcels around warehouses.
Most of that 5 horsepower is used overcoming drag.
Velomobiles have low drag, and can sustain much higher speeds. The current record for a human powered velomobile is 91.556 km (56.89 miles) in one hour.
Obviously that record (almost freeway speed) was set using 1 dude power, which is much less than 5 horsepower.
Do a google image search on "road in Vietnam", and all you'll see is featherweight death traps. I think by "people" you're actually talking about the richest 10% of the world.
People in the USA once drove 500kg deathtraps by default - more than 15 million Ford Model T were sold. I'd happily drive something lighter than a Model T, if it had modern engineering and an infallible driver - particularly if every other vehicle was similarly engineered and had an infallible driver.
Not with the current mindset in the richest 10% of the world.
I think it would require A (driverless cars) to get B (suitability of featherweight cars).
That, and/or shrinking petroleum availability, so that everyone is forced to lighten up their vehicles.
Remember, my caveat was "If we're getting speculative", and was based on your phrase about "magically" converting cars to electric. I think you were being over-literal. The conversion would have to go further than a direct swap, in order to be feasible.
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Hi Entropy,
I've been following this thread since the beginning but not being brilliant with hornresp I haven't had much to add to it.
I know what type of sound you want to achieve as it is pretty much the same as what I'm after. I think you will find that you will get closer to it by focusing on the midbass section rather than the sub. (You are after kick frequencies maybe 60Hz - 150Hz) This range with a little EQ will get the sound you want. I'm not saying ignore the sub, just that a lot of the punch you seek will be coming from the mains.
In my home system I'm using a single ported 15" per side with horn subwoofers below. It has the bass drum snap you want and bass guitar sounds 'right'. At the loudest peaks my amps just show a flicker on the 'signal' light (the light that lets you know the amp is getting a signal, not the clip light) so I'm guessing the power being used is very small.
Using the THX home theater specs at your listening position would probably be enough SPL for you - A home theater on full pelt is very loud - more than loud enough for me anyhow. As people have already said, get a SPL meter and try it.
One other thing to consider is that the recordings you are listening to are probably not mixed properly for live level playback - a lot of rock music sounds bass thin on CD so if you do set up a system to play it 'how it should sound' then other types of music may sound bass heavy.
As an aside, I would definitely build the sub as a wide, low stage and put a huge projector screen above. I'd run cable for some surrounds and have an outdoor system to play concert dvd's on. You could have your own private outdoor festival with the Doors , Led Zep etc, playing live - Brilliant !
I've been following this thread since the beginning but not being brilliant with hornresp I haven't had much to add to it.
I know what type of sound you want to achieve as it is pretty much the same as what I'm after. I think you will find that you will get closer to it by focusing on the midbass section rather than the sub. (You are after kick frequencies maybe 60Hz - 150Hz) This range with a little EQ will get the sound you want. I'm not saying ignore the sub, just that a lot of the punch you seek will be coming from the mains.
In my home system I'm using a single ported 15" per side with horn subwoofers below. It has the bass drum snap you want and bass guitar sounds 'right'. At the loudest peaks my amps just show a flicker on the 'signal' light (the light that lets you know the amp is getting a signal, not the clip light) so I'm guessing the power being used is very small.
Using the THX home theater specs at your listening position would probably be enough SPL for you - A home theater on full pelt is very loud - more than loud enough for me anyhow. As people have already said, get a SPL meter and try it.
One other thing to consider is that the recordings you are listening to are probably not mixed properly for live level playback - a lot of rock music sounds bass thin on CD so if you do set up a system to play it 'how it should sound' then other types of music may sound bass heavy.
As an aside, I would definitely build the sub as a wide, low stage and put a huge projector screen above. I'd run cable for some surrounds and have an outdoor system to play concert dvd's on. You could have your own private outdoor festival with the Doors , Led Zep etc, playing live - Brilliant !
Interesting stuff here guys! I feel I should warn that if you achieve your desired SPL at 25 meters, you'll probably disturb some neighboors (perhaps I missed a post saying you don't have any neighboors?)
Imagine you'll get 110dB at 25 meters, that will drop down to 70dB at 2,5km. So think of that 2,5km radius. Within people will be hearing at least 70dB of your music 😉 20Hz won't be much of a problem, the 80Hz probably would!
Setting up your horn at 2,5 meters would decrease that 70dB radius to 250m.
Just something to consider!
Imagine you'll get 110dB at 25 meters, that will drop down to 70dB at 2,5km. So think of that 2,5km radius. Within people will be hearing at least 70dB of your music 😉 20Hz won't be much of a problem, the 80Hz probably would!
Setting up your horn at 2,5 meters would decrease that 70dB radius to 250m.
Just something to consider!
No, long before the 70's, Charles Pogue Carb. – Fuel-Efficient-Vehicles.org Make of it what you will, but it seems an entirely plausable "concept" to me.
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Hi Y'all,
The usual area given for solar panel power generation to equal the electric consumption for the USA is a square 100 x 100 miles (10,000 miles^2 - Often this is given in the literature as 100 square miles. Oh well.)
The last time I worked through a spreadsheet on the subject (late 80s? early 90s?)I ended up w/ ~ 78 miles on edge, no big difference 🙂, and todays solar panels are more efficient. All the energy consumed in the US, Canada and Mexico combined takes roughly four times that much.
As an exercise: take a map of the USA, and cut four 100x100 mile squares using the map's legend, and position the squares anywhere you like on the map. For me at least it was surprising how comparatively small these large squares are.
Obviously, this wouldn't be the way to distribute power generation, but, it's one way to show that the problem is not technical, it's political.
Regards,
The usual area given for solar panel power generation to equal the electric consumption for the USA is a square 100 x 100 miles (10,000 miles^2 - Often this is given in the literature as 100 square miles. Oh well.)
The last time I worked through a spreadsheet on the subject (late 80s? early 90s?)I ended up w/ ~ 78 miles on edge, no big difference 🙂, and todays solar panels are more efficient. All the energy consumed in the US, Canada and Mexico combined takes roughly four times that much.
As an exercise: take a map of the USA, and cut four 100x100 mile squares using the map's legend, and position the squares anywhere you like on the map. For me at least it was surprising how comparatively small these large squares are.
Obviously, this wouldn't be the way to distribute power generation, but, it's one way to show that the problem is not technical, it's political.
Regards,
Hollowboy and ZeroD, I had to face the blunt realization that boundary conditions (completely outside of the horn) will appreciably impact the horn's impedance, way back inside the throat.
Now it's your turn. . . . Do a Wikipedia search for Kosmos 954. Be open to the possibility that what you think you know, is not reality. . . .
Even if electric solar cells were to hit 90% efficiency, I can assure you the industry has no future. A dinky 25 horsepower electric car would still need 21 square meters of panels, on an ultra sunny day.
Ford (under pressure from people sharing similar world views as yourself) is beginning to force people into lightweight vehicles. Check out some of the customer reviews on the new aluminum F-150 trucks. . . .
Now it's your turn. . . . Do a Wikipedia search for Kosmos 954. Be open to the possibility that what you think you know, is not reality. . . .
Even if electric solar cells were to hit 90% efficiency, I can assure you the industry has no future. A dinky 25 horsepower electric car would still need 21 square meters of panels, on an ultra sunny day.
Ford (under pressure from people sharing similar world views as yourself) is beginning to force people into lightweight vehicles. Check out some of the customer reviews on the new aluminum F-150 trucks. . . .
That assumes of course the intent to power the car directly by solar energy.
Now, if it was an electric car that was recharged by a charge site powered by solar energy. Or used synthetic ethanol generated from a system powered by solar energy...
Right - the battery. . . . .
Which is more environmentally friendly?
1) producing enough batteries & solar panels for 250 million registered cars in the US alone - generating hundreds of tons of very nasty hazardous waste associated with the process?
or
2) pulling oil from the ground to power cars (gasoline) - that releases CO2 (plant food) and H2O (plant food) when burned?
And please do not discredit yourself by asking, what about global warming?
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I'll join this offtopic discussion 😛 Fitting a car with solar panels is useless, even at 100% efficiency.
However, I certainly feel solar panels do have a future, but it's not dependant on any developments in the solar panel field. Would be fine if their efficiency would be no more than 20%.
It has a future if they are capable of increasing the energy density of batteries. Cars on batteries would be a lot more feasible. Regular home's could go off-grid. High power charging of cars would be possible from this home battery's.
So; if battery's get cheaper and more capable, solar power would be perfect!!
@brian: [Sun --> Electricity --> ethanol --> movement] would be rather inefficient..
@entropy: I'll not start the global warming discussion, but oil is not a long-term solution. At some point in time oil will be practically depleted.
However, I certainly feel solar panels do have a future, but it's not dependant on any developments in the solar panel field. Would be fine if their efficiency would be no more than 20%.
It has a future if they are capable of increasing the energy density of batteries. Cars on batteries would be a lot more feasible. Regular home's could go off-grid. High power charging of cars would be possible from this home battery's.
So; if battery's get cheaper and more capable, solar power would be perfect!!
@brian: [Sun --> Electricity --> ethanol --> movement] would be rather inefficient..
@entropy: I'll not start the global warming discussion, but oil is not a long-term solution. At some point in time oil will be practically depleted.
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It doesn't have to be efficient (look up the efficiency of the average ICE). It just has to be cheaper, more environment-friendly and cheaper than current options.
LOL - it's impossible to have a rational discussion with someone who denies the existence of global warming and the environmental impact of excess CO2, so I'll bow out here ;-)
Well, burning the ethanol in a car will still net the same inefficiency + all the inefficiency of producing the ethanol. I'd guess it won't be cheaper, but who knows! I'll bet my money on better, environment-friendly battery's 😉
Liquid fuel will be difficult to beat. Easy, quick and cheap to recharge, easy, quick and cheap to convert to power.
It's the creation and storage of that fuel - that's where I think improvements will make the most sense. Right now that's done by drilling, refining and shipping by tankers to storage sites. Now, what if that process can be simplified and made cheaper and/or easier? 🙂
https://www.sciencedaily.com/releases/2016/10/161012183520.htm
Very nice article! Interesting stuff. The lack of information about efficiency and this:
"A process like this would allow you to consume extra electricity when it's available to make and store as ethanol," Rondinone said. "This could help to balance a grid supplied by intermittent renewable sources."
Makes me think the actual efficiency is something to cry about. All fun stuff, but if it's at less then 10% it's about as ridiculous as a closed box subwoofer for PA 😉
"A process like this would allow you to consume extra electricity when it's available to make and store as ethanol," Rondinone said. "This could help to balance a grid supplied by intermittent renewable sources."
Makes me think the actual efficiency is something to cry about. All fun stuff, but if it's at less then 10% it's about as ridiculous as a closed box subwoofer for PA 😉
Efficiency is only a small part of the equation (if it wasn't we wouldn't be using sealed subwoofers at home either, LOL). Neither would be we be using gasoline engines, as they are also pretty inefficient, especially considering that way that they are actually used. There are other parameters that are equally, if not more, important, in determining the best energy->power conversion process.
You keep saying that but I don't think anyone is trying to argue that solar is going to take over and completely dominate the energy spectrum. There's lots of room for solar and all kinds of other energy creation techniques. I looked into a lot of alternative energy sources before tentatively settling on gasification. Solar was one, a combination of solar and wind was another, hydroelectric is out because I don't have a water source big enough, I looked at Sterling engines (providing energy based on temperature differentials) and I looked at steam and a few others.
https://en.wikipedia.org/wiki/Stirling_engine
Since I have a fully functioning boiler that is active at least 6 months of the year I'm primarily interested in methods that use heat or smoke. Industrial factories are investing heavily into Sterling type solutions to turn waste heat into energy but at this point there's nothing commercially available for a much smaller scale operation. And Sterling and steam type power generators can be a bit dangerous and complicated to build, not to mention that my "boiler" never actually boils so it's not nearly hot enough to run either of those types of systems efficiently. But both of these alternative technologies will be making breakthroughs soon as electricity rates continue to rise. There is a big fat hole in the residential energy creation market and someone is going to step in and fill it. Solar and wind are just the tip of the iceberg as far as competing technologies. As I mentioned a few times, I'm firmly in the gasification camp pending some real world testing.
Regardless which type of energy creation is or will be dominating in the near future there is room for all types. Energy and electricity demands are increasing at an alarming rate, especially in developing countries like China. And if China needs something they are going to make enough of it for everybody. Even here in Canada electricity demand continues to increase year after year and there's no end in sight, people just want more and more and don't want to reduce reuse recycle conserve or moderate their lifestyle in any way unless it involves increasing consumption.
This quote comes right from the BC Hydro site -
This is scary. Constant growth in energy production and there's no way to keep up. A couple of years ago I caught the tail end of documentary on BC power, specifically the new Site C hydroelectric dam. They are going to (maybe already have) flooded 55 sq kilometers of the Peace River valley to create the reservoir. This is 55 sq km of some of the best and most fertile farmland in the country, not to mention several sacred native sites that are reportedly thousands of years old. Nobody cares.
http://www.theglobeandmail.com/news...ves-site-c-hydroelectric-dam/article22108474/
And this still won't be enough power, they always need more. Always more.
When they run out of valleys to flood, when nobody wants coal or nuclear in their back yard, when electricity rates skyrocket to 20, 30, 40 cents or more per kwh, do you still think solar has no future? People are going to buy all they can and plaster their roofs.
All the alternative energy technologies have their place and they will all be exploding soon as power consumption continues to rise and rates continue to increase.
Didn't feel like working on the bathroom this morning.
Hi,
Here is a Hornresp simulation-and outline sketch-using four B&C 18SW115 with more or less arbitrary values/dimensions for the horn:
- compression ratio = 4:1
- horn length = 10 m
- throat = Sd = 1210 cm^2
- mouth: height = 3 m width = 8m
for: barn doors: 3 x 4 m ea.
- Eg set @ 4kW into 2 Ohms (drivers in parallel)
- set bandpass filter 4th order LR 15Hz-160Hz
At the bottom of its passband this design is excursion limited, the higher you go, the more power can be dialed in, and then it becomes thermally limited, and more than 1kW into ea. is possible (if I remember correctly Art has not yet destroyed one of these drivers), this allows for setting an intentional bump for e.g.: the kick drum, or a rising frequency response...
Regards,
Hi,
Here is a Hornresp simulation-and outline sketch-using four B&C 18SW115 with more or less arbitrary values/dimensions for the horn:
- compression ratio = 4:1
- horn length = 10 m
- throat = Sd = 1210 cm^2
- mouth: height = 3 m width = 8m
for: barn doors: 3 x 4 m ea.
- Eg set @ 4kW into 2 Ohms (drivers in parallel)
- set bandpass filter 4th order LR 15Hz-160Hz
At the bottom of its passband this design is excursion limited, the higher you go, the more power can be dialed in, and then it becomes thermally limited, and more than 1kW into ea. is possible (if I remember correctly Art has not yet destroyed one of these drivers), this allows for setting an intentional bump for e.g.: the kick drum, or a rising frequency response...
Regards,
Attachments
Eric,
1) I seldom think much of impedance, other than determining the minimum impedance to inform amplifier choice.
As far as "barn door" boundaries, we know the measured results are not what Hornresp predict. I'll leave it to David McBean to explain why simulating a barn door boundary does not match the measured results.
The graph below shows the response of a single Keystone Sub in green, the response of the same sub with a "wave guide" added in purple.
The Keystone's frontal area is 26.5" x 45", 8.29 square feet.
The 90 degree wave guide built to match the top cabinets dispersion angle used for the measurement has a frontal area of 21.97 square feet. The measurements were done outdoors at 2 meters from the horn mouth, both measurements used exactly the same power settings, and the measurement microphone and mouth locations were at the same exact place on my former property, around 30' from the nearest buildings.
At 40 Hz, just above the sub's "low corner", the additional boundary area adds 2.9 dB SPL. At 100 Hz, what I consider the upper pass band for the sub, the additional boundary area adds 5.6 dB SPL.
That is an average of 4.5 dB SPL increase over the sub's entire pass band, only 2.5 dB less than using two of the same sub with double the power. The measurements shown are for a single wave guide, output increases even more when a pair are used as in the photo below, though I sold the system before I moved to Florida, and did not measure exactly the increase.
Note that the stereo system in the photograph uses only two B&C 18SW115-4 below twenty-eight Eminence Alpha 8" and ten EVDH1AMT 3" diaphragm HF drivers. With typical rock and roll program material, the system's amplifier headroom maxes out at the same peak SPL in each pass band.
As another note, because of the hot, dry conditions I usually operated the system in New Mexico, HF power demands caused by air absorption above 10 kHz were as much as an order of magnitude higher than you will typically use in Seattle.
As I have mentioned before, the same SPL increases occur using FLH, BR, and TH. The wave guides in the photo were used from the early part of this century first with FLH, (before I had computer based measuring equipment) then with BR cabinets, then TH, my favorite of the three cabinet types.
2) Solar cells have been measured at above 40% efficiency using mirrors or lenses to concentrate the area of several times the cell size on the cell. From their lack of commercial availability I'd surmise that the cost and complication to achieve that gain is more than simply using more cells. The heat generated by the solar concentration is problematic for typical PV formulations, making the technology more useful in colder climates, which also have less insolation. For those climates, concentrating lenses or mirrors could be cost effective for applications where PV makes sense.
Todd Reichert's current (2016) human powered 89.58 mph (114.17 km/h) recumbent bicycle world speed record is proof that freeway speeds can be reached and exceeded with very little power. I have not researched Todd Reichert's power output, but standard diamond frame race bike riders put out around 1680 watts at a speed of 27 MPH. Because the faired recumbent is so much more streamlined than a "racing bike", I doubt that Todd needed (or was capable of) much more than 2000 watts to hit nearly 90 MPH.
3) If Ford would use 6061 aluminum instead of melted down pop cans, the damn trucks would not be such a joke, but the average pick-up buyer would not pay the cost for decent materials. Considering a Cummins diesel gets better fuel consumption in far heavier, stronger trucks, I can't understand why anyone would buy Fords, unless for the looks or brand loyalty.
Back to work on my sailboat rig- capturing wind power will make the 12' boat go around 8 times faster than the 2 mph it does using a 200 watt "Electric Paddle". That said, 200 watts is more than I care to sustain, the power output of true athletes is pretty amazing.
Cheers,
Art
Attachments
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This evening I’m going to generate a spreadsheet for various 18” drivers (like I did for 12” drivers) – so that I may quickly compare & sort specifications. I suspect that based on comparing just BL, MMD, Qts, and Xmax values alone, the B&C drivers will be towards the top of the list again – just as they were comparing various 12s.
A 26 foot wide mouth is a long span to cast in concrete. You guys are not making this easy for me. . . . but I look forward to the challenge nonetheless . . . The nice thing about my horn design, is that I’ll be able to try different driver configurations without busting away concrete. . . I'm not sure if I should try to get the mid-bass "kick" out of my bass horn, or if I should reserve the horn playing down low - and build some kick-butt (pun intended) mid-bass horns. . . . (I want an all horn system - no compromise)
Here are some interesting tidbits about CO2:
Should atmospheric carbon dioxide levels ever drop below 150 ppm, there’d be mass plant extinction on Earth - shortly followed by mass animal extinction. Greenhouse growers typically elevate CO2 levels in excess of 1500 ppm, which causes plants grow faster, with thicker stems, and more flowers. Carbon dioxide levels of 4000 parts per million (10 times our current concentration) are considered ideal for life on Earth. In fact, it was during times of significantly elevated carbon dioxide levels that plant life thrived in ways that are difficult to comprehend. The Earth didn’t burn, and the animals didn’t suffer. It was the other way around. . . Plants grew almost a foot per day, and there was abundant food & climate supporting the largest animals to ever inhabit the Earth. Interestingly, adverse health effects to humans occur at about 30,000 ppm CO2.
Using the historical record, our current CO2 concentration of 410 ppm is a lot closer to the extinction level of 150 ppm, than it is to the ideal level of 4000 ppm. Reducing CO2 concentrations is rather nonsensical - based on the historical record.
Lastly, the warm-layer of air that’s predicted by the Global Warming model (i.e. the actual increased temperature gradient from the elevated CO2 greenhouse phenomena) cannot be measured. The most sensitive temperature instrumentation ever created by man has been floated up on weather balloons, and every time the gradient cannot be found. Yet we are to believe something that's too weak to measure is somehow real – and strong enough to damage the entire climate of a planet? But I digress – if makes you feel better Brian Steele, please know that my concrete bass horn will adsorb CO2 from the atmosphere over time. It might be a big horn, but it has a small carbon footprint 😉
A 26 foot wide mouth is a long span to cast in concrete. You guys are not making this easy for me. . . . but I look forward to the challenge nonetheless . . . The nice thing about my horn design, is that I’ll be able to try different driver configurations without busting away concrete. . . I'm not sure if I should try to get the mid-bass "kick" out of my bass horn, or if I should reserve the horn playing down low - and build some kick-butt (pun intended) mid-bass horns. . . . (I want an all horn system - no compromise)
Here are some interesting tidbits about CO2:
Should atmospheric carbon dioxide levels ever drop below 150 ppm, there’d be mass plant extinction on Earth - shortly followed by mass animal extinction. Greenhouse growers typically elevate CO2 levels in excess of 1500 ppm, which causes plants grow faster, with thicker stems, and more flowers. Carbon dioxide levels of 4000 parts per million (10 times our current concentration) are considered ideal for life on Earth. In fact, it was during times of significantly elevated carbon dioxide levels that plant life thrived in ways that are difficult to comprehend. The Earth didn’t burn, and the animals didn’t suffer. It was the other way around. . . Plants grew almost a foot per day, and there was abundant food & climate supporting the largest animals to ever inhabit the Earth. Interestingly, adverse health effects to humans occur at about 30,000 ppm CO2.
Using the historical record, our current CO2 concentration of 410 ppm is a lot closer to the extinction level of 150 ppm, than it is to the ideal level of 4000 ppm. Reducing CO2 concentrations is rather nonsensical - based on the historical record.
Lastly, the warm-layer of air that’s predicted by the Global Warming model (i.e. the actual increased temperature gradient from the elevated CO2 greenhouse phenomena) cannot be measured. The most sensitive temperature instrumentation ever created by man has been floated up on weather balloons, and every time the gradient cannot be found. Yet we are to believe something that's too weak to measure is somehow real – and strong enough to damage the entire climate of a planet? But I digress – if makes you feel better Brian Steele, please know that my concrete bass horn will adsorb CO2 from the atmosphere over time. It might be a big horn, but it has a small carbon footprint 😉