Recent comments in /f/gadgets

DuncanIdahoPotatos t1_iy46ito wrote

Reply to comment by farox in This is the first house 3D-printed from bio-based materials - The new technology could come in at a key moment. by speckz

My city just started 3D printing homes! I was really excited reading the article, particularly because the developer was talking in great length about the cost savings this brings.

Regular homes in that neighborhood start in the 400s (as in $490k).

These new cost saving 3D print homes in the same neighborhood start in the 400s.

My excitement waned.

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LouSanous t1_iy45muh wrote

Reply to comment by a11en in News Release: NREL Creates Highest Efficiency 1-Sun Solar Cell - 39.5% efficiency by TimeSpentWasting

>solar efficiency and limitations

It's really important to note that this "limitation" isn't much of a limitation.

There is functionally infinite sun. The amount of energy reaching the earth at sea level from the sun every second is well over 100 times the total yearly energy consumption of the entire world.

Modern nuclear uses only 5% of the energy in the fuel. Then, the conversion to electricity is somewhere around 35%. So from the energy contained in the fuel, nuclear is about 1.75% efficient.

Coal plants are around 35% as well.

Combined cycle gas is 55-60%.

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llortotekili t1_iy44d45 wrote

Reply to comment by PeaceFar9770 in LG Display’s ‘invisible’ speaker brings sound to any surface in your car by MicroSofty88

Bass requires surface area and excursion (in and out movement) to be reproduced with volume. You can eq to make it more pronounced in comparison to the other frequencies, but you are still limited by the speakers physical characteristics for how low and loud they can play. Judging by the picture,these could maybe play down to 250-200 hz with good output. That's low enough to be a good midrange speaker, but it will still need a woofer to cover bass(20-80hz) and midbass(80-250hz). The good thing about speakers like this is that it allows for an engineer to design a speaker system with very good imagining. They can place these in spots in the vehicle where the sound should actually be coming from. With DSP(digital sound processing) they will be able to place these in a way that lets a car sound like it has a very wide soundstage. Doors for the widest sounds, the widest parts of the dash for most left and right content,and in the center of the dash for center stage content. Bass frequencies aren't as directional as the frequencies these will play so woofers in the doors or inside the bottom of the dash will sound convincing still. Sorry for the text wall, sometimes I get a little too nerdy about audio. Also, I'm going by the picture, didn't read the article. Edit: skimmed the article, what I said seems to be spot on. I would love to see a response graph for these.

TL/DR; They won't produce much bass, but they will allow for accurate sound placement in the frequencies that count for directionality.

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LouSanous t1_iy41cti wrote

Reply to comment by michaelb1 in News Release: NREL Creates Highest Efficiency 1-Sun Solar Cell - 39.5% efficiency by TimeSpentWasting

Triple jct cells are insanely expensive. This article is a bit out of date, but the cost difference holds true. When I was working on the solar car for my university back in 2009, the GaAs cells were hundreds of thousands of dollars in total.

https://www.solarreviews.com/blog/nrel-developing-tech-lower-cost-multi-junction-solar-cells

>To give a cost comparison, utility-scale solar projects now cost about $1 a watt for solar power. A gallium arsenide multi-junction solar cell costs up to $300 a watt at this point.

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