That's certainly true, but note that they said the absorption was 4%, so back of the envelope say that's roughly 40watts of sunlight absorbed. The rest gets reflected.
Now they say "When backed with a silver coating, the metamaterial shows a noontime radiative cooling power of 93 watts per square meter under direct sunshine." I think that's ambiguous and can't tell if that's 93watts net cooling or just 93 watts radiated, but either way you're somewhere between 53 and 93 watts of net cooling effect per square meter. It won't displace your AC unit any time soon, but it's still impressive and potentially very useful.
If true, the silver coated (sterling, or Mylar?) metamaterial could easily replace my 3 ton 12 SEER (36,000 BTU, 3000 watt) AC unit with only 56.6 square meters (24.45 by 24.45 feet) of the unobtanium at 53 watts of net cooling.
That said, at 93 watts per square meter, it is less "bang for the real estate" than solar panels, so we will have to see what the real market price turns out to be, if it really makes it to market.
Art
You don't need to host them on an external site in order to post images here. When creating a message, simply look under the "Additional Options" section and click on the "Manage Attachments" button. The rest should be self-explanatory.
You should give more information on what kind of tops you want to use. How many people are you covering/how loud do you want to go? What kind of dispersion angles do you want to achieve? How many tops per side do you want to run? How heavy or how large can the cabinet be? What kind of budget for drivers do you have?
I would be looking to cover about 100 to 200 people at any given time and I would like to be using between two and three per side.
I need them to be really loud and cover a good area. The budget for the drivers is pretty good but nothing too expensive and I need these to be no wider that 24 inches and no deeper that 24 inches.
I hope I answered the questions well enough for you to suggest some options.
Thank you all once again.
I need them to be really loud and cover a good area. The budget for the drivers is pretty good but nothing too expensive and I need these to be no wider that 24 inches and no deeper that 24 inches.
I hope I answered the questions well enough for you to suggest some options.
Thank you all once again.
For 100 to 200 people surely 1 top per side should be enough. When using the right top of course???
The mid tops will need to at least the bandwidth of the tapped horn subwoofers which in this case probably means 100 Hz or less.
If you have already have the TH18 and the J Bell tops then it depends on what crossover frequency the J Bell tops are good with. You might need a additional cabinet to fill in the gap in the response.
Art Welters SynTripP cab would be a good match. It shows that the 100Hz frequency can be achieved with a pair of 10" drivers.
Generally I find that old school mid drivers have a very low x-max. Many modern midrange drivers have more excursion which allows them to have a wider bandwidth.
If you have already have the TH18 and the J Bell tops then it depends on what crossover frequency the J Bell tops are good with. You might need a additional cabinet to fill in the gap in the response.
Art Welters SynTripP cab would be a good match. It shows that the 100Hz frequency can be achieved with a pair of 10" drivers.
Generally I find that old school mid drivers have a very low x-max. Many modern midrange drivers have more excursion which allows them to have a wider bandwidth.
You might be surprised. Some people want it really properly loud.
At one of the venues I worked at a while ago, a drum-and-bass touring act came through. Their support act was in a small room (probably less than 100 people), required 2x 16A @ 240v feeds, had a pile of 6x 21" folded horn subs at the back of the room, and a big pile of kick bins and a couple of 12" horn-loaded tops per side at the front. The ceiling wasn't high enough to put it all in one place.
During sound check, they dropped light fittings and knocked a WiFi router off the wall.
Of course, such a system could be heard by about 1000 people outdoors, but it'd be family festival levels, not constant-blurry-vision-from-the-bass loud. These guys wanted the latter.
Chris
hahaha Chris661, same here, stack of 8 Tham15's in a small cafe, with large glass windows and loads of booze on glass plates behind/above the bar. Owner loved it but the employees where constantly catching bottles from the plates. And outside you could only hear rattling windows. Ah the fun we had, good times.
You might want to also check out the DIY 60,
https://soundforums.net/forum/low-earth-orbit/diy-audio/12390-60-degree-diy-mid-hi
and DIY90,
https://soundforums.net/forum/low-earth-orbit/diy-audio/11601-new-diy-mid-high
They both use the same high quality drivers, just different horns of course.
Made to high pass at 100hz.
As far as I have been able to find, they are the loudest cleanest boxes one person can get up on a stick, either DIY or purchased.
I couldn't be happier with the ones I built. Outdoors, a pair matches well with 4-6 orbitshifters and/or labhorns
https://soundforums.net/forum/low-earth-orbit/diy-audio/12390-60-degree-diy-mid-hi
and DIY90,
https://soundforums.net/forum/low-earth-orbit/diy-audio/11601-new-diy-mid-high
They both use the same high quality drivers, just different horns of course.
Made to high pass at 100hz.
As far as I have been able to find, they are the loudest cleanest boxes one person can get up on a stick, either DIY or purchased.
I couldn't be happier with the ones I built. Outdoors, a pair matches well with 4-6 orbitshifters and/or labhorns
Do you feel they really need the FIR settings to sound good, or will IIR be sufficient?
Maybe you have not tried both variants, but I thought better to ask!
I recently build a pair TH-18's (V1).
Here are some pics:
I'm gonna put grills on them, with foam behind.
Next project will be some mid/highs for above the TH-18.
Here are some pics:
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
An externally hosted image should be here but it was not working when we last tested it.
I'm gonna put grills on them, with foam behind.
Next project will be some mid/highs for above the TH-18.