Loudspeaker Thunderbolt Look-alike

[mrboojay]

The McCormick Place in Chicago has some up in the ceiling in one area, though they are a bit more narrow and smaller.

[ggms24]

They have those right outside Right Patterson AFB:

That looks nothing like the one I posted lol

[acoustics101]

Just consider the driving source. A Thunderbolt horn has a 10 HP (~7500 watt) blower supplying a high air flow at moderate pressure to a chopper, wheareas the horn in the gym has a compression driver driven by 100 or so watts of audio power. Even though the horn may be very similar, the driving power to it is on the order of 1/75 the power. That in itself would give it about 18.75 dB less output than a Thunderbolt, which in a gym is still a high output (on the order of 110 dB at 100 or 140 dB at 1 meter).

Wow I guess they can't be too loud then if your they had 4 of them in a high school sized gym

[acoustics101]

http://tinyurl.com/3fw2c6y
Here is a video of a horn that resembles a Thunderbolt that would be every bit as loud. It is neither a siren nor a loudspeaker, but a special air horn used by NASA for acoustical stess testing of spacecraft components in a reverberant test chamber. It is now owned by Mike Socal.

Unlike a siren, the pitch is determined primarily by the horn's length. Being almost 7.5 feet long, it has a fundamental frequency on the order of only 105 Hz and carries like crazy. Listen to the long echoes!

[acoustics101]

On measuring, the frequency is actually closer to 100 Hz.

http://tinyurl.com/3fw2c6y Unlike a siren, the pitch is determined primarily by the horn's length. Being almost 7.5 feet long, it has a fundamental frequency on the order of only 105 Hz and carries like crazy. Listen to the long echoes!

[kx250rider]

The shape of the horn, is basically a standard exponential horn. The size is tuned to the size of the horn driver (i.e. the chopper opening in the T-Bolt, or the actual diaphragm in a vibratory horn, or the speaker cone in an audio loudspeaker). There is a lot of very complicated math involved, which I won't pretend to understand, LOL.

Charles

[MKIIProductions]

I have seen a couple of these around here, Especially at the older universities and schools. I have a pic of them around here somewhere... If not I'll just run in and get a pic of em.

[Notre.Dame1003]

Well, I just found out today that my high school has eight, along with eight regular speakers.

[4J25]

They have those right outside Right Patterson AFB:

That looks nothing like the one I posted lol

kind of

[cauberallies]

We had a gigantic one in my former junior high school's auditorium. It was probably bigger than an actual Thunderbolt horn. I wish I would have thought to get a picture before they tore the place down. I remember going in for 7th grade orientation and seeing that on the ceiling and it just totally blowing my mind. I thought it was really a Thunderbolt! At that point(over a decade ago), I had never seen a 'bolt in person.


Apparently, it had something to do with the massive pipe organ system in there, which I also never had the chance to hear, sadly.