OK, you wanted a 'cheap' one. It ain't gonna get much cheaper than this!!!
Real, Old-School, 'Rah-Rah-Rah' sound system. An original, old fashioned Megaphone.
Features:
- Very easy to use
- Built-in support structure (handle)
- Polished Input Channeling Port System (mouthpiece)

Specs:

# of input channels: 1 small one
# of outputs: 1 Big One
Type of outputs: Diaphragm driven
Mode: Mono (if you want stereo, you'd need two)
Type of signal path: Analog
Digital capabilities: Yes, you can speak numerically thru it
Watts: I dunno, how loud can you yell?
Throw: Again, how loud can you yell?

Great for public speaking, announcements, soap box speakers, stressing your point more efficiently at town hall meetings, street sage, unruly children, getting the attention of the person in the front seat, ordering more wings at Hooters, manic gatherings of like minded people, monkey taming, delivering your resignation notice, requesting the attention of inattentive wait staff, dork alerts, delivering explicit instructions to employees more effectively, 'Soft / low Talkers', 8-year olds, poet laureates, more efficient communication with bill collectors and telemarketers, dog park, malcontents, PTA meetings, requesting another beer from 'the little lady' in the kitchen, herding cats, karaoke during power outages, 'dandy's and floozy's', requesting "more salsa" at your favorite Mexican restaurant, 'World Topless Day' parades, inciting general mayhem and of course any time you need a really large funnel.
Measures length 29" x 2.25" at input and 12.75" at output and weighs 1.5 lbs.
$89.