On Thu, 5 Feb 2004 16:20:26 +0100, "Meindert Sprang"
wrote:

"Larry W4CSC" wrote in message
...
Never, EVER connect two transistor amplifiers in parallel......


snip large story

Actually, in high power car systems, they do exactly what you just said that
cannot be done. In such systems, each channel has two amplifiers, carrying
the signal in opposite phase. The speaker is connected to both outputs. This
way, the maximum voltage that can be created across the speaker is doubled.

Better look closer. In "Bridged" mode, the amplifiers are in SERIES,
not in parallel....

There are four 200W amps bridged into 2-channels at 400W each in my
stepvan. These power two 12", 3-way speakers mounted to swing out on
either side of the back of the van on the full-width swinging rear
loading doors. They'll even turn around to the sides pointing the
speakers in opposite directions, if the job necessitates. Two more
speakers, massive JBL pro-sound speakers where even the 15"
bass-reflex woofers are mounted in horns, re-juvenated last year with
600W Eminence Kappa 15LFA beasts, the biggest that would fit into
these cabinets, are wheeled to go on either side of the truck, making
a wall-of-sound DJ machine I rent out to parties, car lots, anyone
needing independently-powered music/PA. A nice DJ mixer board
completes the system, powered from a 500W Tripplite inverter.

It all runs off 700AH golf cart "house" batteries I can separate from
the truck starting batteries for 12-14 hours of battery-operated
continuous music without running an engine or genset. The Honda
EU3000is 3KW inverter-technology super-quiet genset comes on to
recharge via the now-surplus 40A charger off the Amel Sharki ketch my
captain gave me.

It's all legally licensed by ASCAP and BMI to play their entire
portfolio, most of the music you hear.




Larry W4CSC

No, no, Scotty! I said, "Beam me a wrench.", not a WENCH!
Kirk Out.....