This discussion should have been over after Brad's post.

When you bridge a stereo amp to mono, the signal goes to one channel; the signal, reversed in phase, goes to the other channel; and the output is taken from the hot terminal of each channel.

A BTL amp is already two amp channels, bridged!

If you design an amp that runs on the twelve volts of a car electrical system, your maximum peak to peak voltage at the output will be twelve volts (minus some diode drops and other small details). That corresponds to 4.24 volts RMS. That voltage, feeding a 4 ohm speaker, results in an output of 4.5 watts.

The classic advantage of, in fact the reason for, bridging amplifiers is that the output voltage of the amp is basically twice that of a single amp channel. That's because when one of those 12 volt amp channels 4.242 volts, the other channel goes down 4.242 volts. The result, 8.484 volts, outputs 18 watts into 4 ohms.


So what happens when you bridge two BTL amp channels? Well, if the two channels have the same signal, then the output plus of each channel tracks the output plus of the other channel; the same for the output minus.

If you then reverse the phase of the signal going to one of the amps, then the outputs of the two amps will be opposite of one another. This is exactly the output that each of the two BTLs amp already have.

So what will happen? If the amps have zero distortion, your bridged amp will work just like the amp did before bridging. If there is ANY distortion, the distortion in one channel will be fed to the other channel to correct its output when it's not the amp creating the distortion. What will happen? I don't know. It won't be an improvement over an unbridged amp.


It shouldn't. But it might.

When I first read this for some reason my mind pictured a room full of big bootied mamas. And Earnie.

I thought at first at some point Ernie had worked in an old smoke house.

Or a club that only hires bad comedians.

I just ran across a spec that ought to make us think twice before believing the specs we read.

An LG speaker bar's subwoofer is rated "360 W RMS total RMS Output Power." Its power supply outputs 25 VDC @ 1.52 A. That voltage and current represents 38 watts if we ignore semiconductor voltage drops.

Man, that is one EFFICIENT amp!

Today I found Boston butts for $3.29 a pound. I thought that was too high

Hence the term "buzz"

I wonder if they are getting the rating by measuring a short burst of signal.

With large filter caps on the power supply they might get it for a fraction of a second.

Frederick

An old stereo/turntable/tape deck combo unit with 5 watt output transistors claimed to put out 150 watts IPP. What in the... turns out it was Instantaneous Peak Power.

That was before the federal trade commission establish guidelines on how output power is measured. I am surprised that new sound bar can get away with that. Perhaps they haven't heard of the FTC… yet.

Or maybe there was a report citing a power spec of “36.0” and a clerk erased that stray stray spec of dust, hence “360”.

Edit: spelling

I'm sure buzz has got it.





No, that was you.

Couldn't resist.

Did you see anything about 360W WLS or 360W JBF?

You mean couldnt resist posting more useless information? Yeah, we know.