bridge mode etc

[CliffHarrisFan]

I am considering buying certain amps, but they have different wattages depending on if they are in bridge mode or dual parallel mode and I have no idea what any of these terms mean. Anyone offer some insight?
Thanks,
Louis.

[David1234]

This only applies to amps that have two power amp sections. This might be a bass amp with two power amps, or a PA amplifier.

Bridge mode is a way some amps "join forces" to act like one big amp. In bridge mode, your amp is mono and a bit louder. In 'dual parallel' mode, you won't get the full value without having 2 cabs connected.

Not all bridge modes work very well. If you only have one cab, consider avoiding this kind of amp. Get a mono amp or 2 cabs.

Is that a good start?

[CliffHarrisFan]

Yeah, thanks man. Great help

[Son of Bovril]

yeah Bridge mode is where you combine the two sides of a stereo amp to run as a single more powerful mono amp. If the two stereo amps each go down to 4ohms then you will only be able to run bridged down to 8ohms

most amps will be louder and more powerful when running bridged but it is also believed to run the amp hotter

[BassmanPaul]

Dual mono or parallel mono is how you can use both channels of a "stereo" power section to run a pair of cabinets. Each amp is fed the same signal and thus both cabinets put out the same. This is how I've run my system for the last fifteen or so years.

In bridge mode, each power amp channel is fed the same signal except that one is inverted - 180 degrees out of phase with each other. This means that as one channel is going positive the other is going negative by the same amount. Connecting your speaker between the hot output terminals you can obtain around four times the power of a single channel into that same load. The caveat is that you can't get something for nothing. Each amp channel "sees" half the load. For an 8Ω load each channel will see 4Ω and output its rating at that impedance. If the amp is stable to 4Ω/channel you can bridge into 8Ω. If 2Ω stable you can bridge into 4Ω.

Because the amp is working harder in bridge it will indeed run hotter but no hotter than if the amp was driving the same impedance per channel. That is to say that bridge into 8Ω will operate at around the same temperature as parallel into two 4Ω loads.

I hope this helps some what.

Paul

[CliffHarrisFan]

Yeah thanks, I ask because I saw the ampeg SVT-4 pro and got confused lol