Unlike the vast majority of fellow experienced DJs, i have no idea what bridging is, how to do it, and what benefits/disadvantages it gives you.

If anyone can help in explaining it to me i would be very grateful.

When you bridge an amp you turn it in to a mono-bloc. i.e. one channel.

So if you want stereo you need 2 amps. Mono bloc A would run to your left speaker and B to your right.

A situation where someone might bridge is if they upgraded speakers and the current amp wasn't really driven them properly. You could purchase another (would need to be the same) and mono bloc to squeeze more performance out of the speaker.

Quite often people will run bass in mono. I have a huge Martin sub that's used on it's own, initally run in mono with bridged PV1500.

Commonly the mono or bridged mode is doubled the 4ohm single channel output.

On my amps (Ramsa - which are made by Panasonic/Technics) theres a switch at the back that offers Stereo/Mono/Bridged.

There are huge warnings in the manual about NOT selecting bridged mode unless you really want it, and know that the speakers will cope.

DONT TRY THIS - BUT Simplistically, bridging is IN THEORY a method of joining the outputs from the two halfs of a stereo amplifier to give a single output. Dont try this with just any ol' stereo amp. Only amps which are designed/expected to be bridged, so that the two parts are properly balanced to work in a true "push-pull" fashion.

Interestingly, bridged amps are usually capable of producing more output in their bridged mono mode, than the total of their left and right sub-totals.

EG: Heres a spec from an amp that I found quickly via Google for this example:

The amp is capable of:

280 + 280 watts @ 8 ohms stereo
450 + 450 watts @ 4 ohms stereo
700 + 700 watts @ 2 ohms stereo

But (wait for it, wait for it...)

900 watts @ 8 ohms bridged
1400 watts @ 4 ohms bridged


As you can imagine, (wiring aside), if you accidently knocked your amp from STEREO to BRIDGED in transit to a gig, your speakers might never forgive you...

Bridging is not some thing that you can do with two seperate amps, and I don't suggest anybody tries to connect the speaker outputs of two amplifiers together .

"Bridge Mode" is basically available on some power amplifiers to combine the two left and right channels together to make one powerful single channel, with the combined output into an 8 ohm load.

For instance you may have an amplifier with the following specs

2x 150 Watts RMS into 8 Ohms
2x 250 Watts RMS into 4 Ohms
Bridge Mode 500 watts RMS into 8 ohms

This basically means that you can obtain the full output of both channels running into 4 ohms, but in a 8 ohm load - so less speakers!. The draw back, is that with both Left and Right Channels together, then the system is working in Mono, so you lose that nice clean stereo sound that you usually get. The only advantage to this, is to use an Amp in bridge Mode to drive a single high power bass cab. Since Bass Bins and subwoofers do not need or rely on a stereo image.

Three full answers in what? about 15 minutes...thats forum community spirit working at its best.

The use of a pair of bridged amps is also common with "audiophiles" looking to squeeze more "control" out of their speakers.

Quite a few manufacture sell dedicated mono-blocs.

Once again, loads of helpful advice given, Thanks.

Just to change the subject a little, i have been told that if i daisy chain my speakers (one cable from amp > speaker > 2nd speaker) this will give me 4ohms output, is this true? Or do i need to connect 2 cables into the back of the speaker for one channel?

Assuming that theres no "unusual" wiring on the rear of the speakers...eg: Your speakers have got a pair of 1/4 inch jack sockets, or Speakon connectors on them, then yes... In the following set up

8 Ohm speaker <- 8 Ohm Speaker <- AMP -> 8 ohm Speaker -> 8 ohm speaker.

..The amp would see a 4 ohm load on each side (Left / Right)

Andy, there are 2 jack sockets on the back of two speakers. The speaker came with one 1/4 jack socket and the shop where i bought them put another one in for me to enable me to daisy chain them.
Is there problems with this? If there was only one jack input on the speaker how would i be able to daisy chain them?

Back to bridging for a sec, does bridging make the amp work more and deteriorate it quicker?

You should be okay if the shop have daisy chained them for you, basically this just means that they have fitted a 2nd socket and wired it across the existing one.

If your amplifier has 2 speaker sockets for each channel then you can connect a speaker to each socket. Or if you have a speaker with two sockets fitted then you can plug in one lead from the amp to the first speaker and then connect an additional lead between the second socket on your first speaker and plug this into the second speaker. If you choose this method then make sure that the cable between the amp and 1st speaker is adequately rated , I recommend using twin core flexible cable rated at 10A - 20A depending on the output power of the amp.