Multiple amps in same freq band

You could buy one of these ultra link from Beringher

Just to quickly add to what has been said, because almost always the links on amps are simply paralell splits this means that if you use an unbalanced connector anywhere between any of the amps then the whole chain will be unbalanced.

Connecting many amps to one output shouldn't be a problem, for example the output impedance of the Behringer DCX is 160 ohms, the input impedance of an MC2 E series amp is 20,000 ohms. If you connect 12 channels of amp to the one input you still have a load of more than 10 times the output (1666 ohms) you could in this kind of case send this signal down a long multicore without problems too. Following this 'ten times is a good number' rule then you have a theoretical safe maximum of 72 channels of amp that the DCX is capable of driving. I think this is conservative though.

The only time there may be a problem is if you were using completely different amps and one had an imput impedance of say 20k ohms and the other was 2k ohms, in this case the amp with the 2k ohm input would get a larger proportion of the signal, but the difference would be very small unless a very large number of amps were being used or a high impedance output (with inherantly poor line driving capability) was used.

One thing I've been thinking of would be the case of driving similar cabs with different amps.

Let's say I'd use a Proline 2700 in 4ohm bridged to drive two 1850 horns, and say Tapco J2500 to drive another pair of 1850 horns in 4ohm bridged.

Now how does this affect their coupling? Different amps may have really different damping factors and all other values.

this may have more to do with gain structure than frequency.If you go to Rane.com rane notes you can find out how to make up cables.

note that not all amps are the same sensitivity. some give full output from 0.775volts of input some from 1.4volts and there are some other odd ones in between. Quite a few amps have a "sensitivity" switch on the back or sometimes an internal jumper. Make sure they are all set the same or one amp of the same power may be quite a lot quieter than another.

Id also like to point out that there is no such such thing as a stereo jack plug! occasionally people attempt to put two channels through a balanced jack plug but this is not as god intended and should be avoided.... a bit like using XLRs for speakers. LOL let the flame grilling begin ;-)


Edited by demanddeepbass - 04 March 2009 at 3:44pm

The Jack Plug is one of the most misused connectors going. They get used for unbalanced stereo signals, unbalanced mono connections, balanced mono connections, headphones, loudspeaker connections, insert points and occasionally even power connections. All of which causes huge amounts of confusion. Can you imagine what would happen when Johnny guitarist plugs the speaker output of his 3000watt guitar head into your lovely Midas mixer? It's probably similar to what happens when you swear at him pull the plug out and drop it on the metal stage when it shorts, gives him a shock and blows up his amp.
The point is you are never quite sure what is on the end of a jack cable unless you can find the other end which sucks. The same used to be true of XLRs to a lesser extent till the speakon came along. Thankfully XLRs on speakers are very rare now. (although 3 pin XLRs for DMX are much more common now (this is due to lazy lampies not bringing enough 5 pin cable to the gig and wanting to steal your mic cables for DMX))
Professionals should use balanced or unbalanced 1/4" jack plugs with line level signals on them. If its a patch panel it probably makes sense to use a B gauge jack. Putting unbalanced stereo down one cable just causes confusion. If you plug it into a mono balanced input the CMR amplifier will probably null most of the signal. One exception with 1/4" jacks (which is by convention and irritates me greatly!) is headphones. Another (which is an irritating desk manufacturers cost saving measure) is unbalanced insert points.
This is all perfectly clear in my little OCD world and should be in everyone elses!

/end rant.