Stereo to Mono Bridge Circuit Diagram?

[sc2_ct]

Hello,

Does anyone happen to have a circuit diagram for a stereo-to-mono bridge circuit that will handle 250W/channel? Any help would be appreciated.

[Jstas]

That all depends on the amplifier. If you already have an amplifier, look in the owners manual to see if it is bridgable and if it is, it will have a circuit diagram.

[sc2_ct]

Actually, I'm talking about the design for an external bridge, not one in an amplifier. I know that you can do it pretty easily with a couple of relays but I can't remember the wiring needed to do it, nor the relays that are needed.

[Jstas]

Um, I don't care what kind of hoopla you rig up outside of the amplifier if that power supply inside the amplifier does not support bridging of channels, you are going to break something.

Relays can help you do alot of things but they are only going to give you power switching capabilities. If the power supply in that amp does not support the common ground needed to bridge two output channels, all the relays in the world are not going to keep you from frying that power supply in that amplifier.

[PoweredByDodge]

Jstas is absolutely correct... while relays can be used to "Switch" between stereo and bridged, they cannot be used to make a non-bridgeable amp bridgeable... nor can they be used to bridge two amps together (for example, two mono amps).

the relays you may have seen in passing are simply "switches" to allow you to switch from running an amp in mono mode or to stereo mode...

take a look here
http://www.the12volt.com/relays/page5.asp#smsp

there are a few on that page -- clearly you'll see that it allows switching, but NOTHING, i repeat NOTHING can bridge an amp except its internal circuitry -- if its made to be bridged, you can bridge it WITHOUT any relays.. just jump + or the one channel to - of the other (via the speaker) and leave the other two unhooked... look up the owners manual for specifics on which + and which -...

[sc2_ct]

No no no... I'm not trying to bridge a non-bridgible amplifier, I am trying to do so to an amplifier that supports bridging. I want to use an external bridge so that I can add a switch to manually bridge the bridgable outputs from the driver's seat without having to get out of the car, pop the trunk and reach behind all the panels to get to the bridge switch. I also want to be able to do it without ripping open the case on the amplifier.

Actually, I think I can adapt the circuit at the12volt.com that PoweredbyDodge posted (well, the double-relay above the one he posted anyway) to do what I am trying.

Basically what I am doing is trying to get as much control over my system as possible from the passenger compartment (including eqalizer, bridging functions, etc...) because of the design I'm using on the trunk which will make accessing the amplifier controls a real pain in the ass.

[PoweredByDodge]

um -- why dont u just set the amp in bridged mode and leave it there??? why do u have to unbridge / bridge it from teh driver seat -- are u tryin to run two different sets of speakers off it at different times?

[Jstas]

I don't see how that is going to work since you will still have only 2 leads going to the speaker. If you are going to go switching stuff every which way, you are talking about some elaborate wiring. You are going to have to have some serious level of circuit engineering. Seems like much more trouble and cost than it is worth.

What would the benefits to this idea of yours afford you? I am have a really hard time trying to figure out what the benefits would be.