Ok, I know this is probably a stupid idea, but what would happen if i bridged my 4 HU channels to power two 8 ohm speakers? Will it even bridge (won't it have to invert the channels or something?)? Will it fry (my guess)? Also, i heard that many/most modern HU's are already pre-bridged (8 channels bridged to 4), is this true?

Don't tell me just to get an amp or whatever, i just wanna know if this will work .

 

won't work... any "high power" head unit is already bridged (so anything with a +,- wire for each speaker.. common ground head units could in theory be bridged but you'd have to find a way to invert say the rear channels to be able to bridge with the front... even in that case you wouldn't get as much power as a single "high power" head unit channel

 

How do you bridge common ground HUs? I have an old HU (15x4 with common ground for all channels) in my shop for tunes while I work, and I only use two channels. More power would be nice if possible, so if bridging is possible I would love to know how.

 

you can bridge 2 channels into one speaker with isolation transformers.

 

Okay . . . how exactly?
How are isolation transformers different from regular transformers?

 

isolation transformers have a 1:1 ratio

Regular transformers either step up or step down voltages.

I dont see why regular transformers would not work since transformers are close to 100% efficient.

With 2 transformers you wire them in parallel to the speaker , and connected to the speaker leads of each channel.


the same as you would a 2 way crossover with 2 wires in and 2 wires out.

On this page is an example of the 2 transformer principle enclosed in a single unit.

http://www.lashen.com/vendors/CSISpe...ansformers.asp


The downside of transformers is you loose some low end response because of the induction of the windings on the transformer.