Passive X-over

My system will consist of a Rockford 851s powering an adire shiva 12 utilizing the on-board crossover.

I am using an 851x to power 2 midrange, 2 mid bass, and 4 tweeters with the combination of the on-board x-over and caps / coils. My questions are...

1. Should I wire the midrange and tweeters to the "front" portion of the amp and the mid bass alone on the "rear" or should I use a different configuration?

2.  Should I match the crossover impedence to the speakers or to the overall impedance per channel? Currently, all my drivers are 4ohm.

Any other suggestions are welcome...

Thanks,

Gary

1.  You could do this, it's up to you.  I'd simply build the proper 3-way Xover and use two channels of the amp.

2.  Design your crossover for the impedence of the drivers.  Choose your X-points, then determone the proper cap/coil values based on the total impedence load of the drivers you are using.  A properly designed x-over will never let the amp see less than the impedence of one speaker at a time.  BEWARE of using two tweets (for a total 2-ohm load) and 4-ohm mid & bass.  The tweets will be at a higher relative volume level since they will present a lower impedence load.  You will need to incorporate attenuating resisters to adjust for the excess brightness.  I also recomend using a zobel network across your bass driver.

Thanks DYohn, can you tell me about the "attenuating resisters to adjust for the excess brightness".

Gary

Here's one of the best tutortials I know about.  Attenuation is discussed in this. Be sure to use good quality components in the X-over, not cheap stuff from Radio Shack.  Use audio grade, especially for the caps.

http://sound.westhost.com/lr-passive.htm

Cheers!