How to do a two-way with Radian 850PB without a L-Pad and without going active?

uh oh

Well there is no real alternative to the resistors,unless you get really crazy with horns and a kadrillion of drivers.This is why your compresson driver is rated at 50w and your matching woofer is rated at 300w in a PA setup.
The problem with l-pads seems to me not be the lost energy but the dulling of the overall sound,due to inductance.....
Just wich other driver did you have in mind to go with your Radian by the way?
 
I stumbled into a solution for my speakers. It is to use 2 amps, each with a volume control. Don't discount this because it uses 2 amps! No active crossover is required- so technically it isn't active ;) and your horns are so efficient, that a cheap tiny amp such as a gainclone would be plenty. These only cost about $100 if you are clever!
Or maybe one of those tube amps with say 3 watts of output if you are a bigger spender!

The crossover network you would normally use is really a set of filters, so they can be used separately.

I hooked a gainclone from Brian GT with a volume control, to the bass crossover, and connected that to the woofers.

I then used one of those Sonic Impact digital amps connected to the tweeter crossover (and eventually , the tweeters) It also has its own volume control.

I connect the two amp inputs to the output of my CD player with just a "Y" connector.

Yes, I have to adjust the bass relative to the treble whenever I adjust the volume, but it is actually pretty easy to get right, and convenient to be able to make the bass relatively louder at low volumes. This is what a "loudness" control is supposed to do , but mine works better!

If you have a preamp, then you could use the "Y" connectors at the output. Then send one of the outs of the "Y" connector to each of the amps. Only one of the amps would reqire a volume control, and it would only really need to be adjusted once to get the relative volumes right.

Some might dislike the extra pot in the circuit or the less input impedance of the two amps together, but it works great for me!!

I had the same situation as you have- my mids and tweets were way more efficient than my bass drivers.

I used an L-pad at first on my mids and tweeters and it got quite warm and the sound wasn't great at all. With the 2 amps- it sounds GREAT!!

EDIT: The Sonic Impact amps sell for about $30 . The sound quality is pretty shockingly good. Guive 'em a try. Partsexpress.com has 'em
 
I want to know if it's possible to do a two-way speaker system with a Radian 850PB without using a L-Pad and without going active.

This is easy.

Get six Lambda TD15 woofers with faraday motor and wire
them in an array to get about 110dB sensitivity.

Get the woofers here;
http://www.aespeakers.com/phpbb2/index.php?sid=5be7c14d2c0d60a4051ab757900923a8

Price is $279 for the first woofer, $179 for the rest. That is his current pricing method as of today.

You will get crazy good sound quality with those woofers in a 2 way,
they play up to 2khz clean so any low pass under 2khz is easy.

You can save money if you use two TD15's, with an active setup
using two amps so compensate for the sensitivity difference as
those woofers can handle about 500w each.

I think four TD15 would be nice with a center horn.
http://home.pacbell.net/lordpk/lambda/majestic ladies.JPG

I think that picture has four 15" passive radiators in the rear.

or

http://home.pacbell.net/lordpk/lambda/pspkr.jpg