Conference napalm::guitar

    The crossover is rated at 100W (it's a Radio Shack job, so that's
    probably about 70W in reality ...).
    
    The power amp I'm using will be a 60W job.
    
    A 4ohm load wouldn't hurt the amp any ...
    
    Scary

    Electrically, tapping at the output of the crossover or at the speaker
    terminals is identical...????  Did I understand you correctly?
    
    Assuming your drivers are all 8 ohms, the crossover will see 4 ohms at
    each tap.
    
    							Brian

     Scary, I hate to tell you this, but you can't do that without
     having major problems.

     For example, if you had an 800Hz 6dB/oct 8 ohm crossover,
     it would consist of a 1.6mH inductor (L) and a 25mf capacitor (C)
     If you could graph its response, it would look something like
     this:
     			      800Hz
     ---------------------------  -----------------------
     	  Bass			\/ < 3dB down point
     	8 ohm spkr		/\	
     			       /  \	Treble
     			      /    \    8 ohm spkr


     If you put a 4 ohm load across the same crossover, the response
     would be somewhat different:

     		     400Hz		      1600Hz
     -------------------		         ---------------
     	   Bass		\	Midrange	/  Treble 
     	4 ohm spkrs      \        is   	       / 4 ohm spkrs
     			  \   essentially     /
     			   \   wiped out     /

     Inductor and Capacitor values are selected according to speaker specs,
     cabinet design, nominal load impedance, required rolloff: 1st, 2nd,
     or 3rd order, i.e. 6, 12, or 18dB/oct slope 

     Hope this helps :^)

     Neal     	

    That's what I'm saying. perhaps a picture would help make my point
    
                                  
            + --------------- +  /
    C   High                   ||  Tweeter
    R       - --------------- -  \
    O                             
    S       + --------------- +  /
    S   Mid                    ||  Mid range driver
    O       - --------------- -  \
    V
    E       + --------------- +  /
    R   Bass                   ||  Woofer
            - --------------- -  \
        
    	Electrically, aren't the speaker terminals considered the same
    "node" as the crossover (output) terminals ? If a jack were connected
    in parallel with either the crossover terminals or speaker terminals,
    wouldn't the result be the same ? There is a piece of WIRE connecting
    the terminals together. How could they be differant electrical nodes ?
    
    
    Mark

    Seems to me (spoken by the guy that has to look at the diagram when
    putting batteries in a flashlight ..) that I could jumper off the
    speakers, going positive to positive, etc, and still be OK.  Lemme know
    guys, 'cuz I wanna try *something* in a little while after I "get up" -
    no smart remarks ... I'm a 3rd shifter !   8^)
    
    Scary (who's up but really doesn't know why ...)

    
    	I understand what you are asking, Mark, and the answer is
    	no. Because the whole operation of the crossover is determined
    	by the LOAD impedance on each leg of the filter, not what the
    	amp sees at the input of the crossover. You can determine what
    	the amp sees at the input of the crossover if you were to
    	design a 4 ohm crossover. In that case, the value of the cap
    	doubles, and the value of the inductor is cut in half...for
    	each leg. 
    
    	Rat Shack crossovers are overrated power-wise, and saturate
    	much too soon when pushed. The thin copper wire in the coils
    	is the problem. You can tell when a shi++y crossover starts
    	to crap out when the mids and highs fade when the band is
    	cranking and mysteriously comes back between songs when your
    	lead singer is just talking to the crowd. It's because the
    	bass speakers suck alot more power to reproduce the lower
    	frequencies and the mids and highs suffer. If it's only a
    	6dB/oct crossover, you may be getting alot more low end into
    	the mid and high drivers than they can handle, even if you
    	can't exactly hear it. 2nd order (12dB/oct), and 3rd order
    	(18dB/oct) crossovers have sharper cutoff rates to keep things
    	safe. Big coils made from 16 or 14 gauge wire, and 250 volt caps
    	in a crossover makes saturation less likely, but are still
    	inefficient. You can lose ~20% of the power available. Also
    	a pad, or an attenuation network, is needed at the mid and
    	high outputs of a crossover to balance them with the bass cone
    	driver, which isn't as loud. L-pads are available at RS for
    	this purpose.
    
    	Neal
    

    I fixed my problem - I bought another crossover and wired it right ! 
    Now, I'd like to wire in a couple jacks so I can jump from 1 cab to the
    other.  Do I just put jumpers off the "input" jack (pre-crossover) to
    the second (out) jack ?  Sounds good to me, but ....
    
    Scary

    
    	Re .7
    
    		Yeah, but use 16 gauge wire or better.
    
    	Neal
    

    You guys be patient with me, OK ?
    
    Rat Shack sells "closed circuit" jacks (?) and "open circuit" jacks (?)
    
    Which kind do I need ?
    
    Scary (who's learnin' ...)

    
    Open circuit.  Closed circuit jacks are used in things like headphone
    jacks, inserting the plug into the jack causes a switching action (like
    turning the speakers off on a stereo).  
    
    							Brian