Is bi amping worth it ?

OK folks. Listen up. Here's WHY active crossovers are so very much better than passive. A single loudspeaker driver is an inductor, and provides a frequency dependent, reactive load to an amplifier. Looking at the image here, the blue line on the bottom is the frequency dependent impedance curve for an SB Acoustics SB29RDAC Ring Dome Tweeter, and it typical of any dynamic tweeter. As you can see, it is anything but flat, yet it is listed as having a 4 ohm impedance. It's 4 ohms at about 1200 hz, but at 600 hz, has an impedance of nearly 10 ohms.

Now if you put a passive crossover circuit in front of it, you add capacitors, resistors and inductors, which then give you a frequency dependent impedance curve which looks like a Coney Island roller coaster. And that's just for a tweeter high-pass circuit.

Now when you add in mid and bass drivers, with high and low pass filters there... It's a real mess. But we're not done there yet. Nope. Many of your extreme hi-end loudspeakers add in equalization to their crossover designs, which makes that impedance curve even worse. This is very hard for an amp to properly manage. That's why people drop many, many thousands of dollars on things like Krell, Threshhold, Bryston, or Rowland Research solid state power amps.

Now when you use an active crossover, an amp channel only has to manage a single driver. There's no passive, reactive component in between the amp and the loudspeaker driver. Then you don't need a megabuck amp to deal with it.

All of the Linkwitz loudspeaker designs use active crossovers. Earlier designs used analog crossovers, but his last designs were all digital crossovers. There are some digital crossovers that offer DSP EQ, which allows you to tailor the total system response for the room you are in. Then you're not just limited to whatever sound your speakers give you in the room you're stuck with.

The lowest cost active crossovers are typically pro grade, from manufacturers like Behringer, dbx, Rane or even Nady. There are many manufacturers. Some of the best known home audio digital crossovers are from miniDSP.

Another major benefit is that you can use much, much lower powered amps when you use active crossovers. A lot of power is wasted having to push through a passive crossover. You really don't need to push many watts into a tweeter or mid-range driver to get a lot of level out. You could even run a single ended tube amp on your tweeter, and a mid-level tube power amp on your mid-range driver, and a solid state amp for the bass driver. You have a lot of options.

So instead of dropping the Big Bux on some gigantic extreme power amp, you could spend much less on an active crossover and the various much more modestly priced amps of your choice.
 

@russbutton, 

Mike

This is a very interesting thread and good points have been made.  Everyone should try to understand what @russbutton posted.  Bi-amping is complicated.  I owned a pair of bi-amped Bozak Concert Grands for several years and can attest that everything he said is true for those and most traditional or older designs.  It is nevertheless true, however, that there are modern designs where sophisticated passive crossovers have been built that take all of the variables into account.  With these very sophisticated designs there would be no benefit to bi-amping.  So while it can be agreed that generally bi-amping can improve the sound of speakers, that is not always true and we should be particularly cautious of messing with newer, more sophisticated designs where that might not be so.   

Step 1: Connect the preamplifier outputs

1. Run the first pair of interconnects from the preamplifier’s Left Pre Out 1 and Right Pre Out 1 to the input jacks of the two McIntosh 601 monoblocks.
2. Run the second pair of interconnects from the preamplifier’s Left Pre Out 2and Right Pre Out 2 to the input jacks of the same two McIntosh 601 monoblocks.
   This will feed a full-range signal from your preamplifier to both amps for each channel, which is required for passive bi-amping. McIntosh recommends using balanced connections if possible for the best performance. 

• this won’t work ? 

This looks like an AI hallucination.

@russbutton  

I read in your comment above with your sentence included below and I wish I was smart enough to fully understand what it means. It’s a very important statement and wondered if you could explain the relationships of the amounts you’re including here.  Thank you

Passive crossovers built into speakers would seem to conflict with biamp efforts when crossover Control devices are added between the speaker and the amplifier when biamping is done.  Unfortunately most speakers are not stripped of crossovers built-in to speakers before people biamp.  I like biamping because it results in dedicated signals going into each Area of the speaker as well as dedicated power supplies and that’s a big step forward in my opinion.

”its 4 ohms at about 1200 hz, but at 600 hz, has an impedance of nearly 10 ohms”.