Is bi amping worth it ?

@roadcykler Wrote:

There is no objective difference using 2 amps instead of one. There are no speakers that can differentiate where electrons come from. 

See here last page BI-AMPLIFICATION. 😎

Mike

@roadcykler 

There is no objective difference using 2 amps instead of one. There are no speakers that can differentiate where electrons come from. 

While I can’t often justify passive bi-amplification’s cost, I have to disagree with your statement, somewhat.  @ditusa posted a paper from Lansing Heritage which may seem very old but some still has merit today. 

Your statement would be true IF every solid state amplifier were a perfect voltage source but they are not.  The behavior of each amp when providing current varies significantly. 

My experience with amps and speakers and as a speaker builder and investigator lead me to believe that bi-amplification could have measurable benefits. 

In my mind, the issues come from the tendency of speakers to have dips in the impedance curve, especially at the mid bass.  By dips I mean anything less than 4.00 Ohms.  I think these dips are audible, even with a typical modern SS amp with high damping factors.  I think in some cases speakers are even deliberately tuned to have a dip so they are more "discerning" of amplifier "quality." 

These impedance dips can lead to a softening of the DC voltage rails, and provide a path for intermodulation distortion to creep in.  By having a separate amplifier for the "high impedance" part of the speaker you eliminate the bass current draw from modulating the rest of the output.  

Next, there’s the issue of total power demand.  While passive bi-amping does not change the expected voltage swing of each amplifier, the current draw of each amp, and therefore the power, does get reduced significantly due to the high or low pass filter’s increasing impedance away from the crossover point. 

Having said all of that, from a pure efficiency and cost point of view, active bi-amping spanks all of those for benefits of current and power delivery.   Another approach which I feel raises the value of bi-amplification is to use flavorful tubes for the mid-treble and solid state for the bass.  You get the best of both worlds, while eliminating the impedance matching issues of tube amps.   If you put a single cap in series with your tube amp you can really get outstanding dynamic range improvements. 

Hello hardhattg !  Bi amping is worth it if you add an electronic crossover to your system along with the extra power amp. An electronic crossover lets you get a 24 db/octive (very steep) crossover that keeps the tweeter and the woofer from unwanted overlaping each other AND lets you get rid of the (generally low quality) crossovers in the speaker cabinets. It will connect after the preamp and feed the power amps. If you choose a DBX 223, you get to play with the levels and crossover points. Great Fun!  There are different models with different connectors. be sure to get the type you need.

So, open up the speaker cabinets, remove the existing passive crossover parts. Connect the woofer directly to the old terminals (if they have magnetic parts, replace with (at least) brass terminals. Connect the tweeter wires to a new pair of non-ferrous terminals. (If you experiment a lot, add a 20 mfd or larger  high quality capacitor in series with the tweeter to keep the buzz out if you happen to make any sort of mistake when the power amps are on.)  Your power amps now connect directly to the speakers, allowing their damping factor to influence the drivers, vastly increasing their ability to control distortion. The difference will delight you. (High quality cables will really show up now.) Enjoy the music.

@hardhattg 

I am a firm believer in bi-amping speakers that are designed for it. My speakers are old and not efficient, requiring quite a lot of power. I use AR9 speakers which are rated for 400 watts of power. I'm not sure how this changes if you biamp but mine are bi-amped with 2 stereo amps rated at 385 wpc @ 4ohms. I'm not really even sure if the AR rating of 400W is at 4 or 8 ohm. The speakers are rated at 4ohms with FR of 18hz to 30khz. 

When I started with these speakers, I only had one of these amps and the bi-amp feature of the speakers was using jumpers for one amplifier. It would seem that having 385wpc, should have been plenty to produce good solid bass from these speakers but I did not hear what I was looking for at all. They sounded nice but bass was not full or strong or snappy or whatever words can be used to describe really good bass. So...........I bought another identical amp and bi-amped the speakers. The difference was night and day. The bass from these old AR9's is very impressive. I have been enjoying them this way for 25 years or so. I would never take them back to a single amp.............never.

If your speakers are set up for bi-amping, I would do it in a heartbeat. There should be absolutely zero need for another crossover, which in my opinion, would just complicate things and make synergy much more difficult to find. I'm not sure how your speakers were designed but horns are much different than what I have so I can't say but listen to the experts here. Eric_Squires for one. For me, two amps that are exactly the same, has worked extremely well. Your horns may require or work well with something completely different, I do not know. I know there are some large speakers made with a large power class D amp to run the woofers and they suggest that the top end can be run with very low powered SET types. Would not work for mine but it's all in the design. Best of luck but I'd suggest trying bi-amping for sure. You can often try components for 30 day with satisfaction guaranteed. There is no risk and I think you'd be delighted with what you hear. It will give you the best that your speakers have to offer as they were made for this.

@erik_squires Oops, Sorry to screw up your name.