Originally Posted by lovinthehd
Originally Posted by stereoforsale
Guys, I'm new to this thread. I'm eager to learn and I'm very confused. I am passively biamping and have read many articles and posts against it. Anthem's website however, clearly states that this is all a myth. Passive biamping does work, and active biamping is not recommended. I'm not a technician by any stretch, but what the anti-passive-biamp camp does not realize (according to Anthem) is that when you passively biamp, the impedance is signficantly increased and therein lies the advantage. Meanwhile active biamping messes up the carefully designed crossover of any quality speaker and will likely reduce performance. I tend to believe the experts at Anthem, but I do the potential motivation of encouraging people to buy additional amps to boost sales. To put this debate to bed, has anyone, or any reputable magazine, actually tested this??? While judging sound quality may be subjective, I assume you can certainly test if passively biamping gives more headroom.
Just to make it easier to refer to, here's what the faq on Anthem site says:Doesn't passive biamping waste the amp's power because each channel still has to amplify the full range signal and not just the highs or the lows?
No. With the jumpers removed on a biampable speaker, the impedance of each section is not the usual 4 or 8 ohms, but several hundred if not more at the frequencies that the amp is "not supposed to be amplifying". Higher impedance means less current draw. No meaningful amount of current, no wasted power.
Anthem appears to be propagating a myth claiming that anything that reduces the load on an amplifier reduces its audible distortion. That is not true.
According a recurring audio-myth, only an active crossover should be used for biamping, in order to split the band before the power amp instead of inside the speaker, thereby reducing the amount of work each amp channel has to do. While active crossovers do have their place in PA systems, it should be noted that equalizers are also a part of it.
Anthem appears to be propagating a myth claiming that anything that has an equalizer in it is a bad thing. That is not true.
A generic active crossover on its own merely divides the audio band into smaller ones. The carefully custom-designed crossover in a high performance home audio speaker does a lot more. It is responsible for correcting frequency response aberrations of the individual drivers, maintaining phase coherence between drivers, optimizing off-axis response, balancing levels between drivers, setting up impedance, at times improving woofer performance by rolling off not just the top, but also frequencies that are too low and cause it to misbehave, and other things that vary according to model.
Anthem seems to be contradicting themselves by now glorifying "correcting frequency response aberrations of the individual drivers, maintaining phase coherence between drivers, optimizing off-axis response, balancing levels between drivers, improving woofer performance by rolling off not just the top, but also frequencies that are too low and cause it to misbehave, and other things that vary according to model". Those are all things that one does with equalizers.
Tearing out the speaker's own finely-tuned crossover to replace it with an active crossover with generic controls almost guarantees that, just for starters, frequency response will be altered. Different sound doesn't mean better sound. Using the passive crossover in the speaker is indeed the correct way to biamp.
Anthem appears to be demonizing people all who convert speakers from passive to active crossovers by faulting them for being technically incompetent and not performing required engineering steps.
(What's biamping? It's using one amp channel for the speaker's mid-high frequency drivers, and another for the low-frequency drivers. The speakers must have separate inputs for this - be sure to remove the jumpers from the speaker inputs first or amp will become instant toast! If one amp starts running out of power, usually the one driving the woofer, then the other side remains clean instead of becoming part of the problem, a double-win. This is the very idea behind bass management and powered subwoofers in home theater systems.)
Anthem appears to be misleading people by obfuscating the fact that passive biamping requires both amplifiers to amplify both low and high frequencies.
BTW, here's a link to Anthem's faq:
I chased some other links on AVS and they now appear to be broken.
No place in this FAQ does it appear that Anthem admits to the fact that passive biamping introduces the risk of the low and high portions of the speaker not being properly driven in perfect balance, or that if you make an error while setting up the wiring for passive biamping you may short out amplifier channel(s) with the resulting possibility of damage to the amplifier.