Why does bi-amping speakers sound better?
Depending which directions the channels are sent cancelling out more crosstalk between a pair of channels. Not having to push a single amp into distortion is one other reason things will sound better, two amps may have better control over the speakers if just one wasn’t quite inadequate. Variable gains are helpful here, thats one thing I will consider if seeking a second amp. |
http://www2.rdrop.com/users/twest/audio/index.html As discussed extensively below, the solution for the first two issues an active vertical biamp combined with low impedance cabling. The second two issues are addressed by balanced interconnects and reducing power amplifier gain—one of the odd things about audio is preamplifiers don't actually amplify. They attenuate. Line level out of a CD player is a few hundred millivolts RMS, but typical voltages at the drivers are maybe 100 mV RMS. In order to achieve a couple hundred watts of output power, power amplifiers have voltage gains around 30 dB. The preamp therefore ends up attenuating by 50 dB, meaning RMS voltages in preamp output stages, active crossovers, and power amp input stages are hundreds of microvolts. This exacerbates pickup of ground bounce or supply ripple coupling into power amp input stages and degrades op amp performance. The fix is simple; turn the power amp down and the preamp up. In an active biamp, unity power amplifier gain generally provides sufficient SPL and increases the SNR of most parts of the signal path by 30 dB. A secondary benefit is op amps behind the preamplifer's volume control operate closer to their line level sweet spot. With current generation op amps such as the LME49740 the benefit is small compared to speaker and power stage limitations, but there can be noticeable improvement in the volume control IC or with older op amps.
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audioman201581 posts02-10-2017 9:16amIn bi-amping, each amplifier drives a less complicated load. The drivers along with the crossover components have a complex impedance. It consists of a real load and then the imaginary part based on inductors and capacitors. This complex load also varies depending on the frequency of the signal. So if you have a 2 way speaker, the complete load a single amp will see is driver1+driver1 crossover+driver2+driver2 crossover. This is a much more complex load that the amp sees vs just driver1+ driver1 crossover. Theres less complication by eliminating the passives it also equates to zero heat being generated within them relieving that much more strain from the amplifier. If the speakers have large complex crossovers with 1-3 big coils and 4-5 big caps you could be freeing up a good percentage of power that can then be routed directly to the drivers I had once put together a small 30 x 4 channel Nad w Ashley pro crossover used to power some rather large mediocre efficient home made speakers, it did a fine job. Around $500 bought quite a lot of fun |
I will whole heartedly agree that bigger doesn't always mean better, even given amps are similar build and quality. Or that biamping is your ticket to sonic heaven. Everything has to have that "magic" brew and work together. Amplifiers have sweet spots also, and seem to sound very best in specific ranges. I hope that old all power amps sound the same argument doesn't resurface. |
