Questing regarding bi-amping

[BjornB17]

I'm using a UPA-7 to bi-amp my RTi10's. I have a question as to how the biamping works.

Obviously I am doing passive bi-amping as I am using the speaker's internal crossover. The electrical signal send through the wires to both sections of the speakers are obviously full range because there is nothing to filter out the low or high frequencies before they get to the speaker. With that in mind.... what happens to the lower frequency energy in the wire connected to the high frequency section of the speaker? Does the crossover dissipate it in the form of heat, or does the speaker just not draw energy in that frequency range?

Will bi-amping with 2 150 watt amp sections per speaker indeed yield a max power of 300 W per speaker, or will it still be a max of 150 W because the crossover is dissipating the unused electricity?

[xcapri79]

I'm using a UPA-7 to bi-amp my RTi10's. I have a question as to how the biamping works.

Obviously I am doing passive bi-amping as I am using the speaker's internal crossover. The electrical signal send through the wires to both sections of the speakers are obviously full range because there is nothing to filter out the low or high frequencies before they get to the speaker. With that in mind.... what happens to the lower frequency energy in the wire connected to the high frequency section of the speaker? Does the crossover dissipate it in the form of heat, or does the speaker just not draw energy in that frequency range?

Will bi-amping with 2 150 watt amp sections per speaker indeed yield a max power of 300 W per speaker, or will it still be a max of 150 W because the crossover is dissipating the unused electricity?

Essentially the speaker will draw what "it needs". The total current draw actually depends on the impedance of the speaker itself, crossover, connecting wires and internal impedance of the amplifier. This represents the load as seen by the amplifier.

The current drawn by the resistive component of this total impedance is dissipated in heat. Note that the impedance of the speaker is not a constant. It is dependent on the frequency. The impedance of the speaker will change depending on the frequencies available. This in turn affects the amount of current drawn by the speaker.

The crossovers are filters. There are different types of filters that are "tuned" to pass a range of frequencies to a particular speaker.

High frequencies are passed on to the tweeter, mid-range frequencies are passed on to the midrange speakers and the low frequencies are passed on to the woofer.

How is this done? A highpass filter represents a high impedance to low and midrange frequencies and a low impedance to the high frequencies. So effectively only the high frequency current is passed on to the tweeter and the low and midrange frequencies are blocked not dissipated.
The tweeter is a transducer that converts the electrical energy to mechanically vibrating sound energy. Not all of this electrical energy is converted into sound energy. Some of it is also converted into heat and air turbulence.

The midrange and woofers and their respective filters work in a similar manner.

Each type of speaker is designed to work properly within a specific frequency range. Actually, this applies to most electrical and mechanical system not just speakers. They are generally designed to work within a particular frequency range. Outside that range they often do not work very well.

Bi-amping essentially narrows the frequency range that each amplifer needs to provide. The midrange/woofer with their lower impedance will still draw most of the current and the tweeter will generally draw a much smaller amount. Each amp in this case will generally not be generating an equal output. Does this help?

[treitz3]

^^^excellent post^^^ ;)

[hearingimpared]

Nice write up xcapri79!

[BjornB17]

Essentially the speaker will draw what "it needs". The total current draw actually depends on the impedance of the speaker itself, crossover, connecting wires and internal impedance of the amplifier. This represents the load as seen by the amplifier.

The current drawn by the resistive component of this total impedance is dissipated in heat. Note that the impedance of the speaker is not a constant. It is dependent on the frequency. The impedance of the speaker will change depending on the frequencies available. This in turn affects the amount of current drawn by the speaker.

The crossovers are filters. There are different types of filters that are "tuned" to pass a range of frequencies to a particular speaker.

High frequencies are passed on to the tweeter, mid-range frequencies are passed on to the midrange speakers and the low frequencies are passed on to the woofer.

How is this done? A highpass filter represents a high impedance to low and midrange frequencies and a low impedance to the high frequencies. So effectively only the high frequency current is passed on to the tweeter and the low and midrange frequencies are blocked not dissipated.
The tweeter is a transducer that converts the electrical energy to mechanically vibrating sound energy. Not all of this electrical energy is converted into sound energy. Some of it is also converted into heat and air turbulence.

The midrange and woofers and their respective filters work in a similar manner.

Each type of speaker is designed to work properly within a specific frequency range. Actually, this applies to most electrical and mechanical system not just speakers. They are generally designed to work within a particular frequency range. Outside that range they often do not work very well.

Bi-amping essentially narrows the frequency range that each amplifer needs to provide. The midrange/woofer with their lower impedance will still draw most of the current and the tweeter will generally draw a much smaller amount. Each amp in this case will generally not be generating an equal output. Does this help?

Yes, thanks for the explanation!

[comfortablycurt]

Nice write up xcapri79!

x2 on that. Very nice post. That actually answered a few things I'd been wondering about myself.:)

[TNRabbit]

Excellent post there.

To add: The low frequency information going to the upper range speakers is converted to HEAT by the crossover components used for that section.

The high frequency information going to the low range speaker(s) is also dissipated as heat in the crossover but there is much less energy to dissipate in the upper frequency.

[lumpy]

so - could biamping cook the crossover in the speaker?

and what would be better:

A. use one of the two amps in bridged mode for the right channel and the second amp in bridged for the left channel.

or

B. use one of the two amps for the high posts on the L/R speakers and the other amp for the low pass posts on the L/R speakers

[xcapri79]

Excellent post there.

To add: The low frequency information going to the upper range speakers is converted to HEAT by the crossover components used for that section.

The high frequency information going to the low range speaker(s) is also dissipated as heat in the crossover but there is much less energy to dissipate in the upper frequency.

No, the high-pass crossover does not really dissipate the low frequency energy in heat, it just blocks it from actually flowing as it represents a high impedance to that frequency range. Likewise in reverse for the low-pass crossover. Therefore you do not have to worry about biamping "cooking" the crossover with the unwanted frequencies.

Every electrical device has resistive losses so a relatively small amount of this total energy from all frequencies is dissipated in heat. The main heat will come from the actual frequencies that the crossover passes. The heat is proportional to this current squared. So it you turn up the volume too high, then you can "cook" the crossover but usually your ears give out first.