Detailed explanation of Bi Amping?

[Bassmister]

I have Emotiva XT3 Towers and XC1 center.

I have a Onkyo RZ70 receiver

I have dual Klipsch RP 1400SW subwoofers.

A review on YouTube said that these speakers need more watts than traditional speakers because they are 4 ohms.

So I looked for amplifiers and found the Fosi V3 Mono. After reading the review it delivers 200w of actual power to the speakers. So with 3 amplifiers I could power my front speakers. Then I became curious about Bi Amping. Most people say it doesn't do anything and some say it helps deliver more clarity. Because Fosi V3 are inexpensive I bought a single Fosi v3 with a 5A power supply and I bought dual Fosi v3 with a 10A power supply to power to blocks.

I plugged the amps in and so far I'm impressed with the sound.

I have a RCA Y splitter from the preouts and then connect to each bi amp port on the speaker.


Two amps are connected to one power supply and each amp is connected to a high frequency terminal and low frequency terminal. The amps then provide 200w to each terminal.

I read that bi amping won't make a noticeable difference. So I'm asking would a single 500w amp sound better then dual 240w amps?

 

[sam_adams]

Read both of these articles by Rod Elliott:

Benefits of Bi-Amping (Not Quite Magic, But Close) - Part 1

Benefits of Bi-Amping (Not Quite Magic, But Close) - Part 2

Then come to your own conclusions as to whether or not it is worthwhile.

 

[Wolf11Man]

There are people that promote bi-amping, while others call it waste of money. Both are right in their territory
If you have a pair of modern, well build stereo amps of decend power, these will not care to drive a tweeter and a woofer over a passive crossover. So no advantage, but also, no disadvantage I may add.
In the past, when amps were not that solid and powerfull, it may have been audible better to have tweeter and woofer driven by separate amps.

This will get more understandable, with an example. Take a 12 Watt valve amp, which is quite a lot of power from that principle, and connect it to your usual 2-way speaker. Compare that to a 50 Watt amp for the woofer and the valve amp only driving the tweeter. The difference will be audible, as soon as you turn up the volume and play some more demanding music than elves voices with harp sounds.

This may also be true if the speaker has a very complicated passive crossover. These can put some unfriendly load on an amp that is not unconditionaly stable.
Many AVR's offer the option to redirect unused channels for bi-amping. I tried this may times, the result was just not audible, even as I expected much more or at least a tiny advantage. So maybe do your own testing.

 

[Mnyb]

Biamping makes sense if you remove the passive filter and go active so it usually just a gimmick on passive HIFI speakers , possibly it sells more speaker cables …..
It always makes more sense to buy one bigger and better amp , gives even more headroom when needed.

You have a possibility to actually get less fidelity, amp for treble bass and mid must *realy* have the same gain , in consumer amp territory whith fluid and variable specs . I would possibly only trust the same brand and same model bought at the same time to actually have the same gain . Unless you have the means to measure it.

 

[JeremyFife]

Very short answer - no, there is no benefit from bi-amping. Read about it, from an electrical engineering point of view not a subjective one.

Think about two other things;
High frequencies need less power than bass - those Watts are completely redundant.

Here's the one I'm not so sure about... lower resistance (4Ohm Vs 8) needs *less* power not more. It does require more current though - which is what causes some amplifiers difficulty and makes low resistance loads hard to drive. I need to read up on the details of this myself!

Simplify your set-up, remove redundant equipment and focus on what makes a difference. Less to go wrong, fewer cables, just easier all round.

Enjoy the music

 

[Old_School_Brad]

One advantage, perhaps the only one, is that using an amplifier for each speaker can address issues with poor channel separation. However, the amplifier would have to be exceptionally subpar for this to have any noticeable audible impact.

 

[quattro98]

Here's a good article about biamping on ASR. This includes a section on passive biamping with a nice summary.

Bi-amping 101

This article provides a quick look at how bi-amplification works. The conventional scheme is to split the signal into two frequency bands before the power amplifiers that drive the speakers. The bass (LF) amp sees only LF signals and drives only the LF driver (woofer). The treble (HF) amp sees...

www.audiosciencereview.com

 

[Brutus6844]

There are people that promote bi-amping, while others call it waste of money. Both are right in their territory
If you have a pair of modern, well build stereo amps of decend power, these will not care to drive a tweeter and a woofer over a passive crossover. So no advantage, but also, no disadvantage I may add.
In the past, when amps were not that solid and powerfull, it may have been audible better to have tweeter and woofer driven by separate amps.

This will get more understandable, with an example. Take a 12 Watt valve amp, which is quite a lot of power from that principle, and connect it to your usual 2-way speaker. Compare that to a 50 Watt amp for the woofer and the valve amp only driving the tweeter. The difference will be audible, as soon as you turn up the volume and play some more demanding music than elves voices with harp sounds.

This may also be true if the speaker has a very complicated passive crossover. These can put some unfriendly load on an amp that is not unconditionaly stable.
Many AVR's offer the option to redirect unused channels for bi-amping. I tried this may times, the result was just not audible, even as I expected much more or at least a tiny advantage. So maybe do your own testing.

You've quite obviously never heard an elf sing live, in person...let alone an entire *drum of them.

*A group of elves is either called a troupe or, as I thought more appropriate to this conversation, a drum.

 

[DVDdoug]

A review on YouTube said that these speakers need more watts than traditional speakers because they are 4 ohms.

Lower impedance doesn't necessarily make the speaker less efficient at converting electrical energy to acoustic energy.

The sensitivity (loudness) of a speaker is usually rated with 1W at 1 Meter. Or sometimes the speaker is measured with the voltage that makes 1W at 8-Ohms, which is 2.83 Volts. That means a 4-Ohm speaker is actually getting 2W, and if it's putting out the same SPL level as an 8-Ohm speaker it's less energy efficient.

Resistance and impedance (Ohms) is "the resistance to current flow" (Ohm's Law). With lower impedance you get more current and more wattage. Power (Wattage) is a combination of voltage and current. Amplifiers are basically voltage sources so lower impedance usually means more power. That's assuming the amplifier can deliver the current. If the impedance is too low, the amp can be over-stressed or current limited.

Sometimes low impedance speakers, or speakers where the impedance drops at certain frequencies, the speaker may be described as "hard to drive" because some amps can't deliver the current.

 

[Cbdb2]

Read both of these articles by Rod Elliott:

Benefits of Bi-Amping (Not Quite Magic, But Close) - Part 1

Benefits of Bi-Amping (Not Quite Magic, But Close) - Part 2

Then come to your own conclusions as to whether or not it is worthwhile.

He is talking about active xover biamping not BI-wiring like the OP is asking about (using the existing passive xover) which he says has no benefit.

"5.0 - Passive Biamping (aka Active Biwiring)
Although this is a topic I've mentioned briefly, it needs to be discussed properly. Using two amplifiers and two sets of speaker cables to drive the existing passive crossover is something I call 'passive biamping' or 'active biwiring'. Various websites may claim that it's true biamping, but it's not, never was and never will be.


In some cases users may hear an improvement, but make sure that it really is an improvement and not just a difference. Because you have separate amps driving the two sections of the crossover, you can easily have a level mismatch that leads you to think that the sound is 'better'. The gains of the two amps used must be identical, or the original balance between mid and high will be changed. Naturally the specific frequency depends on where the passive crossover splits the signal. Apart from (usually) a slightly easier load on the amps, both amplifiers still reproduce the full audio bandwidth, so there is no effective power gain.


In general, it is likely that the improvement - assuming there is an actual improvement of course - will be small. It will commonly be so small that the additional cost cannot be justified, but this is cold comfort if you've already bought the amplifiers and speaker cables. Speaking of which, make sure that you read the articles on this site about 'high end' (rip-off IMO) speaker cables before parting with large sums of money.


For some additional details on the real differences between active an passive systems, see Active Vs. Passive Crossovers. In particular, loudspeaker damping is always affected (sometimes seriously) by any passive filter, and commonly right at those frequencies where good damping may help control cone breakup and other unwanted effects.

 

[valerianf]

@Bassmister, only if you feel that you do not have enough low frequencies you can switch to bi-amping.
But you do not need it because you are using some subwoofers that have their own amps.
If you enjoy the sound that you have, do not make any change.