Why passive bi amplifying exists???

[Kingnoob]

I can’t seem to tell any difference between being hooked up regular and I’ve tried it twice .
why is this feature included on most avrs ? If it’s pretty useless…

is it snake oil or performance gains people want to gain ?
Is it an industry where features exist that are useless ? Such as bi amplifying with your extra 2 channels If you’re running surround.

 

[Verdinut]

I can’t seem to tell any difference between being hooked up regular and I’ve tried it twice .
why is this feature included on most avrs ? If it’s pretty useless…

is it snake oil or performance gains people want to gain ?
Is it an industry where features exist that are useless ? Such as bi amplifying with your extra 2 channels If you’re running surround.

Passive bi-amping is audiophool bullshit and was obviously promoted by a speaker cable manufacturer to make more money. Of course, there is no advantage whatsoever in passive bi-amplification. With two identical amplifiers being used, you only gain 3 dB in usable output, so it's a real waste of time and money. If an amplifier is not powerful enough, then replace it with a more powerful one.

 

[dlaloum]

If you run a crossover before the amps, and bypass the onboard speaker crossovers, there is additional flexibility to be gained - and the ability to more accurately tune the speaker to the room, also if you are running out of steam on the bass, as the bass and treble are seperate amps, distortion generated in the bass amp (harmonics of which would extend into the high frequencies), won't extend to the highs.

Yes there are potential gains to be had - but many of the gains, are benefits that are generated due to the amp(s) being undersized/specced for the speakers.

In my case, there were only marginal gains to be had with the AVR onboard power and biamping, or with similar power external amps... fitting a much higher powered (high current) external amp, provided the same benefits, with a simpler configuration (and ended up cheaper than running a pair of smaller amps!).

 

[Verdinut]

If you run a crossover before the amps, and bypass the onboard speaker crossovers, there is additional flexibility to be gained - and the ability to more accurately tune the speaker to the room, also if you are running out of steam on the bass, as the bass and treble are seperate amps, distortion generated in the bass amp (harmonics of which would extend into the high frequencies), won't extend to the highs.

Yes there are potential gains to be had - but many of the gains, are benefits that are generated due to the amp(s) being undersized/specced for the speakers.

In my case, there were only marginal gains to be had with the AVR onboard power and biamping, or with similar power external amps... fitting a much higher powered (high current) external amp, provided the same benefits, with a simpler configuration (and ended up cheaper than running a pair of smaller amps!).

What you are referring to in your first paragraph is active bi-amping using active crossovers. With your AVR, you can only get passive bi-amping as there are no inboard electronic crossovers. Active bi-amping is not required for most home installations.

In my HT system, I'm using active bi-amplification with QSC XC-3 Crossover Modules for my 3 front channels, between the subs and the mid-bass drivers. It's required because of the low 200 Hz filter frequency for each of the channels.

 

[Kingnoob]

What you are referring to in your first paragraph is active bi-amping using active crossovers. With your AVR, you can only get passive bi-amping as there are no inboard electronic crossovers. Active bi-amping is not required for most home installations.

In my HT system, I'm using active bi-amplification with QSC XC-3 Crossover Modules for my 3 front channels, between the subs and the mid-bass drivers. It's required because of the low 200 Hz filter frequency for each of the channels.

I’m familiar with active .
Yeah but passive doesn’t really do anything that I can notice so far and I don’t have full range fronts they cut out around 38hz , so I’m running front height channels instead of bi amping . Maybe if my fronts went to 20 hz I’d notice a slight difference.??

 

[dlaloum]

What you are referring to in your first paragraph is active bi-amping using active crossovers. With your AVR, you can only get passive bi-amping as there are no inboard electronic crossovers. Active bi-amping is not required for most home installations.

In my HT system, I'm using active bi-amplification with QSC XC-3 Crossover Modules for my 3 front channels, between the subs and the mid-bass drivers. It's required because of the low 200 Hz filter frequency for each of the channels.

Actually with my AVR's and their BiAmping options, whether using the onboard amps or the pre-outs, the AVR has selectable crossovers, as well as adjustable levels.
So yes - there are inboard/onboard electronic crossovers

I also experimented with the use of Y cables and inline high pass and low pass filters as an alternate approach to BiAmping, but using the onboard crossovers was easier and far more flexible.

I have also used the onboard XOvers on my Crown XLS power amps for the purpose.... (so all the biamp alternatives I experimented with involved crossovers before the power amps)

 

[Kingnoob]

Actually with my AVR's and their BiAmping options, whether using the onboard amps or the pre-outs, the AVR has selectable crossovers, as well as adjustable levels.
So yes - there are inboard/onboard electronic crossovers

I also experimented with the use of Y cables and inline high pass and low pass filters as an alternate approach to BiAmping, but using the onboard crossovers was easier and far more flexible.

I have also used the onboard XOvers on my Crown XLS power amps for the purpose.... (so all the biamp alternatives I experimented with involved crossovers before the power amps)

I cRoss my towers over at 50 hz right now I lowered it from 80 . Subs handle bass duty pretty much even though they’re not really high quality subs they get the job done . Klh & jamo sub. Unless someone has proof bi amplify passive is worth trying again I won’t bother . But I’m curious why so many people do it if it doesn’t do much more then add a few decibels of headroom I’ll not use because I don’t listen loud enough to strain my Klipch speakers or I’d go deaf lol ..
why is passive bi amplify so popular?
Any benefit to doing it ? Or is just snake oil charmer madness??

 

[Verdinut]

Actually with my AVR's and their BiAmping options, whether using the onboard amps or the pre-outs, the AVR has selectable crossovers, as well as adjustable levels.
So yes - there are inboard/onboard electronic crossovers

I also experimented with the use of Y cables and inline high pass and low pass filters as an alternate approach to BiAmping, but using the onboard crossovers was easier and far more flexible.

I have also used the onboard XOvers on my Crown XLS power amps for the purpose.... (so all the biamp alternatives I experimented with involved crossovers before the power amps)

With an AVR, there cannot be any active bi-amping with inboard amps. It's passive bi-amping unless your AVR has preouts, to which active crossovers are connected and feeding signal to external power amps.

 

[j_garcia]

Actually with my AVR's and their BiAmping options, whether using the onboard amps or the pre-outs, the AVR has selectable crossovers, as well as adjustable levels.
So yes - there are inboard/onboard electronic crossovers

Those are effectively just secondary filters, not functioning like a crossover which is tailored to the response of what it is driving. This is not the same thing as an active x-over bypassing the passive network.

I also experimented with the use of Y cables and inline high pass and low pass filters as an alternate approach to BiAmping, but using the onboard crossovers was easier and far more flexible.

That is still passive. While you remove certain frequencies from amplification, the speaker's x-over is still present in the chain and it does not take into account the response of the portion of speaker you are driving.

 

[Kingnoob]

Im using Klipsch they require so little power. Why does audysee set fronts to 40 hz?? Should I just leave them there ??

Those are effectively just secondary filters, not functioning like a crossover which is tailored to the response of what it is driving. This is not the same thing as an active x-over bypassing the passive network.



That is still passive. While you remove certain frequencies from amplification, the speaker's x-over is still present in the chain and it does not take into account the response of the portion of speaker you are driving.

yeah passive is a wash/blunder the only reason I think it exists is to sell more cables and banana plugs . 3db isn’t noticeable if it does that which people claim .. I’m using high efficiency speakers they barely use much wattage. I bet no one can prove passive bi amplify is useful for hifi .

 

[j_garcia]

3dB is noticeable, but studies have shown that it is not what a typical user can easily identify. When asked, users would not define the difference as "louder".

Audessey sets your x-over where your speakers perform well to even out the curve. So if your sub is not as good in the top range and the main speakers are better there, then it will lower the x-over to get the smoothest blend. If you run it multiple times as well, you will almost certainly get slightly different results.

 

[dlaloum]

Those are effectively just secondary filters, not functioning like a crossover which is tailored to the response of what it is driving. This is not the same thing as an active x-over bypassing the passive network.



That is still passive. While you remove certain frequencies from amplification, the speaker's x-over is still present in the chain and it does not take into account the response of the portion of speaker you are driving.

That depends on the speaker... in the case of my Gallo's - the Woofer has a seperate voice coil, which bypasses the XOver, and the mids/highs only use a capacitor.... seperating them, due to the native properties of the drivers.

 

[j_garcia]

That depends on the speaker... in the case of my Gallo's - the Woofer has a seperate voice coil, which bypasses the XOver, and the mids/highs only use a capacitor.... seperating them, due to the native properties of the drivers.

That's a rare case. More common in the 70s and 80s, not so much these days with most brands. For sure there are some out there, but definitely not the norm.

 

[Kingnoob]

That's a rare case. More common in the 70s and 80s, not so much these days with most brands. For sure there are some out there, but definitely not the norm.

still many sites are trying to sell the biamp method .

https://www.crutchfield.com/learn/why-biamp-your-speakers.html

And speaker manufacturers keep building models with the option I’ve even seen bookshelves like rp600 have them. And pricier models .

 

[m. zillch]

The math explaining how this all works is easier than most people realize. Allow me.

Dealers love selling bi-wiring, bi-amping (the passive variety, as found in many AVRs), and bi-preamping (called "HT bypass" by most people) because it makes them bi-profits.

Manufacturers make features/gizmos to meet both consumer demand and dealer demand.

Audio magazines and their reviewers push (or fall for) concepts, fads, and gimmicks to please their advertisers.

 

[dlaloum]

There is only a point to BiAmping if you have lowpass / highpass filters before the power amps...

Some AVR's do this in DSP, some power amps (particularly those from the pro marketplace) have onboard DSP crossovers, or you can get in line passive lowpass or high pass filters, that can be placed in the line level pre out before the power amp.

Your speakers also need to have inputs that bypass any internal crossover within the speaker as well.

I tried this on my setup, with speakers specifically designed for it, but the actual gains were minimal and possibly non-existent (hard to tell whether I was imagining a very slightly smoother top end and deeper bottom... no DBT).

The speakers own designer (Anthony Gallo) although in the first few years after the Nucleus Reference 3 was released he demonstrated the speakers in biamped setups, later switched to using a much higher power amp, and using the simpler traditional single amp setup! (he used a Spectron Musician III, rated at 500W@8ohm and doubling down as impedance halves...)

My own experience with BiAmping of the speakers vs using a higher powered amp (Crown 440W@8ohm) seemed to indicate no benefit (or negligible benefit) from biamping.

If you have a number of lower powered amps, there might, possibly, in some cases, be benefits by crossing over, and using seperate amps for seperate parts of the audible spectrum, as is often done in active speakers.... but it is very much a case by case speaker by speaker and amp by amp situation - and there are loads of situations where there is no benefit to be gained from the additional complexity.

 

[m. zillch]

There is only a point to BiAmping if you have lowpass / highpass filters before the power amps...

Some AVR's do this in DSP,

In current production? Which ones? I had heard of some upscale Onkyos which had that option in the past, but my impression was it's rare.

Sending different ranges of frequencies to the two amps, called active bi-amping, is not so controversial but as the thread's title explains this thread is about the dubious variety of biamping, passive biamping, where both amps receive the full range signal.

"Your speakers also need to have inputs that bypass any internal crossover within the speaker as well. "

Ideally when active biamping, yes, agreed. Also rarely available as I understand it though. [I once sold an a/d/s speaker with a switch to completely bypass its crossover but this was decades ago.] Of course many consumers new to this stuff think that removing their jumper straps gives them direct access to their drivers and bypasses their speaker's crossover though.

 

[dlaloum]

In current production? Which ones? I had heard of some upscale Onkyos which had that option in the past, but my impression was it's rare.

Sending different ranges of frequencies to the two amps, called active bi-amping, is not so controversial but as the thread's title explains this thread is about the dubious variety of biamping, passive biamping, where both amps receive the full range signal.

"Your speakers also need to have inputs that bypass any internal crossover within the speaker as well. "

Ideally when active biamping, yes, agreed. Also rarely available as I understand it though. [I once sold an a/d/s speaker with a switch to completely bypass its crossover but this was decades ago.] Of course many consumers new to this stuff think that removing their jumper straps gives them direct access to their drivers and bypasses their speaker's crossover though.

My old Integra DTR70.4 used to do active biamping (from memory)

I also did it using inline filters (the Harrison Labs FMOD Inline filters) - so at the preamp I just needed identical outputs, and then I used an inline low pass and an inline high pass filter before each power amp...

So would you call that "active" biamping? - seems pretty passive to me! no DSP involved... but there IS a crossover achieved via the two filters, and rather than having a speaker level crossover inside the speaker, you now have a line level crossover in the line level feed from the preamp.

But yeah just running two amps full range and thinking it will provide benefits.... is a little short sighted.

In the case of the Gallo speakers I have, there is a seperate woofer voice coil accessible specifically for biamping.... but the recommended Gallo Sub-Amp for it, has built in crossover functionality (and of course I achieved the same via other means) - so yes I bypassed the crossover.

Of course for the mids/highs, the crossover was still in place, but I filtered out the low frequencies with the inline FMOD high pass.... (yep passively... not active!)

I guess my key point is, you still have to have crossover to get benefits of biamping... it can be active or passive, that does not matter so much.

And yes the way some people think of biamping, simply shows they have not thought it through...

But even with a XO in place, frequently, the benefits are limited... and primarily gained if the amp sizing is marginal... so a manufacturer gets benefits in biamping an active speaker, because they can use 2 cheaper amps, and cheap electronic DSP XO, rather than a single larger more expensive amp, alongside a relatively expensive passive crossover.

The driver to active biamping has been cost rather than performance IMO.

 

[m. zillch]

Yeah when I wrote some older "upscale Onkyos" I was referring to their flagships and Integra line.

According to one of the world experts on bi-amping (the legit variety) the main benefit to the use of an active crossover over passive is they effectively provide full amp power with no waste. In a normal single amp scenario the loudspeaker's passive crossover elements are never 100% efficient so they gobble up, let's say, 5% of the incoming amplifier power and wastefully turn it into heat instead of music signal to send to the drivers. But in active biamping instead an amp goes straight to the voicecoil (because there is no speaker crossover) so nearly all of the power amp's signal gets there intact (assuming the speaker cable being used is adequately thick). Still these gains are rather modest. He said he measured it as being around 1dB in real world use or at the very best 2dB, tops. Far better is to simply get a fundamentally doubly powerful single amp and wire it conventionally with one wire, which achieves a solid 3dB greater maximum potential output. [And it may cost less than buying those two lesser power amps.}

 

[TLS Guy]

I’m familiar with active .
Yeah but passive doesn’t really do anything that I can notice so far and I don’t have full range fronts they cut out around 38hz , so I’m running front height channels instead of bi amping . Maybe if my fronts went to 20 hz I’d notice a slight difference.??

There is no benefit to passive bi-amping unless the speaker has a crossover around 400 to 500 Hz. However even then one amp of twice the power would do just as well or better.