Thoughts on Bi-Amping / Bass Management

F

fttank

Enthusiast
Hi Audioholics,

After reading/ watching tons of material on Bi-Amping, Crossover, Bass Management, Speaker setting, Speaker placement, and so on - I want to ask for thoughts/ opinions on the following thesis:

Bi-Amping (passive/ horizontal) is nicely explained in an article I found (see link at the end of this thread) - I cite: …..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…."

Given that this is true, and passive (horizontal) Bi-Amping has the benefit of maintaining the sound quality in the mid-high frequency when the low one is struggling.

There is this little "If" - I doubt that midrange/ high-end systems - like my Denon X4300H / B&W 2.1 CM8 + ASW610 - ever struggle on the usual all-day listening levels in a everyday living room.

But let's say that this would be a good reason to actually do a passive Bi-Amping setup.

And here it comes:

In addition to passive (horizontal) Bi-Amping the floor standing speakers are set to SMALL, as generally recommended for a 2.1 setup, with a crossover frequency of 80 Hz - following the principle "let the speakers do what they are best at".

But wouldn't this be offloading the fronts even more from low frequency and - in a 2.1-scenario like above - making Bi-Amping based on the argument stated above in fact unnecessary.

Am I into something here?

Regards,

Frank

 
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JerryLove

JerryLove

Audioholic Samurai
Friends don't let friends do passive bi amping. All it gets you is 0-3db of headroom and an empty wallet.

If your running out of power, get a more powerful amp (or more sensitive speakers).
 
ryanosaur

ryanosaur

Audioholic Ninja
@fttank
There are numerous threads here on AH... even just in the last year, detailing how this is a fools errand. Use the SPL calculator to determine how much power you need in actuality to achieve your listening goals. If your speakers will get loud enough without frying anything, you are good. If you have a speaker that is hard to drive, ie low impedance and bad phase angle, then you need an AVR or Amp rated for handling that load.
In general, if you can clear reference level dynamic peaks at your LP, perhaps with a little headroom still, then you are good to go.
I have yet to see anybody truly quantify the effects of passive bi-amping or bi-wiring... on the other hand I've spoken with many professional speaker designers that think it's all a crock.
I thought about doing it, I learned about it, and in theory it sounds great... almost like a magic bullet for better audio. Just like $5K cables and rare jade cable risers... I listened to the speaker designers, and my friends here. I put good amps on good speakers with a single connection (not bi'd) and have great sound.

In general, if you want better sound, you need to upgrade your speakers and check you room... positioning and acoustics in your room, along with good speakers, will do so much better for you than tricks.
 
lovinthehd

lovinthehd

Audioholic Slumlord
Passive bi-amping is a waste of wire and time. If you need a more powerful amp, put an external on the Denon. If you are listening at moderate levels now with good results I doubt even the amp is necessary.
 
F

fttank

Enthusiast
Thanks for your posts... want to stretch that I did not ask for how to configure my system, but trying to understand a bit more of the logics and relations about all that :)

Fun fact:, the industry (B&W, Denon) often advises the opposite of what I mostly read from experts in forums... or experienced myself at home. (Just recently I did another test removing the jumpers on my CM8's and connecting a second pair of cables. All other settings the same. No noticable difference one way or another...)

Here som examples....

From Denons manual to bi-amping:
"You can use the bi-amp connection for front speakers. Bi-amp connection is a method to connect separate amplifiers to the tweeter terminal and woofer terminal of a speaker that supports bi-amplification. This connection enables back EMF (power returned without being output) from the woofer to flow into the tweeter without affecting the sound quality, producing a higher sound quality."

Or the B&W-support to the topic of setting the CM8 to the setting Large or Small in a 2.1 setup:
"However would I advise to set the CM8 speakers to the setting "Large". The CM8 speaker is a full range speaker that would´t fully take advantage of its acoustic qualities. The AVR should be at a crossover of 60 Hz. It bass is a little thin, you could try the setting LFE+Main".
 
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everettT

everettT

Audioholic Ninja
Just marketing for Golden Ears. There are some (a very small collection) speakers that have passive crossovers that have been truly configured for passive biamping. XTZ had one and Gene's Status Acoustics come to mind. If you're speakers have true low bass output some run the lfe to the bass driver, @TLS Guy speakers come to mind, again not common.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Hi Audioholics,

After reading/ watching tons of material on Bi-Amping, Crossover, Bass Management, Speaker setting, Speaker placement, and so on - I want to ask for thoughts/ opinions on the following thesis:

Bi-Amping (passive/ horizontal) is nicely explained in an article I found (see link at the end of this thread) - I cite: …..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…."

Given that this is true, and passive (horizontal) Bi-Amping has the benefit of maintaining the sound quality in the mid-high frequency when the low one is struggling.

There is this little "If" - I doubt that midrange/ high-end systems - like my Denon X4300H / B&W 2.1 CM8 + ASW610 - ever struggle on the usual all-day listening levels in a everyday living room.

But let's say that this would be a good reason to actually do a passive Bi-Amping setup.

And here it comes:

In addition to passive (horizontal) Bi-Amping the floor standing speakers are set to SMALL, as generally recommended for a 2.1 setup, with a crossover frequency of 80 Hz - following the principle "let the speakers do what they are best at".

But wouldn't this be offloading the fronts even more from low frequency and - in a 2.1-scenario like above - making Bi-Amping based on the argument stated above in fact unnecessary.

Am I into something here?

Regards,

Frank

Yes, your down the wrong rabbit hole. What you read is absolute rubbish. There will be no significant power gain, not even 3 db, unless the speakers can be biamped at 400 Hz. Usually even in 3 ways, the upper terminals go to the high bass filter, only occasionally the band pass filter. The power required by a tweeter is about 2 to 5 watts. Yes, that's all. So you gain nothing for the complexity.

Only active biamping makes sense, But even then if one amp runs out of power and other can not come to the rescue. Active biamping makes sense, as you can make a better crossover often, and you can level the woofers. Also a passive crossover can only cut power never boost it, an active crossover can do both.

Don't waste you time with passive biamping.
 
F

fttank

Enthusiast
I never thought of passive bi-amping - note: in an average home listening environment with "average" gear mentioned above - at as at technique to increase power, but more of a way of load-balancing which in best case is resulting in positive effect on sound quality (whatever that means ;-)).

But as stated above, when I tested this I couldn't make out any difference either way. So, for me your statement is conclusive: "Don't waste your time (and wire) with passive biamping"....

Thanks you all for your comments/ thoughts. F
 
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HTfreak2004

HTfreak2004

Senior Audioholic
I’ll admit. Me, too.
There are far better ways to improve SQ without worrying over the power delivery components!

Remember bass management increases the total cost of one’s system yet will have a more noticeable effect without a whole lot of debate:)
 
Pogre

Pogre

Audioholic Spartan
I’ll admit. Me, too.
The confusion comes from you saying you never thought about about passive bi amping, but the description you give is an example of passive bi amping.
 
KEW

KEW

Audioholic Warlord
I never thought of passive bi-amping - note: in an average home listening environment with "average" gear mentioned above - at as at technique to increase power, but more of a way of load-balancing which in best case is resulting in positive effect on sound quality (whatever that means ;-)).

But as stated above, when I tested this I couldn't make out any difference either way. So, for me your statement is conclusive: "Don't waste your time (and wire) with passive biamping"....

Thanks you all for your comments/ thoughts. F
I did not read the article you linked, only the title! But the title is correct (I believe) in that if you are running out of power for the woofer, at least the upper frequencies will not be impacted by that. Bi-amping may make the problem less noticeable (kind of like turning the volume up in your car so you don't hear that the automatic transmission needs fluid).
However, you are not fixing the problem (that there is not enough power to drive the woofer)! The problem is fixed when you get an amp capable of properly driving the speaker!
My point is the argument for bi-amping (based on the title) is only valid if you have a problem (an overload of the woofer in their example) and then it enables the actual problem which will eventually either destroy that amp or driver!!
 
Pogre

Pogre

Audioholic Spartan
I did not read the article you linked, only the title! But the title is correct (I believe) in that if you are running out of power for the woofer, at least the upper frequencies will not be impacted by that. Bi-amping may make the problem less noticeable (kind of like turning the volume up in your car so you don't hear that the automatic transmission needs fluid).
However, you are not fixing the problem (that there is not enough power to drive the woofer)! The problem is fixed when you get an amp capable of properly driving the speaker!
My point is the argument for bi-amping (based on the title) is only valid if you have a problem (an overload of the woofer in their example) and then it enables the actual problem which will eventually either destroy that amp or driver!!
That's a good point. It might sound better, but you're still overdriving the woofers.
 
Kvn_Walker

Kvn_Walker

Senior Audioholic
It's not even mentioned that if you do bi-amping without level matching, you won't be running the speakers as designed. Bass could sound "stronger" for no reason besides having disproportionately more power at a given volume setting than the mid/high section.
 
F

fttank

Enthusiast
Pogre: never thought of passive bi-amping as a way to increase power. :cool:
That because some of the comment suggest "Passive bi-amping is a waste of wire and time. If you need a more powerful amp, put an external on the Denon. If you are listening at moderate levels now with good results I doubt even the amp is necessary."

As stated in my original post you first need to run in a situation where you lack power.
 
TLS Guy

TLS Guy

Audioholic Slumlord
Pogre: never thought of passive bi-amping as a way to increase power. :cool:
That because some of the comment suggest "Passive bi-amping is a waste of wire and time. If you need a more powerful amp, put an external on the Denon. If you are listening at moderate levels now with good results I doubt even the amp is necessary."

As stated in my original post you first need to run in a situation where you lack power.
Yes, but if you do, what you propose will not help at all.
 
F

fttank

Enthusiast
Agreed TLS Guy. I understand that... so, there's progress ;-)
 
P

PENG

Audioholic Overlord
Pogre: never thought of passive bi-amping as a way to increase power. :cool:
That because some of the comment suggest "Passive bi-amping is a waste of wire and time. If you need a more powerful amp, put an external on the Denon. If you are listening at moderate levels now with good results I doubt even the amp is necessary."

As stated in my original post you first need to run in a situation where you lack power.
If you have the wires already, and have the spare channels that otherwise have no use for, then do it. Placebo may or may not help you hear a difference, but there is no down side if you don't have to buy more wires.
 

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