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Question on bi-amping - Page 3

post #61 of 1039
Quote:
Originally Posted by kiwi2 View Post

Take my experience with my 80w amps with my 2-way speakers. With the one 2ch amp, the left and right speaker had one channel each. The woofer and tweeter of each speaker had to share the same one 80w channel.

When I got the 2nd amp and went to bi-amping, the woofer now has its own 80w channel and the twetter has its own 80w channel. The thing to remember though is that lower frequencies demand more power than the higher frequencies.

You are clearly describing active biamping, and that is a good thing, but apparently by not saying "active crossover" every second word, you confused poor Ollie!
Quote:
For example in a full range speaker if the woofer is drawing 50w then the tweeter may only be drawing 10w. So one amp channel will still be getting taxed quite heavily while the other channel is under utilised.

One key point is that woofers tend to be far less efficient than tweeters. With a passive crossover you are forced to attenuate the signal that is provided to the tweeter, which wastes power. Since the speaker has flat response, the same voltage must be required at the speaker's input terminals to get equally loud sound out of both the woofer and the tweeter.

With active crossover, you can use a far smaller amplifier for the tweeter and take advantage of its extra efficiency. By eliminating the tweeter signal from the amplifier that drives the woofer, the active crossover can significantly decrease the amount of voltage required from the bass amp to drive the speaker to the same loudness.

In a 2-way speaker, filtering the tweeter signal out of the input to the bass amplifier may allow you to use an amplifier with as little as 2/3 to 1/2 the power to drive the woofer to the same level. However, you loose all of that benefit with passive biamping since you feed the same full range signal to both amplifiers.
post #62 of 1039
So you guys are saying that my Rotel amps are in effect just paper weights. Whether I had 100 watts or 1000 watts you are saying that the power draw would remain the same as it is with my current set up. So there is no voltage swing increase with bigger amps???
post #63 of 1039

Please don't feed him any more, guys...

post #64 of 1039
Quote:
Originally Posted by kbarnes701 View Post

Please don't feed him any more, guys...

+1. This time he's gone over the edge.
post #65 of 1039
Thread Starter 
Quote:
Originally Posted by arnyk 
Read my lips. All other things being equal, there is no benefit.

But you said earlier that two amps would double the available power! That means more available headroom. What have I said that is incorrect? I'm just following what you are advising and you are not making it easy.
Quote:
No, you can't achieve the benefits of a larger amplifier with passive biamping.

You said earlier in this thread that using two amps would double the available power. Did you not say that?

You said : "The system's total amplifier power has been doubled" and I said the headroom would go up. So am I technically wrong in saying that, or are you disagreeing with me for some other reason? confused.gif
post #66 of 1039
Quote:
Originally Posted by OllieS View Post

But you said earlier that two amps would double the available power! That means more available headroom. What have I said that is incorrect? I'm just following what you are advising and you are not making it easy.
You said earlier in this thread that using two amps would double the available power. Did you not say that?

You said : "The system's total amplifier power has been doubled" and I said the headroom would go up. So am I technically wrong in saying that, or are you disagreeing with me for some other reason? confused.gif

double power is three dB, about "one notch" in terms of our perception of loudness, of theoretical headroom. My old maggies crossed over at 600 Hz and almost split power equally between the tweeter ribbon and the big panel. Most speakers cross over to the tweeter around 2000 Hz or so, and with real program material, the tweeter won't ever use more than 25 percent of the power. So if you have 2 hundred watt amps, you get 100 potentially from the amp connected to the woofer and never ever ever more than 25 watts from the amp connected to the tweeter. Which is not doubling power, even though the amps themselves could add upt o 200 watts in different circumstances.

Moreover, if you aren't audibly distorted, the additional power is meaningless anyway since as a practical matter more inaudibler is not different to our ears and brains than simply plain old inaudible distortion. If you do have audible distortion whether really doubling the power would eliminate all the audible distortion is not certain. 3 dB isn't all that much volume difference in the context of real content that hasn't been compressed into ugliness. In other words, if you are briefly audibly distorting on 10 dB peaks, chances are it's more than just the loudest three dB that contain distortion, because a three dB change in overall volume is a second to second occurrence, at least sometimes, whether you are talking about speech or music.
post #67 of 1039
Quote:
Originally Posted by OllieS View Post
 
Quote:
Originally Posted by arnyk 
Read my lips. All other things being equal, there is no benefit.

But you said earlier that two amps would double the available power! That means more available headroom. What have I said that is incorrect? I'm just following what you are advising and you are not making it easy.
Quote:
No, you can't achieve the benefits of a larger amplifier with passive biamping.

You said earlier in this thread that using two amps would double the available power. Did you not say that?

You said : "The system's total amplifier power has been doubled" and I said the headroom would go up. So am I technically wrong in saying that, or are you disagreeing with me for some other reason? confused.gif

 

Among other things, it's important to understand that doubling the available power makes absolutely no difference to anything unless that power is actually used. If you want to listen at 85dB and you can do that cleanly with a 50 watt amplifier, having a 200 watt amplifier brings absolutely no benefits at all. 

 

If your speakers are (for example) 85db/1w/1m sensitive then you can hit 85dB with just 1 watt of amp power, at a distance of about 3 feet. Even factoring in the fall-off in SPL as distance increases, at a typical domestic listening distance, a 50 watt amp will have loads of headroom. Providing additional power beyond that achieves no useful purpose.

 

Think of headroom like this: if you are building a bridge and the tallest vehicle that will ever pass under the bridge is 18 feet tall, you might decide to built the bridge 21 feet high, giving 3 feet of (literal) headroom. Extending the headroom to 25 feet, or 50 feet, or 100 feet achieves nothing. Once you have the headroom you actually need, then you're done.

post #68 of 1039
Thread Starter 
Okay, but my comment about headroom was not technically wrong. There is more headroom available. That is what I said. Whether it is used or not, that headroom is there. You might not need it now, or may never need it, but if there are circumstances that require it, then you have the extra reserve.

You can't say that the amplifier headroom will not used in all circumstances. How would you possibly know that?

So I don't get why people are telling me that I'm wrong when you guys are just confirming in a roundabout way that I'm right.

Seems like a lot of mental gymnastics to me. rolleyes.gif
post #69 of 1039
Quote:
Originally Posted by OllieS View Post

Okay, but my comment about headroom was not technically wrong. There is more headroom available. That is what I said. Whether it is used or not, that headroom is there. You might not need it now, or may never need it, but if there are circumstances that require it, then you have the extra reserve.

You can't say that the amplifier headroom will not used in all circumstances. How would you possibly know that?

So I don't get why people are telling me that I'm wrong when you guys are just confirming in a roundabout way that I'm right.

Seems like a lot of mental gymnastics to me. rolleyes.gif

 

What circumstances?  Either you have enough power/headroom or you don't.  If you do, you are all set. If you don't, you need a more powerful amplifier. Passive biamping isn’t going to serve any useful purpose.

post #70 of 1039
Quote:
Okay, but my comment about headroom was not technically wrong. There is more headroom available.
No, there isn't more headroom. There's more power in the amplifiers, because you now have two amplifiers drawing power from the wall. But your drivers aren't seeing any more power. Each driver is still seeing 60 watts.
Quote:
So I don't get why people are telling me that I'm wrong when you guys are just confirming in a roundabout way that I'm right.
How many times do people have to tell you you're wrong, before you will admit that they are not telling you you're right?
post #71 of 1039
Thread Starter 
Quote:
Originally Posted by mcnarus 
No, there isn't more headroom. There's more power in the amplifiers, because you now have two amplifiers drawing power from the wall. But your drivers aren't seeing any more power. Each driver is still seeing 60 watts.

Goodness, you people are just contradicting yourselves now. Double the amp power means there is more reserve power available for when you need it. You guys just keep on coming up with examples trying to explain away the additional headroom.
Quote:
Each driver is still seeing 60 watts.

But wait, now YOU are wrong. The driver is not "seeing" 60 watts. That's the amount of available power, not the amount of power the driver draws. You keep telling me that available power and power are two different things. So why are you not following your own advice?
Quote:
How many times do people have to tell you you're wrong, before you will admit that they are not telling you you're right?

But HOW am I wrong? More power, more headroom????? Whether you use it or not is irrelevant . You may decide to turn the volume up one day that may eat into the reserve power. But stop beating around the bush here, for goodness sakes.. rolleyes.gif
post #72 of 1039
Quote:
Originally Posted by kbarnes701 View Post

Quote:
Originally Posted by OllieS View Post

 
Quote:
Originally Posted by arnyk 
Originally Posted by arnyk 

Read my lips. All other things being equal, there is no benefit.


But you said earlier that two amps would double the available power! That means more available headroom. What have I said that is incorrect? I'm just following what you are advising and you are not making it easy.
Quote:
No, you can't achieve the benefits of a larger amplifier with passive biamping.


You said earlier in this thread that using two amps would double the available power. Did you not say that?


You said : "The system's total amplifier power has been doubled" and I said the headroom would go up. So am I technically wrong in saying that, or are you disagreeing with me for some other reason? confused.gif

Among other things, it's important to understand that doubling the available power makes absolutely no difference to anything unless that power is actually used. If you want to listen at 85dB and you can do that cleanly with a 50 watt amplifier, having a 200 watt amplifier brings absolutely no benefits at all. 

Agreed, and this contradicts the audiophile myth that amps are audibly cleaner, the less of their maximum power that you use.

This is what we can expect from a typical solid state amplifier:

http://www.stereophile.com/content/simaudio-moon-evolution-880m-monoblock-power-amplifier-measurements



The reviewer who posted this says outright that the apparent rise in distortion below 100 watts is actually noise. It is 70-90 dB down so not to worry.

Thus the actual distortion curve is pretty much flat below 100 watts, giving a wide range of power levels where its distortion is inaudible. This is typical of solid state amplifiers.
Quote:
If your speakers are (for example) 85db/1w/1m sensitive then you can hit 85 dB with just 1 watt of amp power, at a distance of about 3 feet. Even factoring in the fall-off in SPL as distance increases, at a typical domestic listening distance, a 50 watt amp will have loads of headroom. Providing additional power beyond that achieves no useful purpose.

Agreed, and we need to remember that most are running a system that is at least 3.1 so 1 wpc doesn't give a mere 85 dB, it gives more like 90+. Furthermore the average speaker is more like 90 dB/SPL. In my case my 90 dB SPL speakers, the subwoofer and a middle of the road AVR are good for an easy 88 dB at 12 feet average, 108 dB SPL peak. This is loud!

IME most people who talk about louder than 85 dB average reference level have yet to buy their first peak rading SPL meter, so they are effectively talking out of the backs of their necks! ;-)
post #73 of 1039
Thread Starter 
Quote:
Originally Posted by knarnes701 
]What circumstances? Either you have enough power/headroom or you don't. If you do, you are all set. If you don't, you need a more powerful amplifier. Passive biamping isn’t going to serve any useful purpose.

You see, this is what I'm talking about. You can't even entertain the idea that there may be scenario that may require more power where the additional headroom could be of use. You just can't see it. You're ruling everything out. I said ALL circumstances because not all people use their systems the same way. Some may need more power, so more headroom FOR THEM, would be beneficial.
post #74 of 1039
Thread Starter 
Looking back in the thread and I find this :
Quote:
Originally Posted by FMW 
Biamplifying doesn't cause the speakers to draw more power. They will behave the same with either setup. It simply increases the overhead. Passive biamplification doesn't gain you anything.

More overhead. That is another word for HEADROOM. So what if one person makes use of that headroom? Or are you saying that NO PERSON will ever make use of that headroom under ANY circumstances? Again, HOW do you know this? And if that's true, then what is the point of amplifier headroom in the first place because you people keep on downplaying that aspect of this discussion. rolleyes.gif
post #75 of 1039
Quote:
Goodness, you people are just contradicting yourselves now. Double the amp power means there is more reserve power available for when you need it. You guys just keep on coming up with examples trying to explain away the additional headroom.
We're not explaining it away. We're telling you it isn't there. You're asking the questions. We're giving you answers. And then you're telling us the answers are wrong. If you're so f0cking smart, why are you asking questions? Why don't you go write an EE textbook and explain to us morons how things really work in OllieWorld?
Quote:
But wait, now YOU are wrong. The driver is not "seeing" 60 watts. That's the amount of available power, not the amount of power the driver draws. You keep telling me that available power and power are two different things. So why are you not following your own advice?
Fine. How about if I say, each driver sees a maximum of 60 watts? Does that make it clear now?
Quote:
But HOW am I wrong? More power, more headroom?????
Yep. That's where you're wrong. If you buy a bigger amp, more power means more headroom. If you actively bi-amp, more power means more headroom. If you passively bi-amp, it doesn't.
post #76 of 1039
Quote:
You see, this is what I'm talking about. You can't even entertain the idea that there may be scenario that may require more power where the additional headroom could be of use. You just can't see it. You're ruling everything out. I said ALL circumstances because not all people use their systems the same way. Some may need more power, so more headroom FOR THEM, would be beneficial.
Quote:
More overhead. That is another word for HEADROOM. So what if one person makes use of that headroom? Or are you saying that NO PERSON will ever make use of that headroom under ANY circumstances? Again, HOW do you know this? And if that's true, then what is the point of amplifier headroom in the first place because you people keep on downplaying that aspect of this discussion.
Now you're just trolling. Go away.
Edited by mcnarus - 9/29/13 at 8:32am
post #77 of 1039
Quote:
Originally Posted by OllieS View Post
 
Quote:
Originally Posted by mcnarus 
No, there isn't more headroom. There's more power in the amplifiers, because you now have two amplifiers drawing power from the wall. But your drivers aren't seeing any more power. Each driver is still seeing 60 watts.

Goodness, you people are just contradicting yourselves now. Double the amp power means there is more reserve power available for when you need it. You guys just keep on coming up with examples trying to explain away the additional headroom.
Quote:
Each driver is still seeing 60 watts.

But wait, now YOU are wrong. The driver is not "seeing" 60 watts. That's the amount of available power, not the amount of power the driver draws. You keep telling me that available power and power are two different things. So why are you not following your own advice?
Quote:
How many times do people have to tell you you're wrong, before you will admit that they are not telling you you're right?

But HOW am I wrong? More power, more headroom????? Whether you use it or not is irrelevant . You may decide to turn the volume up one day that may eat into the reserve power. But stop beating around the bush here, for goodness sakes.. rolleyes.gif

 

I'll have one more go at this before I give up and consider you as unteachable (no offense intended).  You say "Double the amp power means there is more reserve power available for when you need it."

 

So when do you need it?  If you are hitting the SPLs you require, cleanly, from the amp power you have, with some headroom, then when will you "need" more than that?  Your question makes no sense - in my bridge example above, 100 feet of headroom and 21 feet of headroom are the same thing!  If the tallest vehicle that will ever go under the bridge is 18 feet, then you will never "need" more than 21 feet of headroom. You seem to think that having amp power you will never need is useful - well it's no more useful than that 100 feet of headroom in the bridge.

 

The amp power you need is the right amount to drive your speakers to the SPLs you require, cleanly and with some headroom 'to be on the safe side' if you will. That's it. More amp power is pointless and wasted.

 

"More power, more headroom????? Whether you use it or not is irrelevant "  ??????????   Excuse me?  Headroom is headroom - as I have explained, when you have enough, you have enough and adding more is pointless. What is the point of 100 feet of headroom for that bridge? Why would it be of any more use than 21 feet?

 

"You may decide to turn the volume up one day that may eat into the reserve power."  Ignoring the issue of whether the speakers can handle more power in the first place, again you are looking at this from the wrong direction. What you need to do is ask yourself "what is the highest SPL I will ever want in my room?". Once you have answered this, then you need a speaker/amp combination that is able to deliver that cleanly. That's it. If that amp works out at 100 watts, then having an amp that is 200 watts does not achieve anything.

 

For example, I use my HT for movies only, so the loudest I ever want the system to play is 105dB on peaks (115dB LFE peaks). That is movie Reference Level. I have bought speakers and amps that enable me to approach that level cleanly, without clipping. What you keep saying is that, no, I actually need more powerful amps so that I can have more headroom for "when I need it". I will never need it. So buying more powerful amps is pointless and a waste of money. I already have sufficient headroom, explained by the fact I hit the required SPLs cleanly, so having even more headroom serves no purpose.

 

Final point: several people in this thread who know what they are talking about, and who have huge experience of AV systems, to the extent in some cases of actually designing systems commercially, have told you how this all works. Ask yourself: who is the most likely to have got this all wrong?  You, or them?


Edited by kbarnes701 - 9/29/13 at 8:49am
post #78 of 1039
Quote:
Originally Posted by OllieS View Post
 
Quote:
Originally Posted by knarnes701 
]What circumstances? Either you have enough power/headroom or you don't. If you do, you are all set. If you don't, you need a more powerful amplifier. Passive biamping isn’t going to serve any useful purpose.

You see, this is what I'm talking about. You can't even entertain the idea that there may be scenario that may require more power where the additional headroom could be of use. You just can't see it. You're ruling everything out. I said ALL circumstances because not all people use their systems the same way. Some may need more power, so more headroom FOR THEM, would be beneficial.

 

 

This is just gibberish now. See my last reply to you where I cover this.

post #79 of 1039
Thread Starter 
Quote:
Originally Posted by mcnarus 
Yep. That's where you're wrong. If you buy a bigger amp, more power means more headroom. If you actively bi-amp, more power means more headroom. If you passively bi-amp, it doesn't

Not according to the author that Arny cited. For passive bi-amping, using two separate amplifiers the available power would double I'm not trolling. Read the damn article instead of just trying to act smart!

If the available power doubled ... then that means that there is more potential headroom available. Otherwise more power would mean nothing under all circumstances. That is PRECISELY what you are saying. You are saying that there is no headroom, but there is. You've just doubled the potential headroom with 2 identical amps!

Stop BSing and trying to be right the whole damn time. rolleyes.gif
Quote:
Now you're just trolling. Go away.

How am I trolling? I am asking the right questions and you keep bullsh*ting me. rolleyes.gif
post #80 of 1039
Thread Starter 
Quote:
Originally Posted by kbarnes701 
The amp power you need is the right amount to drive your speakers to the SPLs you require, cleanly and with some headroom 'to be on the safe side' if you will. That's it. More amp power is pointless and wasted.

But that is what I am talking about!!! Headroom for when you need it. To be on the safe side is just another way of saying what I've tried to say this whole time!

This is all mental gymnastics and this is what is pissing me off to no end. mad.gif

If you decide to be heroic and push the volume further than you normally would where it exceeds the power output of a given amp, adding more reserve power would be beneficial in that case because in such a scenario the additional power would actually have merit. Now you seem to be agreeing with that. Or do you not agree with that?

You guys are just crapping all over me because you aren't explaining this clearly enough, and I'm the one getting frustrated here. rolleyes.gif
Edited by OllieS - 9/29/13 at 9:00am
post #81 of 1039
Thread Starter 
Let me put it another way then I'm signing out because this is beyond ridiculous. You have two stereo amps, 100 watts x 2. You passively bi-amp both stereo pairs, you've doubled the available power, hence 200 x 2.

Now compared to the first stereo amp, you've gained 3dB maximum overhead. So if I push my single stereo amp past the point of no return, whether it be due to SPL, or whatever the case is, the movie or music doesn't matter what it is, then the additional 3 dB would be beneficial.

So far you guys have been telling me 'no, that extra headroom will not help you at all if you don't use it". But I just described a scenario that would use it. I've really had enough of the gymnastics and semantics in this thread. It was helpful up to a point, but now it's just getting out of a control and I seriously can't handle it.
post #82 of 1039
Ollie, in your 100 watt per channel example...

Normal hook up with one stereo amp would provide 100 watts per channel to a stereo pair of speakers.

Bi-amp hook up would provide 100 watts to the tweeter and 100 watts to the mid-range/woofers, again this is per channel.

Let's for simplicities sake say you want to play some bass heavy music at insanely loud levels that exceed the available 100 watts available per woofer channel where is the more or double power coming from?

In both hook up schemes there is only an amp providing 100 watts per channel, no more. In the bi-amp hook up scheme whatever available power going to the tweeters cannot be used by the woofers.
post #83 of 1039
Thread Starter 
Quote:
Originally Posted by 67jason 
Let's for simplicities sake say you want to play some bass heavy music at insanely loud levels that exceed the available 100 watts available per woofer channel where is the more or double power coming from?

I was talking about 2 x stereo 100 watt amplifiers. Both arnyk and the author of the article he cited confirmed that you would have double the available system power with such a configuration. The logic is that if you don't use it then it is redundant. I AGREE!

Comparatively speaking, going from 100 watt to 200 watt, the only thing that changes is the available power reserve. However *if* you use more power over and above 100 watts, then it becomes beneficial. That is where the overhead becomes handy. To me it sounds pretty obvious.
post #84 of 1039
Just let him live with his delusions. It won't kill him to be wrong, and he seems to enjoy it.

But if anyone just lurking here is still confused, here's the bottom line: If you need more power, buy a bigger amp. Passive bi-amping is not the way to go.
Edited by mcnarus - 9/29/13 at 10:21am
post #85 of 1039
Quote:
Originally Posted by OllieS View Post

Quote:
Originally Posted by 67jason 
Let's for simplicities sake say you want to play some bass heavy music at insanely loud levels that exceed the available 100 watts available per woofer channel where is the more or double power coming from?

I was talking about 2 x stereo 100 watt amplifiers. Both arnyk and the author of the article he cited confirmed that you would have double the available system power with such a configuration. The logic is that if you don't use it then it is redundant. I AGREE!

Comparatively speaking, going from 100 watt to 200 watt, the only thing that changes is the available power reserve. However *if* you use more power over and above 100 watts, then it becomes beneficial. That is where the overhead becomes handy. To me it sounds pretty obvious.

I also was refering to the use of two seperate 100 watt per channel amps when I referenced bi-amping in my above post. In the passive bi-amp scheme there is no doubling of power. The woofers cannot use the seperate power going to the tweeter. The woofer does not even know that power is there. How is this benificial in anyway? I cannot even see how this type of bi-amping increases any overhead on the low frequency driver where it is needed the most. The high frequency driver will have a ton of reserves though but will never ever be required under any normal circumstance I can think of. The tweeter will likely never require much more then 25 watts in real world circumstances. So all that overhead will be unused always, even if the woofer is requiring more then its available 100 watts.
post #86 of 1039
Quote:
Originally Posted by OllieS View Post

Can you explain what exactly the benefits would be to using an active crossover.

The advantages of active speakers: instead of a passive crossover soaking up power and introducing phase changes across the frequency spectrum, separate amps with custom designed response curves that power the separate drivers. Powered speakers can sound amazing but the problem is that this control requires a lot of engineering expertise to pull off.
Quote:
Originally Posted by OllieS View Post

I know people say that when bi-amping, you need to remove the speaker links. What is the purpose behind that?

I read this whole thread and I don't see that anyone responded to this - when bi-amping a speaker with 2 sets of speaker inputs you MUST remove the jumpers.
post #87 of 1039
Quote:
Originally Posted by OllieS View Post

But that is what I am talking about!!! Headroom for when you need it. To be on the safe side is just another way of saying what I've tried to say this whole time!

This is all mental gymnastics and this is what is pissing me off to no end. mad.gif

If you decide to be heroic and push the volume further than you normally would where it exceeds the power output of a given amp, adding more reserve power would be beneficial in that case because in such a scenario the additional power would actually have merit. Now you seem to be agreeing with that. Or do you not agree with that?

You guys are just crapping all over me because you aren't explaining this clearly enough, and I'm the one getting frustrated here. rolleyes.gif

I feel your pain! wink.gif

Seems like agreement here with some slight differences in angle of approach and problems with semantics. Yet another at risk of being driven away with quick accusations of trolling and delusions.
post #88 of 1039
Thread Starter 
Quote:
Originally Posted by 67jason 
I also was refering to the use of two seperate 100 watt per channel amps when I referenced bi-amping in my above post. In the passive bi-amp scheme there is no doubling of power. The woofers cannot use the seperate power going to the tweeter. The woofer does not even know that power is there. How is this benificial in anyway? I cannot even see how this type of bi-amping increases any overhead on the low frequency driver where it is needed the most. The high frequency driver will have a ton of reserves though but will never ever be required under any normal circumstance I can think of. The tweeter will likely never require much more then 25 watts in real world circumstances. So all that overhead will be unused always, even if the woofer is requiring more then its available 100 watts.

Can you blame me for being confused when people say :
Quote:
Originally Posted by arnyk 
They slipped one by me. This statement is true:

"The system's total amplifier power has been doubled,"

That's obvious, but we have to remember that amplifier power ..... ... ... ....etc etc etc.

He back-peddled a little by saying that the additional power would not be used unless you needed it. But he acknowledged there would be double the available system power. You and others are painting a different story by telling me that amp power will not double.

And here from the article referenced on page 1 by Arnyk :
Quote:
Passive bi-amping

Passive bi-amping (also known as "fools bi-amping" for good reason) requires loudspeakers with the dual binding posts used for bi-wiring, again with the shorting bar removed. The difference (and profit advantage for the retailer) is that it requires two stereo power amplifiers, instead of one, and an additional pair of speaker cables. (Can you guess who is getting fooled by passive bi-amping?)

In passive bi-amping, the output from the pre-amplifier is fed to a pair of identical stereo power amps. All four amplifier channels are fed the same, full range, signal from the pre-amp. This is important, so take note of it. The output of the power amps is fed to the stereo loudspeakers, the left and right outputs of one power amp to the left and right loudspeakers' high frequency binding posts and the left and right outputs of the other power amp to the left and right loudspeakers' low frequency binding posts. We now have the same, full range signal everywhere. The high frequency part of each loudspeaker's passive internal crossover is doing what it always does with a full range signal, as is the low frequency part of each loudspeaker's crossover.

From the listener's perspective, if all goes well, the sound quality should remain exactly the same. However, the placebo effect insures that most folks who passively bi-amp their music systems report a sonic improvement. The system's total amplifier power has been doubled, which is probably a good thing and may actually result in a sonic improvement at high listening levels.

So again, can you blame me for being confused? Either the power doubles or it doesn't double. Arnyk confirmed it, the author confirmed it. You and others are contradicting this information. So who am I to believe? confused.gif Honestly, if you were in my position, what exactly would you think now?
post #89 of 1039
Quote:
Originally Posted by mcnarus View Post

Just let him live with his delusions. It won't kill him to be wrong, and he seems to enjoy it.

But if anyone just lurking here is still confused, here's the bottom line: If you need more power, buy a bigger amp. Passive bi-amping is not the way to go.

 

+1. There's no more to be said really. If someone doesn't get it after numerous explanations, so be it.

post #90 of 1039
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Originally Posted by 67jason View Post
 
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Originally Posted by OllieS View Post
 
Quote:
Originally Posted by 67jason 
Let's for simplicities sake say you want to play some bass heavy music at insanely loud levels that exceed the available 100 watts available per woofer channel where is the more or double power coming from?

I was talking about 2 x stereo 100 watt amplifiers. Both arnyk and the author of the article he cited confirmed that you would have double the available system power with such a configuration. The logic is that if you don't use it then it is redundant. I AGREE!

Comparatively speaking, going from 100 watt to 200 watt, the only thing that changes is the available power reserve. However *if* you use more power over and above 100 watts, then it becomes beneficial. That is where the overhead becomes handy. To me it sounds pretty obvious.

I also was refering to the use of two seperate 100 watt per channel amps when I referenced bi-amping in my above post. In the passive bi-amp scheme there is no doubling of power. The woofers cannot use the seperate power going to the tweeter. The woofer does not even know that power is there. How is this benificial in anyway? I cannot even see how this type of bi-amping increases any overhead on the low frequency driver where it is needed the most. The high frequency driver will have a ton of reserves though but will never ever be required under any normal circumstance I can think of. The tweeter will likely never require much more then 25 watts in real world circumstances. So all that overhead will be unused always, even if the woofer is requiring more then its available 100 watts.

 

Exactly. Whereas a single 200 watt amp, hooked up in a normal (non biamped) way will actually have additional useful power. 

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