Can biamping blow my speakers?

[damoncz]

Forgive the basic question but I am really baffled.

My setup:
I have a pair of KEF iQ9 speakers(rated 20 to 150 Ohm) and an Onkyo SR-607(7channel x 90 watts). Both speakers and amp are capable of biamping...

My question/problem:
If I biamp my speakers I am supplying 90x2 watts to each speakers...could it burn my speakers if I turn up the volume, since I am sending more power than the could endure? The question I am asking is it almost already happened..After I hooked them, immediately noticed that one of the tweeters on a speaker has gone silent..it simply didn't produce any sound above 2000 Hz. I RMAd that one and tomorrow I am getting the replacement. I don't want to burn this one with bi-amping! So please help!!

Thanks,
Damon

 

[GO-NAD!]

One of your tweeters immediately went silent? Do you mean before you turned up the volume? If that's the case, it wasn't because you overpowered the speaker. Is it possible that when you connected the speaker wire to the binding post that supplies that particular tweeter, that you might've shorted the wire, i.e. wire strands from the positive and negative touched each other?

 

[Lordoftherings]

No sweat, don't fret it.

Hi Damon, and Welcome to Audioholics.

NO, biamping speakers that are biampable from a biamp capable receiver like yours, will not blow your speakers. The only thing that can blow up is your ears.

Bob

 

[GO-NAD!]

Hi Damon, and Welcome to Audioholics.

NO, biamping speakers that are biampable from a biamp capable receiver like yours, will not blow your speakers. The only thing that can blow up is your ears.

Bob

I agree, but that dosen't explain his dead tweeter...

 

[Lordoftherings]

I agree, but that dosen't explain his dead tweeter...

Electrical wiring? Volume level too high? Many possibilities. I just stick with the main question at hand from the thread.

 

[Lordoftherings]

Forgive the basic question but I am really baffled

Not as much as me.

"Baffled" as the front baffle of a speaker?

 

[walter duque]

I bi-amp my center which is rated at 220 watts with 350 watts so far so good. I do play at very high volume. Should not be a problem for you unless you really overdrive them. I used to be worried about it too.

 

[bandphan]

get a bigger amp if you need more power

 

[TLS Guy]

Forgive the basic question but I am really baffled.

My setup:
I have a pair of KEF iQ9 speakers(rated 20 to 150 Ohm) and an Onkyo SR-607(7channel x 90 watts). Both speakers and amp are capable of biamping...

My question/problem:
If I biamp my speakers I am supplying 90x2 watts to each speakers...could it burn my speakers if I turn up the volume, since I am sending more power than the could endure? The question I am asking is it almost already happened..After I hooked them, immediately noticed that one of the tweeters on a speaker has gone silent..it simply didn't produce any sound above 2000 Hz. I RMAd that one and tomorrow I am getting the replacement. I don't want to burn this one with bi-amping! So please help!!

Thanks,
Damon

I think it likely that the biamping had something to do with it. It is not over powering per se, as you would be passive biampimg and the tweeter would just take the power it wants. So in fact when you were biamping you were actually adding only a watt of power to the speaker not 90 watts. So it is actually 90 + 1 Watt, as a tweeter will not draw more than a watt or two on music program.

Passive biamping is not of benefit, but as I have sated before provides opportunities for damage. Crossovers present highly inductive and capacitative loads to the amp, and it will be different for a very speaker.

The high pass section to the tweeter is a capacitative load mainly. Now it is far from uncommon for amps to become unstable and develop supersonic oscillations you can't hear with these types of loads. So it is possible that with that circuit and you amp under certain conditions, with the low pass filter connected to another channel, that a supersonic oscillation blew the tweeter or a crossover component.

I would forget about passive biamping. It is all potential risk and no benefit.

 

[Lordoftherings]

^ About passive Bi-wiring?

 

[TLS Guy]

^ About passive Bi-wiring?

No benefit, and it doubles the risk of a wiring error!

Here is what wrote about biamping recently.

 

[Lordoftherings]

No benefit, and it doubles the risk of a wiring error!

Thanks for your very quick reply.

I'm only bi-wiring (passively) my center speaker, and I uses a Kimber Kable 8TC speaker cable, with 5 wires going to the two woofers (6.5" drivers), and 3 wires going to the tweeter. At the other end (my receiver), I just connect the full 8 wires to the single speaker's binding post.

It has been connected that way for quite a while now (over few years), and it sounds as fine (I think) as if it was connected by just a single speaker cable going to the center speaker (single-wiring), with the cross bars on, of course.

What's your take?

Thanks,

Bob

 

[TLS Guy]

Thanks for your very quick reply.

I'm only bi-wiring (passively) my center speaker, and I uses a Kimber Kable 8TC speaker cable, with 5 wires going to the two woofers (6.5" drivers), and 3 wires going to the tweeter. At the other end (my receiver), I just connect the full 8 wires to the single speaker's binding post.

It has been connected that way for quite a while now (over few years), and it sounds as fine (I think) as if it was connected by just a single speaker cable going to the center speaker (single-wiring), with the cross bars on, of course.

What's your take?

Thanks,
Bob

That is the whole point, it will not change the sound if you use two wires or eight.

 

[Lordoftherings]

Small favor + big appreciation.

Oh, TLS Guy, can I also ask you a small favor?

Could you please check this very short thread (it's only 8 posts long), and give your pro opinion on the subject at hand. I did mentioned your name on my post (#5) of the ditto thread, because I knew that you were the right person to address this matter in the best way possible. Your expertise on speakers, amplifiers and several other components are of the most invaluable assets.

* Here's that thread: http://forums.audioholics.com/forums/showthread.php?t=56857

I really appreciate having someone like you in these Forums, here at Audioholics. For me, you are the true professional technical advisor on audio matters.

I lift my hat to you sir.

Bob

 

[Lordoftherings]

That is the whole point, it will not change the sound if you use two wires or eight.

Hmmm... Thicker wire (bigger gauge) would not make any difference?

About the woofer EMF going back to the receiver and infiltrating the tweeter coming back to it with some distortion or noise?
Is Bi-wiring preventing exactly that? And by the same way, benefitting by not allowing that back EMF to show up it's nasty nose at the tweeter end?

Am I missing something? Or is my understanding not correct?

 

[TLS Guy]

Oh, TLS Guy, can I also ask you a small favor?

Could you please check this very short thread (it's only 8 posts long), and give your pro opinion on the subject at hand. I did mentioned your name on my post (#5) of the ditto thread, because I knew that you were the right person to address this matter in the best way possible. Your expertise on speakers, amplifiers and several other components are of the most invaluable assets.

* Here's that thread: http://forums.audioholics.com/forums/showthread.php?t=56857

I really appreciate having someone like you in these Forums, here at Audioholics. For me, you are the true professional technical advisor on audio matters.

I lift my hat to you sir.

Bob

Speaker impedance specifications mean nothing! Speaker impedance curves are usually complex. However, narrow fronted speakers are going to drop their impedance below 400 Hz for diffraction compensation. For a common 2,5 way speaker, (two woofers one tweeter on top), two thirds of the power will go to the woofers where the impedance will be 4 ohms or less, except at the narrow tuning peaks. If a speaker has two or more woofers it is four ohms, no matter what the manufacturer says. Not only that, voltage and current are always out of phase to some degree, so the current draw will be higher than you would think.

Now transistors amps are limited in the rail voltage because of the breakdown characteristics of semiconductors. So to get power, impedance has to be 8 ohms or less. So an amp really has to be able to drive a four ohm load, or you will not get the power you think. Because of THX certification, receivers do not generally blow up with a four ohm load, but they can't increase current. So most receivers driving the vast majority of speakers on the market, are actually delivering half their rated power. The reason you don't see this as obvious, is because it is only a 3 db reduction in spl.

So if you have two amps of 100 watt power into an 8 ohm load, and one can not increase current as load impedance drops, and the other can. Then then the first amp will be a 50 watt amp driving most speakers, and the other will be a 200 watt amp. That is a significant increase in spl.

 

[TLS Guy]

Hmmm... Thicker wire (bigger gauge) would not make any difference?

About the woofer EMF going back to the receiver and infiltrating the tweeter coming back to it with some distortion or noise?
Is Bi-wiring preventing exactly that? And by the same way, benefitting by not allowing that back EMF to show up it's nasty nose at the tweeter end?

Am I missing something? Or is my understanding not correct?

Thicker wire is a different matter, and depends on the length of the run. 14 or 16 AWG is usually sufficient.

 

[TLS Guy]

I think it likely that the biamping had something to do with it. It is not over powering per se, as you would be passive biampimg and the tweeter would just take the power it wants. So in fact when you were biamping you were actually adding only a watt of power to the speaker not 90 watts. So it is actually 90 + 1 Watt, as a tweeter will not draw more than a watt or two on music program.

Passive biamping is not of benefit, but as I have sated before provides opportunities for damage. Crossovers present highly inductive and capacitative loads to the amp, and it will be different for a very speaker.

The high pass section to the tweeter is a capacitative load mainly. Now it is far from uncommon for amps to become unstable and develop supersonic oscillations you can't hear with these types of loads. So it is possible that with that circuit and you amp under certain conditions, with the low pass filter connected to another channel, that a supersonic oscillation blew the tweeter or a crossover component.

I would forget about passive biamping. It is all potential risk and no benefit.

There is another issue here that I should have pointed out. You can easily clip an amp that is delivering no power. If you give it enough drive and call for voltage greater than the rail voltage an amp will still clip and hard!

Remember with passive biamping both amps are producing the SAME signal at the output terminals. Distortion products are HF. Now the OP thought he could run his speakers at a higher volume than before, but he can't. He will drive his HF amp into voltage clipping. Now with the amp just connected to the High pass filter, it can unleash all its power delivering those distortion products to the tweeter.

As I think about it, this is probably the most likely reason for the OP's tweeter failure.

 

[Lordoftherings]

Hey thanks man, that was already understood.

My point was not for me, but for the people in the other thread.

As for me, I was more asking about the true benefit of bi-wiring.

 

[Lordoftherings]

Emf

Electromotive Force from the woofer magnet.

Or Electric & Magnetic Fields.

* http://infoventures.com/private/federal/q&a/q&a-intr.html

And * http://infoventures.com/private/federal/q&a/qa-intr6.html

Back EMF from the woofer driver coming back to the tweeter driver affects it's performance.