Bi Amp

[Good4it]

Does bi-amping change the sound of the speakers? I'm speaking of true bi amping, not just running 2 sets of wires from one amp to one terminal.

 

[ski2xblack]

If by "true bi-amping" you mean using two amps, but still sending a full range signal to each and relying on the passive networks, then yes, you can and will screw things up if the amps don't have precisely matched gain. Better to skip bi-amping and just get a single, sufficiently powerful amp.

 

[j_garcia]

Passive biamping will not change the sound of the speaker.

 

[lovinthehd]

If he's actually referring to active bi-amping (true bi-amping IMO) and is removing the passive components from the speaker, it likely will change the sound of the speakers, but whether that would achieve an improvement or not.....

 

[Pogre]

If he's actually referring to active bi-amping (true bi-amping IMO) and is removing the passive components from the speaker, it likely will change the sound of the speakers, but whether that would achieve an improvement or not.....

I've read here many times that the crossovers designed for the speaker are best to use. Is active bi amping more useful when you build planning to use it?

 

[lovinthehd]

I've read here many times that the crossovers designed for the speaker are best to use. Is active bi amping more useful when you build planning to use it?

Well, I don't think I'd try to outguess the design of the speakers I currently have with their passive networks. Maybe if I were building a system from scratch with appropriate drivers but really no particular desire to do so at this time. I did think about an Onkyo 818 at one point a long while back, as it had some limited active crossover capability to play with (altho now I do have a couple minidsp 2x4s, and some amps so I suppose I could try someday....)

I think AH's article covers it well enough tho http://www.audioholics.com/frequent-questions/the-difference-between-biamping-vs-biwiring

 

[ski2xblack]

I've read here many times that the crossovers designed for the speaker are best to use.

Well, If Dennis Murphy is responsible for your passive networks, you would be hard pressed to improve on their performance by going active.

Is active bi amping more useful when you build planning to use it?

?? This is a confusing question. Of course one should have a plan when putting together a system, and going with active vs. passive speakers is one of the choices. It seems you may be referring to a specific product you own that you want to change from a passive speaker to an active one. That can be done, but it's not a simple task. Ask an old Klipsch fart. I know.

Maybe I'm confused by the term "active bi-amping". The 'bi-amping' part reeks of audio woo. The way I see things, an active speaker is an active speaker, and a passive speaker is a passive speaker.

 

[Pogre]

Well, If Dennis Murphy is responsible for your passive networks, you would be hard pressed to improve on their performance by going active.

?? This is a confusing question. Of course one should have a plan when putting together a system, and going with active vs. passive speakers is one of the choices. It seems you may be referring to a specific product you own that you want to change from a passive speaker to an active one. That can be done, but it's not a simple task. Ask an old Klipsch fart. I know.

Maybe I'm confused by the term "active bi-amping". The 'bi-amping' part reeks of audio woo. The way I see things, an active speaker is an active speaker, and a passive speaker is a passive speaker.

Oh no. What I mean is, is there an advantage to designing and building a speaker with the intention of using active crossovers instead of passive? I'm pretty sure I get the gist between the 2. Bi amping involves separate amps, 1 for each driver and using a dsp in between instead of caps and coils to set the crossovers, right?

I wouldn't attempt to try anything like that with any of my stuff. I understand enough to know that I don't know nearly enough to even be considering something like that.

 

[ski2xblack]

Bi amping involves separate amps, 1 for each driver and using a dsp in between instead of caps and coils to set the crossovers, right?

You got it, that describes an active setup. And yes, it has many advantages. While not popular in the consumer realm, active speakers dominate the pro-audio side.

I wouldn't attempt to try anything like that with any of my stuff. I understand enough to know that I don't know nearly enough to even be considering something like that.

Referring to making an old Klipsch active? Well, at least it didn't cost me anything to do it. I had plenty of amps lying around, an active crossover (a pro audio device that's basically the old school equivalent of a miniDSP 2x8), some beater 'Scalas to work with, and clearly far too much spare time on my hands. But I like hands-on type learning, so it was worth it. I eventually recapped the networks, cleaned up the cabs, and sold the Klipsch for a modest profit. Currently, the only active speakers I have are the JBL studio monitors up in the office.

 

[Verdinut]

I've read here many times that the crossovers designed for the speaker are best to use. Is active bi amping more useful when you build planning to use it?

A passive crossover will do a good job when it has been designed specifically for the speakers it is connected to.
But it will never be as good as an active crossover which is more precise as the filtering frequency will not change with the changing impedance of a heating voice coil, for instance. The electronic crossover also has the advantage of not reducing an amplifier damping factor, because it does not necessitate an inductor resistance in series with the woofer.

When you are driving a 4 ohm speaker, the amplifier damping factor which is usually rated for an 8 ohm load is reduced by 50%. Add the resistance of the series inductor on top of that, which means more resistance if the crossover frequency of the woofer is below 200 Hz with an amplifier having a low DF, the resulting DF gets really low. Then, the woofer will not give you the right tight bass and punch.

In my situation, I am actively bi-amping the 3 front speakers. I am using Dayton RSS390HF-4 subs in each cabinet and the electronic crossovers are set at 190 Hz. At that frequency, a passive crossover would have required a big series inductor which would have added too much resistance between the amps and the woofers. Also, with a receiver having a power rating of about 180 w/ch at 4 ohms, I wouldn't have much headroom left and risking overloading it.

 

[AcuDefTechGuy]

Does bi-amping change the sound of the speakers? I'm speaking of true bi amping, not just running 2 sets of wires from one amp to one terminal.

True Bi-amp will not improve the sound quality of the speakers if the original single-amp is already providing sufficient power for the speakers.

But for true active bi-amp, the speaker must be designed and made for active bi-amp. In which case, you have no choice but to bi-amp.

For example, if a speaker were designed and made for quad-amp, you have to use 4 amps per speaker.

If a speaker were designed for single-amp, then bi-amp will not improve the sound.

 

[Verdinut]

True Bi-amp will not improve the sound quality of the speakers if the original single-amp is already providing sufficient power for the speakers.

But for true active bi-amp, the speaker must be designed and made for active bi-amp. In which case, you have no choice but to bi-amp.

For example, if a speaker were designed and made for quad-amp, you have to use 4 amps per speaker.

If a speaker were designed for single-amp, then bi-amp will not improve the sound.

There are many advantages to actively bi-amp speakers. I don't agree with you when you say that bi-amping will not improve the sound quality. Ask TLS Guy if he agrees with you.

See the following article: http://sound.whsites.net/bi-amp.htm

 

[Verdinut]

Oh no. What I mean is, is there an advantage to designing and building a speaker with the intention of using active crossovers instead of passive? I'm pretty sure I get the gist between the 2. Bi amping involves separate amps, 1 for each driver and using a dsp in between instead of caps and coils to set the crossovers, right?

I wouldn't attempt to try anything like that with any of my stuff. I understand enough to know that I don't know nearly enough to even be considering something like that.

FYI, have a look at the following article: http://sound.whsites.net/bi-amp.htm

 

[AcuDefTechGuy]

There are many advantages to actively bi-amp speakers. I don't agree with you when you say that bi-amping will not improve the sound quality. Ask TLS Guy if he agrees with you.

See the following article: http://sound.whsites.net/bi-amp.htm

It doesn't matter if he agrees with me or not. Everyone has a different experience and opinion. In my experience, it makes no audible difference. The theoretical difference may be there, but not the actual audible difference.

Now there are exceptions.

In my case, I have the RBH SX-T2/R modular towers. They can be set up as a single unit and can be single-amped. Or they can set up as 2 separate units, and thus 2 separate active amps (bi-amp). I use the bi-amp because it allows me to control the bass unit like a separate subwoofer, which makes the sound significantly better to me than as a single-amp speaker.

Same thing with the Linkwitz Orion (Quad-amp). I can increase or decrease the bass or treble volume separately. That is a plus.

But if you are just bi-amping without being able to separately control the bass or treble, there is no actual audible difference that I have seen.

 

[TLS Guy]

It all depends.

An active crossover enables you to do things a passive network can not.

It widens driver options as speaker sensitivity becomes pretty much irrelevant.

It makes Eq easier, as a passive network can only cut frequencies as an active one can both cut and boost. I know it looks like a passive network can boost but it does not, that only occurs by cutting frequencies around the null. That means loss of sensitivity/efficiency and wasted amplifier power.

That gets to the next point in that passive networks become highly limiting in high power applications. They add a point of unreliability and greatly add to dynamic thermal compression.

The lower the crossover point the greater the benefit of biamping/triamping etc.

As the crossover point drops the value of the inductors and capacitors greatly increases. This adds significant distortion. It also causes nasty impedance irregularites and adverse phase angles. In the worst of cases, and I think as Dr Floyd Toole points out, crossovers in these speakers requiring arc welder amps, are often in resonance. The tip of to this is points on the impedance curve below the DC resistance of the bass drivers. This is a massive quality issue. Not only will the speaker be hazardous to amps, but it also a lousy speaker period and has no case for being marketed. These horrors are not uncommon among the most expensive of speakers.

I am firmly of the opinion that any crossover below 350 Hz should NEVER now be passive but active. There is no longer any excuse for speakers with passive crossovers in these low frequency regions. You could actually now make a valid case for making the divide at 500 Hz.

I note that B & W have raised the bass/mid crossover on the 800 D3 speakers to 500 Hz.

I personally believe that speaker would merit from an active version.

ATC produce very nice monitor and domestic class speakers, and make passive and active versions of the same speakers. I have visited ATC and I'm in no doubt that the active versions sound the best.