Can I bi-amp with the Denon AVR-8500H receiver using a external amp?

[PENG]

Bi-amping is absolutely about gaining power- it uses an active crossover because the insertion loss from a passive crossover reduces the output by a significant amount.

Bi-wiring is totally different in that it uses the speaker's crossover and it still yields the headroom from using the two channels on each speaker, although this is only apparent/useful if the amplifier is driven close to rated/maximum output. Whether is's generally useful is, as we know, up for (endless) debate. Or Facebook- that would be a good place to argue about it.

I have to agree with HD, to gain power one would just use a more powerful amp. There are insertion loss of passive crossovers but it is not significant factor for a well designed power amp. I can drive my LS50 or R900 with a 5 W amp to my normal listening level in a 11X25' room. I do believe the theoretical benefits of passive biamp are most likely not audible to most people but I don't know that for sure.

Active biamping is a totally different animal and the overall results would depend on the "active" crossover design/build, and the competence of the designer, suitability of the speaker etc., there are way more variables involved...

 

[PENG]

Well, It's not something I thought up all on my own.

1. S&V did a review on that NHT Classic Four using an external XO/amp to do just that. NHT advertised it.

https://www.soundandvision.com/content/nht-classic-four-surround-sound-speaker-system

2. I spoke to Shane Rich RBH Chief Engineer about doing the same thing with the RBH SX-6500/8500 towers, and he agreed.

If it were a hit/miss/luck issue, I doubt NHT or RBH would be recommending that.

That's a long article but I will read it later when I have more time. At first glance, they mentioned active crossovers so I don't know why you would call it "pseudo passive". Your pseudo passive term confused me to believe you're still talking about using the speakers build in (inside) passive crossovers. Again, I will read the article but I am anticipating may be it's actually an active biamp scheme, or a "pseudo active" thing that you referred to..

 

[AcuDefTechGuy]

That's a long article but I will read it later when I have more time. At first glance, they mentioned active crossovers so I don't know why you would call it "pseudo passive". Pseudo passive led me to believe you are still talking about using the speakers build in (inside) passive crossovers. Again, I will read the article but I am anticipating may be it is a "pseudo active" thing..

They are still using the internal XO.

The internal XO of the speakers are not removed.

All they did was removed the metal JUMPERS from the binding posts in the back of the speakers.

 

[everettT]

They are still using the internal XO.

The internal XO of the speakers are not removed.

All they did was removed the metal JUMPERS from the binding posts in the back of the speakers.

Sort off. The speakers crossover was designed to receive bass or .lfe to those drivers leaving the upper portions crossover intact when the jumpers are removed. XTZ does/did something similar with a couple of the large towers.

 

[PENG]

They are still using the internal XO.

The internal XO of the speakers are not removed.

All they did was removed the metal JUMPERS from the binding posts in the back of the speakers.

I took another glance, just could resist and wait.. Then I remember we have had this conversation before, and I agree with your "pseudo passive" term that appropriately apply to such a scheme. You are effectively cascading the active and passive filters, but not so luck/hit&miss in that case because they were sold as a "matched kit". The reviewer did mention the alternative of using something else such as an AVR, and I seem to remember someone, probably @lovinthehd brought up an Onkyo model that would fit the bill, but then you would have to make sure the slope matches. My hit/miss comment was made prematurely thinking that you referred to a general/generic scheme. I still think such scheme is more work for potentially no audible gain as the passive crossover is still in place (highfigh might still not like the insertion loss), sort of redundant in terms of sonic benefits, but that's just my opinion.

 

[AcuDefTechGuy]

Sort off. The speakers crossover was designed to receive bass or .lfe to those drivers leaving the upper portions crossover intact when the jumpers are removed. XTZ does/did something similar with a couple of the large towers.

So you're thinking maybe only certain speaker companies (NHT, RBH, XTZ) design their XO to be able to accomplish this "pseudo-active-bi-amp" with an external XO/amp?

Maybe you're right since I don't see other companies saying anything about this.

 

[AcuDefTechGuy]

I took another glance, just could resist and wait.. Then I remember we have had this conversation before, and I agree with your "pseudo passive" term that appropriately apply to such a scheme. You are effectively cascading the active and passive filters, but not so luck/hit&miss in that case because they were sold as a "matched kit". The reviewer did mention the alternative of using something else such as an AVR, and I seem to remember someone, probably @lovinthehd brought up an Onkyo model that would fit the bill, but then you would have to make sure the slope matches. My hit/miss comment was made prematurely thinking that you referred to a general/generic scheme. I still think such scheme is more work for potentially no audible gain as the passive crossover is still in place (highfigh might still not like the insertion loss),sort of redundant in terms of sonic benefits, but that's just my opinion.

The benefit I'm referring to is only the bass control with the external VOLUME knob.

So in this "pseudo-active" system, you could easily change the volume of just the woofers.

If the bass is too much (some people c/o overpowering bass or muddy bass),they can easily lower the bass level with the turn of the external amp volume knob. If the bass is too little, they can easily increase the bass level.

As I've said, only experienced Audioholics should try this, not newbies or the faint of heart.

And only try this with big towers with capable woofers. The goal is to increase the amount of bass from the same towers.

For example, the NHT Classic Four may go down to only 32Hz @ -3dB. But if you bi-amp using external XO/amp, you could get 28Hz @ -3dB and higher bass levels compared to 100% "passive".

 

[PENG]

The benefit I'm referring to is only the bass control with the external VOLUME knob.

So in this "pseudo-active" system, you could easily change the volume of just the woofers.

If the bass is too much (some people c/o overpowering bass or muddy bass),they can easily lower the bass level with the turn of the external amp volume knob. If the bass is too little, they can easily increase the bass level.

As I've said, only experienced Audioholics should try this, not newbies or the faint of heart.

And only try this with big towers with capable woofers. The goal is to increase the amount of bass from the same towers.

For example, the NHT Classic Four may go down to only 32Hz @ -3dB. But if you bi-amp using external XO/amp, you could get 28Hz @ -3dB and higher bass levels compared to 100% "passive".

Okay, got you, thank you.

 

[lovinthehd]

Bi-amping is absolutely about gaining power- it uses an active crossover because the insertion loss from a passive crossover reduces the output by a significant amount.

Bi-wiring is totally different in that it uses the speaker's crossover and it still yields the headroom from using the two channels on each speaker, although this is only apparent/useful if the amplifier is driven close to rated/maximum output. Whether is's generally useful is, as we know, up for (endless) debate. Or Facebook- that would be a good place to argue about it.

What active crossover in this case?

 

[highfigh]

What active crossover in this case?

There is none- that's the reason it shouldn't be called 'bi-amp'.

 

[lovinthehd]

There is none- that's the reason it shouldn't be called 'bi-amp'.

Unfortunately the industry has already screwed that up with the so-named marketing feature on avrs and speakers. I'd love to see it go away and let bi-amping go back to meaning active bi-amping only....but for now stuck with calling it passive bi-amping.

 

[highfigh]

I have to agree with HD, to gain power one would just use a more powerful amp. There are insertion loss of passive crossovers but it is not significant factor for a well designed power amp. I can drive my LS50 or R900 with a 5 W amp to my normal listening level in a 11X25' room. I do believe the theoretical benefits of passive biamp are most likely not audible to most people but I don't know that for sure.

Active biamping is a totally different animal and the overall results would depend on the "active" crossover design/build, and the competence of the designer, suitability of the speaker etc., there are way more variables involved...

But if you used an active crossover, you would see at least 3dB more output at the same power. That's why PA systems use active crossovers, well, for reliability, too. Plus, live sound companies need to pay to ship the equipment when it's on tour, so less boxes costs less.

The amp doesn't enter into the loss from a passive crossover- good or bad, there's a loss of output and unity gain can't be achieved passively without doing some tricky stuff. A highly reactive load from a passive crossover is a factor, but only if the amp design is crap.

We're not talking about using a low powered amp here- the OP is asking about bi-wiring speakers with amps of much higher power output, so whatever you use and how well it works is great, but it really doesn't apply because you're not driving the system as hard. I'm also not saying that low power into really good speakers doesn't work- the average listening level is far lower than most people would expect it to be.

 

[highfigh]

Unfortunately the industry has already screwed that up with the so-named marketing feature on avrs and speakers. I'd love to see it go away and let bi-amping go back to meaning active bi-amping only....but for now stuck with calling it passive bi-amping.

That can change.

 

[lovinthehd]

That can change.

LOL not any time soon it seems. The idea has already been burned into so many consumers that with the extra terminals on their avr they can magically increase power (moar powah!).....

 

[AcuDefTechGuy]

Okay, got you, thank you.

BTW, I do know someone with a pair of RBH SX-6300 towers who is bi-amping the Woofers with the RBH SA-250DSP amp every single day.

He is able to easily control the amount of bass from his towers like you would with a subwoofer using the volume/gain knob on the amp.

If it is true that only certain bi-amp-able towers are capable of being bi-amped this way, then I know for sure that the RBH SX/SV Towers and NHT Classic Four are 100% capable.

 

[highfigh]

LOL not any time soon it seems. The idea has already been burned into so many consumers that with the extra terminals on their avr they can magically increase power (moar powah!).....

Funny thing about marketing- when it grabs hold, people don't want to let go of the idea and eventually, it's like an historical fact.

I remember when someone came into the store where I worked and we had started carrying heavy speaker wire, which was twin lead with heavy, clear insulation- you know the kind, it magnifies the wire so it looks thicker but in reality, it might have been 12 ga. A customer saw it and said "That doesn't make any difference unless the wire is over 50 feet long". He went on to explain that he did TEF analysis of various speaker wire and saw almost no differences. He was doing mostly live sound at the time along with corporate audio projects, but was also a studio engineer.

'Special' wire is still here, weirder than ever. Next time I see him, I'll ask for his opinion on cables with batteries.

 

[PENG]

Unfortunately the industry has already screwed that up with the so-named marketing feature on avrs and speakers. I'd love to see it go away and let bi-amping go back to meaning active bi-amping only....but for now stuck with calling it passive bi-amping.

Hello HD, with due respect to everyone, I won't debate this topic any more but would still like to present other views, especially those base on facts not misconception, such as this one from Anthem. I don't always agree with what the manufacturer says either, but I do when it makes sense in terms of electrical principles, that I do know something about.

Here it goes

https://www.anthemav.com/support/faq.php

"Doesn't passive biamping waste the amp's power because each channel still has to amplify the full range signal and not just the highs or the lows?

No. With the jumpers removed on a biampable speaker, the impedance of each section is not the usual 4 or 8 ohms, but several hundred if not more at the frequencies that the amp is "not supposed to be amplifying". Higher impedance means less current draw. No meaningful amount of current, no wasted power.

According a recurring audio-myth, only an active crossover should be used for biamping, in order to split the band before the power amp instead of inside the speaker, thereby reducing the amount of work each amp channel has to do. While active crossovers do have their place in PA systems, it should be noted that equalizers are also a part of it.

A generic active crossover on its own merely divides the audio band into smaller ones. The carefully custom-designed crossover in a high performance home audio speaker does a lot more. It is responsible for correcting frequency response aberrations of the individual drivers, maintaining phase coherence between drivers, optimizing off-axis response, balancing levels between drivers, setting up impedance, at times improving woofer performance by rolling off not just the top, but also frequencies that are too low and cause it to misbehave, and other things that vary according to model.

Tearing out the speaker's own finely-tuned crossover to replace it with an active crossover with generic controls almost guarantees that, just for starters, frequency response will be altered. Different sound doesn't mean better sound. Using the passive crossover in the speaker is indeed the correct way to biamp."

 

[PENG]

Funny thing about marketing- when it grabs hold, people don't want to let go of the idea and eventually, it's like an historical fact.

Great point, totally agreed, but be careful with the same, but forum talks vs manufacturers marking hypes, about "active" biamp too.

 

[highfigh]

Great point, totally agreed, but be careful with the same, but forum talks vs manufacturers marking hypes, about "active" biamp too.

I think "when the speakers have been designed for..." should be included in the arguments for active bi-amping. It really needs to be a ground up system approach, not an active crossover and amps retrofitted to a group of speakers that were designed to work together with a passive crossover.

However, with a DSP and equalizer that's more advanced than a simple crossover with level controls, phase relationship and amplitude variations can be corrected much more accurately and without the problems caused by a passive system (phase shift, mostly).

I recently did an audio system upgrade in a school gym that had a small Mackie mixer, various mics, an old 60W Bogen 70V amplifier and Atlas in-ceiling speakers rated for 8W max each. I was called by the Athletic committee after being referred by a parish member and when I asked for their expectations and needs, was told they wanted to be able to make announcements as before, but they wanted to play music through the system without it sounding like crap. It didn't even sound good for speaking when I started- not much output and it was just a narrow band of midrange, even though the amplifier's five band graphic EQ had been set with a drastic slope that had the highs buried, the middle at zero gain and the bass boosted. The sliders between the mid/high and mid/low bands were halfway between. Sounded terrrible (use Charles Barkley's voice).

I used a Crown CDi1000 amplifier, JBL Control 70V speakers and a JBL Control sub, with nominal impedance of 8 Ohms. Crossover is active and I would never try to do this with a passive crossover for several reasons- I can't change the -3dB points easily, I can't change the slope easily, I don't need to worry about power/voltage rating of the crossover and I can delay the HP and LP, as needed, to account for the speaker placement. The amplifier also has 5 bands of parametric EQ at the input and another 8 bands after, which makes 'fixing' the sound very easy.

While this isn't a set of speakers in boxes, it is an example of a successful integration of speakers in an acoustical space that doesn't benefit from towers because the walls weren't treated and the reflected sound arrives about 1/4 second after it leaves the front of the stage. The ceiling, however, has 14" Luan pegboard over fiberglass insulation on firring strips and each half is sloped, to allow the sound to reflect off of the floor and hit the ceiling on the other side, where it's partially absorbed.

 

[highfigh]

Hello HD, with due respect to everyone, I won't debate this topic any more but would still like to present other views, especially those base on facts not misconception, such as this one from Anthem. I don't always agree with what the manufacturer says either, but I do when it makes sense in terms of electrical principles, that I do know something about.

Here it goes

https://www.anthemav.com/support/faq.php

"Doesn't passive biamping waste the amp's power because each channel still has to amplify the full range signal and not just the highs or the lows?

No. With the jumpers removed on a biampable speaker, the impedance of each section is not the usual 4 or 8 ohms, but several hundred if not more at the frequencies that the amp is "not supposed to be amplifying". Higher impedance means less current draw. No meaningful amount of current, no wasted power.

[/QUOTE]

I'm not in the camp of "No! Don't do it!" or "There's absolutely no benefit", but I think that most instances of bi-wiring will make little, if any positive difference. If the amplifier(s) used are designed for full range audio, I fail to see why "not supposed to be amplifying" even enters the conversation.