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Bi-Amping without dual speaker terminals

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dannispel

New Member
I have been doing some reading about bi-amping my speakers with the main and zone 2 channels of a 7-channel receiver. It seems simple enough with my Marantz SR5008 (7 amplified channels 100wpc) and Klipsch KG 5.5 fronts. However, the websites that I've looked at have said that the only candidates for bi-amping are speakers with dual posts i.e. one for tweeter/mid and one for sub. They say that speakers with only one set of posts like my Klipschs cannot be bi-amped, but they fail to give a reason why. College physics taught me that running wire out of the main and zone 2 of my receiver would give me 2 X 100wpc = 200wpc into my speakers, and the internal crossovers could handle that power as they see fit. Am I missing something here? I thought about just giving it a go, but I'd appreciate some advice if doing so would cause damage to the speakers or receiver.

Dan
 
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You'd damage your amp. Don't do it.

If you added inputs to your speakers and rewired their crossovers properly, then you could bi-amp. With just one pair of speaker jacks, you would be shorting two amplifier outputs together, which is forbidden. You'd just burn out both amps and then need a tech to repair it, or buy a new amp, your choice. If extremely lucky, you might just trigger protection circuitry, shutting the amp off, but I wouldn't count on that.

It would be the same as running your speaker wire from one amp's outputs to another amp's outputs instead of to a speaker. Flash and smoke likely, if you want a show.

Bridgeable amplifiers would allow you to increase power, but that isn't what you have.
 
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For starters, you cannot bi-amp with an AVR because all those little amplifier channels are sharing the same power supply. Bi-amp literally means two amplifiers as in separate amplifiers with their own power supply. Furthermore, bi-amping truly requires the use of active crossovers. Even if you had all that your speakers only have one set of binding posts meaning there's no way to separate the high and low frequencies.

Your college physics didn't do you any favors. Because all those amplifier channels are sharing the same power supply, the more of them you use the less power per channel it can deliver. AVR's are rated with only 2 channels driven, 100wpc in your case. Add 2 more channels driven and it may only be able to supply 70wpc, maybe less and for every additional channel driven the wpc drops even more. You also need to consider that the high end might use 5 or 10 watts maximum, the rest is wasted. Therefore, with only 2 channels driven the AVR is able to provide more power for the power hungry low end than it would be able to with 4 or more channels driven.
 
Hopefully, Dan didn't try it before retiring for the evening. His green corner was off when I first responded.
 
Thanks for all the replies.
I have NOT tried it. Thought I'd get some advice first. However, I'm still curious about some of the mechanics of this.
musichal said:
It would be the same as running your speaker wire from one amp's outputs to another amp's outputs instead of to a speaker.
Click to expand...
This is true, but it would be like running a wire positive to positive and negative to negative. I've done this with car batteries, and it essentially just makes a battery with the same voltage but double the available wattage. Makes your boat stereo run forever and you can still start the boat. Seems like the same principle with a receiver. Once you put speakers (a resistor) between the positive and negative terminals of the amplifier there's no Rice Krispies.
F1nut said:
Because all those amplifier channels are sharing the same power supply, the more of them you use the less power per channel it can deliver.
Click to expand...
I didn't know this. It was my understanding that the amplifier's power consumption would change when I, for example, turn on another zone. If I'm drawing a maximum of 100 wpc X 2 = 200 w in my main zone and then turn on zone 2, I would draw 100 wpc X 4 = 400 w from the wall all the way up to a maximum of 700 w if all 7 zones are cranked. The breakers in my house allow way more power than that to be drawn from a circuit.

Dan
 
Unfortunately, most AVR power supplies aren't that stable. While the receiver might output 100X2 in stereo, it usually drops to something around 75X5 in surround, then 50X7 as you add more speakers. So, in actuality, the speakers will see less peak power when biamped from an AVR.

As to the speakers not having dual binding posts, to allow biamping, don't play around and try anything. Your AVR will definitely see a dead short, and most likely be blown during the attempt. Some ideas are best left on the design floor. This is one of them. :eek:

Now, if you do attempt biamping, post a video on Youtube. 'Cause I want to see that! And it's a shame we don't have Smell-O-Vision. Nothing like fried electronics! :naughty:
 
independent of the side issues of sharing grounds, using a single speaker (per channel)
requires that you have separate non-shared connections inside to the treble and bass
drivers.

then you would need a crossover with an adjustable crossover frequency to send high
signals directly to the treble drivers and in parallel send the low signals to the bass
drivers.

unless your AVR can supply two independent signals to the bass then you are the
test case for bass being shareable due to non-directionality of low frequency signals.
I prefer to have that Fast-and-furious-46 car with the glass packs sound from
left to right as it zooms (on two wheels, no less) from left to right.

you are far better off going full active with external crossover and 4 speakers,
and if you can route the signals in and out of your AVR using that external
crossover you might be able to do this. but using a sub-woofer is the modern
expedient bi-amp solution.

700w total - what exactly are you listening to (often?) - opening tracks to "Top Gun"
Grateful Dead concert (bootleg), Nine Inch Nails. on CV D9s, JBLs?
 
700 W was just a theoretical maximum; I’d be more worried about my head blowing than anything else at that point! I might still try it, but not with the main system components. I will be sure to get a video if I do and report back.
It sounds like the power to the speakers may not be 2X like I’d imagined, but even 1.5X power increase from biamping when I’m listening in stereo (60% of the time) would be sweet!
 
Once again, the high end will only draw 5 to 10 watts maximum, the rest is wasted. Therefore, you will not have a 1.5X overall power increase.

Forget you ever thought about bi-amping, which again is impossible with an AVR anyway.
 
dannispel said:
Thanks for all the replies.
I have NOT tried it. Thought I'd get some advice first. However, I'm still curious about some of the mechanics of this.

This is true, but it would be like running a wire positive to positive and negative to negative. I've done this with car batteries, and it essentially just makes a battery with the same voltage but double the available wattage. Makes your boat stereo run forever and you can still start the boat. Seems like the same principle with a receiver. Once you put speakers (a resistor) between the positive and negative terminals of the amplifier there's no Rice Krispies.

I didn't know this. It was my understanding that the amplifier's power consumption would change when I, for example, turn on another zone. If I'm drawing a maximum of 100 wpc X 2 = 200 w in my main zone and then turn on zone 2, I would draw 100 wpc X 4 = 400 w from the wall all the way up to a maximum of 700 w if all 7 zones are cranked. The breakers in my house allow way more power than that to be drawn from a circuit.

Dan
Click to expand...

dannispel said:
700 W was just a theoretical maximum; I’d be more worried about my head blowing than anything else at that point! I might still try it, but not with the main system components. I will be sure to get a video if I do and report back.
It sounds like the power to the speakers may not be 2X like I’d imagined, but even 1.5X power increase from biamping when I’m listening in stereo (60% of the time) would be sweet!
Click to expand...


You've convinced me. Make sure to use some good strong amps and have that camera ready.
 
bowtie427ss said:
Mmmmmmmmmmmm...

The sweet sweet smell of ozone and burnt capacitor electrolyte.

Two cameras please. One covering the gear, and the second to capture the expression on your face immediately following the flash of silence.
Click to expand...

Might also be a good idea to have a defibrillator handy when you flip those switches...
 
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