Using a 2 x 200watt Amp vs. BiAmping with 120watt x 4?

[zildjian]

Hey everybody,
I would like your opinion on my set up, I have a Denon 3806 Receiver which as most of you know, has the option of redirecting the internal amp's 6th & 7th surround channels to biamp the main L&R's. I'm doing this currently, powering the tweeters and midrange drivers separately with the Denon's "120wpc", and it's great, no problems. However, I have a very nice true 2x200+watt power amplifier that I am going to put in to power the main L&R channels (no biamping, 2x200 alone. Would you all think of this as inferior to the 120x4 biamped configuration or would the 200x2watt configuration be more ideal?

I'm already taking some load off the Denon by using my old Parasound amp bridged (260watts x1) to power just my center channel (DefTech CLR 3000). If I add the 2x200watt amp to power the mains, then all the Denon is doing is powering the two surrounds, kind of seems like a waste to not use more of the amps in the denon in that set up.

My main speakers are Def Tech BP2000s, the original versions with the built in 300W subs that are sealed, not looser ported version.

Before someone suggests it, I'll go ahead and address the issue of using the Denon to say, power one section of my mains like the tweeters, and using the external power amp to power the midrange drivers. In that set up, one would be unable to set the levels balanced between the two sections of the speaker as the tweeters or mids would be too high or low compared to the other section. Wouldn't you all agree?

Ultimately, I'll probably just play around with the set up & see what I perceive as sounding best, but I would like everyone's input and thoughts, as that's what this board is for right! Internet forums, what a great information resource!
Thanks,
Brad

 

[fergusonv]

Keep in mind that even if you bi-amp with the denon your still using the same limited power supply in the denon and it's not like your adding more amplification to the speaker.

 

[AVRat]

The 200W amp should provide slightly better dynamics and more headroom.

Have you taken any measurements to see if your current bi-amp configuration maintains the speaker’s balance? If the balance is maintained, the bi-amp configuration may perform just as well. If not, the bigger amp is preferred to let the speaker crossover maintain the balance.

 

[zildjian]

Keep in mind that even if you bi-amp with the denon your still using the same limited power supply in the denon and it's not like your adding more amplification to the speaker.

Sure it's the same power supply (All power supplies are limited), but this biamping does provide for 2 extra channels of current to be drawn from that same power supply. The Denon's power supply won't provide significantly more current per channel if it's only asked to power two channels verses if it's powering four. Sure it's closer to the rated "120wpc" when driving two channels, but if driving four, lets say 100wpc is achieved, that's still more power being drawn from the power supply than with the 120 x 2 set up, hence providing more amplification to the speaker. If I'm off about any of this, please correct me.

Adding the external power amp on the other hand (which realistically, I'll probably end up doing permanently), does add more power supply to the system.

 

[PENG]

Sure it's the same power supply (All power supplies are limited), but this biamping does provide for 2 extra channels of current to be drawn from that same power supply. The Denon's power supply won't provide significantly more current per channel if it's only asked to power two channels verses if it's powering four. Sure it's closer to the rated "120wpc" when driving two channels, but if driving four, lets say 100wpc is achieved, that's still more power being drawn from the power supply than with the 120 x 2 set up, hence providing more amplification to the speaker. If I'm off about any of this, please correct me.

Adding the external power amp on the other hand (which realistically, I'll probably end up doing permanently), does add more power supply to the system.

IMHO you are right.

 

[cam]

Keep in mind that even if you bi-amp with the denon your still using the same limited power supply in the denon and it's not like your adding more amplification to the speaker.

Each channel, regardless of the rated wattage has a limit. If you have 120 watts x 2, you can not achieve 240 watts x 1, but you may be able to achieve 160 watts x 1. The channel, or lets say, output device, can only draw so much from the power supply, but that's not to say that the power supply has reached it's limits. But now if you bi-amp using 4 output devices, (of course your model has to be designed to do this) you may be able to achieve 90 watts to each channel. So you can actually increase the amplification from 120 watts x 2 to 90 watts x 4 in bi-amp mode. I know you are going to say that this is all pie in the sky because you are still dealing with a common power supply but, remember this, if you have a reciever that can produce 120 watts x 5 all channels driven, you can not get 300 watts x 2 or 600 watts x 1. If it was all just relavent to the power supply I guess you could, but the limiting factor here is the channel itself. I hope this rambling makes sense.

 

[cstpeter]

Zildjian, I made a similar adjustment to my system. I was bi-amping my Polk LSi9's (4 ohm) with the Denon 3806; I switched to a Rotel RB-991 (200x2) and experienced a significant improvement in headroom, detail, soundstage, imaging, etc. I'm sure this had a lot to do with trying to drive 4 ohm speakers with an AVR. The Denon was doing a satisfactory job when bi-amped, but I felt something was lacking, and I was right.

I'm curious for your results--provide an update when/if you switch it up, would ya?

 

[j_garcia]

While you are achieving more power total to the speaker, it is still off the one power supply, and that means less total headroom across the board. There is no getting around that. Go with an external amp and don't look back.