The Onkyo TX-NR5007 manual states on p. 23 that the front and surround back terminal posts can be "bi-amped to provide separate tweeter and woofer feeds for a pair of front speakers A that support bi-amping, providing improved bass and treble performance". (my emphasis)
This statement may be wrong, but its quite clear! (by the way, I am considering the Paradigm Studio 100 in the process of upgrading my system, and have downloaded the manual. The Paradigm manual states that there are benefits to passively bi-amping theses speakers, which again seems to contradict some of what you can read on these boards. Go figure).
Originally said by a few, but repeated by thousands and thousands, the internet has allowed such audiophile myths to propagate. I'm afraid that audio manufacturers have found it is easier to agree with the myths instead of risking loosing money by fighting them. Most speaker makers also would rather provide an extra set of cheap binding posts than loose a potential customer.
I think I understand the argument about the limitation of the power supply, but the fact remains that this power supply can feed all of the 9 amps that this receiver contains. I am doubling the number of amps that are used by such speakers by passively bi-amping the speakers. Assuming that the power supply has enough capacity to feed those, am I not at least increasing the available power for the speakers?
It is important to understand what the Federal Trade Commission (FTC) requires when receiver makers state their amplifier power specifications. Look at
what Onkyo says for your receiver:
Front L & R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%,
2 channels driven, FTC)
Center
145 W (8 ohms, 20 Hz–20 kHz, 0.05%,
2 channels driven, FTC)
Surround L & R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%,
2 channels driven, FTC)
Surround Back L & R
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%,
2 channels driven, FTC)
Front High/Wide
145 W + 145 W (8 ohms, 20 Hz–20 kHz, 0.05%,
2 channels driven, FTC)
Note that these power ratings apply
only when 2 channels are driven. What power is available when all channels are driven is not stated, and not required by the FTC (
see section IIB in the third column). It still may be plenty powerful when all channels are driven, but it certainly will not be 145 watts per channel. Although nothing Onkyo says fails to comply with what the FTC requires, they are still misleading you and nearly everyone else who reads that.
So when you drive your two speakers with 4 amplifier channels instead of 2, how much power is available to the speakers? Short of doing your own measurements (if you had the right instruments), you won't know.
So far, I've only skirted around the main controversy about bi-amping:
Just what does change when you switch from one amp channel driving both a woofer and tweeter (in a 2-way speaker) to one amp channel driving the woofer and another amp channel driving the tweeter?
I've never heard a reasonable explanation of what could be different other than more power. I've heard a lot of dubious suggestions (usually invoking some amount of audiophile voodoo), but none of them convince anyone who knows basic electronics that they are genuine. Its easy to understand that if you need more power, get a bigger amp. But bi-amping (or bi-wiring - don't even ask) is not supported by any reasonable scientific explanation nor has it been demonstrated to be audibly different. But if you want to start a serious forum fistfight, try telling that to an audiophile who has spent buckets of money on multiple amps to bi-amp his speakers.
My other hobby is photography and it is not nearly as confusing!
You definitely got that right
. Imagine the howls and laughter that would come in response to an offer like this:
Psst, hey bud, I have an internet contact who sells the most incredible cryostatically treated lens cleaner that effectively doubles the resolution of your camera. You can get 4 oz. of this stuff at the bargain price of $139.95.
