Originally Posted by MikeR397
I've been trying to learn a little more about passive bi-amping from the receiver. Please correct me if I'm wrong, but for example with the Marantz 7008 (or 7009), with 125w per channel at 8ohms, a biamp configuration is likely net gaining ~50 watts at most overall, which would be comparible to a single 175w channel...
By this, I mean the mid/tweeter will get a 125w channel (which they will never use more than 50w of at non-eardrum blowing levels) and the 3 power hungry woofers in the CM10 will get a 125w channel all to themselves (as opposed to sharing 125w with the mid and tweeter). The woofers is where the power is actually used, so the benefit in biamping is that they always get thier own 125w regardless of what the mid/tweeters are getting. Thus, the benefit is listening at loud levels, where the mid and tweeters are drawing ~50w on thier 125w channel, the subs are still getting/limited to using 125w max (still a nice benefit over 75 available with a single channel in this example).
Presuming I'm understanding this correctly, then wow is there a lot of mis-information running around the "showcase floor rooms"...
OTHO, I've also read that anything over 100W will get 95%+ perfection out of the CM10's, and I shouldn't be stressing so much about the Marantz's 125w vs Denon 4520ci's 150w ratings wrt to "optimizing the CM10's best sound potential," especially with the partial added benefit of still biamping the CM10's with either receiver.
I think you have a much better understanding of passive bi-amping.
Yes, there is a lot of mis-information circulating out there!
There are a couple of things I would like to point out to you.
1) when you remove the jumper straps off of the crossover on
The back of the CM10 you state that the split is the 3 woofers
On the bottom post and the top post would have the
Mid-woofer and tweeter. (That would be ideal)
Recently I was involved in a discussion on the Paradigm speaker
Forum about bi-amping the Studio 100's which have the same
Driver configuration as the CM10. After some research it was
Determined that the "split" on the 100's was the tweeter on
The top post (only) and ALL other speakers on the bottom
Post! (Not ideal) The tweeter may only use 20 watts max!
No real benefit with bi-amping there.
2) the more channels you use the lower the watts to each channel.
Remember it's only ONE power supply. Take a look at the
Bench tests for the 2 AVR's you are considering. Notice how
The more channels you have "engaged" the lower the "power"
To each channel. For example: you bi-amp the CM-10's engaging
All channels. Now you are no longer getting the 125 watts to
The bottom posts! Also your center is no longer getting 125
One important thing to remember is that you will RARELY
Have full power going to all speakers at the same time!
(Except during a very intense and prolonged action scene)
( Listening to music utilizing ALL of your speakers)
You are correct in assuming that you will probably never use
More than 100 watts per channel to get you to very loud
Listening levels. If you configure your bass management
Correctly on your AVR and let the powered subs take over
Playing the low bass notes that may be sent to the speakers
You will use even less power and your speakers will play cleaner
And louder too!
Here is a fun calculator to see how much power you actually
Use to get LOUD. The sensitivity of the CM10=90.
Example: using the CM10 sensitivity of 90, sitting 15
Feet away from the front 3 and using 7 speakers
With ONLY 10 watts you can hit 98db's!!! Very Loud!