Originally Posted by RichB
My speakers are flat down to the low 20's, so I agree with you.
I use the 7.1 and Pure Direct and I believe it provides the most accurate and detailed sound in my room.
I also go so far as to turn off all video processing including: Standby pass-through, Lip-Sync, Video Conversion, and I set Video Mode to Game.
My speakers lowest impedance is 3 ohms so they are moderately hard to drive.
Currently, I am using the Outlaw 7500 (made my ATI) but I have an ATI3005 on order for a little extra juice.
I did not get the 7 channel amp to bi-amp because the owners and folks at ATI said it was unnecessary. I can always upgrade the ATI3005 and add the two channels.
I like its peak indicator so I can have some idea if I am clipping the amp. Most owners say they never see it come on, so I expect that I am all set.
This is a beast of an amp.
I've decided to bi-amp, based on the classical music material that I listen to. Way too many times, the average musical passage is recorded & played-back at low volume levels. So naturally, I crank-up the volume and with my luck the crescendo kicks-in and scares the living lights out of me. During some of crescendos, the peak to average ratio can be as high as 30dB (1,000 more) which can easily not only fry the tweeter but also the midrange driver.
[Dramatization for illustration purposes] Let's assume, our average playback requires 1 Watt, and during crescendo, the amp is being asked to sink 1,000 Watts into the speaker. And, if the amp can't deliver 1,000 Watts... The output stage will saturate and produce enormous amount of intermodulation distortion and in wost case the sine waves will become square wave .. will fry the tweeter and midrange drivers.
There's very high probability that low frequencies will demand much higher output levels, the bass section amplifier may clip ... However, its clipped signal will not cross-couple into mids and highs if the speaker is bi-amped with 2 separate amplifiers.
There is an article which states that 50% of power will be distributed for frequencies from 50-350 Hz, and other 50% from 350-20,000Hz. Base on my initial calculation, it's around 200Hz.