If I read the manual correctly, it would appear that even when you do not engage a HP filter at the 80hz, there is always a summing of the 5 channels and filtering of the low pass to the sub. In otherwords the.1 channel is always adding bass from the other 5 channels. Is this correct?

If so, how could one truely use a ICBM with this pre-amp for greater crossover flexibility? seams like the 950 will be adding unwanted processing in the back ground . . .

Adrian

Adrian,

You only get this behavior using the analog 6 channel direct inputs. The subwoofer channel gets redirected bass from the other five channels regardless of the position of the switch on the back. This does not happen with the digital processing.

There was a debate about this when the 950 first came out. Because of the 950's digital bass management, putting an ICBM on the 950's pre-amp outputs is clearly unnecessary, but there was some concern like yours regarding an ICBM at the 950's six channel analog input. The condition you are describing (in which the five full range channels are unchanged while the sub channel is a combination of .1 and redirected bass from the full range channels) was called "double bass" during some lengthy and often heated debates. Outlaw's stance was and still is that "double bass" is not typically going to be detectable in a real-world application such that using the 5.1 analog input with the analod bass management "off" is not objectionable (they studied this during design to confirm their assumptions). Putting an ICBM in the mix is something that I don't think was ever heavily discussed, although several people expressed the concern that the extra low-pass crossover could skew things. Personally, I would choose to instead use the 950's analog bass management (which I am currently using for DVD-Audio and SACD on my 950) rather than adding an ICBM. For someone who already has an ICBM the options are different, and some concern is understandable. I can see an argument in favor of retaining an existing ICBM - depending on where the ICBM's crossover points are set, the entering "full range" channels have already had much or all of the material that would pass the 950's low-pass crossover removed, so the material added to the .1 channel would be even less than appears in the normal "double bass" condition.

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