I spoke with the Outlaws about this, and this is what I understood the situation to be regarding the 5.1 bypass BM.

There are generally three classes of users who would be typically using this input, and these are:

Those people who have "small" speakers and a subwoofer - For these people, the 80Hz switch should be "on", as their mains cannot reproduce the low bass that is present in most music, and therefore a sub is needed to reproduce this range. All bass below 80Hz is routed to the subwoofer. The LFE is generally not used on multi-channel music discs, but in those instances when it is, it would be routed to the sub also. This matches the setup that would be used in normal DVD movie playback.

Those people who have truly "large" speakers all around, and no subwoofer - In this instance, the 80Hz crossover switch would be "off". Since there is no subwoofer attached, what is coming from the subwoofer output does not get used. In those infrequent discs that do have an LFE channel, this generally contains redundant information, so there is nothing lost: the low bass is also coming from the other speakers.

Those people who have speakers that are too large to be considered "small", yet too small to be considered truly large, i.e. they are able to reproduce down to 40-50Hz or so, and they are also using a subwoofer. This category encompasses a large segment home theater speakers, such as floor standing units and mid-size bookshelf models. While the mains can reproduce bass, their ability to reproduce low bass is limited. The lowest ranges of the string and electric bass fall into this category, as does the low ranges possible in music that uses synthesizer or sampling.

It is for these people that it was decided to provide "summed" bass below 80Hz on the subwoofer output regardless of the position of the crossover switch. This allows the subwoofer output to augment the bass that is already in the main speakers, yet is not being reproduced by the mains with enough weight to the lowest octaves. In other words, it is "filling" in at the low end, where speakers in this class are starting to diminish in bass response.

Outlaw mis-calculated the number of people who fall into this last category who don't find this feature useful, or more likely don't understand the usefullness of it. I can see that it would be useful if I had speakers that fell into this class to have the ability to fill in the bass region where my mains were beginning to roll off. There is technically no "double bass" in this situation because of the natural rolloff of the bass from the mains.

Anyway, I've been told that they have taken our feedback into consideration, and in the future will expand the available options.

[This message has been edited by soundhound (edited April 11, 2003).]