Upgrade for Thiel 1.6 - Or a waste of $$

Hardly a "gimmick". Relieving a driver from this stress, reduces compression, allows for greater dynamic range and if the subs are seperately powered, allows the main amplifier to work with less stress. This may be more so with typical class A/AB amps which may be able to maintain the preferred class A bias longer. All in all it may change the true sound and performance in a good way. Thiel offers both active (more expensive), which is what would allow for the above, and passive filters(less expensive), which would not offer all of the above mentioned advantages. Balancing all this can be tricky, but, Thiel seems to have found a unique way to make it easier than is usually the case. This may all be academic, as I don't think your budget contraints will allow for this option.

Okay, just for fun I set the Pre/Pro to Stereo (from bypass) and told it the main speakers were small/60 and then small/80.

The effect was less than wonderful. The Thiels lost detail and the soundstage crumbled. I did pick up a hefty amount of bloated bass from my REL subs. Didn't hear enough to get me on my hands and knees to dial them in. I'm sure the pre/pro didn't help either.

I'll keep an eye out for a tube pre with HT bypass....it seems like a logical next step.

I hear the logic behind the low freq shuffle, but can't let go of the simple fact that a speaker is engineered to achieve a certain level/type of sound across a known range of freq.

If we change that range - wouldn't we ideally want to change the speaker design to take advantage? When the low freq are no longer present, how can a vent or port function as it was meant to?

It's probably painfully obvious that I'm a writer by trade -- and not an engineer.

Oh, and I can afford the Thiel Bypass Box -- but the Subs are another story.

I've only heard the monster one at the local dealer and that was with 7.2s -- so I don't know what I was actually hearing.

A Soprano! Of course!

Great point - almost makes me miss grad school.