In reply to:

The QS8's are rated to 65Hz, but "flat" down to only about 95Hz. So, the implication is that there is a coverage gap (or at least uneven response) between 60 and 95Hz, although I realize that the rolloff on the QS8's is gradual and not absolute. Are you saying that it would be very unlikely or impossible to have DD or DTS surround content in that range (below 95Hz)?

For what we're talking about - home theatre - and in the rooms sizes we're talking (in the range of 500 sq. ft and smaller), the sub carries all the low frequency effects - which is a good term - it's a feeling and a rumble - not musical and not discernable as the program audio it's reproducing - if you listen to a sub by itself, you're not going to pick out dialog or soundtrack - not even Barry White's voice. The sub carries all the low frequency (thus the .1 discrete channel!) for all the speakers in a home theatre setup.

For what you can actually hear - and want to hear - in a directional or immersive manner, you use mains and surrounds. They're mixed by an audio engineer to spatialize the sound, ie: rain should be mixed equally to all channels assuming the POV is in the middle of the rainstorm, and only to the front channels if the POV is inside a building looking out a window. Another thing that should be mentioned is that DVDs are mass-market, they don't specifically mix them for people with home theatre setups, because we're definately a very, very small minority. Now does this mean they throw a high-pass filter on the surround channels during mixing? Of course not. But they mix under the assumption that even of end users with surround speakers - 90% will be using Bose/Sony/whatever HTIB. It would be nice to think that someone out there was constructing something just for us, but it's just not the case. In short - the surrounds don't HAVE to carry low frequencies (or else Axiom WOULD make a 6.5" dual woofer setup).

In reply to:

What would be the theoretical advantages of having a more full-range-capable surround speaker and setting a lower crossover point, rather than the QS8/80Hz example? Is there a valid hypothesis that a future QS12 (with a bigger box and bigger drivers) and lower crossover point to the sub would be "better"?


Theorically, you'd have more localized bass in the surrounds, but I'll go with my rubber stamp answer on this one - if you can audibly pick out the surrounds, they're not doing their job, it's a hard thing to swallow... you've just paid $470US for a pair of speakers you're not supposed to hear? It's subtlety, sometimes it's best to go with the bayonet instead of the cannon.

In reply to:

Or, to put it another way, what are the relative disadvantages of just setting the sub crossover point higher (at 80Hz or even 100Hz)?


For what the surround channels carry, and for the part they play in HT, they're not required to carry ultra-low frequencies, but the higher they're crossed-over, the more you may lose - it's a balancing act. At an 80Hz crossover point - you'll get the sound of a jet flying from the right surround overhead to the left main, for instance, you'll be able to hear it move "over" you, but the jingling-of-keys-in-the-pocket effect comes from your sub. That part, acoustically, you'll never realize - it won't seem like "hey, these turbine engines are flying over me, but the rumble is coming from beside my TV."

If you feel like doing any home research, hook your sub up through the driven lines from one of the surround channels. That'll show you what you should be listening for to see if you're missing it being spatialized.

Bren R.