I started some of this discussion/controversy a couple of pages back in responding to a question about the "pure clean sound" of the speakers. And I was saying that it was almost impossible to know what that was, as the room, set-up, etc. exerted so much influence on the sound. I think this discussion is relevant to Audyssey, so I'd like to take a crack at why I think it's important to clarify what I, and perhaps a couple of others, have been trying to say.
I originally used the term "room modes" too loosely and corrected myself in a subsequent post, referring instead to speaker/room interaction. Igor Zep's post above: "This is designing for the boundary gain, not room modes" is the same reason I preferred the phrase speaker/ room interaction. I was referring primarily to boundary gain. The fact that some speakers are specifically designed to benefit from boundary gain is undeniable. If you don't believe that, try pulling your subwoofer(s) out into the middle of the room and listen to how it sounds. Where did my bass go, indeed? In fact, the most common, virtually universal, advice on subwoofer placement is near (1'-2'?), but not too near a wall. Of course, the speaker manufacturer can't know your specific room dimensions or volume, or where you have nulls, although many do try to help those issues in their designs. For instance, they may offer different sizes of subwoofers with different power amps, and they may offer different porting options. Most of us understand that larger rooms, or the desire to run our systems at very high volumes, require larger more powerful speakers. The manufacturer's give us different models and it's up to us to try to match them intelligently with our rooms. That was a point I was trying to make in my original posts.
But I think it's also important to understand that not all speakers are designed to use boundary gain in the way that subwoofers and many direct radiating speakers are. I used the example of planar speakers--large electrostatic panels such as Magnepan or Martin Logan. I believe I have seen owners of both speakers post on this thread. Those large thin panels are specifically designed not to be placed close to boundary walls. I believe the placement recommendations I remember seeing on the really large panels (73" and up) is a minimum of 3'-4' from a wall. A friend of mine, who owns an audio store, and who has sold Magnepans for 40 years, places his large panels 6' from a wall in his private listening room. Again, try that with a direct radiating speaker and see what it does to the bass. But the Magnepans sound great that way. They aren't really designed to go as deep as comparably large direct radiating speakers, and they aren't so dependent on boundary gain in order to optimize their performance. Those are examples of completely different technologies with completely different strategies with respect to room interaction. Does the manufacturer need to know the specifics of our room sizes, dimensions, or configurations in order to design speakers intended to generally work with rooms in a particular way? In these two cases: near a boundary wall, versus well away from a boundary wall. Well, obviously not from those two examples. But if we want to derive the maximum benefit from our audio systems, it's something we might want to give some thought to.
The relevance to Audyssey is equally obvious. The set-up guide, and the long-term subscribers to this thread advise people coming here for advice to be very diligent in their speaker placement, prior to running Audyssey. We can't expect Audyssey to correct all of our fundamental placement mistakes, or compensate for inherently inadequate amplifier power, or speaker capability. So, we bear some responsibility to understand the design intent of our speakers; follow the suggested protocols where we can regarding speaker placement, whether it's close to or well away from boundary walls; observe appropriate toe-in (or not) recommendations; in some cases tilt-up or down for maximum tweeter directionality (think height or rear surround speakers, for instance); consider power requirements vis-a-vis distance to MLP, and so on, to optimize our performance. Typically, we will have to experiment a bit, which is one of the first pieces of advice usually given, often after a request for photos of the room.
From the beginning, the point of all this to me has been the importance of trying to understand the specific design goals and capabilities of our systems, to maximize those capabilities generally in accordance with manufacturer recommendations, and then to apply Audyssey in a similar fashion. Again, the typical advice is to apply Audyssey as methodically and diligently as we can, in accordance with manufacturer recommendations, and then to experiment, if we wish, from that "reference" standpoint. In my experience, it is an iterative process. Studying Audyssey makes me want to understand the rest of my audio system better. Then, as I experiment with my speaker arrangement, or bass traps, or whatever, I re-run Audyssey and achieve ever better results. But it all starts with the appropriate applications of all system components, including speakers, in a way that is consistent with the original design intent.
Last edited by mthomas47; 08-01-2014 at 10:08 AM.