How do I "compromise" speaker placement

Most people think that you can measure your way to the best placement, but it doesn't work. See the following thread for something that actually works:

http://forum.audiogon.com/cgi-bin/fr.pl?rspkr&1197744079&openmine&zzDcstep&4&5#Dcstep

Bob, let's not get into that 83dB stuff again. We'll NEVER agree on that, but you're having fun with it and are welcome your concept.

As for measuring your way to proper setup, I was thinking of tape-measure, not SPL. Indeed, SPL can help, but only after you've optimized as best you can with Master Set and still want to further tame a node, either with traps or active EQ (attenuation only) such as Rives.

You've got to get the speaker working together coherantly and minimize intermodulation distortion. Once you've done that, then tweaking with room treatment or EQ can get you even flatter. Intermodualtion distortion is often heard as glare and loudness. When it's controlled, then you can actually listen several dB higher without fatigue. Said another way, 83dB with intermodulation distortion sounds louder and more fatiguing than 88dB without intermodulation distortion.

So, I say, address this first. Moving the speakers a fraction of an inch can make a big difference in perceived sound.

Dave

Bob, you can get the EQ "right" at any listening position, but if you left the IM distortion in then it'll sound like CRAP, no matter what speaker you use. Go to any audio show and you'll hear it in room after room. (Harsh, edgy, grating sound from really good components).

Like you said, "You paid for the speaker, why not get all you can from them?". Until you minimize IM distortion you can't enjoy your system to the max, no matter how flat the EQ. My method is set the speakers first, for the best combination of low IM Distortion and minimal bass nodes, then start addressing any problems that remain with room treatments and/or active EQ.

Dave

IM distortion is also caused by speaker-to-speaker timing misalignments. If you think it's important for the drivers within a speaker to be properly time aligned, then you'll likely agree that getting both speaker firing in sychronicity will also be beneficial. It very critical, yet easy to hear when done correctly.

Dave

Yes Bob, very similar to that, but not exactly. With phase you can have speakers literally pushing a pulling against each other. With IMD it's more about timing of the direct signals arriving in-phase but not at the same time. It's easiest to imagine thinking of a mono signal through a stereo system. It'll come equally out of each speaker, so time alignment of the two speakers must be precise or you hear an inbalance and/or a smearing.

In an anechoeic environment that would be simply time alignment, but then you add the room interaction and the nodes and you do get cancellation, emphasis and timing all rolled together. In my experience, you perceive it as added harshness and loudness. When it's minimized (I doubt that it can be eliminated) the loudess measured with an SPL meter is the same, but your perception is that the loudness declined. It's amazing. You find yourself comfortably listening to music 12dB or so louder.

My understanding is only as a layman and from the little I've been told by Rod Thomson based on his training by Sumiko.

Dave

No Bob, it's sound pressure level instead of distance. With the sumiko Master Set the distances are rarely equal, because of the room annomalies. The Master Set takes into account multiple interactions at once.

Dave