Dunlavy SC IVA X-over resistor values

if DALs have a narrow dispersion then why is distance and angle from the sidewalls so critical, as well as the reflectivity of these walls?

Precisely because they have narrow dispersion!

Narrow dispersion speakers, when listening far-field, are typically very finicky about position. Think about an ordinary light bulb versus a flood light - what you see is a combination of direct and reflected light. It is the same with hearing.

To continue the analogy, the lighting in the room will be most even with the omnidirectional light bulb (more reflected light). The light bulb is clearly less sensitive to location/direction. The flood light will be much more sensitive to placement/direction...only with careful positioning can one get the desired reflected light to evenly illuminate the sweetspot. It is the same with speakers - wide dispersion makes placement very easy.

And even yet when these speakers are properly coupled within their own cabinet and to the room cabinet that surrounds them they truly become three dimensional and much less critical to placement. Ya just got to venture out and do it. Tom

Shadorne, I've read your response a couple of times and it does not make sense to me. Assuming you meant an unshaded light bulb (360 degree radiation) compared to a spot light (believe flood lights come in a wide variety of radiation patterns) in your analogy, it seems to me the opposite would be true.

From my reading on speaker placement, acoustics, and room treatments, it appears that a minimum of 10 msec delay is typically recommended for reflected sounds compared to direct sounds. This minimizes smearing and improves clarity. Now the narrower the dispersion (more focused, like a spot light) from a given speaker, the less the intensity of the sound waves reflecting off the sidewalls. Conversely, the wider the dispersion pattern, the greater the intensity of the reflected sound waves and the more important placement and/or treatment would become to satisfy the 10 msec or greater delay objective.

Both DAL and Duntech designs are fairly wide dispersion which is why sidewall reflections are critical to optimum set up.

Shadorne, I've read your response a couple of times and it does not make sense to me.

What you hear is a combination of direct and reverberant energy. The 10 msec rule is for precise imaging - getting a fix on where a sound came from, however, your brain still adds or hears the reverberant energy that occurs after 10 msec (it tends to be ignored however in terms of direction provided the brain figures it is part of the sound). You need to read up on Haas effect - bascially anything up to 30 or as much as 40 msecs gets added to the sound by your brain ( you hear it - which is why a certain amount of reflected sound/echo/reverb enhaces the audibility of music). Anything that occurs much later than 40 msecs is often regarded as a distinct or different sound by the brain - this is why large highly reflective gymnasiums make for terrible sound.

Bob Katz has written some stuff on this, as have many others. Don't ask me why our brains work this way but they do.

My comment was that in a "far-field" a narrow dispersion design type of design can be tricky with placement.

I believe Dunlavy recommended placing some of his designs on the long wall, far apart at 120 degrees, and toed in
- this is closer to "headphones" than a more conventional 60 degree equilateral triangle speaker setup (you get far more direct sound and less reverberant sound with Dunlavy's suggested setup).

However I must add that I don't have at home experience playing with DAL's and your extensive experience seems to contradict my understanding...perhaps other DAL owners can chime in...

I hope we are not getting cross threaded on this ;-)

I readily admit that DAL's are some of the most highly regarded speakers of all time!