2. speakers
  3. 159604-20253

Does the first reflection point actually matter??

Hello my friends,

So please read the whole post before commenting. The question is nuanced.

First, as you probably know I’m a huge fan of the well treated room, and a fan boy of GIK acoustics as a result, so what I am _not_ arguing is against proper room treatment. I remember many years ago, perhaps in Audio magazine (dating myself?) the concept of treating the first reflection points came up, and it seems really logical, and quickly adopted. Mirrors, flashlights and lasers and paying the neighbor’s kid (because we don’t have real friends) to come and hold them while marking the wall became common.

However!! In my experience, I have not actually been able to tell the difference between panels on and off that first reflection point. Of course, I can hear the difference between panels and not, but after all these years, I want to ask if any of you personally know that the first reflection point really matters more than other similar locations. Were we scammed? By knowing I mean, did you experiment? Did you find it the night and day difference that was uttered, or was it a subtle thing, and if those panels were moved 6" off, would you hear it?


Best,


Erik
erik_squires

Showing 3 responses by mijostyn

mijostyn's avatar
mijostyn
8,570 posts
 
It is easy to absorb frequencies down to about 250 Hz. If one does not get overly aggressive with the treatment the spectral balance of the sound will not shift much. For those of us with full spectrum room control it does not matter as any shift can be easily corrected. 
mijostyn's avatar
mijostyn
8,570 posts
 
20% is a huge amount of wall area. First of all, the area you treat is going to depend on a number of variables like how big the room is, were your listening position is relative to the speakers, the type of speakers used, etc. Only 4% of my front wall is treated. 

Brownsfan, I mention this above. Speakers with limited or controlled dispersion patterns will require less treatment than speakers that are omnidirectional. They will have fewer early reflection points/zones.
Examples are horn speakers, dipoles and line sources. 
mijostyn's avatar
mijostyn
8,570 posts
 
 Great dissertation Duke.

 The rooms most of us listen in usually do not reverberate, they are to small. A 10,000 seat indoor venue reverberates.

The reflections in our rooms occur relatively early and die off quickly. The early ones that reach your ears are interpreted as part of the music the effect being that of a blurred picture which in audiophile terms is a lack of detail and a blurred image. Preventing the earliest reflections from getting to your ears is always worth while including those of us with full spectrum room control. Zones, points or whatever the goal is to block reflection by absorption. We have discussed how to locate these areas. Absorbing sound below 200 Hz is difficult. The lower you go the more difficult it becomes.

Over doing it is just as bad as not doing it at all. It is just a waste of money and cosmetically unacceptable not to mention that it sounds as if your head is stuffed full of cotton.

Duke alludes to a very important point. Certain speaker designs by virtue of the way they radiate sound create fewer and/or less powerful  reflections. Horns, dipoles and line sources are examples. You don't have to worry about absorption below 200 Hz if there is no reflection.
More to discover