Speakers that Disappear

[gobble]

Ya right, speakers/drivers can be designed which are more room friendly, or say to which the room acoustics are excited to a lesser degree.

How does one do that? Once the sound waves leave the cone, what controls are there to excite the room any less?

--G0bble

 

[Dr.Bass]

How does one do that? Once the sound waves leave the cone, what controls are there to excite the room any less?

--G0bble

Different wave forms have different kinds of loading and reflection patterns within the same room. Speaker/driver designers do have knowledge and control over the wave form pattern/characteristics a speaker produces. I suppose it is controlled at all levels including driver design, cross over design and cabinet design. That is the reason some speakers are strictly advised to be away from the walls while some are meant to be right against the wall. I am not technically equipped to explain what parameters in the design stage decides these factors, I am only suggesting what I have observed.

 

[odyssey]

How does one do that? Once the sound waves leave the cone, what controls are there to excite the room any less?

--G0bble

Think of dispersion and directivity patterns - many speakers don't have controlled directivity and when the dispersion is wide, placing them closer to the walls will mean a lot of reflections off of it. This is also the reason why many speakers need to be kept away from the side walls. Toe-in, Toe-out recommendations are done on on/off-axis responses.
Speakers that use waveguides typically all have controlled directivity (an example is the Emerald Physics speaker). These speakers can be placed close to the side walls without any noticeable degradation in sound.

There are other characteristics as well that make some room friendly than others

cheers

 

[odyssey]

1) does your setup do heights? I mean just as one can hear left and right spatial separation and fore and aft spatial separations, do you hear vertical spatial cues? Example: consider two windmeisters - one on a trumpet, another on a soprano sax, standing side by side separated by 3-4 feet, both blowing away to glory. If the recording mic is placed on a stand somewhere between them at some equidistant location in front of them at normal mouth height, one would hear the trumpet's sound emanating from normal ear level, and the sax at stomach or groin level. Do you hear this?

I am assuming this question is not limited only to Dr Bass's system...

your ear/brain deciphers in 3D, not 2D. This is how you can decipher height of sound sources, not just right/left positions. There is an entire sub-field of study called HRTF that deals with it and you might even find filters online that you can manipulate over a headphone connection to get artificial effects of sound sources. In a system setup well (assuming the speakers/system supports it), you will hear this 3D effect. There have been in the past (perhaps still available) 3D spatializers boxes that one can put into their system to get some sort of 3D envelope sound.

cheers

 

[jls001]

I am assuming this question is not limited only to Dr Bass's system...

@Sridhar: Thx for the reply.
The question was generic, directed at all members since I find that forum is constant fount of knowledge and wisdom.

 

[arvindrao15]

I have had this kind of experience some years back,i had a creative 4.1 ch computer speaker set.I placed all 4 speakers underneath my Couch and placed the woofer at the end of the couch on the side(The woofer was in a tight position in between the end of the sofa and the wall) I played some songs on it,and it was really hard to tell the source of the sound.I also called some friends and made them listen to it,they said that the sound is coming from the deck(which was at the front) It never occurred to them that the sound was actually coming from underneath them!