Five feet from the front wall

@dsper Wrote:

Five feet from the front wall

Just what does "X" feet from the front wall mean? Is this from the front of the speaker or the back of the speaker?

The front baffle of the speaker. 😎

Mike

Read the question?  That’s no fun.  Kinda like reading the directions first.

@paulrandall 

I stated, I thought clearing, that the reference is the face of the driver, not anywhere else. 

@invalid 

It makes not difference whether or not you are direct driving ribbon speakers although you have to be careful. The tweeters have VERY low impedance, < 1 ohm and can burn up some amps. All planer dipoles benefit from subwoofers. It is not a mater of speed. Speed has nothing to do with it. Lack of spurious resonance's, time and phase coherence along with the right crossover point have a lot to do with it. 

@lanx0003 

That is the wrong way to look at it lanx. Sounds that reach your ear after 10 ms are perceived as an echo. Less than 10 ms and they are perceived as one with the direct sound. That does not mean these sounds are not distorting what you are hearing, they are in a big way. They are sound that was not present on the recording and as such are distortion. They change frequency response (amplitude) and screw up phase affecting the image.  

@bdp24 

If is extremely hard to over dampen a room. Most system/rooms that I have auditioned are under dampened. What people think is dull and lifeless is generally much more accurate, they are just use to sizzling hot with echoes and have a hard time reorienting themselves. Turn the volume up, way up to 95 dB. If the sound wants to cut your throat you are underdamped.

That is the wrong way to look at it lanx. Sounds that reach your ear after 10 ms are perceived as an echo. Less than 10 ms and they are perceived as one with the direct sound. 

I'm not sure where you received that information from. The reference to a 5 ms time interval was made by Haas (1951), who stated that a single reflection arriving within 5 to 35 ms can be up to 10 dB louder than the direct sound without being perceived as a secondary auditory event (echo). The shortest possible interval is 5 ms.  You can find this information in the following reference.  Should you need more details, let me know.

Haas, Helmut, The influence of a single echo on the audibility of speech, J. Audio Eng. Soc., Vol. 20, Issue 2, pp. 146-159, March 1972 (English translation by Dr. Ingr. K.P.R. Ehrenberg of Haas’ original German paper published in Acustica 1, pp. 49-58, 1951).

@mijostyn: Just for the record, I much prefer an "over"-damped room to an "under"-damped one. My current one is on the over-damped side, and I have found diffusion to keep all the output of my dipoles audible, whereas I believe damping (please, not dampening 😉) would absorb the high frequencies too much. But then I use dipole planars, which produce very little output to their sides, and therefore very little sidewall reflections. The loudspeaker/room is an integrated system, you can't separate the two.