When I measure, it’s from the front of the speakers to the front wall and when I do toe in, it’s in relation to the front wall as well. So I have two systems. The first has the front of the speakers four feet from the wall and no toe in and the other has the speakers 42” from the front walls and about 10° toe in. All the best. |
The distance from the front wall is going to effect the mid and upper bass/lower midrange. If the face of the woofer is three feet from the front wall, the distance to the wall and back is 6 feet, that is the wavelength of about 185 Hz. Thus 185 Hz and the frequencies around it are going to be reinforced. As you move the speaker closer to the front wall the reinforced frequency increases, as you move away the reinforced frequency decreases. At five feet it is about 100 Hz. Other frequencies are attenuated. None of this is good. Sound absorption on the front and side walls is very important but it is only effective above 200 Hz at best. If you could set up the speakers 10 feet from the front wall you could reinforce 55 Hx. 28 feet would reinforce 20 Hz. All this is impossible in residential situations. All the above is the reason that digital room control is so important particularly in the bass. Any other changes in sounds quality with speaker positioning depend on the timing of reflections which depends entirely on the room. These reflections effect fine detail and imaging. If reflected sound can travel 100 feet before reaching your ear you hear an echo. Thus the more sound absorption you use anywhere in a room the more you are going to decrease the likelihood you will hear an echo, which IMHO is a good thing as the echo was not in the recording. Some people actually like echoes as they add a false sense of spaciousness. All the echoes of the venue where the recording occurred are on the record. Studio recordings frequently have echo added to them to create dimension. Live recordings generally do not need it. Sorry for preaching. |
@bdp24 Thanks, my question was the simple one of do I need to explain what x feet from the front wall means. Regarding speaker placement, I always try to get the best bass relative to where room logistics force the listening chair to be. I agree that measurements are at best a generalization as I have never had a "perfect" room. There's always walls of different dimensions or an opening on one wall that isn't mirrored on the other side of the room.
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Based on my reading I agree with bdp24 regarding the 5' minimal placement, at least for dipoles. Bell Labs research determined the 10 ms minimal delay between direct and reflected sound for best clarity. That applies to side wall reflections as well (less so with dipoles due to directivity), which is why there are so many recommendations for identifying the primary side wall reflection points and applying diffusion or absorption panels there. |
I have been using dipoles exclusively since 1979, I currently use 8 foot Sound Labs ESL and they are between 2 and 2.5 feet(towed in) from the front wall. The wall behind a dipole should always be heavily deadened. I use 4" thick acoustic foam tile, but that is all you have to do with them other than use subwoofers below 100 Hz. Dipoles have a lot of trouble with the longer wavelengths. I hate to disagree with Bell Labs, but that is a purely subjective evaluation. Any sound within 100 ms of the direct sound is sound that was not in the recording and by definition is distortion. After 100 ms it is an echo or a different sound altogether. Dipoles are 180 degrees different than other types of loudspeakers because the sound that comes off the back is 180 degrees out of phase with the front wave which means that at three feet from the wall 185 Hz is attenuated. At 5 feet 100 Hz is attenuated which is not good for bass. It is a lot more complicated than this as again other frequencies are reinforced. I keep my speakers closer to the wall because higher frequencies are easier to manage with acoustic absorption. Below 200 Hz there is not much you can do other than digital room control. The issue that causes such varied opinions is that some distortions sound good to some people. They can add warmth and ambience to a recording. Being the stubborn purist that I am I only want to hear what is on the recording. It seems to me that like @rauliruegas I find that systems that are devoid of most distortions sound better.
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