Obtaining the very best from your hifi system can involve a fair amount of experimentation. That said, there are a set of general guidelines that you can adhere to. However as they say, ‘the devil is in the details’ and no amount of guidelines can cover the multitude of acoustic variations that are found in room, floor and furnishing dimensions, seating positions and treatments.
One ‘tweak’ that is simple to experiment with is loudspeaker placement and ‘toe in’. What tends to occur with most loudspeakers is that the loudspeaker will tend to direct acoustic energy outwards towards the seated listener and also sideward’s towards the walls and furnishings. It is this off axis sound energy which can be the most difficult to deal with. This is especially the case with lower frequencies consisting of longer wavelengths. Depending on the distance from the loudspeaker, these reflected waves can tend to confuse a critical listening experience and it may manifest itself in the form of a slight degradation in the quality of the sound.
Critical listeners will pay close attention to room acoustics, in the form of tube traps and other acoustic dampening materials especially on the side walls, in order to absorb and attenuate this reflected acoustic energy.
Irrespective of room acoustics, your basic equilateral triangle speaker placement is a good starting point in your search for the acoustic nirvana. This simple triangulation concept places you the listener at the apex of an equilateral triangle and the 2 loudspeakers being the other 2 points. Importantly all three distances and angles will ideally be the same. In addition to this, the listener’s ear should ideally be at tweeter height (usually approximately 900mm from the floor).
Speakers should also be placed out from the rear wall in order that the bass is correctly loaded as per the manufacturer’s recommendations. In addition to this, using the triangulation method, your speakers should not be too close to the side walls. Ideally these should correspond to equilateral triangulation rules whilst still being as far away from the side walls as possible. Naturally this will have a direct bearing on your seated position. In practice, all these factors will add up to applying a good dollop of compromise to achieve the best results. To give an example, there will not be many who will tolerate a chair placed in the ‘sweet spot’ in the event it blocks a major thoroughfare. So compromise is both necessary and practical.
And then you also are aware that small speakers are great for small spaces and larger speakers for larger spaces.
So now you have covered off all the above, what further ‘tweaks’ can you do to extract the last drop of performance from your system. You all know of the concept of ‘toe in’ of your speakers and most will tweak them in towards the listening position as a token towards this concept.
Lets then look in greater detail at what ‘toe in’ is trying to achieve and then ask if you can detect significant differences when you vary the angle of ‘toe in’ on your speakers.
The concept of ‘toe in’ is that it should have a direct effect on ‘imaging’ and ‘soundstaging’. For your information, imaging is the virtual image created by the vocalist as he or she is singing in the centre of the band and when it is right you can virtually reach out to touch the imaginary holographic image of the singer right in front of you.
Soundstaging is the virtual stage with the various instruments appearing as before your eyes from left to right across the stage and forward back to fill a 3D space. Once again it is as if you are witnessing a virtual holographic image of the band before you when listening to it. When the soundstaging is correct, you should be able to pick out various instruments and the stage should extend well beyond the placement of the loudspeakers.
Radical experiments in speaker placement and ‘toe in’.
If you keep your goal of imaging and soundstage uppermost in your mind, I suggest you may be able to negate some of the negative effects of side wall reflections by placing your speakers very close to the side walls and to toe them in to a far greater extent than normal. This radical speaker placement and ‘toe in’ concept may prove worthwhile in allowing for greater speaker placement and seating position flexibility, all the while, working to maximize the positive aspects of imaging and soundstaging.
With radical speaker placement and ‘toe in’, bass responses should remain consistent or better, on account of the bass becoming additionally loaded by the side walls. Improved bass issues aside, imaging and soundstaging should also benefit due to the reason as the side wall reflections may be greatly negated in comparison to a traditional equilateral triangle loudspeaker/listening model. This effect could be further enhanced in the event you were to remove any side wall acoustic treatments, as in effect these treatments work to remove acoustic energy, which is no longer necessary to do so as the speakers are now so close to the side walls that the dispersive sound energy can be added to the forward sound energy and considered to be a single source.
My recommendation is that you try it for yourself to see if the perceived benefits of close in side wall placement and greater ‘toe in’ work in combination to provide enhanced bass response, imaging and soundstage in your system.