Friday, May 18, 2012

Speaker Positions: Elevating Your System to a New Height

You have to be pretty much brain dead to not appreciate that when repositioning a speaker in a room, such changes produce desirable or undesirable effects. For example, major movements create shifts in the width, height, and depth of the soundstage and emphasise or de-emphasise certain frequency bands. This stuff is old hat, but what people usually do when repositioning a speaker is to move it about the room on its speaker stand changing its position in only two dimensions (L-R or F-R).

The last time I checked, we live in at least a three dimensional universe which adds up-down to the number of choices you have when repositioning your speakers. Yup, I looked outside again just now to make sure and yes it is still a 3-D world.

SOOO, why even bother? That's sort of like asking "Why not just leave the speakers in the box they came in and hook up the wires." But before dismissing this possibility as snake oil, ask yourself this: When was the last time I changed my speaker stands? I bet the resounding answer is never.

Speaker manufacturers take great pains to choose the distances speaker drivers are from each other on the baffle board, some using the effects of inherent phase distortion in crossover networks to place the resulting acoustic wave produced by both drivers involved at the crossover point in phase with each other. Placing your speakers at the proper height for the room is equally as important.

Several folks have already written terrific books on the subject of room tuning and their success in business demonstrates that such attention to detail is worthwhile. They too may have overlooked this third dimension. So what's up with that (pun intended)?  Why is it OK to swap a preamp but not speaker stands? Why is it OK to move a speaker left or right but not up or down?

There is a bit of science behind why the height off of the floor impacts the sound; the same science used to position speakers on the baffle board with respect to each other: acoustic phase. From my previous article on "Speaker Dispersion and the Sweet Spot," you saw how a speaker begins to beam as the frequency rises for no other reason than the physical length of the acoustic wave begins to match the diameter of the speaker driver. A similar phenomenon goes on between the drivers and the room boundaries, one of these boundaries being the (often overlooked) floor and the length of the acoustic wave interacting with the speakers (the sound bouncing off of the floor and then back to the speaker).

My recommendation is this: once you get the speakers in that "right place" by moving then L-R and F-R, see what effects moving the speaker up/down has on fine tuning their positions. Just as small movements of 1/4" (6mm) can make the difference between a good and great sound stage in the horizontal plane, so can raising or lowering your speakers off of the floor in the vertical plane.

I would start by placing small pieces of granite under the tiptoes or speaker spikes and listen primarily to the bass. Again, small changes should make noticeable differences so find chunks of granite of various thicknesses to give this a try. Going to a Custom Granite Counter store and picking up discarded pieces is an easy thing to do and one where they will most likely not charge you a dime for helping get rid of this small waste.

If your spikes are adjustable, try extending the spikes in 1/4" increments and listen to the results. You may find that what you were previously satisfied with as a speaker's "best place" can in fact be improved upon again. The good thing about repositioning, is that if the effect is undesirable, you can always back it out.

So here is a tweak that you can do for free and one that may have a huge impact on music appreciation. "Give it a go!" as our friends the Brits would say.

Yours for higher fidelity,
Philip Rastocny

I do not use ads in this blog to help support my efforts. If you like what you are reading, please remember to reciprocate, My newest title is called Where, oh Where did the Star of Bethlehem Go? It’s an astronomer’s look at what this celestial object may have been, who the "Wise Men" were, and where they came from. Written in an investigative journalism style, it targets one star that has never been considered before and builds a solid case for its candidacy.

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