Are You Hearing Everything You Paid For?

You may not be hearing everything you paid for from your loudspeakers.

Recent years have brought a parade of midsize towers, shorter floor-standers whose tops reach somewhere between the navel and the breastbone, to my studio either for review in these pages or for other reasons. Many of these have been fine loudspeakers, some very fine indeed. But almost without exception, they have all suffered a common weakness: they’re too short to qualify as “real” towers, but far too tall for stand-mount or bookshelf placement.

Of course, the market dictates size along with most everything else. Many shoppers want something a bit smaller, and cheaper, than full-blown towers, and down-sized towers fit the bill on both scores, the wood box being far and away the most expensive component of a typical, mid-market loudspeaker design.

Well and good, but there’s a problem. Seated-ear-height, depending on your chair and your personal elevation, is somewhere between 38 and 44 inches for most of us. These mid-tower speakers nearly all stand less than 40 inches tall, and some of them are well under that mark, a few barely reaching an honest yard in elevation. And that’s a problem, because it means that such designs—and all I’ve encountered recently are either 2-way or 3-way layouts (or “two-and-a-half-ways” that deploy multiple woofers, with one functioning as a normal 2-way reaching all the way up to the tweeter, and another one or more as bass-only drivers)—locate the tweeter at or even below our seated-ear-height.

This is an issue not because we need to be directly on-axis to the tweeter, which is almost always the driver with the broadest and most even dispersion, vertically as well as horizontally, but because we really do wish to be very nearly on-axis to the “in-phase lobe” of the speaker’s mid/high-frequency output, which always has a much narrower vertical-dispersion sweet-spot than the tweeter itself. Just where, height-wise, this occurs, and whether its aim is perfectly horizontal or up- or down-tilted, is a function of complex, interactive factors, mostly the types of drivers, their spacing, and crossover circuit topology and implementation. But it is always well below the tweeter axis (I make exception for the few “tweeter-under” designs out there, none of which are mid-towers of my acquaintance), and often has a slight down-tilt, which together mean that the speaker's designed response is really only audible to a listener, at the proper distance, seated cross- legged on the floor.

It’s easy to test your setup. Play any steady-state signal rich in higher-frequency noise, do the stand-sit-squat test at your normal listening position, and note your position where the sound is the brightest.

Don’t believe me? It’s easy to test your setup. Play any steady-state signal rich in higher-frequency noise: a test disc (or file) with pink noise is ideal, but an AV receiver’s level-cal “match tone” will do, and in a pinch, so will inter-station FM-band noise (you’ll have to defeat the tuner’s FM-muting function, usually by selecting the manual-tune monaural mode). Now, in stereo listening-mode but with just one speaker playing (disconnect the other) do the stand-sit-squat test at your normal listening position, and note your position where the sound is the brightest: with the most prominent “hiss” and “shh” components, as opposed to the “hoo” and roar of lower-frequency elements. Measure your ear height where this occurs—a folding carpenter’s rule is the easiest tool for this. I’ll bet you it is as much as 6 inches or even a foot below your ears’ altitude when seated in your listening chair. (Dedicated nerds can repeat the test halfway to the speaker, and then draw a line, mentally, between the two heights to determine the aim-angle of the in-phase lobe. Extra credit for repeating these tests on the other speaker.)

What to do? Well, you could build plinths to elevate your speakers, or saw a few inches off your listening-chair’s legs. But far more practicable is simply to back-tilt the speakers. I use CD jewel cases slid under the front edge of the speakers (floor-spikes removed or retracted), initially; almost always, a one- or two-jewel-case elevation does the trick, but there have been stubborn, three-jewel-box cases. Now repeat the stand-sit-squat test to determine how close you’ve come to directing the desired lobe to the seated-ear position, and adjust as necessary.

You probably won’t want to go through life with jewel-boxes stuck under your speakers, so simply measure the distance from the speaker’s bottom-front edge to the floor—or instead, as I do, measure the baffle’s actual deviation from plumb using the level function of your iPhone’s compass app). Now you can replicate that angle by adjusting the speakers‘ screw-in spikes or glides.

Sound better? Airier? “Deeper,” imaging-wise? More lifelike transient attacks? More convincing cymbal shimmer?

I thought so.

COMMENTS
dommyluc's picture

There's a new kind of product just entering the market that may solve the nearly deadly dilemma many in your situation are facing. They are called, for lack of a fancier term, "speaker stands". I only hope that they help listeners hear all that their speakers have to offer.

Daniel Kumin's picture
Yeah, bvut I was specifically addressing "mid-" or "mini-towers," increasingly popular types in recent years. Either will be unstable and/or goofy-looking on a conventional stand. You could probably kluge up a plinth of some sort to good effect, but the cosmetics will be an individual judgement.
FrankReed's picture

It's a common problem in the last years. And there are two reasons for it. The first one is that thing when some company (manufacturer) produces his products, then goes with them on the market, and some part of his devices has defects due to which the sound is distorted. The second thing is when a well-known brand produces a new model of the device, intentionally exceeding the expectations of his regular customers, and as a result, we get frustrated with the device' quality. There's a lot of best essays written by students on this topic, and even more research, so I hope the problem will be solved in the near future.

sandeepmohan's picture

I have experienced exactly what you say and its pretty evident that the tweeter isn't in line with my ear, even though I am seated in a lower chair. I have a Blumenhofer Genuin FS5 (Now discontinued) that has a sloped front baffle and uses a compression driver as the tweeter. I do believe I am at a slight advantage with this design. What are your thoughts?

Daniel Kumin's picture
If I am not mistaken this is a bookshelf-type speaker, which can (and should) be placed on a stand selected for proper elevation, so not really relevant to the discussion, which was about floor-standing types.
Jonasandezekiel's picture

What about a speaker with a d'appolito array..in other words, with a tweeter in the middle of the speaker baffle, flanked by two larger drivers? Would that necessitate raising the speaker even higher?

Daniel Kumin's picture
No. the purpose of a d'App array (and I know Joe D'App, as he's known, a bit) is to control vertical dispersion deliberately while leaving horizontal dispersion MOL unaffected, thereby reducing potential image- and tonality-sucking reflections from the relatively close ceiling and floor. If the speaker's in-phase lobe is aiming over (or below) your head due to its height or angle, the type of driver array, whether TW (2-way), TMW (3-way), or MTM-W (d'App) is comparatively immaterial.
karlzeiss's picture

I have also experienced exactly what you say!

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