Shopping for a speaker system is not unlike shopping for any other audio component, except that it is arguably even more important to listen to it first and on as many occasions as possible.  The first and most compelling reason is the size and weight of speakers.  The manufacturer may allow you to audition a system in your own home, with freedom to return it for refund, but they certainly will not pay the round-trip freight, and that is usually substantial.  Further, a speaker system requires careful placement and alignment in the listening room, a process that can take several hours, if not days.  In some cases involving very heavy speakers, this process can require one or more people from the manufacturer to come to your home and do the installation.  Needless to say, you really want to be confident in your selection before starting this possibly arduous job.  But the needed level of buying confidence depends on quality listening sessions outside your home.  This paper was written as a help to achieving quality listening sessions in general.  A quality listening session is one that informs, one that brings you closer to a decision about whether to buy and what to buy.

Walk into any audio showroom, whether an annual audio show or an audio salon, and you are listening to speakers.  Unfortunately, you are also listening to sources, DAC’s, preamplifiers, amplifiers, cables, etc.  What you are also listening to is the room, and this is frequently the forgotten “component.”  As a shopper, your job is to separate the speaker system out from all of these other influences, a potentially daunting assignment.  Where do you start?  I recommend that you start by reading all of the reviews you can find on the speaker system before you ever start listening.  Some would argue with this approach, claiming that the reviews can instill unwarranted prejudice.  Please take the advice or leave it, depending on your personality.  In any case, don’t expect the audio reviewers to make the decision for you, but their perspectives are a good starting point.  Once this is done, begin to visit high-end audio shows and audio salons where one or more speaker systems of interest are available for audition.  What you are trying to do is experience the system in a room/setup that really sounds good to you.  This may take some time and it may take traveling to a few shows because the sound you hear is a product of many variables which are capable of spoiling the sound.  Once you find the speakers in a system that sounds very good to you, then and only then do you know that the speakers are capable of pleasing you in your home.  If this does not happen after listening to several systems that include the speakers of interest, consider the possibility that you may not want this speaker system after all.  This statement reflects the invaluable principle that a system that sounds good is usually comprised of good sounding equipment, whereas a system that sounds bad may have any one or all components spoiling it.  Good sounding systems teach you much more than bad sounding systems do.

Before walking out of any given room that doesn’t sound right, ask yourself why you don’t like the sound.  Often, bad sound is bright sound that contains accentuated highs and sizzle, annoying artifacts that interfere with experiencing the music itself.  Mature audiophiles usually don’t like this bright sound because they are expecting the presentation to sound natural and believable.  If you enjoy bright sound, particularly unnaturally bright sound, this paper is not for you.  It is the fetish of a large percentage of junior audiophiles to have plenty of tweeter and woofer sound, a badge of technological accomplishment.  No offense is intended here, but as audiophiles mature, their need to explicitly hear the drivers and the associated pretentious detail and boom tends to wane in favor of more natural sound.  In fact, many seasoned audiophiles regard it as a necessary milestone of accomplishment that the speakers are not heard or noticed at all.

When bright, sizzling sound is present, wait before you walk out; the speakers may not be at fault.  The problem may be room reflections.  One of the most egregious room faults is ceiling reflection.  It always effects the high frequencies, those emitted by the tweeter.  Many tweeter designs are susceptible to this problem, particularly those of the dome variety because they have a wide, polar symmetrical radiation pattern, meaning that they emit substantial energy upwards toward the ceiling.  Long revered for their broad lateral projection pattern, think sofa listening positions, they are equally broad vertically.  The floor is easily kept from being a reflector by carpet or rugs, but the ceiling is not so easy to deal with.  (The writer does know of a case in which the ceiling was fitted with sheep skins to absorb reflections, something his wife accepted with measurable disdain.)  Consider the regions of the ceiling, one for each speaker, that would reflect sound like a billiard ball, starting from the tweeter and ending at the listener’s head.  If you are at all good at pool, you will find this path easily drawn within your mind.  Then ask yourself at what angle this path emerges from the tweeters, where 0 degrees represents sound emerging straight out of the driver.  Is it 30 degrees, 45 degrees, 60 degrees?  Let us call this angle the reflection path emission angle (RPEA).  Most tweeters, including dome tweeters, have diminished radiation output at 60 degrees, so you would like the reflection path emission angle to be around 60 degrees or greater.  

The figure below depicts the effect of ceiling height and listening position on the RPEA, from which it can be seen that a higher ceiling is an advantage (increases the angle), and a near listening position is also an advantage, for the same reason.

It is immediately obvious that the higher the ceiling, with all else remaining the same, the more favorable (larger) this angle.  It is also obvious that the angle gets larger as the listening seat moves toward the plane of the speakers.  Do you hear brightness and sizzle?  Try to make this angle larger by moving closer to the speakers, even if you have to get down on your knees.  The argument here is not that you would like to listen at this proximity in general, but that moving in on the speakers lets you see if the sizzle is coming from ceiling refection.  Using this technique, you may be able to all but eliminate the room effects and really get an idea of what the speakers themselves are doing.  If the room has high ceilings, say 10 feet or greater, the problem is greatly diminished anyway, and if the ceiling is vaulted, so much the better.  All too often the listening rooms at shows have 8-foot ceilings.  If there is sizzle, simply hunker down and approach the speakers from the center position, moving progressively closer to the plane of the speakers.  If the ceiling reflection is a problem, you will find this problem gradually receding as you move up on the plane of the speakers.  If this does not happen, the problem is not the ceiling.

A very similar argument and procedure can be applied to the first reflections from the side walls of the room.  Again, as you move up on the plane of the speakers, the wall reflection path emission angle is increased, and all of the foregoing statements and rationale remain true.  As you move back to the “preferred” listening position, any degradation you hear, particularly with regards to the upper frequency range, is owing to room reflections primarily.

A second consideration is also addressed by the same procedure, and that is the effect of path length ratio.  The loudness of sound is reduced by the length of propagation from the source.  Hence, it suppresses the significance of room reflections when the reflection path becomes increasingly longer compared with the incident (direct) path.  As you approach the plane of the speakers, the reflection path length is diminished slightly, while the incident path length is diminished greatly.  Thus, the path length ratio (reflection path length / incident path length) is greatly increasing, which reduces the effect of room reflections.  Both reflection path emission angle and reflection amplitude significance are changed favorably by approaching the plane of the speakers, allowing you to suppress the room effects and hear more completely what the speakers themselves are doing. 

Strictly speaking, the best example of approaching the speakers occurs when you also adjust the speaker tow-in, because this makes it possible to retain the same incident (direct) emission angle through the experiment.  Obviously, this is not possible in shows and not practical in salon listening rooms (they don’t want you messing with their room setup), so this margin of correctness must be forgone.  Leaving the tow-in unchanged, one could argue that if he can suppress the room effects before he creates too great an incident emission angle, the experiment has served its purpose.  Alternatively, you could position yourself squarely in front of one speaker, disregarding the collapse of sound stage, and simply check to see if sizzle and glare are reduced.  A particularly accommodating room operator may even be willing to turn off one channel to make this single speaker listening experiment more elegant.  

If room circumstances are not favorable, and if you are not aware of this and careful about it, you may find yourself blaming the speaker for having too much treble.  The manufacturer may take exception with you on this point because they have probably tested the design in an anechoic chamber and adjusted it for flat response.  But keep in mind that the listening room is not an anechoic chamber.  In truth, the speaker and the listening room are inseparable parts of a composite system that delivers sound to the listener.  One should consider that he may be obligating himself to a comprehensive room treatment job before all has ended, but for the short term he is trying to decide on the speakers.

Let us consider the following flow chart summary:

• The room sounds very good.  Consider possibly buying the speakers.
  • The tweeter is a dome.
    • Consider whether your listening room is large enough, with a high enough ceiling, to replicate the sound you are hearing in the demo room.
  • The tweeter is a ribbon, even a very long “line source” ribbon.
    • The ceiling height is not an important factor.
• The system sounds bright.
  • The room is on the small side, with perhaps a low ceiling.
  • Approaching the speakers, the problem subsides.
    • The problem is the room.
  • The problem does not subside.
    • The problem is possibly with the speakers or the electronics.
    • Look for another venue using different electronics, in an effort to isolate the performance of the speakers from that of the electronics.

The so called “line source” tweeter, i.e., long ribbon, has a very nice advantage in rooms with low (8 ft) ceilings because the vertical radiation aperture is very narrow so very little energy is directed to the ceiling.  The same can be said with regards to the floor, though this is usually a non-issue due to carpet or well-placed rugs.

The high frequencies are not the only part of the spectrum that can be disturbed by a non-ideal room.  The bass is also very dependent on correct circumstances.  In fact, it is possible to all but completely eliminate the bass by the effect of unfortunate room reflections.  On the other end of this extreme is boomy, muddy bass that can also be the work of the room.  Of course, the speakers could be at fault here, and this requires that the room effects be understood and even eliminated in order to make a proper assessment of the speakers themselves.  Whereas the ceiling and side walls play the major roles for the high frequencies, the front wall (behind the speakers) and back wall (behind the listener) are the predominant offenders to the bass.  Briefly, at frequencies at which the wall reflections re-enforce the incident wave from the speakers, you get boom.  At frequencies at which the reflections cancel the incident wave, you get a hole or “suckout”.  Eliminating these reflections is quite a chore, something rarely accomplished in show or demo rooms.  The art of achieving the best bass response in a room comes to a choice of speaker and listening seat positions that causes the dips from one wall to be helped by the re-enforcement from the other wall, so that the best overall fill occurs over a wide frequency range.  Rarely is this done analytically.  However, the very possibility of this solution suggests that careful experimentation will find a good result.  But bass isn’t the only thing that matters, and so the final solution must accommodate best sound stage, high frequency reflection suppression, etc.  Fortunately, the same technique of approaching the plane of the speakers is helpful across the entire frequency range, because the incident wave can be made to overpower all of the reflections if you get close enough to the speakers.  Admittedly, this technique does not generally work as well for the bass, and you may have to content yourself that the room setup simply won’t support good bass, especially if the speakers are rated to extend to much deeper bass than you are hearing in the room.  If this happens, it is time to look for an audition in another venue where, perhaps, things are setup more favorably. 

If you are beginning to get the idea that speaker shopping is a lot of work, you are reading this correctly.  Patience is the order of the day, and if you are able to take your time, you can make the process enjoyable and adventurous.  If it ever becomes stressful and urgent, it is time to give it a rest until you have fresh energy to bring to it.   

---

The information contained herein is presented in good faith and with all hopes of helping the reader to find the best equipment for an audio system.  Neither the author, nor Bella Sound LLC, assumes any responsibility or liability due to loss on the part of the reader, owing to or believed to be owing to the content of this article, or resulting from or believed to be resulting from an application of the information contained herein, regardless the level of expertise engaged thereto.