In the old days of the mid-twentieth century, it was considered a badge of virtue for any audio system to render each of the speakers (drivers) audible. People would remark with awe and wonder that the bass could be heard emerging from the woofers, the mids from the midranges, and so on. They affectionately called this kind of sound “HiFi”. If you couldn’t hear the tweeter, they would ask, “Where’s the sizzle?” Since then, times have changed, playback systems have become much more sophisticated, and listeners have evolved immensely. And with all of these changes, expectations have moved very far from where they started. We shall examine the nature of one such evolutionary change herein.
Some clarification deserves to be made up front. There is no fault in hearing bass, midrange, and treble per se, but we do not want to hear the drivers that are producing these parts of the spectrum, otherwise we are listening to drivers, not music. One could rightfully take this progress one step further and state that we do not want to hear slices of spectrum at all. Again, we want to hear the music we endeavor to play. To the newbies to audio this can be hard to grasp because their experiences and expectations have not evolved as far; they are still stuck in the trenches of analysis and categorizations. There they will stay until they have done their due time, like the rest of us.
But for those who demand more than notable indicators and quantifiable metrics, for those who expect the rapture of music in all its compelling reverie, we shift our focus elsewhere. For those debuting a finer level of expectation and a burgeoning appetite for realism, we offer this advice, “Don’t stay in a listening room that proudly promotes the existence of its drivers.” This is a very simple test, and it can quickly reduce a bewildering pallet of audio show listening options down to a surprisingly few that should be in serious contention for your buying dollar. Let us be clear, hearing the separate drivers does not alone convict any one piece of equipment of being the culprit. Sizzling sibilance can be caused by speakers, but it can be caused by amplifiers, DAC’s, speaker/interconnect cables, and even digital cables. It can also be the product of a bad listening room itself, improper placement of speakers within the room, or inadequate room treatment. Sound that reflects off the walls, floor or ceiling and arrives at the listener’s ears will present an aftershock, a delayed recurrence of the original sound from the speakers, that calls attention to itself, particularly in the treble.
The moral of the story, if you encounter such a room at a show, is that something is wrong, and you will not be able to learn any more about the room than this, “Something is wrong.” When listening to audio shows or the single playback systems of individuals, the rule of thumb is this, “Only the good rooms teach you anything.” You can be sure that everything in a good sounding room is good, but you cannot be sure of anything in a bad sounding room, except that at least one thing is bad.
“I hear the tweeters!”
This can be caused by the tweeters themselves, or perhaps they are too loud for the rest of the system. It can also be that the time alignment between the tweeters and the midranges is wrong, in particular, the treble arrives to your ears too early. Another possibility is that the tweeter is “ringing,” that’s right, like a bell. In this case the treble lasts too long, it does not stop when the signal stops, again calling attention to itself. But other causes exist. Long speaker cables that have a high characteristic impedance compared to the speaker impedance can support standing waves, making the treble persist too long. This gives rise to a bright sound. Amplifiers are not immune to this fault. They can be “voiced” too bright with an unfortunate selection of internal components. As mentioned, digital cables can do some unexpected damage to the high frequencies, though brightness is less common than spatial smearing. Remarkably, faults in the AC supply, including power conditioning and AC cabling can leave sizzle and grunge in the sound, where better AC equipment would clean this up. Many recordings have this flaw as well, that the high frequencies are bright and exaggerated, so be sure to request another selection if you are inclined to like the system and want to give it every chance of exonerating itself.
“I hear the midranges!”
This is very often the fault of the speaker, whether the midrange driver or the enclosure. It is a fundamental weakness of the common piston or cone style driver, that sound travels from the center, outward toward the surrounding edge. Unless the diaphragm is adequately damped, this sound propagation will continue repeatedly from center to surround to center, particularly at specific frequencies within the midrange, resulting in ringing. Great strides have been taken in speaker enclosure design and fabrication to reduce baffle ringing, box talk, and internal standing waves, any one of which can allow the midrange to persist longer than it should. These are egregious faults because they are resonances that are not under the control of the amplifier – they are not music. If you hear the midrange, very often, though not always, the speaker system is the culprit. Try placing your hand on the speaker enclosure. You should not feel any vibration. If you do, there is no correction but to seek out a better speaker system. If you do not feel vibration, there are other mechanisms, as discussed above, that can allow the midrange to persist at certain frequencies, and the effect is to annoy the listener with artificial awareness of that part of the spectrum.
“I hear the woofers!”
There are two major causes for hearing the woofers. The first is an absence of sufficient damping in the woofer drivers themselves. This derives from driver “Q” and the strength of the driver “motor.” The second cause is poor enclosure design or execution. The aggregate system of driver, enclosure, and materials/execution combine to result in a speaker that may ring. As stated before, ringing is a lack of damping that results in persistence, and persistence calls attention to itself. This is the muddy, booming bass that youngsters sometimes find exhilarating, but is quickly identified and rejected by serious audiophiles. A second possible contributor to these bass flaws can be an inadequacy of amplifier damping. Amplifier damping, usually specified as damping factor, is an important amplifier characteristic that allows the speaker system to perform the intended degree of damping and control. Insufficient amplifier damping, as may result in a damping factor of perhaps 20 or less, can allow the speaker to ring, though the speaker design itself is good. In the past this used to be a common problem with all types of amplifiers, but in recent times it is almost entirely the weakness of tube amplifiers, or amplifiers in general that lack sufficient power to take authoritative charge of the speaker diaphragm. Where amplifier power is healthy, especially where solid state amplifiers are used, suspect a faulty speaker design when the bass has these problems.
The evaluation principle stated earlier bears repeating: A good sounding system tells you that everything in the system is working well, whereas a bad sounding system only tells you that at least one thing is spoiling the party. Therefore, go to audio shows expecting to find good sounding rooms and take your lessons from them. Consider purchasing some or all of their equipment. But of the bad sounding rooms there is only this to say, “Leave, because they tell you nothing.”
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.
