SERIAL NUMBERS: _________________ HANDCRAFTED BY: ______________________________ ______________________________ ______________________________ _______________________________ DESIGNED BY NEIL PATEL FOR AVALON ACOUSTICS This product is certified to meet the requirements of the European Union (EU) Electromagnetic Compatibility (EMC) Directive (89/336/EEC).
Table of Contents 1 Introduction ............................................................................................................................4 2 Unpacking Instructions ..........................................................................................................5 Introduction ...........................................................................................................5 Contents .........................................................................................
9 Accuracy of Bass Reproduction .......................................................................................... 33 Introduction .......................................................................................................... 33 9.1 Sensitivity to Time-Related Information .................................................................. 34 "Fast Bass" .............................................................................................................. 34 9.2 Rationale .........
1 Introduction is the most technologically advanced high-energy transducer ever created. Our focused research over a period of four years has produced a range of advancements in each aspect of loudspeaker performance. Proprietary conductors and magnetic technologies, as well as new techniques in cabinet construction, have been combined with the first implementation of full range neodymium driver motors, for the expressed purpose of empirical improvements in all aspects of energy transfer.
2 Unpacking Instructions Introduction Your AVALON ACOUSTICS loudspeakers were shipped in a two heavy-duty crates to ensure their safe arrival. It is recommended to save these crates for possible future use. Due to the weight of the speakers, it will require two persons to un-crate them and position them for listening. Please arrange for your dealer or another able bodied person to assist in this project.
2.1 Opening the Crate The crate features a one-piece top assembly which is fastened to the crate bottom with screws around the lower perimeter. To unpack, remove the screws and lift the upper portion of the crate straight up (this will require two people). Next, slide each speaker part way off of the crate base so that the plastic bag can be unfastened from the enclosure bottom. Please note that the binding post is on the back of the speaker. Be sure to slide speaker to end and not the side.
2.2 Installing the Grilles The grille assemblies are behind a panel on the outside of the speaker crate. Remove the screws securing the panel, and then carefully pull the grilles straight out. The grilles are installed with friction fasteners and press into place on the speaker cabinets. Please see Figure 2.2. Orientation of the Felt Anti-Diffraction Mask The grille assembly includes a felt anti-diffraction mask.
2.3 Replacing Grille Pins The grille pins installed on the grille assemblies are fragile and can be easily damaged. Should any of the pins break, you may replace them using the following procedure. 1. Place the grille assembly face-down on a padded surface (a towel or carpeting). 2. Remove the damaged grille pin by pulling it straight out with a small pliers or similar tool. Please refer to figure 2.4. Make sure that the complete pin is removed and that there are no pin fragments left in the mounting hole.
4. Carefully pull the grille cloth away from the frame mounting hole. The mounting hole must be clear of all obstacles during pin installation. 5. Place the exposed end of the grille pin in the open mounting hole. Check to insure that the grille cloth is not trapped between the pin and frame. Use a small hammer and gently tap the new grille pin in place. Then, pull the insertion tool off the new pin and verify that the pin flange is flush with the surface of the grille. Please refer to Figure 2.6.
3 Wiring Instructions Introduction The crossover is encapsulated in a sealed, non-accessible chamber in the bottom of the speaker cabinet, to minimize the effect of vibration on the components. The ISIS is equipped with high-quality binding posts for connecting the speaker cables. Spade lugs are recommended for cable terminations. Connecting the Speaker to the Amplifier 1. Place the speaker in its approximate location, then lay the speaker on its side, using a soft surface to avoid scratching the finish. 2.
4 Break-in Period Your new AVALON ACOUSTICS loudspeakers have an initial break-in period. They will not perform to their full sonic potential when first installed in your system. This is partially due to a residual polarization of the dielectric materials used in the crossover capacitors and internal wiring.1 As music is played through the loudspeakers, the electrical signal will gradually anneal these materials.
5 Maximizing Performance These details are imperative to obtaining optimum results from your AVALON ACOUSTICS loudspeakers. Break-in The break-in period is critical to maximizing sonic performance and should take place before other adjustments (see the discussion on page 11). The break-in should begin with three to six hours of quiet music, followed by 200 to 300 hours of loud and dynamic source material.
Toe-In Adjusting the toe-in angle of the speakers is useful in tailoring the sound to best match the characteristics of your system and listening room. When the speakers are facing straight forward, they tend to create a large, expansive sound-stage, painted with broad brush strokes. As they are rotated toward the listening position, the image becomes more compact, with increased focus, creating a greater sense of intimacy.
First Reflection Points Since the ear/brain system tends to integrate the sounds arriving within a 10 millisecond time window, it is important to control the early reflections arriving from the sidewalls to the listening position. A hard-surfaced wall can produce a strong frequency-dependent reflection that can interfere with the reproduced sound-stage, as well as change the perceived tonal balance of the system. Therefore, damping these first reflection points is strongly recommended.
6 Care of Your Loudspeakers Cabinet (Hardwood Finish) AVALON ACOUSTICS’ hardwood finished loudspeakers are supplied with a special polish and two lint-free polishing cloths, in order to properly care for the high quality furniture lacquer. The following polishing instructions should be observed: IMPORTANT: Use the supplied furniture polish ONLY. Do NOT use cleaners that contain ammonia, strong solvents, or abrasive materials. Use of these materials can degrade, scratch, or even DESTROY the finish. 1.
7 Warranty Your AVALON ACOUSTICS loudspeakers are warranted to the original, registered purchaser against defects in workmanship and materials for a period of three years from the date of first purchase, provided that the enclosed registration card is returned to the factory within seven days of the purchase date. If the registration card is not returned within the seven day period, this warranty is null and void, and you will not be notified of future updates.
Warranty Statement 1. AVALON ACOUSTICS warrants the materials, workmanship, and proper functioning of this product for a period of three years to the original registered purchaser, provided that the completed registration card is returned to AVALON ACOUSTICS within seven days of the date of purchase. If the registration card is not returned to the factory within the seven day period, this warranty is null and void.
6. The above warranty is the sole warranty given by AVALON ACOUSTICS, and is in lieu of all other warranties. All implied warranties, including warranties of merchantability or fitness for any particular purpose shall be strictly limited in duration to three years from the date of shipment from the factory, and upon the expiration of the warranty period (three years), AVALON ACOUSTICS shall have no further obligation of any kind whether express or implied, including but not limited to merchantability.
8 Room Acoustics and Speaker Position Introduction The listening room forms the final link of the playback system, as important as any other component in the chain. Just as an otherwise superb system is handicapped by an inferior pre-amplifier (for example), so can a well-matched system be hindered by poor room acoustics. It is not necessary to listen to your system in a specially-designed sound chamber in order to enjoy it.
An Optical Analogy Let us use a visual analogy to aid our understanding of acoustics. Imagine that you are in a room that is lit only by a candle in its center. There is (approximately) a uniform amount of light cast in all directions. If a large mirror is held closely to candle, one half of the room becomes darkened, while the other half receives twice as much light.
8.1 Standing Waves The parallel surfaces of most listening rooms can lead to a potential problem in the low frequencies. A sound wave can be repeatedly reflected from opposing surfaces, back and forth. If the distance between the surfaces is an integral multiple of one-half the sound wavelength, a standing wave will be set up. This means that the incident and reflected waves combine with each other so that a stationary pattern of high and low sound pressures is established in the room.
8.2 Flutter Echo These parallel, reflective surfaces can also produce a different audible problem. If there is little absorption at higher frequencies, a musical transient containing high frequencies, such as a hand clap or the strike of a percussion instrument, can be heard bouncing repeatedly between the surfaces. Called flutter echo (or slap echo), these multiple reflections can obscure musical detail.
8.3 Early Reflections Another situation that can reduce the subjective quality of reproduced sound is the presence of early reflections. By early reflections, we are referring to reflected sound waves that reach the listener within 10 to 20 milliseconds of the direct signal from the loudspeaker. When a reflected sound reaches the listener more than 40 milliseconds later than the direct sound, the reflection is heard as a discrete echo.
Avoiding Early Reflections The speed of sound is approximately one foot (30 cm) per millisecond. Therefore, to preserve the natural soundstage on your recordings, there should be no reflected sounds arriving at the listening position with a path length less than ten feet (3 meters) longer than the direct path from speaker to listener (see Figure 8.1).
Since the floor is within 5 feet of the speaker, it is best to have a carpeted floor to absorb floor reflections. A thick, dense carpet and pad will absorb lower frequencies more effectively than a thin one. Due to their complex structure, carpets and pads of natural materials, such as wool and jute, will exhibit a more uniform absorption over the frequency spectrum than synthetic materials will. It is not necessary to acoustically treat the entire room to achieve good results.
8.4 Bass reinforcement By bass reinforcement, we mean the effect of the room boundaries on the propagation of sound. It is widely known that speaker placement relative to the floor and walls can affect the relative amount of bass that the system produces. To make this interaction more clear, let us refer to the optical analogy of the candle. Similar to the way that the mirror reflected the light of the candle, so can the surfaces near the loudspeaker reflect the sound waves back into the listening room.
Figure 8.4 - Same conditions as above, except speaker is 6.6 feet from the reflecting surface. Note how the reinforcement now occurs at a lower frequency. By properly selecting the distances to each surface, we can extend the inroom bass response of the speaker much deeper than its anechoic response. Please see Figure 8.5. This is because the bass reinforcement provides a boost which is complementary to the bass roll-off that would be present in an anechoic chamber. Figure 8.
Conversely, improper placement of the loudspeakers can result in uneven frequency response. This results in diminished bass quality. Please refer to Figure 8.6. Figure 8.6 - Uneven frequency response caused by improper placement of the speakers. In this case, the speaker is 2.0 feet from both the side and rear walls.
Figure 8.8 - In-room response when the speaker is placed 3.6 feet from the side wall, and 6.6 feet from the rear wall. There are typically three reflective surfaces near each speaker: the floor, the rear wall, and the side wall. Each of these surfaces produces its own reflection, and hence its own cancellation and reinforcement. By properly selecting the distances to each surface, we can provide a uniform and extended bass response.
8.5 Summary of Recommendations Now that we have looked at some of the common problems of listening rooms, as well as their cures, let us summarize our findings and recommendations. Flutter Echo and Standing Waves These situations are the result of the room having parallel, reflective surfaces. The potential problems are independent of the audio system, and need to be addressed at the source.
Speaker Placement Although your AVALON ACOUSTICS loudspeakers may be placed in a wide variety of positions relative to the walls of the room, it is still wise to experiment a bit to achieve optimal results. The suggested minimum distances for the ISIS are 3 feet from one wall (side or rear), and 5 feet from the other (all distances are measured to the center of the woofer cone). This will provide the proper degree of bass reinforcement, as well as minimize early reflections.
8.6 A Listening Room Example In order to make these points more clear, an example of a room layout is given in Figure 8.9, illustrating the principles we have given. DRAPERIES SHELVES SPEAKER EQUIPMENT SHELVES CHAIR DESK AM P TABLE AM P SOFA TABLE SPEAKER SOFA TAPESTRY Figure 8.9 - Example listening room. The area around the speakers is free of objects that would produce early reflections.
9 Accuracy of Bass Reproduction Introduction We have all had the experience of listening to speakers with poor bass quality. Perhaps the bass was muddy, or ill-defined. Possibly the bass was exaggerated or bloated. In any case, these type of distortions are distracting and can keep us from enjoying the full measure of the performer's intent. Concerning the reproduction of low frequencies, AVALON ACOUSTICS pursues a different design goal than most other speaker manufacturers.
9.1 Sensitivity to Time-Related Information It is widely known that the human ear/brain system is extremely sensitive to time-related distortions. This can be understood when one realizes that directional and spatial information is provided by inter-aural time (and phase) differences. During the period of man's evolution, the ability to accurately determine the direction and distance of sound sources conferred a decided survival advantage, hence our present day aural sensitivity to time-related information.
9.2 Rationale There is an old saying, "There's no such thing as a free lunch." There are many trade-offs in speaker design, as in almost any area one can think of. In this case, the trade off is between transient response and anechoic frequency response (the speaker's frequency response in an anechoic chamber). Almost all manufacturers have chosen to sacrifice transient response for improved anechoic frequency response.
9.3 Measurements of Audio Equipment It should be recognized that measurements are not the final arbiter of sound quality of audio components. Often times a measurement standard has evolved because it is easily performed, or because it is easily repeatable, or it has shown some link to certain audible characteristics. Unquestionably, it is the latter criterion which is the most important one.
Loudspeaker Measurements Returning to loudspeakers, a similar situation has developed. Although nobody listens to music in an anechoic chamber, loudspeaker measurements are commonly performed in them.3 Although various proposals have been made for performing low frequency measurements in a more realistic setting, there has been no agreement as to what that setting should be. Loudspeakers continue to be measured in a test chamber that is equivalent to the absence of any room at all.
Designing for Accurate Bass Reproduction How, then, does one arrive at the goal of a loudspeaker that provides tonal accuracy in the listening room? The answer, in large part, comes in the form of the digital computer. It is possible to create a mathematical model of a listening room, and predict the response of a given speaker in that room. With the computer model, it is quite easy to change the position of the speaker in the room, or other parameters of the model.
9.4 Listening Qualities We have seen how many speaker systems store resonant bass energy, resulting in ringing and poor transient accuracy. Now we will turn our attention to the listening experience, and describe how these measurable properties correlate with our subjective impressions. There are two main factors which affect subjective low-frequency accuracy, frequency response and transient response. At low frequencies, these two descriptions are different aspects of the same event.
Transient Response Effects A speaker with poor transient response will store energy, releasing it after the initial musical transient has passed. This causes a loss of detail and obscures important musical information. Also associated with poor transient response is a narrow-band resonance, which can emphasize specific notes. When listening for the low-frequency transient accuracy of a speaker, it will be useful to utilize a broad variety of recordings.
9.5 Important ISIS Recommendations Built as an identical pair of transducers, ISIS retains one difference between right and left channels that is noteworthy. Very low frequency bass coupling with the room is selectable in one of two orientations. Even serial numbers should be placed as the left channel, while odd serial numbers are designated as the right. This is the optimal set-up for most situations, producing the widest stage spread.
10 Features Advanced light weight driver diaphragm materials minimize energy storage and time-domain distortion. Each driver individually tested and matched for optimum performance. Smooth, wide polar response for superlative imaging capabilities. Moderate impedance characteristic allows for ideal interface with any amplifier. Crossover circuitry is hard-wired with surface-only conductors, eliminating deleterious sonic effects of printed-circuit boards.
11 Specifications Driver Complement 1" Concave Diamond Diaphragm tweeter 7" Concave Ceramic Midrange 2-13" Nomex-Kevlar Composite Woofers All drivers utilize proprietary neodymium magnetic technologies. Sensitivity 90 dB Impedance 4 ohms nominal Frequency Response 20Hz to 45kHz Recommended Amplifier Power 75 to 750 watts Wiring Methods Two position binding post Dimensions 60" high 14.
12 Notes 44