Avalon Compas User Manual Download Page 42

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9.4 Conclusion

Most loudspeakers have been designed to perform well in the frequency

domain when measured in an anechoic test chamber. We have seen how

this design paradigm produces audible bass distortion and exaggeration.
While these exaggerations may sometimes seem impressive in the short term,

they quickly prove to be distracting from the musical intentions of the

composer. At A

VALON

COUSTICS

, we design all of our speakers to minimize

resonance and stored energy, thereby ensuring transient accuracy. As you

listen to music on A

VALON

COUSTICS

loudspeakers, your enjoyment of the

music will grow as you hear the full measure of low-frequency detail, without
exaggeration, and come close to the heart of the artist's intent.

Summary of Contents for Compas

Page 1: ...Y NEIL PATEL FOR AVALON ACOUSTICS This product is certified to meet the requirements of the European Union EU Electromagnetic Compatibility EMC Directive 2004 108 EC Because the permanent magnets attached to the loudspeaker drivers produce magnetic fields it is recommended that the product not be positioned in very close proximity to computer monitors or television sets ...

Page 2: ......

Page 3: ...Symmetry 13 Toe In 14 Apex Couplers 14 First Reflection Points 15 Corner Treatment 15 6 Care of Your Loudspeakers 16 Cabinet Hardwood Finish 16 Grille Assembly 16 Drivers 16 7 Warranty 17 In the Event of a Problem 17 Warranty Statement 18 8 Room Acoustics and Speaker Position 20 Introduction 20 An Optical Analogy 21 Basic Room Acoustics 21 8 1 Standing Waves 22 8 2 Flutter Echo 23 8 3 Early Reflec...

Page 4: ... Room Frequency Response 36 9 3 Measurements of Audio Equipment 37 A Correlation with Amplifier Measurements 37 Loudspeaker Measurements 38 Designing for Accurate Bass Reproduction 39 Frequency Response Effects 40 Listening for Size Distortions 40 Transient Response Effects 41 9 4 Conclusion 42 10 Features 43 11 Specifications 43 12 Notes 45 ...

Page 5: ... reproduction Proprietary low jitter circuitry clarifies image boundaries to a high resolution standard suitable for professional monitoring where microphone placement and phasing are critical Utilization of the same diaphragm materials throughout the array adds to the continuity of harmonic structure in a crisp seamless musical presentation devoid of stored energy its rock solid imaging presented...

Page 6: ...ollowing items two loudspeaker cabinets two grille assemblies the owner s manual one set of six Apex Couplers an accessory bag The grille assemblies and owner s manual are contained in an outer compartment on the top of the shipping crates The Apex Couplers and accessory bag are packed together on the bottom of one of the loudspeaker cabinets The accessory bag contains replacement grille pins a sm...

Page 7: ...tion 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 Stand the speaker up and the bag can be slid off the top Please refer to Figure 2 1 Figure 2 1 To unpack the loudspeakers 1 Remove screws 2 Lift case 3 Slide speaker then undo bag 4 Stand speaker up then remove bag ...

Page 8: ...steners 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 Should the felt mask be removed be sure to note the correct inside outside orientation when re installing it The tweeter and midrange openings are beveled on the side that faces the listener away from the speaker Figure 2...

Page 9: ...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 3 Insert the new grille pin in the grille pin installation tool see figure 2 5 Figure 2 4 Removal of broken grille pin Check for pin fragments in the mounting h...

Page 10: ...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 6 Reposition the grille cloth that was pulled away from the frame mounting hole in step 4 The cloth should lay flat and wrinkle free Figure 2 6 Installing grille pin into COMPÁS grille frame Note that after installation the grille pin flange is flush ...

Page 11: ...e Speaker to the Amplifier 1 Carefully unscrew the large fastening knob on the binding post allowing the fastening plate to expose the posts see Figure 3 1 2 Insert the spades from your speaker cables under the terminal plate 3 Fasten the spades in place by tightening the large fastening knob Figure 3 1 Back view of the speakers showing the connections from the amplifier to the loudspeaker Check t...

Page 12: ...tem be played continuously using either a digital source in the repeat mode or an FM broadcast signal The recommended break in procedure is as follows Initial warm up three to six hours of quiet music Extended break in 200 to 300 hours of loud and dynamic source material e g Tangerine Dream Optical Race RCA 2042 2 P During the break in period the sonic properties of your loudspeakers may undergo s...

Page 13: ...elt anti diffraction masks make physical contact with the face of the loudspeakers as air space between the felt and the speaker face will adversely affect sound quality Speaker Placement and Symmetry Selecting the proper room position for your AVALON ACOUSTICS loudspeakers can dramatically improve their performance The following points highlight the fundamental concepts in loudspeaker positioning...

Page 14: ...ry to achieve the proper angle for your listening situation The optimum angle is usually between three and ten degrees inward Apex Couplers Supplied with your AVALON ACOUSTICS loudspeakers are six Apex couplers used to couple the speakers to the floor thereby minimizing time smearing resonance effects The result is an increase in focus and solidity of the sonic images On hardwood floors you may pr...

Page 15: ...e damping these first reflection points is strongly recommended Please refer to Section 8 3 Early Reflections beginning on page 24 for further information Corner Treatment It is important to control the first reflections of low frequency sound which normally occur at the corners behind the loudspeakers These reflections can cause significant distortions in phase and amplitude resulting in muddy ba...

Page 16: ...er is beveled on the side toward the listener to provide optimal dispersion characteristics Drivers The drivers require no regular maintenance Do not attempt to clean the tweeter dome as they are easily damaged If desired you may remove dust from the woofer cone by using a small soft dusting brush IMPORTANT Use the supplied furniture polish ONLY Do NOT use cleaners that contain ammonia strong solv...

Page 17: ...three year period A complete statement of warranty is given below Please take the time to fill out and return the enclosed warranty registration card In the Event of a Problem In the unlikely event of a problem with your AVALON ACOUSTICS loudspeakers the component most susceptible to failure is one of the driver units If driver replacement is required have your dealer contact AVALON ACOUSTICS The ...

Page 18: ...USTICS will provide replacement as quickly as possible Out of warranty claims will be billed for labor materials return freight and insurance as required Any product for which a warranty claim is accepted will be returned to the purchaser and cost of return shipping and insurance will be factory prepaid within the boundaries of the USA Units to be shipped outside of the USA will be shipped freight...

Page 19: ... do not allow exclusion or limitation of incidental or consequential damages or limitations on how long implied warranties last so the above limitations and exclusions may not apply to you 7 AVALON ACOUSTICS does not authorize any third party including any dealer or sales representative to assume any liability for AVALON ACOUSTICS or make any warranty for AVALON ACOUSTICS The unit must not have be...

Page 20: ...t up can greatly increase your listening satisfaction no matter what your listening situation Listening in a properly set up room can be a startling experience Due to the limitations of the two channel format and the listening environment the illusion of actually being transported to the recording site cannot usually be achieved However an uncanny sense of realism can be created Perhaps it is best...

Page 21: ...the cloth rather than being reflected back into the room Thus we can see that the energy can either be absorbed or reflected A similar situation occurs with sound waves although we must account for the much greater wavelengths of audible frequencies Of course no material is a perfect absorber or an absolute reflector Furthermore the sonic absorption coefficient of a given material usually varies w...

Page 22: ...used by parallel reflective surfaces practically every listening room suffers from this problem to some degree However several factors are working in our favor here First as the room size increases the affected frequencies become lower and thereby less audibly apparent Second the presence of shelving or furniture against the walls will break up the large surfaces reducing the magnitude of the prob...

Page 23: ...il The situation is analogous to standing between two parallel mirrors when the outline of your reflection becomes more difficult to discern due to the additional reflected images present Again it is only necessary to reduce the reflectiveness of one of the surfaces in each pair of surfaces to eliminate flutter echo Since we are concerned with the high frequencies any soft material is appropriate ...

Page 24: ...20 milliseconds of the direct sound the ear brain system integrates the two sounds so that only one sound is heard This integration is done in such a way that spatial information is preserved providing an acoustical picture of the physical space that created the reflections However the source recording also contains ambient information that portrays the original recording site Early reflections in...

Page 25: ...th a path length less than ten feet 3 meters longer than the direct path from speaker to listener see Figure 8 1 This means that if the speaker or listener is placed closer than about 5 feet to a wall or other surface that surface should be covered with sonically absorbent material Reflected Sound Direct Sound Figure 8 1 The reflected sound must travel further than the direct sound and therefore r...

Page 26: ...good results Strategic treatment of specific locations can realize considerable benefits Remember that when sound waves reflect from a flat surface the angle of reflection is equal to the angle of incidence just as a mirror reflects light waves Therefore the most important location for sound absorbing material is the point where the sound waves reflect to the listener see Figure 8 2 Reflected Soun...

Page 27: ...bstantially in phase with the original wave When this condition is met the coupling coefficient between the speaker diaphragm and the air increases and the speaker efficiency increases This changes the actual frequency response of the speaker and is not attributable to standing waves or other room resonances By selecting the distance from the speaker to the reflective surface we can determine the ...

Page 28: ...h is complementary to the bass roll off that would be present in an anechoic chamber 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 Figure 8 5 Anechoic response and in room response with the speaker placed 4 6 feet from the rear wall and 3 0 feet from the side wall Note how the bass response is e...

Page 29: ...ngth equals about four times the distance to the boundary the reflected wave is antiphase to the original wave resulting in a cancellation dip in the output At frequencies above this level the effect becomes less significant and creates similar but smaller variations in output Figures 8 7 and 8 8 illustrate these concepts Figure 8 6 Uneven frequency response caused by improper placement of the spe...

Page 30: ...d bass response it is recommended that the loudspeaker be placed between two and five feet from one of the walls side or rear and between three and ten feet from the other wall The measurements are made from the wall to the center of the woofer cone The exact distances are not overly critical although the two distances should not be within about 33 of each other A good rule of thumb in establishin...

Page 31: ...on is the use of DAAD s more information is available at www acusticaapplicata com High Frequency Absorption and Room Symmetry Since flutter echo is a high frequency effect it becomes much easier to manage potential problems in this area Almost any item attached to the walls will be less reflective at high frequencies than the bare walls themselves Draperies wall hangings paintings bookshelves and...

Page 32: ... devoted to music reproduction and the other end for another use such as a study or office In this way the area behind the listener will contain items that will reduce problems with standing waves and or flutter echo while the zone around the speakers remains relatively free from reflective objects If you wish to achieve an even more spacious sound stage it may be useful to place a sonically absor...

Page 33: ...reflections A tapestry is hung opposite the draperies to absorb the reflection from the side wall and to help maintain left right symmetry The area behind the listening position contains items which help break up standing waves and flutter echoes Heavily upholstered sofas will help avoid low frequency standing waves while a carpet absorbs early reflections from the floor DRAPERIES TAPESTRY SHELVES...

Page 34: ...g 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 Specifically we believe that the complete absence of stored resonant energy is of paramount sonic importance First we will discuss some of the technical aspects of bass reproduction and perce...

Page 35: ...rized as tight clean quick or fast Fast Bass The term fast bass would seem to be an oxymoron on the surface After all it is the slowness of a note that makes it a low frequency Nonetheless the term provides an accurate description of our subjective impression Many people have erroneously ascribed fast bass to the use of a light diaphragm or the use of a powerful energizing system 1 In fact it is n...

Page 36: ...l performance Anechoic vs In Room Frequency Response It must be remembered that very little listening actually takes place in anechoic chambers Placement of the speakers in a real world listening room will boost the bass response of the speaker as explained in Section 8 Room Acoustics and Speaker Position beginning on page 20 Since a loudspeaker with perfectly flat anechoic frequency response will...

Page 37: ...asurement of audio amplifiers The power output and distortion of an amplifier is invariably measured into an eight ohm resistor It is widely acknowledged that this standard is far removed from the actual conditions in which the amplifier will be used One doesn t listen to resistors one listens to loudspeakers and the load that the speaker presents to the amplifier is nearly always highly reactive ...

Page 38: ...s it is difficult to separate the effects of a room s bass reinforcement from standing waves and other resonances associated with that room 3 Since an anechoic chamber which performs accurately to low frequencies is extremely large and expensive other measurement methods are also commonly used These include near field measurements when the microphone is extremely close to the driver and half space...

Page 39: ...his enables one to design the speaker so that it interfaces properly with the listening environment and provides correct bass response in real world environments The accuracy of the computer model must also be tested in the physical world using pink noise warble tones and time delay spectrometry for verification The final and most important check is the listening test Theory and measurements becom...

Page 40: ...uating these distortions of size is a recording of a small group of unamplified acoustic instruments made with a simple microphone set up Listening for Size Distortions Play a recording of this type with the volume adjusted to achieve a natural playback level As you listen create a mental image of the players based on sounds being recreated Then ask yourself Does this sonic image correspond to the...

Page 41: ...line played by a synthesizer As you listen to the bass line are the individual notes of equal level or are some of them more prominent than others Electronic instruments can be more useful for this test since acoustic instruments have resonances of their own which can hide flaws in the speaker unless you are intimately familiar with the instrument and the recording Similarly an electric bass that ...

Page 42: ...mes seem impressive in the short term they quickly prove to be distracting from the musical intentions of the composer At AVALON ACOUSTICS we design all of our speakers to minimize resonance and stored energy thereby ensuring transient accuracy As you listen to music on AVALON ACOUSTICS loudspeakers your enjoyment of the music will grow as you hear the full measure of low frequency detail without ...

Page 43: ...avior for superlative multi channel blending and imaging capabilities Non reactive fully damped 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 Proprietary jitter reduction circuitry for unsurpassed image definition and stability Careful crossover co...

Page 44: ...ic Midrange 2 9 5 Ceramic Honeycomb Woofers Sensitivity 91 dB rated impedance Impedance 4 Ohms Nominal Frequency Response 27Hz to 24kHz Recommended Power 50 to 500 Watts Wiring Methods Two Position Binding Post Dimensions 46 117 cm High 11 28 cm Wide 17 43 cm Deep Weight 152 pounds 68 kg each ...

Page 45: ...45 12 Notes ...

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