Manuale d’uso / di manutenzione del prodotto Sentinel del fabbricante Avalon Acoustics
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Serial Numbers ____________________ Handcrafted by: _________________________________ _________________________________ _________________________________ _________________________________ This product is certified to meet the requirements of the European Union (EU) Electromagnetic Compatibility (EMC) Directive (89/336/EEC).
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Table of Contents 1 I nt ro du ct io n ................................................................................................................... 5 Ov e rv ie w .................................................................................
9 R oo m Ac ou st ic s an d Sp ea ke r Po si ti on ......................................................................... 41 In t ro du ct i on ..............................................................................................4 1 An Op ti ca l A na lo g y .
5 1 Introduction Overview The Avalon Acoustics Sentinel Active Reference System represents the application of edge-of-the-art loudspeaker technology in every area of high accuracy transducer development.
6 1.1 Low Noise Floor A key element in achieving the sonic goals mentioned in the previous section is significantly reducing the noise floor. The term "noise floor," in this discussion, refers to the stray uncorrelated energy that is produced as an artifact by the loudspeaker.
7 1.2 Coherent Energy Transfer Coherent energy is both an aspect of the absolute quantity of energy, and also the speed with which that energy begins and ends.
8 1.3 The Active Reference System A definitive transducer project of this magnitude demands the holistic integration of diverse design goals, including perfect phase response, critical damping, and point source accuracy.
9 2 Unpacking Instructions Introduction Your Avalon Acoustics loudspeakers and sub amplifiers were shipped in seven heavy- duty crates to ensure their safe arrival. It is recommended to save these crates and boxes for possible future use. Due to the weight of the system, the listening room floor structure must be extremely robust and reliable.
10 2.1 Room Preparation and Verification The Sentinel Active Reference System weighs over 1,100 pounds (about 520 kg). It is therefore crucial to verify the soundness of the intended listening room floor structure and to insure that the structure can safely support the device.
11 2.2 Crate and Box Placement for Unpacking Because of the weight and size of the Sentinel Active Reference System, it is important to plan the layout of your room and carefully place the crated devices within the listening environment BEFORE unpacking.
12 2.3 Opening the Crates All of the crates features a one -piece top assembly which is fastened to the crate bottom with screws around the lower perimeter. To unpack the crossovers, remove the screws and lift the upper portion of the crate straight up (this will require two people).
13 To unpack the upper speaker cabinets, remove the screws and lift the upper portion of the crate straight up (this will require two people). Carefully lift the cabinets by the small overhang at the base. See Figure 2.3. CAUTION: Three people are required for unpacking.
14 2.3 Opening the Sub Amplifier Crates The Subwoofer Amplifiers are also packed in heavy-duty crates. To unpack, remove the screws and lift the upper portion of the crate straight up (this will require two people). Carefully lift the amplifiers off of the crate base.
15 3 System Set-up WARNING: Failure to follow the set-up and wiring instructions explicitly may cause damage to your loudspeakers and void your warranty.
16 Left / Right Channel Matching The two system channels (left and right) are consecutively serialized at the factory. The elements of each channel are matched as a set for both their electrical and aesthetic characteristics.
17 3.1 Lower Speaker Cabinet Set-up CAUTION: Three people are required for the set-up procedure. To avoid injury, do NOT attempt to set-up by oneself. 1. Carefully lift and place each lower speaker cabinet in its measured final location, as it becomes more difficult to move once the Apex ‘ couplers are attached.
18 3.2 Upper Speaker Cabinet Set-up CAUTION: Three people are required for the set-up procedure. To avoid injury, do NOT attempt to set-up by oneself. 1. Lay the upper speaker on one side, using a blanket or other soft material to avoid scratching the finish.
19 5. Carefully lift each upper speaker cabinet by the small overhang at the base, and place it directly on top of the lower speaker cabinet, with the set- up blocks between them. Then gently slide the upper cabinet slightly forward to expose the wiring tubes in the lower cabinet (See Figure 3.
20 cabinet slightly, remove the front set-up block, and lower the single front Apex ‘ Coupler into its receiving socket. Figure 3.5 – Removal of the set-up blocks between upper and lower speaker cabinets.
21 3.3 Crossover Cabinet Set-up CAUTION: Three people are required for the set-up procedure. To avoid injury, do NOT attempt to set-up by oneself. 1. Lay the crossover cabinet on one side, just behind the speaker cabinet, using a blanket or other soft material to avoid scratching the finish.
22 3.4 The Felt Anti-Diffraction Mask The anti-diffraction masks are installed at the factory, and fit within the recesses on the cabinet face. It is very important that the felt mask make physical contact with the face of the loudspeaker, as air space between the felt and the speaker face will adversely affect sound quality.
23 3.5 Sub Amplifier Set-up Place the Sub Amplifiers in their final set-up positions, allowing 8 inches at the rear for tightening the speaker output connectors. The power transformer in the Sub Amplifier is located at the front-center of the unit. Ideally, a few feet should separate this area from components which potentially could pick up hum.
24 4 Wiring Instructions WARNING: Failure to follow the set-up and wiring instructions explicitly may cause damage to your loudspeakers and void your warranty. Introduction The Sentinel crossover is designed specifically for use with the drivers in the upper speaker cabinet.
25 4.1 Wiring and Field Interactions The Sentinel Active Reference System is an extremely revealing, high-energy device. Therefore, it is important to carefully plan the placement and routing of wires when setting up your music reproduction system.
26 4 . 2 C o n n e c t i n g U p p e r S p e a k e r C a b i n e t t o C r o s s o v e r 1. Locate the upper speaker cabinet wiring harnesses: a four-conductor wiring harness with labels "HIGH" and "MID" for the tweeter and midrange, and a two-conductor wiring harness with labels "LOW" for the woofer.
27 4 .3 Co n n ec t i ng S pe a k er C ab l e t o th e Cr o s so v e r 1. Locate the input terminal block on the bottom of the crossover cabinets. Route your own SINGLE-WIRED speaker cables to these INPUT terminals.
28 4.4 Connect Speaker Cable to your Amplifier Although it is possible to power the Sentinel Active Reference System with a single stereo amplifier, it is recommended to separate the amplification into left and right channels. This is accomplished by using two mono amplifiers.
29 4.4 Connecting Subwoofer to the Sub Amplifier 1. Locate the lower speaker cabinet wiring harnesses: two single-conductor wiring cables with the label "SUB". These harnesses are hard-wired directly to the lower loudspeaker cabinet sub drivers, in order to provide the most unobstructed signal path.
30 4.5 Connecting Preamplifier to the Amplifiers The Sentinel subwoofer section is actively powered by its own subwoofer amplifier, whereas the upper speaker section is powered by your own amplifier that is directly connected to the Sentinel crossover cabinet.
31 5 Break- in Period Your new Avalon Acoustics Sentinel Active Reference System has an initial break-in period. It will not perform to its full sonic potential when first installed in your system. This is due to a residual polarization of the dielectric materials used in the crossover capacitors and internal wiring.
32 6 Subwoofer Amplifier Design Principle The Sentinel subwoofer amplifier provides essential support for the lowest octaves of the musical spectrum. As a fundamental component of the Sentinel Referen.
33 1. Set the Master Gain on the subwoofer amplifier (see Figure 6.1) to match the output level of your main amplifier. This adjustment is both equipment and room dependent and should be tuned by ear while performing careful listening tests. Consult your dealer should you need assistance.
34 7 Maximizing Performance These details are imperative to obtaining optimum results from your Avalon Acoustics loudspeakers. Break-in The break-in period is critical to maxi mizing sonic performance and should take place before other adjustments (see the discussion on page 29).
35 Room Treatment and System / Listener Position Selecting the proper room and listener positions within your listening environment can dramatically improve system performance.
36 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 side walls to the listening position.
37 8 C a r e o f Y o u r A v al o n L o u d s p e ak e r s Cabinet 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.
38 9 Warranty Your Avalon Acoustics loudspeakers are warranted against defects in workmanship and materials for a period of five years, ! provided that the enclosed registration card is returned to the factory ! within seven days of the purchase date.
39 Warranty Statement 1. Avalon Acoustics warrants the materials, workmanship, and proper functioning of this product for a period of five years, provided that the completed registration card is returned to Avalon Acoustics within seven days of the date of purchase.
40 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 part.
41 1 0 R o o m A c o u s t i c s / S p e a k e r P o s i t i o n Introduction The listening room forms the final link of the playback system, as important as any other component in the chain.
42 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.
43 10.1 Standing Waves The parallel surfaces of most listening rooms can lead to a potential problem at any frequency. 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.
44 10.2 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.
45 10.3 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.
46 Avoiding Early Reflections The speed of sound is approximately one foot (30 cm) per millisecond. Therefore, to preserve the natural sound stage on your recordings, there should be no reflected soun.
47 It is not necessary to acoustically treat the entire room to achieve 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.
48 Low Frequency Reflections The first significant reflection of low frequency sound waves comes from two corners behind the loudspeakers. Another important reflection occurs on the wall behind the speakers, midway between them. Similarly, low frequency corner and wall reflections take place at the opposite wall, behind the listener.
49 10.4 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.
50 As frequency increases and wavelength becomes more similar to the distance to the boundary, the phase difference between original and reflected waves increases, and the air coupling effect is diminished.
51 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.
52 10.5 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.
53 Early Reflections When arranging the furnishings in your listening room, remember that reflective objects should not be within a five foot radius of either the speaker or listener to avoid early reflections.
54 10.6 A Listening Room Example In order to make these points more clear, an example of a room layout is given in Figure 9.6, illustrating the principles we have given. Figure 9.6 - Example listening room. The area around the speakers is free of any object that would produce early reflections.
55 11 Listening Position Just as loudspeaker positioning and room treatment can address the issues of standing waves, flutter echo, reflections, and bass reinforcement, careful attention to listening position is crucial to achieving accurate sound stage placement, tonal balance, harmonic structure, focus, and image size.
56 Summary When the listener and system are situated properly within a carefully planned and set-up listening environment, the Sentinel multi-way system can deliver high-energy output with point-source accuracy.
57 12 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.
58 12.1 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.
59 12.2 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.
60 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.
61 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.
62 12.3 Listening Qualities 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.
63 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.
64 12.4 Active Subwoofer System Designing a loudspeaker system for accurate low-frequency reproduction is a challenging proposition. Given a reasonable listening environment, there is very good correlation between the anechoic and in-room responses at frequencies above 350 Hz.
65 13 Features • Application of new cabinet research featu res nineteen separate aperiodically damped internal chambers in three distinct speaker cabinets for superior resonance control. • Advanced light weight driver diaphragm materials minimize energy storage and time- domain distortion.
66 14 Specifications Loudspeaker Driver Complement 1" concave ceramic dome tweeter 3 _" concave ceramic dome midrange 9" Nomex-Kevlar composite cone woofer T wo 1 3 " Nom e x- Ke v l ar c o m po site c o n e su bw o o fe rs Sensitivity 88 dB (2.
67 15 Notes.
Un punto importante, dopo l’acquisto del dispositivo (o anche prima di acquisto) è quello di leggere il manuale. Dobbiamo farlo per diversi motivi semplici:
Se non hai ancora comprato il Avalon Acoustics Sentinel è un buon momento per familiarizzare con i dati di base del prodotto. Prime consultare le pagine iniziali del manuale d’uso, che si trova al di sopra. Dovresti trovare lì i dati tecnici più importanti del Avalon Acoustics Sentinel - in questo modo è possibile verificare se l’apparecchio soddisfa le tue esigenze. Esplorando le pagine segenti del manuali d’uso Avalon Acoustics Sentinel imparerai tutte le caratteristiche del prodotto e le informazioni sul suo funzionamento. Le informazioni sul Avalon Acoustics Sentinel ti aiuteranno sicuramente a prendere una decisione relativa all’acquisto.
In una situazione in cui hai già il Avalon Acoustics Sentinel, ma non hai ancora letto il manuale d’uso, dovresti farlo per le ragioni sopra descritte. Saprai quindi se hai correttamente usato le funzioni disponibili, e se hai commesso errori che possono ridurre la durata di vita del Avalon Acoustics Sentinel.
Tuttavia, uno dei ruoli più importanti per l’utente svolti dal manuale d’uso è quello di aiutare a risolvere i problemi con il Avalon Acoustics Sentinel. Quasi sempre, ci troverai Troubleshooting, cioè i guasti più frequenti e malfunzionamenti del dispositivo Avalon Acoustics Sentinel insieme con le istruzioni su come risolverli. Anche se non si riesci a risolvere il problema, il manuale d’uso ti mostrerà il percorso di ulteriori procedimenti – il contatto con il centro servizio clienti o il servizio più vicino.
