Avalon Acoustics AVALON INDRA manuel d'utilisation

S ERIAL N UM BERS : ________________ H A NDCRAFTED B Y : ____________ ___________ ____ ____________ ___________ ____ ____________ ___________ ____ ____________ ___________ _____ INDRA R D ESIGNED BY N EIL P ATEL FOR A V A LON A COUSTICS This product is cert ified to meet t he requirements of the European Union (EU) Electromagnet ic Compatibility (E[...]

Table of Contents 1 Introduction ............................................................................................................................ 4 2 Unpacking Instr uctions .......................................................................................................... 5 Introduction ..........................................[...]

9 Accuracy of Bas s Reproduction .......................................................................................... 33 Introduction .......................................................................................................... 33 9.1 Sensitivit y to Time-Relat ed Informati on .....................................................[...]

4 1 Introduction Congratulations on your purchase of A V ALON INDRA , one of the most technologica lly advanced high -energy t ransducers ever creat ed. I NDRA represents t he c ulminat ion of 20 years of researc h an d developme nt in the areas of tra nsient response, bandw idth, noise fl oor and octave - to -octave energy balance. The result sets[...]

5 2 Unpacking Instructions Introduction Your A VALON A CO USTICS loudspea kers w ere shipped in a heavy-duty crate to ensure their safe arriva l. It is rec ommended to save these c rates for p ossibl e future use. D ue t o t he w eight of the speakers, it will require two persons t o un -crat e t hem an d position t hem for listeni ng. Please arran[...]

6 2.1 Opening the Crate The crat e fea tures a on e- piece top assembly w hich is fast ened to t he crate bottom with screw s around the lower perimeter. T o u npack, remove the screws and lift the upper portion of t he crate straight up (this will require two people). Next, slide ea ch speake r part way off of t he cra te base so t hat th e plasti[...]

7 2.2 Installing the Grilles The grille asse mblies are behind a p anel on th e outside of the speaker cr ate. Remove the screws securing the panel, and then c arefully pull the grilles straight out. The grilles are insta lled w ith friction fast ene rs and press into place on the speaker ca binets. Please see Figur e 2.2. Orientation of the F elt [...]

8 2.3 Replacing Grille Pins The grille pins installed on the grille assemblies are fragi le an d can be easily damaged. Should any of the pin s brea k, you may replace them using t he following procedure . 1. Place the grille assembly face -dow n on a padded surface (a towel or carpetin g). 2. Remove the da maged gri lle pin by pull ing it straight[...]

9 4. Carefully pull t he grille cloth away from the frame mounting hole. T he mounting hole must be clear of all obst acles durin g pin inst allation. 5. Place t he exposed end of th e grille pin in the open mount ing hole. Check to insure that th e grille cloth is not trap ped between the pin and frame. Use a small hammer and gently t ap the new g[...]

10 3 Wiring Instructions Introduction The cross over is housed in a sealed, non -accessib le chamber in the b ottom of the speak er cabinet, to minimize t he effect of vibration on t he component s. The I NDRA is eq uipped w ith h igh -quality binding post for connect ing t he speaker cables. Spade lugs are r ecommended f or al l cable termi nation[...]

11 4 Break-in Period Your new A VALON A C OUSTICS loudspeakers have an i niti al break-in period. They will not perform to their full sonic pot ential when first i nstalled in your system. This i s pa rtially due to a residual polarization of the diel ectric materials used in the crossover capaci tors and internal wiring. 1 As music is pl ayed thro[...]

12 5 Maximizing Performance These details are imperative to obta ining optim um r esults from your A VALON A COUSTICS loudspeakers. Break- in The break -in period is critical to ma ximizing sonic performan ce and should take place before other adjustmen ts (see the discus sion on page 11 ). The break-in should begi n w ith t hree t o six hours of q[...]

13 Toe- In Adjusting the toe -in angle of t he spea kers i s use ful in tailoring the sound to best mat ch the characteristic s of your system and li stening room. When the speakers are fac ing straight forward, t hey t end t o crea te a la rge, expansive so und-st age, pai nted w ith broad b rush strokes. As they are rot ated toward the listening [...]

14 First Reflection Points Since the ear/brain system tends to integrat e t he sounds arrivi ng within a 10 millisecond time w indow, i t is important to control th e early reflec tions arr ivi ng from t he sidewal ls to th e list ening position. A hard -surfaced w all can produce a strong frequency-de pendent reflection that can interfere with the[...]

15 6 Care of Your Loudspeakers Cabinet (Hardwood Finis h) A VALON A COUSTICS ’ hardwood finished loudspeakers a re suppl ied with a special polish and tw o lint -free polishing c loths, in order to p roperly c are for the h igh qualit y furniture l acquer. The followi ng polishi ng in structions should be observed: IMPORTANT: Use the supplied fur[...]

16 7 Warranty Your A VALON A COUSTICS loudspeakers are warra nted to the original, registered purchaser agai nst defec ts in workma nship an d mat erials for a period of three years from the date of first purchase, pro vided th at the enclosed registration card is returned to th e factory within seven days of the purchase date. If the registration [...]

17 Warranty Statement 1. A V A LON A C OUSTICS warran ts th e materi als, workma nship, a nd p roper functioning of thi s product for a period of t hree years to t he origi nal regi stered purchaser, provided th at the completed registration card is returned to A VALON A COUSTICS within seven days of the date of purchase. If the regis tration card [...]

18 6. The above w arrant y is the sole warrant y given by A VALON A COUSTICS , and is in lieu of all other wa rranties. All implied warranti es, including warranties of merchanta bility or fitness for an y particular purpose shall be st rictly limited i n duration t o t hree years from the date of ship ment from the factory, and upon the exp iratio[...]

19 8 R o o m A c o u s t i c s a n d S p e a k e r P o s i t i o n Introduction The listenin g room forms t he fina l link of t he playback system , as import ant as any oth er c omponent in the chain. Just as an oth erwise su p erb system is handicapp ed by a n inferi or pre -ampl ifier (for example) , so c an a well-mat ched system be hi ndered b[...]

20 An Optical Analogy Let us use a visual ana logy to aid our underst andi ng of acoustic s. I magine 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 direc tions. I f a large mirror is h eld closely t o candle, one ha lf of t he room bec omes darkened, while the other[...]

21 8.1 Standing Waves The paral lel surfaces of most list ening rooms c an lead t o a pot ential probl em in the low frequencies. A sound wave ca n be repeatedly reflect ed from opposing surfaces, back an d forth. If t he dist ance betw een t he surfaces i s an integra l mult iple of one-half the sound wa velength, a stan ding wave will be set up. [...]

22 8.2 Flutter Echo These paral lel, r eflective surfaces can also produce a different audible problem. I f there is little absorption at higher frequencies, a musical transient containin g high frequencies, such as a h and clap or t he strike of a percussion instrument, ca n be heard bouncing repea tedly bet ween the surfaces. Cal led flutter ec h[...]

23 8.3 Early Reflections Another sit uation t hat c an reduce t he subject ive qualit y of reprod uced s ound is the presence of early reflections. By earl y reflect ions, we are referri ng to reflected sound w aves that reach the list ener w ithin 10 t o 20 milliseconds of the direct signa l from the loudspeaker. When a reflec ted sound reac hes t[...]

24 Avoiding Early Reflecti ons The speed of sound is approximat ely one foot (30 cm) per mi llisecond. Therefore, t o preserve the natural soundstage on your recordings, t here should be no reflected sounds arriving at the listening position with a path length less than t en feet (3 meters) l onger than the direct path from speak er to list ener (s[...]

25 Since the floor i s wit hin 5 feet of the speak er, it is b est to have a carpeted fl oo r to absorb fl oor reflect ions. A thic k, dense carpet and pad will absorb l ower frequencies m ore eff ectively t han a thin one. Due to thei r compl ex structure , carpets an d pads of na tural ma terials, such a s w ool and jute, will exhibit a more unif[...]

26 8.4 Bass reinforcement By ba ss reinforcement , we mean the effect of the room boundarie s on the propagation of sound . It is wi dely kn own t hat speaker placement relative to the floor a nd wall s can a ffect the relative amount of bass that the system produces. To make this i nteraction more clear, let us refer t o th e opti cal analogy of t[...]

27 By pr operly selec ting the distanc es t o ea ch surfa ce, we can extend the in - room bass response of the speaker m uch deeper than its anechoic response. Please see Fig ure 8.5. This is bec ause the bass rein forcement p rovides a b oost which i s complement ary to t he bass roll -off t hat w ould be present in an anechoic chamb er. Figure 8 [...]

28 Conversely, improper p lacement of the loudspeakers can re sult in une ven frequency response . This results in diminished bass qualit y. Please refer t o Figure 8.6. As fr equenc y increases and wavelen gth becomes more similar to the distance t o the boundary, the phase difference bet ween origi nal and reflected wa ves in creases, a nd the ai[...]

29 There are t ypically three reflective surfaces near each speaker: t he floor, t he rear wall, and the side w all. Eac h of these surfaces prod uces its ow n reflection, a nd h ence i ts own cancellation and reinforcement . By prope rly selecting the dist ances t o each surface, we can provide a uniform a nd extended bass response. C onversely, i[...]

30 8.5 Summary of Recommendations Now that we have l ooked at some of the common probl ems o f listenin g rooms, as well as their cures, let us summarize our findin gs and recommendations . Flutter Echo and Standing Waves These sit uations are t he result of the r oom having p arallel, reflec tive surfaces. The potent ial probl ems are independent [...]

31 Speaker Placement Although yo ur A VALON A COUST I CS l oudspeakers may be p laced i n a wide variety of positi ons rel ative to t he walls of the ro om, it is sti ll wise to experiment a bit to achieve optimal results. The suggest ed minimum distan ces for the INDRA are 3 feet from one w all (side or rear), a nd 5 feet from t he other (all dist[...]

32 8.6 A Listening Room Example In order to make t hese points more clear, an example of a r oom layout is given in Figure 8 .9, illustrat ing the prin ciples we have given. Figure 8.9 - Example l istening room. The area around the spea kers is free o f objects that would produce earl y refl ect ions. A tapestry is hung opposite t he draperi es to [...]

33 9 Accuracy of Bass Reproduction Introduction We have all ha d the experienc e of list ening to speakers w ith poor bass quality. Perhaps th e ba ss w as muddy, or ill-defi ned. Possibly the b ass was exaggerated or bloat ed. In any ca se, t hese type of distortions are dist racting and can keep us fr om enjoying th e full measure of the performe[...]

34 9.1 Sensitivity to Time-Related Information It is w idely know n that the h uman ear/brai n system is ext remely sensit ive to time-rel ated distortions. Thi s can be understood when one rea lizes that directional a nd spatial information is provided by in ter - aural ti me (and phase) differences. During th e period of man's evoluti on, t [...]

35 9.2 Rationale There i s an old saying, "There's no such thin g a s a free l unch." There are many trade-offs in speaker design, as i n almost a ny area one can think of. In thi s case, t he t rade off is between t ransient response and anechoic frequency response (the speaker 's freq uency response in a n anech oic chamber). [...]

36 9.3 Measurements of Audio Equipment It should be recognized th at measurement s are not th e f inal a rbiter of sound quality of audio comp onents. Often times a measurement standa rd h as evolved because i t is easil y perf ormed, or bec ause it is easily rep eatable, or it has shown some lin k to c ertain audible characteristi cs. Unqu estiona[...]

37 Loudspeaker Measur ements Returning to loudspeakers, a sim ilar situation has developed. Although nobody listens t o music in an a nechoic chamber, l oudspeaker mea surement s are commonly perfor med in th em. 3 A lthough vari ous proposals have been made for performing low frequency measuremen ts in a more real istic setting, there has been no [...]

38 Designing for Accur ate Bass Rep roduction How, then, d oes one arrive at the goal of a loudspea ker th at provides t onal accuracy in the listeni ng room? The a nswer, in large part , comes in t he form of t he digital comput er. It is possible to c reate a mat hematical model of a listening room, a nd predi ct the response of a gi ven speaker [...]

39 9.4 Listening Qualities We have seen how many speaker systems store resonant bass energy , resulting in ringing and poor transient accuracy. Now we w ill turn our attention to the listening experienc e, and des cribe how these measurab le properties correlat e with our subjecti ve impressions. There are two main fac tors whi ch affect subject iv[...]

40 Transient Response E ffects A spea ker with poor t ransient response will st ore energy , releasin g it after t he initial musical transient has pa ssed. This cau ses a l oss of detai l and obscur es important musica l informati on. A lso associat ed with poor transient response i s a narrow- band resonance, whic h can empha size specific notes.[...]

41 9.4 Conclusion Most loudspeakers have been designed to perf orm well in th e frequency domain when mea sured in an anechoic test chamber. W e h ave seen how this desi gn pa radigm p roduces audibl e bass di stortion and exa ggeration. While these exaggerat ions may sometimes seem impressive in th e short term, they quickly p rove to be distracti[...]

42 10 Features  Advanced ultra-light weight ceramic and Nomex/Kevla r driver di aphragm material s minimize energy storage a nd time -domain distortion.  Each driver in dividually tested and m atched for op timum performance .  Smooth, wide polar resp onse for superl ative ima ging capab ilities.  Non -react ive, fully da mped impeda nc[...]

43 11 Specifications Driver Complement ( 1) 1 ” Concave Ceramic NeoDymium Tw eeter (1) 3 .5 ” Concave Ceramic Do me Midra nge (2) 7 " Nomex Kevlar Comp osite Cone W oofers Sensitivity 87 dB Impedance 4 ohms nominal Frequency Response 28 Hz t o 25kHz Recommended Power 50 to 200 w atts Wiring Methods 2 Position Binding Post Dimensions 41&quo[...]

44 12 Notes[...]