Manuel d'utilisation / d'entretien du produit WT3 du fabricant Dayton
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Online Use r’s Guide Revised: May 1 1, 2008 WT3 is produced b y: Dayton Audio 725 Pleasant Valle y Drive Springboro, Ohio 45066 US A http://www.da y tonaudio.com Copyright © 200 7-2008 by John L. Murphy , Andersonvill e, TN USA All Rights Res erved.
Minimum Requir ements for the PC The minimum requireme nts to run WT3 are: • A PC with a processor runni ng at no less than 500 MHz wi th 64 MB RAM • One available USB port • A display with resolution of at least 800 x 600 pixels WT3 runs under Microso ft Windows 98, Me, 200 0, XP and VISTA operating s ystems.
Quick St art for the WT3 Woofer Tes ter *** VERY IMPOR TANT SAFETY N OTE *** NEVER conne ct the test leads of the WT3 to a speake r that is connect ed to any other equi pment or to an equipment ground! Seve re damage could occur to the WT3 unit or to the other equip ment.
6) Select “I mpedance Calibration ” under the “Impeda nce Analyzer” menu. The software will sweep the resist or and plot the results. The uncalibrat ed impedance is displayed and the calibrat ion is complete.
9) Measure the driver's V(as). Once you have measured t he driver's free air param eters the "Measure V(as)" button becom es enabled. Select one of the three meth ods to measure the V(as). Then pr ess the “Measure V(as)” button to start the measurement procedure.
Window s Vista - Additional Se tup Require ments PLEASE N OTE: STEP 2 IS CRI TICAL FOR WIND OWS VIS TA USER S! 1. Go to the Windo ws Control Panel and open the “Sound” control panel. A t the "Pla ybac k" tab mak e sure that "USB Audio Co dec" is selected as the default sou nd system for playback.
3. Click OK to close the "Sound" control panel. Note that this setup mu st be performed once for each USB port with which the WT3 unit will be used. Also, when starting WT3, always click on the Speaker icon in the task b ar and make sure the W indows Volume Control is s et at maximum .
Introducing W T3 No other loudspeaker par ameter measurement s ystem is as fast or as eas y to use as Dayton Audio’s WT3. WT3 emp loys powerful new DSP measurement t echniques to provide highl y accurate parameters in seconds.
The WT3 T oolbar The WT3 Toolbar provid es easy access for man y frequently used commands. M emory show and hide operations are especiall y convenient with the toolbar. Note that empt y memories are gra yed out until data is saved to them. Once the y contain data the y become enabled to switch between show and hide modes.
Using the W T3 Memories The WT3 software features 20 user memories for saving your detailed measurements alon g with much other user entered inform ation about the driver. Ea ch memory consists of the impedanc e and phase plots, the test setup i nformation (test box v olume, added mass etc.
View Menu: Clear Me mory These commands erase the contents of t he specified memor y. • From the keyboard, use Ctrl+Alt+1, C trl+Alt+2 etc. through Ct rl+Alt+0 to clear the contents of memories 1 t hrough 10 • Use Ctrl+Alt+Shif t+1, 2 etc.
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Frequentl y Asked Q uestions a bout WT3 Q: Why do I h ave to wait 90 seconds for the WT 3 hardware to w arm up? A: The initial 90 second waiting period dela y is required in order for the hardware power suppli es to ramp up and stabilize. To perform pr ecision measurements down to 1 Hz very wide low frequen cy bandwidth is required.
Removing WT3 from your Comp uter You can easily remove W T3 from your computer’s hard d rive if needed. • Go to the control panel and doub le click on the “Add/Remove Programs” icon • When t.
File Menu The commands under the File menu are as follows: ew (Ctrl+) Clears all current data to creat e a new empt y WT3 project file. Each project file holds up to 20 measurements in individual m emories. The memories can be displ ayed or hidden by clicking the corresponding memor y buttons on the toolbar.
Import Impedance Data… Opens a file dialog to select a .tx t (or .zma) file containi ng data to be imported to the W orkbench. Within t he .txt file each data point must be on a single line in the fo rmat: “Frequency Impedance Phase” with the frequency, impedance and phase data separated b y a tab or spaces.
Recent Files... A list of recentl y used files is displayed for eas y access. Exit (Ctrl+Q) Exits the application. The ke yboard shortcut is ver y convenient.
Edit Menu The commands under the Edit menu are as follows: Undo (Ctrl+Z) Undo is not impl emented Cut (Ctrl+X) Cut is impl emented for various text fields. Tex t is cut and placed on the clipbo ard for pasting to another location if desired Copy (Ctrl+C) Copy is implemented for various text fields.
Preferences This command opens the Preferences Dialog (sho wn below) where you can chan ge various printing, measurement and displa y settings Plots can be switched between fine and bold lines separately for displa y a nd printi ng. You can select metric units separatel y for Volumes and other unit s.
View Me nu The commands under the View menu are as follows: Toolbar Select the Toolbar command t o alternately hide or show t he toolbar. Status Bar Select the Status Bar com mand to alternatel y hide or show the status bar at t he bottom of the main page.
From the keyboard, use Alt+1, Alt+2 et c. through Alt+0 to save to memories 1 throu gh 10. Use Alt+Shif t+1, 2 etc. through 0 to save to memories 10 th rough 20. For example, to save the cur rent response to Memor y 5 you would press and hold the Alt ke y and then press the 5 ke y.
Impedance Analyzer Menu The Impedance Anal y zer Menu contains command s for running measurements and for performing calibration of the test lea d resistance and master cali bration as follows: Measure Free Air Parameters This command causes W T3 to run an impedance s weep and then extract the driver's free air parameters.
Impedance Sweep Use this command to per form a simple impedance sweep without the extracti on of any parameters. Driver parameters will be cleared to pr event any confusion. Impedance Calibration. .. When first installed, W T3 is calibrated to within about 2 % for the impedance range under 100 Ohm s.
Test Leads Calibration ... When the software is first i nstalled the default test lead impedance is 0.3 Ohms which is t ypical of the units. Use this comm and to refine the test lead calibration for your WT3 unit. Shown below i s the test leads calibration dialog.
Help Menu The commands under the Help menu are as follows : Help Topi cs The complete WT3 User’s Guide can b e found under the Help menu > Hel p Topics. User Information Enter your personal inform ation in this windo w. This is the information that will di splay at the Splash Screen and in the title bl ock of your printed reports.
Using WT3 to Mea sure a Woofer's P arameters The basic steps to measure a driv er's parameters are as follows. Before starting, be sur e the unit has been calibrated. • Start by connecting the W T3 hardware unit to a USB port on your PC. • Next, launch the WT3 software.
Using WT3 to Mea sure a Tweeter 's Parameters A typical sealed back mo ving coil tweeter operates as a ver y small closed box s y stem and therefore can be characterized b y it's closed box resonance a nd Q, F(sc) and Q(tc). You can use WT3 to measure both of these parameters for tweet ers as well as woofers and midr anges.
Here is a typical result wh en measuring a tweeter: We can read the tweeter's resonanc e frequenc y, F(s) (or, more strictly F(sc)), di rectly from the impedance plot or note the value at the M easured P arameters F(s) field. Just as with a closed box, the system's Q(tc) is read from the Q(ts) field.
Using WT3 to Mea sure a Resistor Before starting, make sur e the WT3 unit has been calibrated and has stabilized for at least 90 se conds. Measure the value of a resis tor as follows: • Launch the WT3 software and make su re the volume is set at m aximum.
at 0 degrees except for a slight rise at the high frequ ency limit. Here the measured value of 9.998 Ohms is seen to closel y match the resistor's specified value of 10 Ohms +/- 0.1%. At full playback volume the "noise" on the measu rement is usually onl y one or two pixels as seen above.
Using WT3 to Mea sure an Induc tor Before starting, make sur e the WT3 unit has been calibrated and has stabilized for at least 90 se conds. Measure the value of an i nductor as follows: • Launch the WT3 software and make su re the volume is set at m aximum.
phase response (red) is se en to be near zero degrees at low frequ encies and increases to 90 de grees at high frequencies as expe cted for the simple (R-L) test circuit. The measured value of 0.9893 m H is in good agreement with the indu ctor's nominal 1.
Using WT3 to E valuate a Closed Box Lo udspeaker A closed box t ype of loudspeaker system is characterized b y a resonance frequency F(sc), an electri cal Q value Q(ec), a mechan ical Q value Q(mc) and a t otal Q value Q(tc).
Here is a typical result wh en measuring a single ful l range driver in a closed box type enclosure: By inspecting the impedance plot we c an determine that this is a closed box type of loudspeaker system from the presence of th e single impedance peak in th e low frequency ran ge.
Using WT3 to E valuate a Vented Box Lo udspeaker A vented box t ype of loudspeaker system can be characteriz ed by it's equivalent closed box Q(tc) and the vented enclosure's Helm holtz tuning frequenc y F(b) . You can us e WT3 to measure both of thes e parameters for an y vented box loudspeaker system.
Here is a typical result wh en measuring a single ful l range driver in a vented box type enclosure:.
In order to read the vent tuni ng frequency, F(b), more precisel y we can adjust the frequenc y display limits to zoom in on the frequency range containing the two imped ance peaks as shown below: At .
Using WT3 to E valuate a Complete Speak er System You can use WT3 to measu re the impedance of com plete multi-way loudspeaker s ystems. Based on this impedance curve we can tell a numb er of things about the s ystem, such as whether the woofer u ses a closed or vented enclosure.
Here is a typical result wh en measuring a complet e 2-way speaker s ystem: We can see that this s ystem employs a vented woofer s ystem with the vented enclosure tuned to abo ut 40 Hz. Even with a mini mum impedance of just o ver 6 Ohms this would often be consider ed to be a nominal 8 Ohm louds peaker system.
Using WT3 to Dia gnose Loudspeak er Fault Conditions When carefully applied WT3 can be used to spot common p roblems with a speaker system. For example, the screen belo w shows two impedance measurements of th e same two-wa y speaker s y stem. The green (lower) plot shows t he normal impedance response of this s ystem.
In the screen below you see the same system as above but th is time with a shorted tweeter. The green (upper) plot again shows the normal impedance respons e of this system.
Now let's examine sim ilar fault conditions for the woofer. Th e screen below shows the same 2-w ay system as above with the green plot representing the normal s ystem and the oran ge plot showing the system in a fault mode w ith an open circuit woofe r.
Finally, here is a screen s hot showing the same s ystem with the woofer in a short circuit fault condition (lower blue trace). As we see in these examples of ten a system fault is most easil y detected by comparing the suspect s ystem to a known good s ystem.
Using WT3 to De sign a Zobel Netw ork Zobel networks are used to control the impedance of a loudspeaker drive r in the upper frequenc y range where voice coil inductance normall y causes the impedance to ris e with increasing frequenc y. Zobel networks are used to help crossov ers do a better job of keepin g the highs from passing to the woof er.
we can get it in the upper frequency range. Let's start with around 1 uF for the capacitor and s ee what we get for a new impeda nce response. The screen below shows the new impedanc e response in purpl e with the original (uncom pensated) response in blu e.
Below is the impedance wit h the capacitor increased to 2 uF (blue tr ace). The ori ginal (uncompensated) impedance is s hown in green. The 2 uF capa citor has flattened out th e impedance so that it rises onl y slightly above 8 Ohms.
The screen below shows the effect of inc reasing the capacitor to 3 uF (blue trace). The inc rease from 2 to 3 uF gave even further i mprovement as the impedance above resonan ce is now quite flat. J ust to see what happens, let's increase the cap acitor further to 5 uF.
Below we see the effect of incre asing the capacitor to 5 uF in t he lowest (blue) trace. It seems we have gone too far with the incr ease to 5 uF. The impedance in the 2 to 3 kHz range has been redu ced to the DC resistance value and is now rising above the previous m easurement with the 3 uF capacitor.
Un point important après l'achat de l'appareil (ou même avant l'achat) est de lire le manuel d'utilisation. Nous devons le faire pour quelques raisons simples:
Si vous n'avez pas encore acheté Dayton WT3 c'est un bon moment pour vous familiariser avec les données de base sur le produit. Consulter d'abord les pages initiales du manuel d'utilisation, que vous trouverez ci-dessus. Vous devriez y trouver les données techniques les plus importants du Dayton WT3 - de cette manière, vous pouvez vérifier si l'équipement répond à vos besoins. Explorant les pages suivantes du manuel d'utilisation Dayton WT3, vous apprendrez toutes les caractéristiques du produit et des informations sur son fonctionnement. Les informations sur le Dayton WT3 va certainement vous aider à prendre une décision concernant l'achat.
Dans une situation où vous avez déjà le Dayton WT3, mais vous avez pas encore lu le manuel d'utilisation, vous devez le faire pour les raisons décrites ci-dessus,. Vous saurez alors si vous avez correctement utilisé les fonctions disponibles, et si vous avez commis des erreurs qui peuvent réduire la durée de vie du Dayton WT3.
Cependant, l'un des rôles les plus importants pour l'utilisateur joués par les manuels d'utilisateur est d'aider à résoudre les problèmes concernant le Dayton WT3. Presque toujours, vous y trouverez Troubleshooting, soit les pannes et les défaillances les plus fréquentes de l'apparei Dayton WT3 ainsi que les instructions sur la façon de les résoudre. Même si vous ne parvenez pas à résoudre le problème, le manuel d‘utilisation va vous montrer le chemin d'une nouvelle procédure – le contact avec le centre de service à la clientèle ou le service le plus proche.
