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Operation Manual

22410 70th Avenue West • Mountlake Terrace, WA 98043 • Phone 425-775-8461 Fax 425-778-3166

www.audiocontrol.com

P/N 9130430

© 1997 All Rights Reserved

Summary of Contents for SA-3051

Page 1: ...er One Third Octave Real Time Analyzer With Memories and Digital SPL Display Operation Manual 22410 70th Avenue West Mountlake Terrace WA 98043 Phone 425 775 8461 Fax 425 778 3166 www audiocontrol com P N 9130430 1997 All Rights Reserved ...

Page 2: ...SA 3051 SA 3052 Operation Manual ...

Page 3: ...extreme at 175dB SPL 3 6 Chapter 4 Acoustical Testing with the SA 3051 SA 3052 Overview 4 1 Basic Procedure 4 2 Body Effects 4 3 Sound Pressure Level and Hearing Loss 4 3 Chapter 5 SA 3051 SA 3052 Applications Sound System Equalization 5 1 Hi Fi Equalization 5 1 Multi Channel THX Equalization 5 2 Sound System Equalization 5 4 Monitor Speaker Equalization 5 4 Fold Back Monitor Equalization 5 5 Feed...

Page 4: ...SA 3051 SA 3052 Operation Manual ...

Page 5: ...rranty and tells how to obtain service for the SA 3051 SA 3052 We trust that you ll never need to use this section Section 8 Specifications lists the SA 3051 SA 3052 s specifications Notational Conventions Within this manual several different notation conventions are used to indicate various facets of the SA 3051 SA 3052 s features Small Caps Indicate a marked feature on the unit like the control ...

Page 6: ...SA 3051 SA 3052 Operation Manual ...

Page 7: ...0 second temporal averaging Peak hold Balanced XLR microphone balanced TRS phone jack and unbalanced RCA connector inputs 175dB sound pressure level measurement optional A and C weighting filter optional Portable battery operation SA 3052 Parallel printer port SA 3052 Test Instruments vs Toys There is a fundamental difference between the many real time analyzers currently available on the market t...

Page 8: ...ardest to design and manufacture and are usually only found on the most expensive read unaffordable analyzers Class II filters are easier not easy just easier to design and manufacture than Class III filters Any real time analyzer intended for serious measurement work will use filters that at least meet Class II standards The filters used in the SA 3051 SA 3052 analyzer meet or exceed the standard...

Page 9: ...nter Output The printer output option provides a Centronics parallel interface for a PC compatible printer not pro vided The analyzer to printer cable is a standard PC type parallel printer cable also not provided The printed output is a form with suitable blank spaces for recording the time and place of the mea surement and other data followed by the a printed representation of the real time spec...

Page 10: ...SA 3051 SA 3052 Operation Manual ...

Page 11: ...uit that prevents operation of the instrument below critical battery cell volt age This prevents total battery discharge which shortens the cell life To continue operation the SA 3052 may be operated from the AC power line The batteries may be re charged by plugging the SA 3052 into a suitable source of AC power with the front panel Power switch set to the Off position for a period of 9 to 10 hour...

Page 12: ... standard curve that may be recalled each time that the SA 3051 SA 3052 is used Pink Noise The internal pink noise generator is an accurate digital laboratory grade test source The pink noise out put is accurate throughout the measurement range to within 0 25dB The maximum output provided at the tip sleeve phone jack is 1 volt into a 600 load unbalanced ring and sleeve grounded or 150 mW into a 4 ...

Page 13: ...Input 3 A tip ring sleeve phone jack is used for connecting to balanced and unbalanced sources Connect unbalanced sources by using a tip sleeve 2 conductor plug inserted into this jack This input has an impedance of 10 kohms and is suitable for signal levels from 56dBu to 36dBu An input signal of 0dBu represents 100dB SPL Input 2 This is a standard audio RCA connector with an input impedance of 1 ...

Page 14: ...ower markings Printer Interface SA 3052 This is a female 25 pin connector DB 25F used for connection to an external PC type printer not supplied The connector is wired for a parallel interface printer This connector is present only on the AudioControl Industrial SA 3052 which is equipped with the printer interface option A description of the pin connections can be found on page 3 4 Print SA 3052 T...

Page 15: ...ng is suited to signal monitoring and the Slow setting works well for pink noise measurements 7 You can determine the sound pressure level at the microphone by pressing and holding the SPL push button for one second until the display changes to the digital mode This will display the sound pres sure level in 1 10th dB resolution The SPL bargraph is always 4dB per step regardless of the setting of t...

Page 16: ...ighest peak level in any of the SA 3051 SA 3052 s thirty display bands This display may be stored in any memory location averaged etc 1 Press and hold the Rta Recall button for one second The red RTA LED is now flashing indicating the peak hold mode is active The display now holds the overall peak level for each of the thirty bands 2 Pressing the Rta Recall button again exits the peak hold mode Pe...

Page 17: ...tout showing only the RTA curve may also be printed by double clicking pressing twice quickly the Print button Operation 3 3 Figure 3 1 Printout Example AUDIOCONTROL INDUSTRIAL SYSTEM ANALYSIS By Client _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Date _ _ _ _ _ _ _ _ Address _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ Telephone _ _ _ _ _ City _ _ _ _ _ _ _ _ _ _ _ State _ _ _ _ ZipCode _ _ _ _ _ _ Job _ _ _ _ _ _ _ _...

Page 18: ...ve the SA 3052 for a period of 8 to 10 hours twice the discharge time 4 The battery charger automatically adjusts the rate of charge as the battery reaches full charge The Power Charge LED will glow red then flash slowly when a full charge is reached Once this occurs the battery charger switches to trickle charge mode to maintain the battery at full charge Operating the SA 3052 on AC power will ev...

Page 19: ...rned off Leave it plugged in for at least two hours to charge If the Charge LED by the power switch does not light then you may not have AC power and the battery cells are not charging If this revives the SA 3051 SA 3052 you can resume normal operation using AC mains power Be sure to charge the batteries for another six to eight hours before using the portable battery mode Plugging the SA 3051 SA ...

Page 20: ...asurements from 100 to SPL 175 The high SPL mode only works in the digital SPL display mode Don t use the SPL 175 microphone for RTA measurements Selecting the SPL operating mode is very simple 1 Press and hold the SPL button to enter the digital SPL mode 2 The display will alternate HI and LO Release the SPL button when the appropriate mode is displayed 3 When the digital SPL mode is in the HI ra...

Page 21: ...l signal The real time analyzer RTA breaks the signal up into equal octave per centage bands and displays the signal level of each band individually The display can be LCD a video display or an LED matrix The SA 3051 SA 3052 uses the latter method In the real world very few things are perfect and expensive sound systems are no exception Traditional ly loudspeakers are measured in an anechoic adj a...

Page 22: ...e store response several times 6 Recall the stored curves and derive a curve that is an average of all of them See page 3 2 for instruc tions on averaging The rationale behind averaging is to help filter out response flaws that are caused by the microphone position versus those flaws that are caused by the acoustical environment and its interaction with the sound system 7 Now adjust the equalizer ...

Page 23: ...eful the reflection can cause response errors because of the multiple paths into the microphone Ideally the microphone should be suspended in free space In reality three feet should be adequate spacing In an automobile the three foot rule may turn into science fiction On the other hand that s the environment that the system is going to be listened to in In this case the rule goes out the window Yo...

Page 24: ...alization use the SA 3051 SA 3052 to make a preliminary assess ment of the situation Use several microphone positions finally drawing a curve that represents the average of a representative sample of the positions We recommend no less than 3 different positions in a one to three foot cube around your listening position Next adjust the various level controls on the speakers themselves to smooth out...

Page 25: ...eaker Placement We and every speaker manufacturer we ve ever talked to can t over emphasize the importance of proper speaker placement Some speakers require very particular placement in relation to the back and side walls all speakers demand careful placement in relation to your home theater s characteristics Start by consulting the speaker s owner s manual and don t be afraid to experiment a lot ...

Page 26: ... achieve a spatial average of the listening room Set the SA 3051 52 display to 2 dB per step with the speed set on Slow Averaging 20 second averaging The system volume level should be set at a reference position of approximately 90 dB and pink noise should be used as test material Starting with the center channel use the following procedures a Take a measurement in each seating position and store ...

Page 27: ... context is especially critical because any response aberration in the control room monitor speakers has an inverse relationship on the material being monitored once the material is removed from the room and played on other equipment Consider Your playback system has a midrange bump in it around 3kHz and a fairly flat high end You re mixing some material down using these speakers as a reference Wh...

Page 28: ...ker back into the microphone This will change your tuning on the monitor equalizer Feedback tuning What could be simpler Make the sound system feed back find the feedback frequency on the equalizer and notch it out slightly Repeat as necessary One third octave equalizers make this a tricky proposition to say the least Before the SA 3051 SA 3052 the process of finding the feedback frequency on the ...

Page 29: ...se source compatible with their input format For instance a turntable requires a pink noise record a tape machine requires a pink noise tape Pink noise sources are available for all common high fi sources including CD players The diagrams in Figures 5 2 to 5 7 show how to wire everything The 1dB step setting gives maximum resolution Most purely electronic devices should be able to easily exceed th...

Page 30: ...SA 3051 SA 3052 Operation Manual Figure 5 5 Checking a tape recorder Figure 5 4 Checking a signal processor or preamp Figure 5 6 Checking a power amplifier 5 7 ...

Page 31: ...d s play out of setting the bias 1 Connect the pink noise output to the deck s input 2 Put in a cassette set the record levels start recording 3 Monitor the deck s playback output with the SA 3051 SA 3052 4 Adjust the bias for flattest overall response It s advisable to start with the bias control at minimum then increase it until you see a maximum occur in the mid band 500 Hz 2 kHz then continue ...

Page 32: ... Set the SA 3051 SA 3052 for a display reading about 3 LED s below the top of the display Use the 1 dB step setting Count three LED s down from the flat portion of the line shown on the display Move to the right or left until you intersect the falling portion of the line shown on the display Now move straight down to read the approximate crossover frequency Store this reading in one of the memorie...

Page 33: ...ntrol Lastly the signal is scaled to the correct level by the dB Step switch One Third Octave Filters After the input circuitry the signal drives the inputs of thirty one third octave filters and the broadband SPL circuit Since the SPL circuit is simpler we ll discuss it first The input to the SPL circuit is a broadband signal It is rectified filtered and applied to one input of the multiplexer se...

Page 34: ...ransfers the contents of the temporary display memory to another RAM location for safekeeping On recall the µP does the opposite moving the data from RAM to the temporary display memory LED Display The SA 3051 SA 3052 display gets its data from the µP bus The display is row and column multiplexed to conserve power Eight bit latches hold the row and column data for each column in the display The in...

Page 35: ...s with the SA 3051 SA 3052 equalizer that voids your warranty 5 The warranty is also void if the serial number is altered or removed or if the SA 3051 SA 3052 equalizer has been used improperly Now that sounds like a big loophole but here is all we mean by it Unwarranted abuse is A physical damage don t use the SA 3051 SA 3052 equalizer to level your pro jection TV B improper connections 120 volts...

Page 36: ...d how many people forget this 3 A return street address No PO Boxes please 4 A daytime phone number in case our tech has a question about the problem you are having You re responsible for the freight charges to us but we ll pay the return freight back We match whatever shipping method you send it to us so if you return the unit overnight freight we send it back overnight We recommend United Parcel...

Page 37: ...SI S1 11 1986 ClassII Type E specifications Frequency Range 30 1 3 octave bands from 25 to 20 kHz on ISO preferred 1 3 octave center frequencies Center Frequency Accuracy 2 of design center Band Center Frequencies 25 31 5 40 50 63 80 100 125 160 200 250 315 400 500 630 800 1000 1250 1600 2000 2500 3150 4000 5000 6300 8000 10000 12500 16000 20000 Hz Display Spectrum Display 9 x 30 LED matrix SPL Di...

Page 38: ... 1997 AudioControl Industrial All rights reserved 22410 70th Avenue West Mountlake Terrace WA 98043 425 775 8461 Fax 425 778 3166 www audiocontrol com ...

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