AC 23B OPERATORS MANUAL
Contents
1. s LOW OUT is unused CHANNEL 1 CHANNEL 2 STEREO STEREO 3W 2W 3W gt lt gt R39 R80 CIE J 4 WAY MONO SUB OPTION J10 LE SHIP Manual 7 REAR PANEL MONO 4 WAY AND MONO 5 WAY INSTALLATION Input Mono 4 and 5 Way labels in this row IGH OUT MID 3W LOW 2W LOW 3W OMIT 2W BER STEREO 3W D HIGH OUT O 3W LOW 2W 3W OMIT 2W ee MNED 1 IN HI Bowen MADE IN U S A PIN 2 POSITIVE RANE CORP st CHANNEL2 CHANNEL1 O O 9 TASSIS GND N STEREO STEREO ji 3w ee ee 2w 3w J 2w SOMA OMIT 4W MONO ser Sonnets somt CLASS 2 EQUIPMEN Heh OUT HI MID OUT 5W LOW OUT JONO MONO 5W CHANGE INTERNAL SWITCH FOR MONO JONO 4W OMIT MONO MID QUT SUB OUT MONO 4W 5W IN np Mid Amp al Low Amp 6 ____ High Amp nod 5 High Mid Amp Te 2 _ Sub Amp oe THIS OUTPUT IS NOT USED FOR 4 WAY MONO OPERATION 4 WAY USERS SEE INTERNAL SWITCH INSTRUCTIONS ON PREVIOUS PAGE Observe the labels below the Inputs and Outputs for Mono operation MONO INPUT Connect the output from your mixer or other signal source only to the CHANNEL 1 INPUT for Mono opera tion do not use the Channel 2 Input Pin 2 is hot per AES standards SUBWOOFER OUTPUT Connect the SUB OUT to the input of the subwoofer2. then you will have to use an additional delay source to align the high and mid drivers The built in delay system in the AC 23B is designed to accommodate the majority of common speaker configurations if you encounter confu sion or difficulty with your particular system it is best to consult your dealer or the Rane factory for assistance b If this decrease in the display due to the DELAY control occurs at a low frequency crossover point below about 150 Hz set the DELAY control to minimum and leave it there Frequencies below 150 Hz are actually omnidirec tional so that phase misalignment is virtually inaudible below this point Subwoofers will often possess long folded or straight horns resulting in the diaphragm being well behind the rest of the stack Most authorities agree that phase alignment of subwoofers is unnecessary Lower the microphone until it is vertically midway between the mid and low drivers Repeat steps 2 through 5 using the crossover LEVEL control MUTE switch and next DELAY control You may start each series of steps 2 through 5 at a different volume as necessary but once the Levels are set in step 3 do not alter these until step 5 is completed Once all of the crossover DELAY controls are set then adjust the output LEVEL controls as outlined on page Manual 14 Manual 11 Time Delay Adjustment Using SPL Meter amp Tone Generator Now that good quality realtime analyzers are becoming more affordable an
3. 2W E MNED 1 IN PIN 2 POSITIVE PIN 3 NEGATIVE dk ok 2 CHANNEL 1 Oo PIN 1 CHASSIS GND ow maw waw 2w ow 2 2w OMIT 4W MONO SET SWITCHES AS sHown t HIGH OUT HI MID OUT 5W Low OUT OMIT MONO MONO 5W CHANGE INTERNAL SWITCH FOR M FOR MONO JONO 4W OMIT MONO MID OUT SUB OUT MONO 4W 5W IN 4 High Amp Hox 4 _ Mid Amp 2 Sub Amp Low Amp Note The switching in the AC 23B will result in a Mono 4 Way configuration with the crossover ranges SUB LOW MID amp HIGH from left to right across the bottom front panel By connecting a patch cable from the CHANNEL 1 HIGH OUT to the CHANNEL 2 INPUT the LOW MID crossover range changes from 70 Hz 1 kHz to a higher range of 190 Hz 7 kHz Switch CHANNEL 1 to 3 Way and CHANNEL 2 to 2 Way Note DO NOT follow the Mono 4 Way Switch Instructions on page Manual 7 it must be set to 5 Way MONO INPUT Connect the output from your mixer or other signal source only to the CHANNEL 1 INPUT do not use the Channel 2 Input Note For this alternate Mono 4 Way installation connect a patch cord from the CHANNEL 1 HIGH OUT to the CHANNEL 2 INPUT as shown Pin 2 is hot per AES standards SUBWOOFER OUTPUT Connect the SUB OUT to the input of the subwoofer amplifier or bass bin amp LOW OUTPUT Connect the MID OUT to the input of the low frequency amplifier MID OUTPUT Connect the
4. MID 3W LOW 2W LOW 3W OMIT 2W CHAWINED 2 TT STEREO ra HIGH OUT O 3W LOW 2W O 3W OMIT 2W a MINED 1 IN HIGH O1 Gr 2B POWERI MRANE CORP PIN 2 POSITIVE Aa 2 CHANNEL1 O 9 8 mere Gib Ay C STEREO STEREO 33 E E aw WE MN 2w wiw Z60mA Crios OMIT 4W od SET SWITEMES AE sown f ____ _ HIGH OUT HI MID OUT 5W our OMIT MONO mono 5W CH Y INTE NAL SWITCH FOR N fi ONO aW OMIT MONO Mip our SWB MONO 4W 5W IN High Amp amp TT High Amp Mid Amp ia ame C j Mid Amp Om Low Amp a Om Low Amp Observe the labels above the Inputs and Outputs for Stereo operation Lk CHANNEL 1 INPUT Plug the left output of the mixer equalizer or other signal source to this Input Pin 2 is hot per AES standards CHANNEL 2 INPUT Plug the right output of the mixer equalizer or other signal source to this Input HIGH OUTPUTS Connect the CHANNEL 1 HIGH OUT to the left channel input of the high frequency amp and the CHANNEL 2 HIGH OUT to the right channel input of the high frequency amp MID OUTPUTS Connect the CHANNEL 1 MID OUT to the left channel of the mid frequency amp and the CHANNEL 2 MID OUT to the right channel of the mid frequency amp LOW OUTPUTS Connect the CHANNEL 1 and 2 LOW OUTS to the left and right channels of the low frequency
5. or bass bin amplifier LOW OUTPUT Connect the LOW OUT to the input of the low frequency mid bass amp MID OUTPUT Connect the MID OUT to the input of the mid frequency amplifier HIGH MID OUTPUT FOR MONO 5 WAY ONLY Use this Output only for Mono 5 Way applications Omit this output when using the AC 23B as a Mono 4 Way Crossover Mono 4 Way Switch Instructions are on the previous page In 4 Way the AC 23B internally bypasses the High Mid section and defeats all front panel High Mid Controls For Mono 5 Way connect the HIGH MID OUT to the input of the high mid frequency amplifier HIGH OUTPUT Connect the HIGH OUT to the input of the high frequency tweeter amp 2 WAY 3 WAY switches Converts each channels outputs from 3 Way to 2 Way For Mono 4 or 5 Way slide these switches to the 3 WAY position MONO STEREO switch Push this to the MONO in position POWER input connector Use only a model RS 1 or other power supply approved by Rane This unit is supplied with a remote power supply suitable for connection to this input jack Chassis ground point A 6 32 screw is used for chassis grounding purposes Always connect the crossover chassis to the ampli fier chassis See Chassis Grounding on page Manual 1 for details Manual 8 REAR PANEL ALTERNATE MONO 4 WAY INSTALLATION Patch Cable Input Mono 4 and 5 Way labels in this row p DAN oN OS D 3Ww 2W p OUT O 3W LOW 2W D 3W OMIT
6. sistency accuracy and plain old good sound that very few ears on this earth can deliver They are affordable easy to use and amazingly effective You owe it to yourself and your audience to at least look into one of these analyzers you ll wonder how you managed at all without one Whether by analyzer or ear here are a few recommended methods of setting the crossover output Levels Manual 14 Setting Levels Using a Realtime Analyzer NOTE If you are running two Channels tune up only one Channel at a time 1 Set all LEVEL controls on the crossover to minimum leave Delay and Frequency controls as set previously 2 Place the analyzer microphone at least 15 feet away from the speaker stack on axis dead ahead and about chest level Minimize any background noise fans air conditioners traf fic etc that could affect the readings 3 Run pink noise through the system either through a mixer channel or directly into the crossover Turn all amplifier con trols at least half way up 4 We will use the 3 Way mode here as an example the procedure applies to all configurations Turn up the INPUT LEVEL control s on the crossover about half way 5 Slowly turn up the LOW LEVEL control on the crossover un til you hear a healthy level of noise through the low frequency drivers it should sound like rumble at this point 6 Adjust the display controls on the analyzer so that it shows the greatest number of 0 dB LED s g
7. the lowest frequency and ending with the highest Adjust the SPL meter and or crossover output until you get a 0 dB reading on the meter After this point do not change the controls on the SPL meter While leaving the LOW LEVEL control at the 0dB adjust ment just obtained press the LOW MUTE switch on the crossover so that the pink noise disappears from the bass speakers revel in the silence Now slowly turn up the MID LEVEL control so pink noise is heard from the mid frequency speakers Without changing any settings on the SPL meter adjust the MID LEVEL until you obtain a 0 dB reading on the SPL meter Now the low and mid speakers are set at the same level 7 Now press the MID MUTE switch on the crossover so that the pink noise again disappears 8 Repeat this process for each frequency section of the crossover ending with the highest frequency NOTE It is possible that you may turn one of the frequency section output LEVEL controls all the way up and still not have enough volume for a 0 dB read ing as determined by previous section levels This is probably due to different sensitivities of amps speakers and other level controls in the system When this happens re set the SPL meter so that it reads 0 dB on this frequency section you may have to down range the meter and re adjust the crossover level control Now go back and re adjust the previous crossover level controls turn ing these down to get a O dB reading on
8. the meter Nn ion 9 Once the HIGH LEVEL control is set for 0 dB on the meter disengage all of the MUTE switches on the crossover and check that noise is emitting from all the speaker components The crossover should now be aligned Make any overall level adjustments with the MASTER LEVEL controls and leave the output level controls unchanged Constant Directivity Horn EQ Mod Constant Directivity or CD horns need additional equal ization to help cover the same area a long throw horn can cover Additional circuitry has been added to the AC 23B for additional equalization of the High Frequency outputs for the CD Horns This modification should only be attempted by an experienced technician It is important to know the 3 dB down point of the CD driver s frequency response The manufacturer of your driver should be able to supply you with a frequency response curve Find the point where the high end szarts to roll off and look for the point on the chart that is 3 dB down from that point toward the right as the higher frequencies roll off Find the frequency at the bottom of the chart of this point an approximate is fine you don t have to be exact Find the closest frequency in the table below to determine the correct value capacitor to install in the AC 23B to correct for this high frequency roll off STEP BY STEP PROCEDURE This procedure is for CD horn EQ on the High output in Stereo 3 Way mode For a Mono 4 or 5 Way system
9. to this Input Pin 2 is hot per AES standards CHANNEL 2 INPUT Plug the right output of the mixer equalizer or other signal source to this Input HIGH FREQUENCY OUTPUTS Connect the CHANNEL 1 HIGH OUT to the left channel input of the high frequency amp and the CHANNEL 2 HIGH OUT to the right channel input of the high frequency amp LOW FREQUENCY OUTPUTS Connect the CHANNEL 1 LOW 2Way Output to the left channel input of the low frequen cy amplifier and the CHANNEL 2 LOW 2Way Output to the right channel input of the low amplifier If you need a summed Mono Low Ouput see Monoing the Low Outputs on page Manual 7 2 Way 3 Way switch Converts the outputs from 3 Way to 2 Way This switch removes the Low frequency crossover from the sig nal path Low frequencies are now routed to the Mid frequency Output Be sure to slide the switches to the 2 Way position Note The Low frequency outputs are still active and may be used as additional subwoofer outputs STEREO MONO switch Set this switch to the STEREO out position POWER input connector Use only a model RS 1 or other power supply approved by Rane This unit is supplied with a remote power supply suitable for connection to this input jack This is not a telephone jack The power requirements call for an 18 24 VAC center tapped transformer only Using any other type of unapproved supply may damage the unit and void the warranty Two years parts and labor is worth
10. with a CD horn on the high output only place C16 in Channel 2 1 Remove the top and bottom covers of the AC 23B 2 Locate the positions for C15 and C16 on the Schematics page 3 and on the circuit board See Assembly Diagram 3 Clean the solder pad on the underside of the board so that the appropriate capacitor can be inserted Install the capacitor and solder the leads from the underside using fresh solder Clip the excess leads 4 Replace the top and bottom covers Rane Corporation 10802 47th Ave W Mukilteo WA 98275 5098 USA TEL 425 355 6000 FAX 425 347 7757 WEB www rane com 106001 Manual 15
11. you will have to obtain an additional external delay source to align the high and mid drivers The built in delay system in the AC 23B is designed to accommodate the majority of common speaker configurations if you encounter con fusion or difficulty with your particular system it is best to consult your dealer or the Rane factory for assistance b If this decrease in the display due to the LOW DELAY control occurs at a low frequency crossover point below about 150 Hz set the LOW DELAY control to mini mum and leave it there Frequencies below 150 Hz are actually omnidirectional so that phase misalignment is virtually inaudible below this point Subwoofers will of ten possess long folded or straight horns resulting in the diaphragm being well behind the rest of the stack Most authorities agree that phase alignment of subwoofers is unnecessary Otherwise you will have to obtain additional delay equipment to align these to the rest of the system Tune the tone generator to the next lower crossover frequency and then repeat steps 2 through 5 using the appropriate level and delay controls Once the DELAY control is set you may re adjust any of the crossover LEVEL controls at the begin ning of each alignment procedure Once all of the crossover DELAY controls are set then re adjust the output LEVEL controls as outlined on page Manual 14 Delay vs Frequency Table If you do not have the equipment necessary to electronically align
12. 50 x 436 46 a Fso 4406 aas lars ZEK a E 7o 4a 6 A efo 850 350 850 4 AC 23B OsO0 o OFF O O 0 oto O J LO O OF SOl o Saven CROSSOVER oio o 10 MIN MAX o MIN MAX Ois ieg a MINN MAX gt 7 o 10 van sk iid LeveL Lever DELAY PREGUENCY LEVEL MUTE DEA FREQUENCY Lev LEVEL MUTE DELAY FREQUENCY LeveL MUTE FREQUENCY ere Lever 7 OD M MONO AW OR SW INACTIVE O 5W MID HIGH MID LOW MID 5W HI sH MID 5W HIGH AID HIGH HI 3H T ery rr ma aarsie yy cre Observe the labels above the controls for stereo operation Not used in 2 Channel 2 Way Mode Channel 1 MASTER LEVEL control Sets the overall Level of Channel 1 without altering the relative settings of the Low and High frequency Outputs Unity gain for all level controls is at 7 LOW LEVEL control Sets the Level of signal going to the Low Frequency output in this channel Refer to Setting the Output Level Controls on page Manual 14 LOW MUTE switch When pressed to the iv position all signal is removed from the Low Frequency Output This eases tune up procedures as described on pages Manual 11 15 LOW DELAY control Adds from 0 to 2 ms of time Delay to the Low Frequency Output only This allows a low frequency driver to be electronically phase aligned with a mid frequency driver whose diaphragm is situated behind the low frequency diaphragm Refer to Time Delay Adjustment Procedure on page Manua
13. ANE OPERATORS MANUAL AC 23B ACTIVE CROSSOVER 3W LOW MID 2W INACTIVE 240 400 7s 500 70 FREQUENCY SUB LOW 3W MID HIGH MID 2W LOW 2W LOW HIGH ze fa KOT 6 Ove 0 MIN m Oio EEVEE MUTE DELAY FREQUENCY MID LOW HIGH 2W INACTIVE RARE i 9 C 0 o MIN MAX Level LeveL MUTE DELAY CH 1 MASTER io 100 7 0k LEVEL Level O OA MASTER SUBWOOFER 5W MID HIGH MID caren 4W MID HIGH MONO 4W OR SW INACTIVE 3W LOW MID 2W INACTIVE 240 400 iso 350 130 300 IOo 70 1k FREQUENCY u LOW MID 3W MID HIGH 2W LOW HIGH 250 700 1 0k 2 04 sae 190 7 fas FREQUENCY AW INACTI SW HIGH MID HIGH HIGH LOW MID HIGH 2W INACTIVE 2W LOW O AC 23B ACTIVE CROSSOVER OC 5 4 A6 Ton 010 LEVEL 59 4 Cl MIN MAX LEVEE MUTE DELAY 4W INACTIVE 5W HIGH MID 4O MN MAX LeveL DELAY LOW QUICK START Labels above the controls refer to the unit being operated in the 2 or 3 Way Stereo mode Labels below the controls re fer to the unit being operated in the 4 or 5 Way Mono mode Set the STEREO MONDO switch appropriately The fact that the AC 23B is a multiple function unit means the outputs are switched around in Mono mode To operate the unit in Stereo 3 Way mode be sure the rear panel switches are set for STEREO 3 WAY Fol
14. AY control Adds from 0 to 2 ms of time Delay to the Mid frequency Output only 4 MID HIGH MID crossover frequency selector Sets the crossover frequency between the Mid and High Mid Outputs NOTE Both the CHANNEL 1 HIGH LEVEL control and CHANNEL 2 MASTER LEVEL control are automatically bypassed when the AC 23B is switched to MONO on the back panel Adjusting these controls has no effect in the Mono mode HIGH MID LEVEL control This controls the Level of signal going to the High Mid Output only in 5 Way Mode NOTE TO 4 WAY MONO USERS An internal switch S5 determines 4 or 5 Way mode Our apologies We must ship the units in the 5 Way mode since normal Stereo 3 Way operation demands it a fact not the least bit obvious but nevertheless a fact it remains See the Mono 4 Way Switch Instructions on the next page The HIGH MID LEVEL control HIGH MID MUTE switch HIGH MID DELAY control and HIGH MID HIGH FREQUENCY control are out of circuit and will have no effect regardless of their settings in 4 Way Mode Manual 6 HIGH MID MUTE switch Removes all signal from the High Mid Output when pressed to the i position This control is dis abled in 4 Way mode HIGH MID DELAY control This control adds from 0 to 2 ms of time Delay to the High Mid Output only This control is disabled in 4 Way mode D HIGH MID HIGH crossover frequency selector This control sets the crossover Frequency between the High Mid and High Frequency Outputs Thi
15. HIGH MID OUT to the input of the mid frequency amplifier Be sure the CHANNEL 1 HIGH LEVEL and the CHANNEL 2 MASTER LEVEL controls are set at 7 for unity gain between Channels HIGH OUTPUT Connect the HIGH OUT to the input of the high frequency amplifier STEREO MONO switch Be sure this switch is in the STEREO out position Yes STEREO A Mono circuit is created when Channel 1 is patched into Channel 2 and the correct signal flow depends on this switch 2 WAY 3 WAY switches Converts each channels outputs from 3 Way to 2 Way For this configuration set CHANNEL 1 to 3 Way and CHANNEL 2 to 2 Way POWER input connector Use only a model RS 1 or other power supply approved by Rane This unit is supplied with a remote power supply suitable for connection to this input jack Chassis ground point A 6 32 screw is used for chassis grounding purposes Always connect the crossover chassis to the ampli fier chassis See Chassis Grounding on page Manual 1 for details Manual 9 OPERATING INSTRUCTIONS Selecting Crossover Frequencies Most speaker manufacturers supply low and or high frequen cy cut off points for each driver especially if these are supplied in a system These cut off frequencies are based on each driver s per formance at and beyond this point with a certain safety margin to accommodate more gentle filter roll offs and resultant higher output beyond the recommended performance range The AC 23B util
16. LEVEL LEVEL MUTE DELAY FREQUENCY LEVEL MUTE DELAY FREQUENCY MASTER LEVEL control Sets the overall Level of the entire unit in Mono mode without changing relative settings of the individual Sub Low Mid High Outputs Unity gain for all Level controls is 7 SUBWOOFER LEVEL control Sets the Level of signal going to the Sub Output See page Manual 14 SUBWOOFER MUTE switch Removes all signal from the Sub Output when pressed to the iz position This eases the system tune up procedure as described on pages Manual 11 16 SUBWOOFER DELAY control In Subwoofer applications this control has virtually no effect and will normally be set to MIN minimum Refer to page Manual 10 SUB LOW crossover frequency selector This 41 detent selector sets the crossover frequency between the Subwoofer and Low Outputs Refer to page Manual 10 to determine the proper setting for your system LOW LEVEL control Sets the Level going to the Low frequency Output LOW MUTE switch Removes all signal from the Low Output when pressed in LOW DELAY control Adds from 0 to 2 ms of time Delay to the Low Output only Refer to page Manual 10 for alignment procedure LOW MID crossover frequency selector Sets the crossover frequency between the Low and Mid frequency Outputs MID LEVEL control Sets the Level of signal going to the Mid Output only MID MUTE switch Removes all signal from the Mid Output when pressed in MID DEL
17. amp Pink Noise Generator The MUTE switches on the AC 23B make using an SPL meter an easy and relatively accurate means of tuning a system The Rane RA 30 has everything you need an SPL meter and a pink noise source If you can t get one of those right now obtain a good SPL meter and a pink noise generator from a local elec tronics store You may also use a sweep or tone generator in place of a pink noise source If so be sure to look at several different tones within each crossover section to get a good average driver response jai Run pink noise into the crossover Inputs through the mixer or directly as is convenient Make sure all crossover output LEVEL controls are turned all the way down and all amplifier level controls are at least half way up to start with Turn the crossover MASTER LEVEL s half way up Place the SPL meter at least 15 feet from the speaker stack and about chest high Once positioned make sure that the SPL meter re mains in the exact same location for the rest of the procedure N w Minimize all background noise fans air conditioners traffic wild animals etc to get accurate readings Set the SPL meter to C weighting Slow if switches are present Slowly turn the LOW LEVEL of the crossover up until there is a healthy rumble coming from the bass speakers For this A example the 3 Way configuration is used the same proce dure applies to all configurations starting with
18. amplifier respectively If you need a summed Mono Low Ouput see Monoing the Low Outputs on page Manual 7 STEREO MONO switch Set this switch to the STEREO position 2 WAY 3 WAY switch Converts the outputs from Stereo 3 Way to Stereo 2 Way Be sure the switches are in the 3 WAY position POWER input connector Use only a model RS 1 or other power supply approved by Rane This unit is supplied with a remote power supply suitable for connection to this input jack This is not a telephone jack The power requirements call for an 18 24 VAC center tapped transformer only Using any other type of unapproved supply may damage the unit and void the warranty Two years parts and labor is worth safeguarding Chassis ground point A 6 32 screw is used for chassis grounding purposes Always connect the crossover chassis to the ampli fier chassis See Chassis Grounding on page Manual 1 for details Manual 5 FRONT PANEL MONO 4 WAY AND 5 WAY CONFIGURATION Mono 4 Way and 5 Way labels in this row CH 1 LOW 3W LOW MID MID 3W MID HIGH HIGH CH 2 LOW 3W LOW MID MID 3W MID HIGH HIGH 0 a i 50 ks rc as a iso 406 406 oF on OM Oa si Wor 2 O _ wists LEVEL MUTE DELAY FREQUENCY papei LEVEL POWER MD a INACTI 7 O AN MASTER SUBWOOFER 5W HIGH MID HIGH HIGH SUTIS x jb b bea bal Observe the labels screened below the controls for Mono operation oio T 10 MIN MAX MIN MAX 100
19. d easier to use there are few reasons why one of these should not be regularly used in any sound system If an analyzer is simply not available an accurate delay setting can be obtained by using an SPL meter obtainable at most local electronics stores the best is the Rane RA 30 and some kind of variable tone generator In order to exclude the effect of room acoustics and imper fect driver response only the crossover frequencies are to be emitted one at a time by the tone generator First the highest crossover frequency is run through the crossover and each of the two speakers sharing the crossover point is set separately to an arbitrary 0 dB level on the SPL meter When both drivers emit the crossover tone simultaneously the combined response should read 3 dB higher on the meter If the drivers are not phase aligned some cancellation will occur on axis resulting in a combined response ess than 3 dB Turning the delay control up causes the lower frequency driver to electronically move back ward until the SPL meter reads 3 dB then the two drivers are electronically aligned and the on axis cancellation is eliminated This procedure is repeated for the next lower crossover point s STEP BY STEP PROCEDURE A 3 Way mode consisting of high mid and low drivers is used here as an example For other configurations use the same procedure starting with the highest crossover point and repeating steps 2 through 5 for each lower crossover poin
20. e lay controls by ear is supposedly possible but very tricky and unreliable The fol lowing methods are a couple of but by no means all means of In Phase Axis Response Without Time Delay setting time delay Corrected In Phase Axis with Time Delay on the Low Driver Time Delay Adjustment Using Realtime Analyzer amp Pink Noise This method outlines the use of a realtime analyzer pink noise generator and flat response microphone to set crossover time delay Some references will be made to the Rane RA 30 realtime analyzer for those with the intelligence and good taste to use one of these regularly The procedure applies to virtually any analyzer system We recommend using a 1 3 or 2 3 octave analyzer as either of these is more likely to match your specific crossover points than a one octave analyzer And it s important to match the analyzer to the crossover point as closely as possible for proper phase alignment otherwise the analyzer readings may be misleading STEP BY STEP PROCEDURE A 3 Way mode consisting of High Mid and Low drivers is used here as an example For other configurations use the same procedure starting with the highest crossover point and repeating steps 2 through 5 for each lower crossover point NOTE Ifyou are running two separate channels on the crossover tune up only one channel at a time using the same procedure for both 1 Place the analyzer mic about 15 feet in front of the speaker stac
21. en the drivers are properly phase aligned and no delay is necessary leave the MID DELAY control at full minimum ii If the meter reads ess than 3 dB slowly turn up the MID DELAY control until the meter just reads 3 dB Now the drivers are electronically phase aligned and the delay control should be left in this position at all times unless the speaker system is physically altered m iii If you have turned the MID DELAY control all the way up and still do not obtain a 3 dB reading you will have to physically move the high driver farther forward until the SPL meter reads 3 dB The amount of displacement correc tions available from the delay depends on the actual cross over frequency the higher the frequency the less amount of correction capability If the drivers are built into a single cabinet and or it is impossible to change relative positions then you will have to obtain additional delay to achieve proper phase alignment iv If turning the MID DELAY control up makes the SPL reading decrease instead of increase this means that the high driver is actually in front of the mid driver adding delay to the mid driver then only worsens the situation There are a couple of ways to deal with this a Try to move the high driver back as far as possible without losing stability in balancing the speaker stack You may want to raise it up as well to restore dispersion close to the stack If you cannot move the high driver then
22. er input Consult the Rane factory for a replacement or substitution zing there is an incompatibility in the grounding configuration between units somewhere Your mission should you accept it is to discover how your particular system wants to be grounded Here are some things to try 1 Try combinations of lifting grounds on units that are supplied with ground lift switches or links 2 the rack screws to another grounded chassis If your equipment is in a rack verify that all chassis are tied to a good earth ground either through the line cord grounding pin or Units with outboard power supplies do not ground the chassis through the line cord Make sure that these units are grounded either to another chassis which is earth grounded or directly to the grounding screw on an AC outlet cover by means of a wire connected to a screw on the chassis with a star washer to guarantee proper contact 4 Please refer to the included RaneNote Sound System Interconection for further information on system grounding WEAR PARTS This product contains no wear parts Try moving the device away from high magnetic field sources such as large transformers used in power amplifiers Manual 1 FRONT PANEL STEREO 2 WAY CONFIGURATION Stereo 2 Way labels in this row kee 2W LOW ZH r LOW 3W LOW MID 3W moe HIGH LOW 3W LOW MID MID 3W MID HIGH HIGH MASTER 2W INACTIVE dine agi ph im Pes LOW HI 2W INACTIVE H T 5
23. ess than 3 dB Turn ing up the DELAY control causes the lower driver to electroni cally move backward until the analyzer reads 3 dB then the two drivers are electronically aligned and the on axis cancella tion is eliminated Voice Coil Displacement Inches Hz 75 145 3 6 9 70 1 1 5 2 2 5 3 5 80 1 1 5 2 2 5 3 5 100 1 1 5 2 2 5 3 5 150 1 1 5 2 2 5 3 5 200 1 1 5 2 2 5 3 5 gt 250 1 1 5 2 2 5 3 5 300 1 1 5 2 2 5 3 5 T 400 1 1 5 2 2 5 4 gt 450 1 1 5 2 2 5 4 4 500 1 1 5 2 2 5 4 L 800 1 1 5 2 3 5 Ik 1 1 5 2 2 3 6 9 1 2k 1 1 5 22 3 5 9 1 5k 1 iS 23 35 2k 1 1 5 2 3 MAX Q 2 5k 1 1 5 2 3 MAX O x 1 1 7 2 4 MAX 3 6k 1 1 7 MAX 4k 1 1 8 MAX 6k 1 2 MAX 7k 1 2 MAX MAX MAX 12 15 18 21 24 5 6 7 8 MAX 5 6 7 8 MAX 5 6 7 8 MAX 5 6 7 MAX 5 6 7 MAX 5 7 8 MAX 5 5 7 MAX 6 8 MAX 6 8 MAX 6 8 MAX 7 MAX MAX Displacement a Figure 3 Front to Back Displacement Distance Manual 13 Setting the Output Level Controls Choosing the crossover frequencies was the easy part Now it gets real fun The idea is to set the output Level controls on the crossover so that the entire speaker system has a uniform flat response Unfortunately the room in which the speakers are placed has a habit of always getting into the act so things get messy As a result there seems to be two schools of thought regarding the use of active crossovers The Set It Once And Glue It School The phil
24. izes 41 detent crossover frequency selectors which are precision potentiometers The detents will assure con sistent accuracy from Channel to Channel and unit to unit This is a distinct advantage over the continuously variable designs with low tolerance parts possible knob misalignment and panel screening variations Even with 41 choices it is possible that the exact recommended crossover frequency may not fall on one of the detents on the selector Not to panic for these sound reasons 1 The AC 23B possesses 24 dB octave roll off so the crossover points may be set to the nearest detent above or below the recommended limit with virtually no hazard to the driver or degradation in sound quality If extremely high power levels are expected it is safer to defer to the high frequency driv ers and shift the crossover point up in frequency rather than down 2 Detents do not rely on knob alignment silk screen accuracy parallax and other variables which erode the accuracy of continuously variable designs Chances are that even careful visual alignment on these will often yield a frequency error greater than a full detent on the AC 23B 3 If it is absolutely critical to obtain the exact crossover fre quency Mil Spec P A etc the selector can be positioned between detents if necessary This of course will require the aid of a precision signal generator and other equipment to verify the exact setting For best overall system results t
25. k and at a height about midway between the high and mid drivers Turn all crossover LEVEL controls fully down 2 Connect the pink noise source to the crossover INPUT or mixer or wherever is convenient Turn up the crossover MAS TER LEVEL control and the MID OUT control until noise is heard only from the mid driver at a comfortable volume 3 With a healthy but not uncomfortable volume of noise from the mid driver set the analyzer DISPLAY LEVEL control so the LED s corresponding to the high crossover frequency are reading 0 dB this would be a green LED at the crossover fre quency with any of the Rane analyzers For example if your high crossover frequency is 2 kHz set the RA 30 inthe 1 dB mode and then adjust the RTA LEVEL control until the green LED is lit in the 2 kHz band There easy Press in the MID MUTE switch on the crossover so the tone is removed from the mid driver Without re adjusting either the meter or the crossover Input or Mid Level controls turn up the HIGH LEVEL control until the tone coming from the high driver reads 0 dB a green LED at the crossover frequency 5 Now release the MID MUTE switch on the crossover so that pink noise is heard from both the high and mid drivers Switch the display sensitivity to 3 dB on Rane analyzers not neces sary with full scale analyzers and observe the display reading at the crossover frequency i If the display shows a 3 dB reading then the drivers are properl
26. l 10 LOW HIGH crossover frequency selector This 41 detent selector sets the crossover frequency between the Low and High frequency Outputs Refer to Selecting Crossover Frequencies on page Manual 10 HIGH LEVEL control Sets the Level of signal going to the High frequency Output only Channel 2 MASTER LEVEL control Sets the overall Level of Channel 2 without altering the relative settings of the Low and High Outputs POWER switch and indicator Two guesses When this yellow LED is lit you guessed right the unit is on and ready Manual 2 REAR PANEL STEREO 2 WAY INSTALLATION Right Input Left Input Stereo 2 Way labels in this row Se OUT D 33W LOW 2W S 3W OMIT 2W ae MINED 2 IN STEREO 3W 2W G OUT O 3W LOW 2W D 3W OMIT 2W a MNED 1 IN 1h AC 23B POWER MADE IN U S A PIN 2 POSITIVE E RANE CORP a CHANNEL2 CHANNEL1 C vy Di ESIS CND An STEREO STEREO z 3awoi2w 3w Om 2w 260mMAI sma wma _ O O ae SWITCHES SHOWN CLASS 2 EQUIPMEN HIGH OUT HI MID ip ad SW LOW OUT OMIT MONO MONO 5W CH INGE INTE NAL SWITCH FOR WONO 4W OMIT MONO MID OUT SUB OUT MONO 4W 5W IN mHE O Tem e Low Amp Low Amp Observe the labels above the Inputs and Outputs for Stereo operation CHANNEL 1 INPUT Plug the left output of the mixer equalizer or other signal source
27. lowing the labels above the controls and jacks in logical order you will find Channel 1 Master Input LEVEL LOW Output MID Output and HIGH Output with the same for Channel 2 If you need a summed Mono Low Ouput see Monoing the Low Outputs on page Manual 7 To use the unit as a Mono 5 Way first check that the Chan nel 1 and 2 switches are set to 3 WAY and the other switch is set to MONO Connect the INPUT source to Channel 1 only Following the labels below the jacks look at SUB OUT then IMPORTANT NOTE CHASSIS GROUNDING If after hooking up your system it exhibits excessive hum or buz look over at LOW OUT now go back to MID OUT then over to HIGH MID OUT and then proceed to the HIGH OUT An internal switch determines 4 or 5 Way mode Our apologies to 4 Way users We must ship the units in the 5 Way mode since normal Stereo 3 Way operation demands it a fact not the least bit obvious but nevertheless a fact it remains Pity See page Manual 6 for Mono 4 Way configuration In agreement with IEC and AES ANSI standards AC 22B wiring convention is pin 2 Positive pin 3 Negative return pin 1 chassis ground See the Sound System Interconnection Rane Note included with this manual for more information on cabling and grounding requirements CAUTION Never connect anything except an approved Rane Power supply to the thing that looks like a red tele phone jack on the rear of the AC 23B This is an 18 VAC center tapped pow
28. n the front of or behind the other this lobe or dispersion pattern gets tilted usually upward toward the driver that is further behind This gets hard to put up with because the end result is that your speaker system will have two three four or more tilted radiation patterns and only two or three people in the house will have decent seats This rampant lobing error can make a sound system a real headache to listener and operator alike The idea is to be sure that all drivers are vertically aligned and that all components are always in phase Then all the main lobes are on axis well behaved and the system enjoys the widest possible dispersion pattern so that everyone gets good sound The one catch is that in many cases it is physically or otherwise impossible to get all the drivers vertically lined up at the sound source This is where time delay comes in By electronically delaying the signal going to the front driver enough time allows the sound from the rear driver to literally catch up to the forward driver s voice coil so that signal from both drivers is emitted in phase and it works Time delay makes an appreciable improvement in overall sound The trick is finding the proper time delay amount hence this manual Unfortunately the amount of time eo a delay is a function a of two factors the 7 amount of horizon l tal displacement between driver voice coils and the actual crossover frequency involved Setting d
29. osophy here is to use the crossover to flatten system response as much as possible without room acoustics involved This means setting up the system outside unless you happen to have a very large anechoic chamber handy and with the aid of a realtime analyzer and pink noise source ala RA 30 adjust all of the crossover outputs so that the system is as flat as possible Once the system is tuned the crossover is then locked behind a security cover posted guard is optional and never again touched It is then the job of the system equalizer s to normalize or flatten the system to each different room The Fix It With The Crossover School Here the crossover knobs get a good workout for the cross over is used at each location to help flatten the system along with the equalizer Some even maintain that a good active crossover can work alone like a parametric equalizer in the hands of an ex pert This does require experience skill and the right equipment to back it up not to mention a licensed set of ears Regardless of which school you profess the absolute impor tance and effectiveness of some kind of realtime analyzer in your system cannot be overstressed No this is not a callous plug for our other products analyzers in general have come a long way They re out of the lab i e closet and into the hands of every smart working musician and sound technician An analyzer will save tremendous amounts of time and provide the absolute con
30. reen on Rane equipment below the crossover point 7 Now slowly turn up the MID LEVEL on the crossover until the display shows the same output level average as the Low frequency section 8 Repeat this procedure for all crossover frequency sections lowest to highest so that the end result is as flat response as possible on the analyzer display IMPORTANT Compression driver or horn roll off bass roll off and room acoustics usually cannot be corrected by the crossover If you are using constant directivity horns see page 18 If for example you are adjusting the High frequency controls and observe a decline in frequency response somewhat above the crossover point then set the crossover LEVEL control for equal display level near the crossover point and leave it there Then use an equalizer or bank of tweeters to correct the roll off problem If you are tuning the system in a room the room acoustics will greatly influence the system response as shown by the analyzer Check the system response on an analyzer at several other locations and adjust the crossover as necessary to reach a fixed compromise setting if desired If you plan to use the analyzer only once to set the crossover set up the speaker system in a qui et place outside or in a very large concert theater and run pink noise at low levels with closer microphone placement to keep the room acoustics out of the picture as much as possible Setting Levels Using an SPL Meter
31. ry to choose the speaker components so that each operates well within its recommended limits This will provide valuable leeway so that you may move crossover points in order to fine tune the system and will also yield higher system reliability If at all possible beg borrow or best yet always use some kind of realtime analyzer to tune your crossover and fine tune the system for each different location with an equalizer Refer to the following pages for further align ment details Manual 10 Time Delay Adjustment Before jumping feet first into the realm of time delay and how to adjust it realize why on earth this delay is really neces sary For a short course on time delay Linkwitz Riley and other mouth watering details we urge you to read the Linkwitz Riley Crossovers RaneNote from Rane s website Problems pop up when two different speakers emit the same frequency as occurs in the crossover regions of two three four and five way systems Because the two drivers are displaced verti cally cancellation occurs somewhere off axis because the sound waves have to travel different distances from the two speakers and hence will arrive out of phase This forms a lobe or radia tion pattern bounded on either side by cancellation lines or axes which narrow the dispersion or listening area of the speaker Fine So we put up with it But to make matters worse when the two drivers are horizontally displaced that is one is i
32. s Channel Refer to page Manual 15 for guidance with the Level control settings LOW MUTE switch When pressed to the iz position all signal is removed from the Low frequency Output This eases tune up procedures as described on pages Manual 11 15 LOW DELAY control Adds from 0 to 2 ms of time delay to the Low Frequency Output only This allows a low frequency driver to be electronically phase aligned with a mid frequency driver whose diaphragm is situated behind the low frequency diaphragm Refer to page Manual 10 LOW MID crossover frequecny selector This 41 detent selector sets the crossover frequency between the Low and Mid Out puts Refer to page Manual 10 MID LEVEL control Sets the Level of signal going to the Mid Output in this Channel only MID MUTE switch Removes all signal from the Mid Frequency Output when pressed to the in position MID DELAY control Adds from 0 to 2 ms of time Delay to this Channel s Mid Output MID HIGH crossover frequency selector Sets the frequency between the Mid and High Outputs in this Channel HIGH LEVEL control Sets the Level of signal going to the High Output only POWER switch and indicator Two choices on or off If the power supply is plugged in this yellow LED is lit and the POWER button is depressed then the unit ready to operate Manual 4 REAR PANEL STEREO 3 WAY INSTALLATION Right Input Left Input Stereo 3 Way labels in this row UT
33. s control is disabled in 4 Way mode HIGH LEVEL control This controls the Level of signal to the High Output only POWER switch and indicator Two choices on or off If the power supply is plugged in this yellow LED is lit and the POWER button is depressed then the unit ready to operate See the Following Pages for Mono 4 or 5 Way Installation Mono 4 Way Switch Instructions Be sure all power and audio is turned off Remove the top cover of the AC 23B N Locate the 4 WAY 5 WAY switch see diagram 3 Move the switch from the 5 WAY position to 4 WAY A Replace the cover The AC 23B is now set for Mono 4 Way Mode The HIGH MID OUTPUT duplicates the MID OUTPUT frequencies with a different low pass setting as determined by the HIGH MID HIGH FREQUENCY control and is not normally recommended for use since the tweeter crossover point will be inaccurate This operation must be reversed to operate the unit in either Stereo 3 Way or Mono 5 Way Mode I STEREO lt MONO Monoing the Low Outputs It is possible to mono the Low Frequency Outputs of the AC 23B by an internal jumper Set both Low Delays to 0 1 Remove the power cord and the AC 23B top cover 2 Move the header to the J10 mono sum position 3 Moving the header to the SHIP position puts the Low Out puts back in stereo as shipped from the factory 4 Replace the cover The mono output is now at Channel 1 LOW OUT Channel 2
34. safeguarding Chassis ground point A 6 32 screw is used for chassis grounding purposes Always connect crossover chassis ground to ampli fier chassis ground See Chassis Grounding on page 1 for details Manual 3 FRONT PANEL STEREO 3 WAY CONFIGURATION Stereo sii labels in this row SSS LOW SW LOW MID MID HIGH HIGH oa LOW o E mm MID HIGH HIGH 4 6 Nae 234 ee 6 iso 750 pe K e fas a 3H 4 4 6 iso 750 LO O OF i m i lo zo Pa Ol s 7 z S66 g P fee oF eer o 10 o 10 70 MIN MAX o 10 LOF miN max y 7 0K E Qu 10 onio O MIN MAX Y 7 O miN max 190 anio Fo 10 LeveL LeveL MUTE DELAY FREQUENCY LEVEL MUTE DELAY 1 FREQUENCY 1 LEVEL greve tee mute DELAY FREQUENCY tever tires M FREQUENCY evel power 8 O OA TAASTER SUBWOFER SUB LOW sw MID MIGH MD Low Low MID Lw HIM MID Sw aH DJ HIGH HIS ad TT Observe the labels screened above the controls for stereo operation Channel 1 MASTER LEVEL control Sets the overall Level of Channel 1 without altering the relative settings of the Low Mid High frequency Outputs Unity gain for all Level controls is at 7 Channel 2 MASTER LEVEL control Sets the overall Level of Channel 2 without altering the relative settings of the Low Mid High Outputs LOW LEVEL control Sets the Level of signal going to the Low frequency Output only in thi
35. t Set the tone generator to the highest crossover frequency and plug it into the INPUT of the crossover Turn all crossover LEVEL controls fully down N Position the SPL meter mic about 15 feet in front of the speak ers and at a height about midway between the high and mid drivers It is very important that the meter remain in exactly the same position throughout the test so affix it to a mic stand small tree or other stable object Set the switches on the SPL meter to C weighting to minimize background noise air conditioners fans traffic wild animals etc as these will effect the meter reading Slow if available Be sure Qo Slowly turn up both the crossover MASTER LEVEL control and the MID LEVEL control until the tone is heard through the mid driver Adjust the SPL meter control and or the cross over LEVEL controls until you obtain a 0 dB reading on the meter Verify that no sound is coming from any other speakers except the mid driver 4 Now press in the MID MUTE switch on the crossover so the tone is removed from the mid driver Without re adjusting either the meter or the crossover Input or Mid frequency Level controls turn up the HIGH LEVEL until the tone coming from only the high driver reads 0 dB on the SPL meter Release the MID MUTE switch so the tone is emitted from both the high and mid drivers Check the SPL meter reading Manual 12 wn ion i If the meter reads 3 dB th
36. the system as described in previous sections you may use the table below to obtain a rough and approximate phase align ment of your drivers Measure the horizontal displacement between the voice coils of the two adjacent drivers sharing the same crossover point then find the column in the table nearest your actual displacement Move down this column to the proper crossover frequency as indicated on the left of the table the cor responding delay knob setting will then be the closest for your system For example if you have a two way system crossed over at 800 Hz with the compression driver voice coil located about 9 behind the woofer voice coil the delay knob setting corre sponding to a 9 displacement at 800 Hz on the table would be 5 as indicated on the front panel In order to phase align two drivers you must observe only the crossover frequency which is common to both drivers Pink noise can be used if all other frequencies are disregarded since room acoustics and imperfect driver response will cause errone ous alignment attempts Using pink noise as a source each driver is individually tuned to an arbitrary 0 dB level on the analyzer display only at the crossover frequency When both are turned on simultaneously the combined response of the two drivers should read 3 dB higher at the crossover frequency on the display If the drivers are not phase aligned some cancellation will occur on axis resulting in a combined response l
37. y phase aligned and no delay is necessary leave the MID DELAY control at minimum ii If the display shows ess than 3 dB reading slowly turn up the MID DELAY control on the crossover until the display shows 3 dB Now the drivers are electronically phase aligned The Delay control should be left in this position unless the speaker system is physically altered iii If the MID DELAY control is all the way up and you still do not have a 3 dB red reading you will have to physi cally move the high driver farther forward until the display shows 3 dB red The amount of displacement correction available from the Delay depends on the actual crossover frequency the higher the frequency the less amount of cor rection capability If the drivers are built into a single cabi net and or it is impossible to change relative positions then you will have to obtain additional external delay to achieve proper phase alignment such as the Rane AD 22B iv If turning the MID DELAY control up makes the display reading decrease instead of increase this means that the high driver is actually in front of the mid driver adding delay to the mid driver only worsens the situation There are a couple of ways to deal with this a Try to move the high driver back as far as possible without losing stability in balancing the speaker stack You may want to raise it up as well to restore dispersion close to the stack If you cannot move the high driver
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