cross over and time delay

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   hi guy and girls. i dont know any thing about cross overs or time delay. apart from they spilt tha signal and delay it. so what would i need for a 3 way system, i got w-bins HD15 horns and will have something like MT121. could you help me on what product i need to do that. maybe give me some names or links thanks

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Aawoodz Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 19 July 2009 Location: norfolk Status: Offline Points: 33	Post Options Post Reply Quote Aawoodz Report Post Thanks(0) Quote Reply Topic: cross over and time delay Posted: 23 August 2009 at 4:56pm
	hi guy and girls. i dont know any thing about cross overs or time delay. apart from they spilt tha signal and delay it. so what would i need for a 3 way system, i got w-bins HD15 horns and will have something like MT121. could you help me on what product i need to do that. maybe give me some names or links thanks

studio45 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3881	Post Options Post Reply Quote studio45 Report Post Thanks(0) Quote Reply Posted: 23 August 2009 at 7:00pm
	Behringer DCX2496, fo sho, £250 max contains all functions you need. thomann.de or bluearan.co.uk For a basic explanation of delay, well: soundwaves travel at a certain speed, your system is all horn loaded so the sound takes a certain amount of time to travel down the horn and out to the listener's ears, your horns are different lengths so the times involved are different, you use delay on the shorter horns so that their soundwaves line up with the longer horns. You on the bus? :)
	Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA

Aawoodz Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 19 July 2009 Location: norfolk Status: Offline Points: 33	Post Options Post Reply Quote Aawoodz Report Post Thanks(0) Quote Reply Posted: 23 August 2009 at 7:16pm
	thank you very much. i now kinda know. i take that tha cross over goes after tha mixer and before tha amps. do u have any tips for settin it up? Thanks

Joe Average Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 26 April 2008 Location: United Kingdom Status: Offline Points: 1221	Post Options Post Reply Quote Joe Average Report Post Thanks(0) Quote Reply Posted: 23 August 2009 at 7:26pm
	Set the crossover to slightly overlap between the bass/mid but not on the mid/top. Delay waie, best to apply about 20" delay to the MT and leave the rest alone. Should notice quite a substantial difference even with such a short delay. I have been tinkering about with a couple of mine lately, two racks on two stacks is a very nice way to do direct comparisons, even the shortes or smallest change in delay times can be noticed. Suck it and see would be my best answer, this is how I worked it out. (took three bloody days though)
	http://www.mrfatbastard.com

studio45 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3881	Post Options Post Reply Quote studio45 Report Post Thanks(0) Quote Reply Posted: 24 August 2009 at 2:15am
	might need some delay on the hd's as well to line them up with the w bins. are they ported w's? Its not too difficult to measure for correct delay alignment with an spl meter and some test tones if you've got a big room to do it in, and want to get scientific :)
	Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA

Aawoodz Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 19 July 2009 Location: norfolk Status: Offline Points: 33	Post Options Post Reply Quote Aawoodz Report Post Thanks(0) Quote Reply Posted: 24 August 2009 at 1:55pm
	yer they are ported w-bins, are the test tones on a cd then you play them through the rig and match it all up, or what do you do? i take it you would have to change the setting for indoor and outdoor? thanks

colinmono Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 10 October 2007 Location: Midlands UK Status: Offline Points: 1113	Post Options Post Reply Quote colinmono Report Post Thanks(0) Quote Reply Posted: 24 August 2009 at 2:18pm
	Good basic info on sound system setup (how and why and where the crossover goes) here: http://en.wikipedia.org/wiki/Loudspeaker#Loudspeaker_system_design More good info on delays here http://www.speakerplans.com/index.php?id=faq2 If you buy a Behringer DCX to use as a crossover (its the best option unless you've got lots of cash to spend) it has an auto align feature which will work out delays for you. You need the ECM8000 measurement mic too to use this function. Or, as has been suggested, you can do it by playing a test tone at the crossover frequency, then adjusting the delay until you get the highest output, i.e. the two speakers are in phase. Actually, when people recommend this method, they usually say to flip the polarity of the speaker you are adding delay to, then adjust for the quietest output, then flip the polarity back. You can download test tones here http://binkster.net/extras.shtml#cd If you were going to use this method, ideally you would want a test signal generator so you can play a test signal exactly at your crossover frequency.

studio45 Members Profile Send Private Message Find Members Posts Add to Buddy List Old Croc Joined: 16 October 2007 Location: United Kingdom Status: Offline Points: 3881	Post Options Post Reply Quote studio45 Report Post Thanks(0) Quote Reply Posted: 24 August 2009 at 2:22pm
	no same setting for indoor and outdoor, to check for correct time alignment you do this: Pick a frequency to cross over from one bin to the next eg about 80Hz for your Wbins into your HD's. Set this up on the crossover with zero delay. Now get out your SPL meter and play a test tone at 80hz, it should come out of both bins at the same volume when listened to individually (one at a time) If it's not then turn one cab up or down till they are about the same. Its easiest to do this with just one of each type of cab playing even if there are more in the stack. Now invert the phase of one cab EG the HD15. - this means reverse its polarity (Yes these terms have meanings outside of Star Trek episodes!). There may be a button marked Phase, Polarity or Φ on the crossover or you may have to swap the red and black wires on the amplifier. Now play the test tone again thru both cabs at the same time, it may have got quieter or louder, don't worry. Now you adjust the delay. Starting at zero mS, advance the delay on the HD15. The SPL reading should decrease and decrease to a point and then start to increase again as you add more delay. What you want is the delay value at the point of minimum SPL. This means that at that delay value the waves from the "in-phase" W bin and "out-of-phase" HD15 are cancelling each other as perfectly as possible. You should be able to hear this as well as the difference should be about 10dB SPL. Now put the connections/phase setting on the HD15's back to normal (button out/red to red and black to black.) Now the waves from each bin will be nearly perfectly in phase at the crossover frequency and reinforce instead of cancelling. This is what you are trying to achieve. (you can also do this without the phase reversal steps, but then you are looking for a peak in SPL which is harder to hear though still readable with the meter.) Now repeat for the other frequency bands using appropriate test tones. As you get up to the tweeter bands things become more difficult as the difference between the "right" and "wrong" delay value gets exceedingly small and SPL measurements are affected by reflections from the room boundaries. But this does not mean you should delay your tweets differently for indoor and outdoor gigs even if your meter says so! Try moving it 5cm left and watch the reading change 6dB...aargh.... You can also measure the length of your horns and use that to get approximate delay values, not taking into account group delay (look it up). IE if your W bins have around 1m horn and the HDs have about a 50cm horn, you'll want to delay the HD's by about (50cm/100cm)/344ms-1 = 0.00145 seconds = 1.45 mS. SO thats (short horn/m÷long horn/m)÷speed of sound (344m/s)x1000=delay in mS. For a ported design like your W's though group delay is quite important so you want to take it into account, and try and use the measurement method. Ding ding, tickets please....
	Studio45 - Repairs & Building Commotion Soundsystem -Mobile PA

Aawoodz Members Profile Send Private Message Find Members Posts Add to Buddy List Registered User Joined: 19 July 2009 Location: norfolk Status: Offline Points: 33	Post Options Post Reply Quote Aawoodz Report Post Thanks(0) Quote Reply Posted: 24 August 2009 at 11:42pm
	wow thanks mate you have really put alot of effort in to explaining it for me and im really great full. i will have a good go at it thanks greatly

colinmono Members Profile Send Private Message Find Members Posts Add to Buddy List Young Croc Joined: 10 October 2007 Location: Midlands UK Status: Offline Points: 1113	Post Options Post Reply Quote colinmono Report Post Thanks(0) Quote Reply Posted: 26 August 2009 at 2:19pm
	Just discovered Rog has put a couple of handy test CD's up recently, should be useful for playing test tones so you can get your delays right (its even covered briefly in the PDF that accompanies the sine wave CD). There is some overlap with the Bink CD link I posted before, but you can never have too many test CD's! See: http://www.voidacoustics.com/support.asp