Members deepblue Posted June 14, 2007 Members Share Posted June 14, 2007 What do I need to know about this? What does it mean exactly? Link to comment Share on other sites More sharing options...
Members kevinnem Posted June 14, 2007 Members Share Posted June 14, 2007 well in a perfect world you want the sound from each cone/horn to reach your ears at the same time, .. in some cases this means that the woffer has to be delayed a few milliseconds so that the sound comeing out of the horn has a chance to "catch up" with sound form the woffer, then they can travel through the air as one. There are a lot of more complex issues involved here, but for a basic concept that is about it. Are you planning on aligning a system you have? Link to comment Share on other sites More sharing options...
Members jwlussow Posted June 15, 2007 Members Share Posted June 15, 2007 We have done this in the past using a Driverack. There are times and venues that really need this to clean up the sound. In the old days I think we used to measure the distance from the kick to the sub. It's been a while. Link to comment Share on other sites More sharing options...
Members deepblue Posted June 15, 2007 Author Members Share Posted June 15, 2007 well in a perfect world you want the sound from each cone/horn to reach your ears at the same time, .. in some cases this means that the woffer has to be delayed a few milliseconds so that the sound comeing out of the horn has a chance to "catch up" with sound form the woffer, then they can travel through the air as one.There are a lot of more complex issues involved here, but for a basic concept that is about it.Are you planning on aligning a system you have? Well with a small system (15's/horns over 18" subs...one pair each) I was wondering if it is a consideration and if so how one would go about it old school as I wouldnt buy a driverack for this. I mix in all kinds of small rooms but occasioanally outdoors so as mentioned I was wondering about this. Link to comment Share on other sites More sharing options...
Members agedhorse Posted June 15, 2007 Members Share Posted June 15, 2007 Wouldn't worry about it. Link to comment Share on other sites More sharing options...
Members dboomer Posted June 15, 2007 Members Share Posted June 15, 2007 When the sound from the two speakers (woofer and tweeter) don't reach your ears at the same time it creates phase cancellations (and causes a hole in the frequency response. When you time align you slightly delay the speaker with the earilest arrival (usually the woofer) and it will bring the level back up. This is something that you cannot do with an equalizer and is why an RTA is not always a good solution. The RTA will show you the hole in the frequency response but since it is caused by phase cancellation boosting the eq only makes the phase cancellation worse and the hole gets deeper. This is also why most auto EQ wizards don't work ... they can't tell the difference. DSP crossovers can usually make this situation better (or almost eliminate it) Link to comment Share on other sites More sharing options...
Members Dogoth Posted June 16, 2007 Members Share Posted June 16, 2007 I agree with agedhorse. At that level there are probably much bigger things that effect your sound more than driver alignment. With that said, If you want to experiment (and keep it old school), Rane makes a Crossover model AC 22B that looks like it'd work. I've seen them go used on E-bay for a good price. Link to comment Share on other sites More sharing options...
Members Prog Posted June 16, 2007 Members Share Posted June 16, 2007 this means that the woffer has to be delayed a few milliseconds so that the sound comeing out of the horn has a chance to "catch up" When you time align you slightly delay the speaker with the latest arrival (usually the woofer) So, ... Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted June 16, 2007 CMS Author Share Posted June 16, 2007 Don, you meant the speaker with the *earliest* arrival gets delayed. Link to comment Share on other sites More sharing options...
Members dboomer Posted June 16, 2007 Members Share Posted June 16, 2007 Jeez ... you're so picky! OK ... earliest:p Link to comment Share on other sites More sharing options...
CMS Author Craig Vecchione Posted June 16, 2007 CMS Author Share Posted June 16, 2007 Jeez ... you're so picky! OK ... earliest:p Well, you got to sit on the Peavey Chopper, so I get to pick on you and be jealous. Link to comment Share on other sites More sharing options...
Members mshifflett Posted June 17, 2007 Members Share Posted June 17, 2007 I agree with agedhorse. At that level there are probably much bigger things that effect your sound more than driver alignment. With that said, If you want to experiment (and keep it old school), Rane makes a Crossover model AC 22B that looks like it'd work. I've seen them go used on E-bay for a good price. I use this same crossover, but don't you mean the Rane AD22B? I use this as well due to the fact that I run front loaded top cabinets over LAB subs. I have to delay the tops around 10 feet to get good results. The AD22B works great! Link to comment Share on other sites More sharing options...
Members Dogoth Posted June 17, 2007 Members Share Posted June 17, 2007 I use this same crossover, but don't you mean the Rane AD22B? I use this as well due to the fact that I run front loaded top cabinets over LAB subs. I have to delay the tops around 10 feet to get good results. The AD22B works great! It appears that they make both model numbers. I remember using one back in the mid 80s (it was analog I'm sure) and did a quick search. The AC 22B was the closest one I could find (I'm not sure of the exact model # of the unit I used (I may need a way back machine to find out for sure:) )). I'd say either unit would do the job just fine. P. S. I think the AD series is the older one (a search of RANE's site was a bit fruitless), which means that you could probably pick one up used for a better price. They probably all still work perfectly. RANE stuff rocks ! Link to comment Share on other sites More sharing options...
Members agedhorse Posted June 18, 2007 Members Share Posted June 18, 2007 AC 22B Link to comment Share on other sites More sharing options...
Members mshifflett Posted June 18, 2007 Members Share Posted June 18, 2007 The AC22B crossover will delay the subs only. If you need to delay the tops you would need to get with something like the AD22B delay unit. It is a very cool piece. It has two channels with memory, and measures in three different units. Link to comment Share on other sites More sharing options...
Members Scodiddly Posted June 18, 2007 Members Share Posted June 18, 2007 In general it won't make a big difference within a speaker, say between woofer and tweeter. What we often use delays for is to align between speaker systems in a bigger venue - under-balcony fills delayed to match better with the main speakers is a typical example. Link to comment Share on other sites More sharing options...
Members agedhorse Posted June 18, 2007 Members Share Posted June 18, 2007 The AC-22 will delay the LF out (in stereo mode) and the mid and low out in mono mode. They are intended for "aligning" front loaded low end with high frequency horns. This would not be desireable if you had a horn loaded LF section as there's nowhere near enough delay time available on either this or the AC-23B. My assumption is that the 18" sub boxes were front loaded. Personally, I feel that the whole delay issue between components in this level application is a waste of time and effort. For aligning to a long horn loaded sub box, the effort may have some benefits. Link to comment Share on other sites More sharing options...
Members mshifflett Posted June 18, 2007 Members Share Posted June 18, 2007 The AC-22 will delay the LF out (in stereo mode) and the mid and low out in mono mode. They are intended for "aligning" front loaded low end with high frequency horns. This would not be desireable if you had a horn loaded LF section as there's nowhere near enough delay time available on either this or the AC-23B.My assumption is that the 18" sub boxes were front loaded. Personally, I feel that the whole delay issue between components in this level application is a waste of time and effort. For aligning to a long horn loaded sub box, the effort may have some benefits. I totally agree with this. Most of the time it is not going to make that much difference, especially inside at smaller venues. I use the AD22B because I have more than 10 feet of wrapped sub horn that I need to compensate for and the crossover does not have that much delay. If all of your stuff is front loaded, don't waste your time and money. Link to comment Share on other sites More sharing options...
Members Dogoth Posted June 18, 2007 Members Share Posted June 18, 2007 Personally, I feel that the whole delay issue between components in this level application is a waste of time and effort. I gotta agree for the most part on this one. Let's say you compensating for a front to back time/distance figures of say 2 to 6 inches then what do you do about the triangulation factor (the time difference that occures when you're above or below the horizontal line of the speaker (using a traditional design model with the drivers positioned in a vertical array (tweaters on top - woffer on bottom)))? This distance will change as you move around the room so you really can't delay for it accuratly. What about using an array of multiple boxes and the time delays between each? What about the considence of your sound source with reflections fron the glass windows on one side of the room, the mirror behind the bar and the glossy floor (all of which may be percieved with nearly as much SPL as your original source)? These comb filter creating reflections will change as well as you walk around the venue. In a studio situation where you're delaying for a particular "sweet spot" driver time delay can be effective (Urei made a famous Time aligned X-over and speaker based on the Altec 604 Coaxial driver). Part of the reason Urei's design was so succesful was because Altec had already fixed the aformentioned triangulation factor (The coaxial design fixed a lot of time/phase problems (although it did introduce a few new problems)). In the end trying to fix live sound problems by driver time alignment is sort of like duck hunting with a BB gun (you'll probably miss the target but even if you do hit it you'll probably only wing it (sorry I just love analogies (OK go ahead and shoot this one down:D )). Link to comment Share on other sites More sharing options...
Members mshifflett Posted June 18, 2007 Members Share Posted June 18, 2007 In the end trying to fix live sound problems by driver time alignment is sort of like duck hunting with a BB gun (you'll probably miss the target but even if you do hit it you'll probably only wing it (sorry I just love analogies (OK go ahead and shoot this one down:D )). That is one of the best I have heard in a long time! Link to comment Share on other sites More sharing options...
Members agedhorse Posted June 18, 2007 Members Share Posted June 18, 2007 Let's say you compensating for a front to back time/distance figures of say 2 to 6 inches then what do you do about the triangulation factor (the time difference that occures when you're above or below the horizontal line of the speaker (using a traditional design model with the drivers positioned in a vertical array (tweaters on top - woffer on bottom)))? This distance will change as you move around the room so you really can't delay for it accuratly. What about using an array of multiple boxes and the time delays between each? This is EXACTLY the mathamatical argument that I used when discussing this issue with "Where" and while he couldn't understand the math I presented, he felt compelled to suggest that I was an idiot and had tin ears. He was the same one who said he could hear the difference of a couple of feet of speaker cable. Of course the bull{censored} alarm went off full-tilt on that one! Look as the entire set of solutions to see where the RANGE of the solution lays. What you will find is a range that may in fact have an average of ZERO, which is probably the best (overall) solution. Link to comment Share on other sites More sharing options...
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