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items: Ultimate Line Array ($?)
items: Re: And now for something a bit more realistic
items: Re: Ultimate Line Array ($?)

Ultimate Line Array ($?)
type: item
description: Just having a little fun here... if we had no worries about budget and a fairly large living room or family room that was to be converted to a listening room, besides all the room acoustic stuff (which is important of course), what would you do as the ultimate expression of the line array principles discussed in this forum. Critique my example or come up with your own or both: 1) Multiple DEQX or whatever they are called along with Pass amps, or possibly wire all the drivers up in series and build OTL tube amps for the mids and tweets. 2) Jordan JXr 6HD, it seems to me that this would be the ultimate centerpiece of a line array system if we all got past Ted Jordans insistance that they not cross to a tweeter or super tweeter. Of course, Ted knows an order of magnitude more about this stuff than I ever will, but if we stick to Jim's latest research, then we cross them up high (but not two high, I think we have 2.5 inches center to center to work with here...), and in keeping with all the lessons learned by the full range guys spreading out to two and three ways with help up high and on the bottom, we find a driver that has a close enough center to center spacing but covers the bandwidth where we are most sensitive to crossovers, and I can't think of anything better than the new JXr 6HD. How about 25 per side so we have around 6.5 feet of line length, and we run them 300Hz to 6Khz, which should be a walk in the park for these beauties. 3) I think the dipole guys are onto something, but many have reported that the Jordans don't sound that great out back, so we keep them sealed, and put another line of 25 behind the first one, and now we have a more perfect dipole because the two lines are better balanced and we use the digital filters to decide up to what frequency we have a dipole. That addresses another issue of how much of a good thing is still a good thing. As some have debated how high up you want the dipole effect in a given room, now you control it from lets say…
creator: Greggo
date: 2006-07-05T13:19:56-00:00

Re: And now for something a bit more realistic
type: item
description: OK, I am bored so I am going to reply to my own message... Aside from getting my math wrong on the Aura 18s, it occured to me that maybe I want to come close to doing something like this someday, so what would I really do if I was using my own money and do I think it would come close to the system above. Here is my own answer to my own question in replying to my own post...this makes me the ultimate net junkie loser: 1) I will listen with these speakers roughly 9-10 feet apart and 9-12 feet from the listening chair, and I am only concerned with the sound while seated, not caring about standing listeners... 2) So I think I only need four Fountek NeoCD 2.0 ribbons in each speaker, again running 6kHz on up. 3) Still waiting for someone to convince me that the Jordan JXr 6HD is not the ultimate starting point for a line array speaker, so until then I will stick with this idea and since the driver and frame is 3" tall, stack 9 of them in each array for a line length of 27 inches, which is a little short of ideal but will probably still deliver a much more dynamic sound than point source systems employing similar drivers. The Mark Audio site shows a recommended sealed cabinet volume that has an Fb of around 150Hz, so I would probably cross over just above that, maybe around 220Hz to help keep things clean down there. 4) Keeping everything in one cabinet, how about a total of eight Seas W18E001 6.5 inch woofers, two above the mid/tweet array facing front and two below, with two sets of two mirror imaged on the back of the cabinet, for bipolar bass (and no BSC circuit required...), and if I am not mistaken their specs actually make them good candidates for MLTL cabinet design. 5) I would go active between the woofer and mids, and passive between mids and tweets, and go Pass DIY for the amps, and now I think I would have a great small to medium size room line array for around 5-6k in parts. This just might be a real world project someday soon. How would you improve on it? Gr…
creator: Greggo
date: 2006-07-06T17:19:02-00:00

Re: And now for something a bit more realistic
type: item
description: Greg, I'll try to answer below. 1) I will listen with these speakers roughly 9-10 feet apart and 9-12 feet from the listening chair, and I am only concerned with the sound while seated, not caring about standing listeners... Eventhough you are sitting while you are listening, I strongly suggest that the design be such that it operates in the near field. Please read the Near Field Line Array White Paper to understand that we want to have long enough lines to create a near to far field transition beyond the estimated listening distance. To many benefits to the near field arrangement. Hence, I'm suggesting your woofer and tweeter line be long enough for this requirement. 2) So I think I only need four Fountek NeoCD 2.0 ribbons in each speaker, again running 6kHz on up. I'm thinking 6 to 9 of these ribbons to achieve the near field listening distance criterion. 3) Still waiting for someone to convince me that the Jordan JXr 6HD is not the ultimate starting point for a line array speaker, so until then I will stick with this idea and since the driver and frame is 3" tall, stack 9 of them in each array for a line length of 27 inches, which is a little short of ideal but will probably still deliver a much more dynamic sound than point source systems employing similar drivers. The Mark Audio site shows a recommended sealed cabinet volume that has an Fb of around 150Hz, so I would probably cross over just above that, maybe around 220Hz to help keep things clean down there. I'm not in love with the small Jordans for this application. The issue is that it takes a boat load of them and they are expensive. The issue is that in a line array application you have to cross them to tweeters as the combing and sensitivity roll off will eat your lunch on the high end. Furthermore, they don't go low enough to prevent you from needing both a woofer array and likely a subwoofer. Thus you might windup with a 4 way speaker. I'm thinking a two way with mid-basses and ribbon tweeters with per…
creator: Jim Griffin
date: 2006-07-07T01:32:23-00:00

Re: And now for something a bit more realistic
type: item
description: Greg, I'll try to answer below. 1) I will listen with these speakers roughly 9-10 feet apart and 9-12 feet from the listening chair, and I am only concerned with the sound while seated, not caring about standing listeners... Eventhough you are sitting while you are listening, I strongly suggest that the design be such that it operates in the near field. Please read the Near Field Line Array White Paper to understand that we want to have long enough lines to create a near to far field transition beyond the estimated listening distance. To many benefits to the near field arrangement. Hence, I'm suggesting your woofer and tweeter line be long enough for this requirement. 2) So I think I only need four Fountek NeoCD 2.0 ribbons in each speaker, again running 6kHz on up. I'm thinking 6 to 9 of these ribbons to achieve the near field listening distance criterion. 3) Still waiting for someone to convince me that the Jordan JXr 6HD is not the ultimate starting point for a line array speaker, so until then I will stick with this idea and since the driver and frame is 3" tall, stack 9 of them in each array for a line length of 27 inches, which is a little short of ideal but will probably still deliver a much more dynamic sound than point source systems employing similar drivers. The Mark Audio site shows a recommended sealed cabinet volume that has an Fb of around 150Hz, so I would probably cross over just above that, maybe around 220Hz to help keep things clean down there. I'm not in love with the small Jordans for this application. The issue is that it takes a boat load of them and they are expensive. The issue is that in a line array application you have to cross them to tweeters as the combing and sensitivity roll off will eat your lunch on the high end. Furthermore, they don't go low enough to prevent you from needing both a woofer array and likely a subwoofer. Thus you might windup with a 4 way speaker. I'm thinking a two way with mid-basses and ribbon tweeters with per…
creator: Jim Griffin
date: 2006-07-07T01:32:23-00:00

Re: And now for something a bit more realistic
type: item
description: Jim, Thanks for the thoughtfull reply. I need to re-read your paper as I thought the line length issues at the frequencies I was thinking would hold up better. Anyways, I certainly have nothing but the utmost respect for the systems both you and Rick have engineered, but I can't help but wonder if there is more magic to be squeezed out of a line array that has the primary drivers working from under 300Hz up past 4kHz, with those drivers having a c-t-c spacing close enough to avoid any comb filtering. This range seems to get cited fairly often as one that, if left undisturbed by crossovers and differing transducers, can yeild a most musical and coherent presentation. This is the allure of the Jordan driver for me, granted the fact that they are not exactly the best value in terms of dollar per driver, and this is made worse by the number you need to fill a decent line length. But the idea that one could approach the silky smooth sound of a good full range driver with the dynamics and soundstage of a line array keeps nagging at me. I also wonder if you had enough of them, like 16 or 25, that they would hold up well into the low 200s or high 100s for a lower level crossover. At that point, I think it would be easy to find a stack of 4-8 woofers that would gladly work together to handle 20-200 Hz with ease. I guess the bottom line is, if you did go from a 2-way design to a three way, how would you do it and where do you get the most return? Based on all the anecdotes from the single driver guys, I would vote to start experimenting with wide bandwidth drivers like the jordans to come as close to the full range ideal as possible. I think most people just find the idea of spending all that money for such little drivers, and then crossing them to a tweeter to just be too irratating to take seriously. I would like to try someday, just to find out for sure. Thanks for pointing out that the DEQX can be thought of as much more than just a crossover, I have no idea why this did …
creator: Greggo
date: 2006-07-07T02:36:27-00:00

Re: Ultimate Line Array ($?)
type: item
description: >>what would you do as the ultimate expression of the line array. I'm working on something evil. Email if curious.
date: 2006-07-10T15:33:28-00:00

Re: Ultimate Line Array ($?)
type: item
description: >>Multiple DEQX or whatever yes, or whatever >>Pass amps yes, but there are more affordable choices that won't affect performance. >>or possibly wire all the drivers up in series and build OTL tube >>amps for the mids and tweets. I don't consider this 'ultimate', I see it as counterproductive. >>Jordan JXr 6HD Yes, but there are better line array designs that using 2" drivers. >>I think the dipole guys are onto something Personal preference design. Coke or Pepsi ? >>Tweets - I don't think this is quite as important as the rest The tweeters will be the heart and soul of your sound system, this is where you need to focus on. >>TC Sounds 12" aluminum woofers [40hz to 300hz] That would be pretty good, not ultimate though. If you want ideas, email me. >>Aurasound 18s yes. This is the easier part, building a monster subwoofer. Many woofer candidates that can do this job well. >> I will listen with these speakers roughly 9-10 feet apart and >>9-12 feet from the listening chair I would make a tall array, not shorcuts in spite of a short listening distance. >>So I think I only need four Fountek NeoCD 2.0 ribbons in each >>speaker, again running 6kHz on up. Regardless of the design you choose, four tweeters is a compromise, do a full blown array with mids and tweeters. >>Still waiting for someone to convince me that the Jordan JXr 6HD >>is not the ultimate starting point Building any loudspeaker begins with quality tweeters. Great midranges mated to 'ok' tweeters never sound good. On the other hand, quality tweeters with 'ok' midranges can be made to sound much better. You need to focus on the tweeters and then the midrange quest is so easy. I can tell you right now that finding exceptional tweeters is a more difficult task as the market has very few to choose from if you want to make a line array but the market is saturated with quality midranges or midwoofers that can easily do the task. Stay away from this type of design, you can do better DIY style. http://www.mcintoshlab…
date: 2006-07-10T15:53:09-00:00

Re: And now for something a bit more realistic
type: item
description: >>I can't help but wonder if there is more magic to be squeezed out >>of a line array that has the primary drivers working from under >>300Hz up past 4kHz, Lets take a few steps back. The speaker builder may crossover their mid/tweeter in the 3khz - 5khz range because they usually skimp on the tweeters when planning a design. Very few that make DIY line arrays use the high end tweeters, instead they use cheaper tweeters and cross them over higher because they can't hang with a lower crossover point. To squeeze out more magic: Find an exceptional tweeter that can be taken down to 1500hz - 2000hz {as Jim said} and the system not only will integrate well with almost any midwoofer, but the perception of better sound and imagining is had. By taking the full range driver up to 4khz, then crossing to a tweeter, this won't give you that magic. Sure you can make it work, but it's not as sweet as the other choice. I can take an exceptional ribbon or planar tweeter and make a full array with them and use $1 midwoofers and you will be blown away by how good the sound is. I can't say the same if the situation is reversed. Suppose you did some tests and realized this is the path that indeed works well. If your tweeters need to operate at 1500-2000hz to perceive the 'magic', then that implies your midwoofer will operate up to 1500hz - 2000hz in which case, it's easy to find midwoofers that can do this job easily with great SQ, and the full range driver isn't really needed.
date: 2006-07-10T16:11:16-00:00