$1 aurasound drivers in an array?

[r-carpenter]

Re: $1 aurasound drivers in an array?

Mike, model diffraction response in Tolvan diffraction modeler. It'll give you an idea of how many drivers you want to use in array. The taller the array, more issues you will have to deal with and more complicated filtering will be needed. But also, more efficient it will become with less distortions. After you decide, how big it is, you can look in to filtering options. 3" Aura has a clean mid-range and it'll shine in the array.
High Qts lands in to a open baffle configuration. Is it going to be wide baffle, U-pole or narrow baffle dipole, is up to you. Impedance of an array is easy enough to adjust by series/parallel wiring.
Before getting in to shaded arrays, curved arrays and so on, try to do it step by step and resolve the simple issues. I don't mean to sound condescending, it's just frequency response of an array is not formed the same way as a conventional loudspeaker.

[johnnyrichards]

Re: $1 aurasound drivers in an array?

Wolf once told me it would be the magnetic gap height-the VC length. So in this case 8.4-7.2= 1.2mm Xmax... IIRC...

Actually, that 1.2mm would be +/-... One way Xmax would be 0.6mm

[mikejennens]

Re: $1 aurasound drivers in an array?

Mike, model diffraction response in Tolvan diffraction modeler. It'll give you an idea of how many drivers you want to use in array. The taller the array, more issues you will have to deal with and more complicated filtering will be needed. But also, more efficient it will become with less distortions. After you decide, how big it is, you can look in to filtering options. 3" Aura has a clean mid-range and it'll shine in the array.
High Qts lands in to a open baffle configuration. Is it going to be wide baffle, U-pole or narrow baffle dipole, is up to you. Impedance of an array is easy enough to adjust by series/parallel wiring.
Before getting in to shaded arrays, curved arrays and so on, try to do it step by step and resolve the simple issues. I don't mean to sound condescending, it's just frequency response of an array is not formed the same way as a conventional loudspeaker.

Thanks Roman. I downloaded the BSC designer from the Tolvan website. I'd like to go with a narrow baffle because, if I understand correctly, imaging is usually better. I'm leaning toward 10 or 12 drivers per side. I'll probably leave room somewhere for a tweeter around the 33" height level, in case I feel it needs one. I have a few Vifa tweeters, some ND16's, a couple of Foster horns, a couple of Klipsch horns, and a handful of others. I'll be running it with a sub, so I'm not planning on using a woofer at this time. However, I have a few lying around (Klipsch KG3?, Infinity Qa, a Fisher 12", a Seas 10", some old MCM non-descript 10".
I appreciate your comment about keeping it simple. I have no intention on a curved array; even if I wanted to, cutting the holes and recesses flat is beyond my woodworking skills. Please keep the suggestions and advice coming.
Now I need to get my garage warm enough to work in for a while. I have this one to start and at least 2 other speaker projects going on now. And then there's the jewelry boxes I want to make for my granddaughter and two other little ladies. And then there's around-the-house projects, and then there's... ( I'm sure I'm not the only one with no lack of projects...)
Thanks again,
Mike

[jhollander]

Re: $1 aurasound drivers in an array?

it's just frequency response of an array is not formed the same way as a conventional loudspeaker.

Roman can you expand on this comment? Other than comb filtering and interference issues from integrating point sources and line sources I’m not sure what you mean.

[LouC]

Re: $1 aurasound drivers in an array?

Lou, I'd love to see your take on an array.

I tried a single tweeter version way back in the day. Wife nixed actually using it, wish I had those mid woofers back!
Found a good home for them in a custom built home theater room.

THIN BLUE LINE ARRAY

[r-carpenter]

Re: $1 aurasound drivers in an array?

Roman can you expand on this comment? Other than comb filtering and interference issues from integrating point sources and line sources I’m not sure what you mean.

If you are designing a TM or an MTM system, frequency response of your woofer measured at 1 meter (or whatever desired condition are) remains accurate for modeling. Crossover/box effects can be predicted fairly easily and accurate. If you take the same exact woofer, arrange 10 or so of them in line, combine frequency response will change and the line will experience a degree of the high frequency loss. You may look at it as the cancellation or efficiency issues but in the end, you can't take response of one single driver, change the efficiency and impedance, based on the number used and wiring scheme and use that for crossover design.
Same with the tweeter response BTW. (single VS line)
Measuring the array is also more difficult and requires understanding. For example, in near field, slight changes in Mic position will throw the response all over the place. it happens because of the driver's signal interfering with each other. Gated MLS is only capturing the signal for a very short period of time, eliminating boundary reflections. This is fine and dandy except the fact that woofers are near the floor. So, at the first glance, gated MLS response will be all over the place. So, one needs to move in to far field and get it away from reflective surface. With the array it may be more difficult due to the size and proximity of the boundary. it's not that it's impossible, just physically difficult.
This is why quite a bit of ball-parking and fudging is performed (unless of cause there's an anechoic chamber handy).
I suggested Tolvan modeler for rough estimate of the number of drivers and resulting effect. The TS of the Aura will decide the loading same as if you were building a TM. The final crossover design needs to be done based on the actual measurements of the woofers and common sense will come in handy.
There's also another subjective issue. Where do you move the crossover point? Lets say for example you can cross the tweeter to the woofers at a 1000hz. I know it's not realistic but just for the conversation sake. Now the tweeter is handling all the upper and dives in to mid-range. The line array effect of this huge 3-dimentional sound and realistic vertical virtual size of the instruments will be diminished. So, ideally, you want to run your woofers as high up as you can but that of cause depends on multitude of other factors.
I find that the most common sense array that will not over-blow the size of the instruments and performers is around 5-6ft tall. it's usually easier to design as well. IMO of cause.

[jhollander]

Re: $1 aurasound drivers in an array?

Lou, Roman, and Mike thanks for the responses this is turning into a very informative thread.

[mikejennens]

Re: $1 aurasound drivers in an array?

Lou, Roman, and Mike thanks for the responses this is turning into a very informative thread.

I'm with John, this IS turning into a very informative thread. Thanks for all the input.
Mike

[bolland83]

Re: $1 aurasound drivers in an array?

5-6 ft, hmm, lets see, that's about 18 drivers, at about 3" each, that's 54" of drivers. That actually works out good with the 16 ohm impedance. 3 groups of 6 drivers, each group of 6 wired in parallel for 2.66666 ohms, and the 3 groups wired together in series comes out to just a hair shy of 8 ohms, perfect.

[WernerM]

Re: $1 aurasound drivers in an array?

This is getting very cool. Thanks for the link Lou to the THIN BLUE LINE ARRAY, the write up was very informative, and even helped me to understand the effects Roman was refering to...

[r-carpenter]

Re: $1 aurasound drivers in an array?

I just read through Lou's Blue Line as well. Looks like he went through the same issues designing and measuring as I did. I can only imagine his conversation with Rick which would probably end up with "welcome to my world" :D
Anyway, I think this thread is becoming very informative and useful. I would sum up that the loading and low end extension should be approached as with conventional loudspeaker. (you wouldn't use 1.5Qts driver in the ported box) Driver summation in the array needs to be considered and finally, measurement techniques should be approached slightly different. I am glad, this thread is not turning in to: let's throw 50 drivers in and see what happens.
Here's another sample of HF loss from my Sony thread. http://techtalk.parts-express.com/at...6&d=1323825298 this dipole at 1.5M

[mikejennens]

Re: $1 aurasound drivers in an array?

...I am glad, this thread is not turning in to: let's throw 50 drivers in and see what happens....

Me too. Although I'm buying 50 of the drivers, I only want to use as many as "practical." I like the idea of 5 to 6 feet being a good target. Thanks for all the input.
Mike

[WernerM]

Re: $1 aurasound drivers in an array?

Me too. Although I'm buying 50 of the drivers, I only want to use as many as "practical." I like the idea of 5 to 6 feet being a good target. Thanks for all the input.
Mike

Would it be possible to use the remaining drivers in a line array type center? I.E. if you go with say 18 drivers per side like bolland suggested, that would be a total of 36 drivers for the L/R combo. This would leave you with 14 drivers, and I just wonder if it is possible to use 8 of those 14 and do a center array. That would leave you with 6 for spares incase one or two should ever fail...

I really don't know if it has ever been done, or tried so just wondering.

[dcgold2000]

Re: $1 aurasound drivers in an array?

Would it be possible to use the remaining drivers in a line array type center? I.E. if you go with say 18 drivers per side like bolland suggested, that would be a total of 36 drivers for the L/R combo. This would leave you with 14 drivers, and I just wonder if it is possible to use 8 of those 14 and do a center array. That would leave you with 6 for spares incase one or two should ever fail...

I really don't know if it has ever been done, or tried so just wondering.

http://www.billfitzmaurice.com/SLA.html

[mikejennens]

Re: $1 aurasound drivers in an array?

Would it be possible to use the remaining drivers in a line array type center? I.E. if you go with say 18 drivers per side like bolland suggested, that would be a total of 36 drivers for the L/R combo. This would leave you with 14 drivers, and I just wonder if it is possible to use 8 of those 14 and do a center array. That would leave you with 6 for spares incase one or two should ever fail...

I really don't know if it has ever been done, or tried so just wondering.

It's worth thinking about. However, I'm pretty much set on two channel stuff. I have a decent HT, but I don't watch a lot of TV or many movies. Plus, I don't kn ow that I'd have room for a center channel that size. I definitely appreciate the suggestion, though. Please... keep 'em coming!
Mike