Bose PAS like

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Something like the Bose PAS is for me.
http://www.bose.com/controller;jsessionid=BHr86C7GTXnq0DLQgVYRXtVy37knKylQHvdJl0Y5RrnsqGvrvyfX!-1885516663!-916327495?event=VIEW_STATIC_PAGE_EVENT&url=/musicians/solutions/index.jsp&linksource=content_fls_solutions&pageName=/musicians/index.jsp
I tried it, and it’s cool. Maybe there’s something wrong with my hearing but it sounds great. And it’s very popular, seems to be selling well.

But it’s too expensive.

So I’m thinking tossing together a line array with a sub.
Madisound has these which look lightweight and up to the task for the array.
http://www.madisound.com/imgs/NS3-194-8E.pdf
$10.50 ea.

WinISD I can get 99SPl with an array of these.
I would skip the tapering as I don’t think Bose does.
I’ve ruled out NSB’s over weight and portability.

So now the Bass. It looks like Bose is a bandpass of sorts. It’s small and compact. Light but not what I would consider lightweight. I’d like to get 40hz out and keep the weight down. Bandpass or small horn? Something compatible with the array. What do you all recommend? Is this feasible?

Keep in mind here, the reference here is Bose PAS, not your typical sound reinforcement system. I do expect to equalize it to get it to sound right as I expect Bose builds in their equalization.

Thanks,
 
Yes - thanks - I read Jim Griffin paper, JBL, and Meyers sound one. All good, but some conflicting information. Bottomline is the Bose PAS seems to work well, so somehow line arrays are good for this.

I'd want to be around 30lb on weight for the sub, so maybe this helps indiciate size.

I'd be using it for Pro-Sound use, but as Bose has it "Personal Amplification System" and not for a whole band - just me.

Sorry - I don't know how to get the link to work, but google on:
Cylindrical site:www.bose.com

Will take you to them.
 
Raintalk, I wonder if you are setting your sights a little low by using Bose as a benchmark.

Bose don't use very good drivers, but they charge a premium for what you could build very cheaply. An array of the Tangband W3-871 would be an easy choice, crossed to some subs at say 200 Hz. The 871 only needs a notch filter to get a nice smooth response, no tweeter needed. Bose would not need to much eq if they used decent drivers. Notice how their brochures are loaded with pretty pictures, but no real information? There is good reason - their stuff isn't up to scratch when you look at actual measurements.

Bill Fitzmaurice who frequents this forum sells kits suitable for PA use and I would trust his stuff over Bose.
 
Maybe, but it’s all very subjective. The Bose are pretty popular and portable. You’ll be seeing them in more and more clubs. And I’m sure many would say they could build speakers cheaper that sounded better but the Bose somehow fits a need. If I can put together a speaker system that sounds as good as a Bose with better portability, for a fraction of the price then I’ll be happy.

Looks like it’ll take a couple of bandpass boxes to match the array close enough. Or maybe a Bill Fitmaurice tuba – but then tuba’s are pretty bulky.

The W3-871’s would be too bulky for my use. And I don’t see them available anywhere.

I see PE has some Aura’s for a darn good price that might be good enough with a tweeter added.
http://www.partsexpress.com/pe/pshowdetl.cfm?&DID=7&Partnumber=299-015&scqty=18
 
Maybe, but it’s all very subjective.

I'd say talk to some seasoned PA guys and they will give you more than a maybe!

Buyouts are always good - just check the response is reasonably smooth. Quite a few on this forum do line arrays with cheap fullrangers like those you linked.

High up on my list would be the Adire HE10 and HE12 kits. They are good down to 50 Hz, although I'd add a sub below that. They are not too big, anything smaller won't get much output or efficiency.

The Tuba isn't really that big, and its super cheap. The Autotuba is so small its ok for home use. Cheap way to get decent output out of something fairly compact.
 
I had a look at the bose website, I assume you are talking about those tiny line arrays, right?

They look slim, but they occupy the same space as much larger speakers due to the base. They get wide dispersion due to the small drivers and the use of an array.

Here's what I'd do for a DIY version (which should be quite a bit better then theirs for less cost).

I think it would make more sense to use slightly bigger drivers like the TB 871 and then put that on top of a compact sub. Say get a Tuba 18 and make it the base for your array. The TB drivers will get down to 200 Hz and only need a simple notch filter to get them nice and smooth.

Granted it won't look quite as slim, but it will probably in fact occupy about the same space. If you really want it to look tiny and even slimmer, then there is a smaller version of the 871. Here's an example

An externally hosted image should be here but it was not working when we last tested it.
 
The base on that thing is very wide ... the input panel is 25" wide so it must be about 28" or more for the actual base! Occupies probably the same floorspace as a Tuba 30! ... then the bass module is also required, which uses only 2 x 6.5" woofers. They are probably high excursion drivers with 1" excursion which Bose typically use in their HT subs (supplied by TC sounds.) However, the 8" driver used in the Autotuba moves about the same amount of air but probably has another 10 db of efficiency and output due to horn loading.
 
In your initial post you suggest using the new Aura 3" driver. Then further down you reject the TB 871, which is almost identical, for being 'too bulky'.... and certainly the other aura 3 incher + a tweeter, as you later suggest, would be even more bulky than an 871. I guess I don't really understand your criteria for driver selection... it seems like either you really want to use Aura drivers (which is fine), or you really want to use something you chose yourself (which is also fine). In either case, go for it.
 
If weight is an issue build them in modules that will stack into an array and clip together. Probably better than basing your choice of driver on the weight of the magnet. I say get the driver that well perform and give you bang for buck, then find out how to make it a suitable weight. Those TB drivers are tiny and very light. If you use an idea like Darren's in the link I showed, they will have a very light box - curving makes this possible.
 
Full Range Line Array

Before you jump off the bridge with a line array using full range drivers you should read and look at the graphs that Darren Kuzma took on his array. The link and photo are above this post. Notice the equalization that Darren had to use to accomodate the roll off in the treble and the lack of bass/midrange response. Darren was using the 2"
Tang Band drivers for his array.

If you use larger drivers you can get a little more bass than what Darren was able to achieve, but the high end will roll off even lower and more. The issue with the high end is that the spacing between drivers is too great so comb lining takes place (see my white paper). The directivity suffers so the frequency response starts to fall from flat over the upper octave (10-20 kHz). Hence, you need the equalization to flatten out the response. If you want average sound, you can get there from here but even that will take equalization to prevent ear bleed.

I like the TB W3-871S but even it will need a tweeter for the high end as I did with my Needles array (the skinny array in the photo).

http://home.earthlink.net/~selahaudio/_uimages/LineUp.jpg

Jim
 
The space from driver centre to centre is most likely considerably less even with the 871 than in a typical hifi speaker. This is even better with the 2" driver.

Also consider that this is for PA use. Some of the finer points of hifi speaker design are not really critical and I don't see that the rolloff of the fullranger at the top end is going to be missed. Many use it and are happy with it even for hifi use.

Jim,

as far as lobing is concerned, and possibly a few other issues, isn't it worse to put a tweeter in the centre? I would have thought a series of small fullrangers would be better, except that a dedicated tweeter may have a more extended and flat response and have lower IMD, etc.
 
Paul, the way my Needles array was designed to be more of extended M's in a MTM. These arrays are intended to be used in a room wherein the listening distance would be within an 8-14 feet range. Hence, you get the line array effect for the low end of the band where it is most noticeable but the tweeter fills in where the listener is seated. Power tapering is used to better anchor the sound to the center of the array and to match to the tweeter.

For a PA application you would need a true tweeter line to achieve sound balance throughout a larger room as you suggest.

The center to center spacing for the W3-871S (mounted with frames touching) would be about 3.63". The c-t-c for the smaller W2 drivers that Darren used is about 2.25" with their frames touching. In my mind--as proven by Darren--you would need equalization to make either array sound OK. EQ is not a dirty word for pro sound applications.

Jim
 
Hence, you get the line array effect for the low end of the band where it is most noticeable

I'm not entirely sure what effect you are talking about - the big soundstage? I would have thought that was more a mid and upper thing? Or perhaps you are talking about something else ....

Power tapering is used to better anchor the sound to the center of the array and to match to the tweeter.

What exactly is this power tapering? Is it more power to the drivers closer to the centre?
 
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