Planar or Neo for array

[unknownuser]

Right now i have a NSB array that im thinking about upgrading. I have budgeted for just over $320 including new crossover.

right now i have 16 nsb's mounted on an open baffle with 12 of the oknyo buyouts.

now, if my math serves me right i can either put 32 Neos a side or i can put 6 Pt2p's per side for about the same price.

my question is which one is the better choice?

oh, and any crossover help would be greatly appreciated.

Thanks


(Originally posted by: Devon)

[rudyjakubin]

> now, if my math serves me right i can either
> put 32 Neos a side or i can put 6 Pt2p's per
> side for about the same price.

> my question is which one is the better
> choice?

> oh, and any crossover help would be greatly
> appreciated.

Definitely the Planars. The crossover point will determine the parts needed. Below 3kz you'll need 3rd and 4th order crossovers. I went as low as 1700 hz with Cauer Ellyptics. A total of 6 components per speaker.

[unknownuser]

if you dont mind me asking, why the planars?

what is it about them that make them better for a line array?


(Originally posted by: Devon)

[rudyjakubin]

http://img.photobucket.com/albums/v641/rjakubin/PlanarGapsduetoframes.jpg


> if you dont mind me asking, why the planars?

1. Sound Quality is so much better than domes.

2. The Center-To-Center gaps is much closer than with domes.

3. The c-t-c of the neo is 13560/1.75 = 7748 hz.
So above 7748 comb lines start to develope.

[thylantyr]

The best recipe for NSB/PT2 array is;

Per tower;
16 NSB ported, ~90-100hz tuned.
10 PT2

Alternative;
You can use sealed NSB or dipole [less upper midbass]

You can use eight PT2.

Anything less isn't as sweet.

With proper electronics, system wiring, and
power amps, you can take the NSB/PT2 array to
new heights people never thought possible.

[dastardly]

> 1. Sound Quality is so much better than
> domes.

> 2. The Center-To-Center gaps is much closer
> than with domes.

> 3. The c-t-c of the neo is 13560/1.75 = 7748
> hz.
> So above 7748 comb lines start to develope.

Your picture also shows the disadvantage. You don't get as much reinforcement due to the minimal overlap of the wavefront with the planer vs the neo.

[rudyjakubin]

http://img.photobucket.com/albums/v641/rjakubin/Speaker-1.jpg


> Your picture also shows the disadvantage.
> You don't get as much reinforcement due to
> the minimal overlap of the wavefront with
> the planer vs the neo.

How much would you need???

For an example my arrays;
10 - 5 1/4" Dayton Aluminums at 85 db wired 3-2-2-3 for a total of 4.8 ohms has an SPL of 97.2 db.
6 - Dayton Planars at 94 db wired 2-2-2 for a total of 5.3 ohms has an SPL of 96 db.

4th order crossovers for the woofers drops the SPL to around 96 db. So they match, almost, 94 db for the Planars is a little optimistic also. Anyways, I don't need baffle step correction for the speakers. They're pretty much flat in room response & the bass/treble controls are centered.

1 - Planar @ 8 ohms = 94 db
2 - Planars @ 4 ohms = 97 db
3 - Planars @ 2.67 ohms = 98.7 db
4 - Planars @ 2 ohm = 100 db
8 - Planars @ 1 ohm = 103 db

The graph was taken from Jim Griffin's white paper which can explain line-arrays much better than I can;
<A HREF="http://www.audiodiycentral.com/awpapers.shtml">http://www.audiodiycentral.com/awpapers.shtml</A>

[dastardly]

> How much would you need???

> For an example my arrays;
> 10 - 5 1/4" Dayton Aluminums at 85 db
> wired 3-2-2-3 for a total of 4.8 ohms has an
> SPL of 97.2 db.
> 6 - Dayton Planars at 94 db wired 2-2-2 for
> a total of 5.3 ohms has an SPL of 96 db.

> 4th order crossovers for the woofers drops
> the SPL to around 96 db. So they match,
> almost, 94 db for the Planars is a little
> optimistic also. Anyways, I don't need
> baffle step correction for the speakers.
> They're pretty much flat in room response
> & the bass/treble controls are centered.

> 1 - Planar @ 8 ohms = 94 db
> 2 - Planars @ 4 ohms = 97 db
> 3 - Planars @ 2.67 ohms = 98.7 db
> 4 - Planars @ 2 ohm = 100 db
> 8 - Planars @ 1 ohm = 103 db

> The graph was taken from Jim Griffin's white
> paper which can explain line-arrays much
> better than I can;
>
> <A HREF="http://www.audiodiycentral.com/awpapers.shtml">http://www.audiodiycentral.com/awpapers.shtml</A>

Yes, I read the paper that is where I learned of the issue about the reduced reinforcement of the planars vs round tweeters.

I am just making the point that the woofer driver sensitivity will increase at a greater rate than the ribbons, and some care must be taken. Note how the woofers are 12db above the individual woofer sensitivity and the tweeters are only 2db. Take the NSB instead at 86db, and the fact that more are needed to get a good line height, and the possibility that you want a slightly higher impedance, and the woofer array quickly approaches 4-6db greater sensitivity than the tweeter array with the ribbons. And, as noted in the white paper it is prefereable to pad the tweeter array slightly rather than the woofer array.