# Near field line array



## Diru

Here we go , I know there are some out here that are into this so lets begin....

Do they have to be expensive like these , hell no. It's a lot of hype.









Can you make them on the cheap, sure can.


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## Abaddon

So what exactly is the concept of these line array speakers?

No single origin point?


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## dBassHz

Abaddon said:


> So what exactly is the concept of these line array speakers?
> 
> No single origin point?


Some essential reading:
http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
http://www.jblpro.com/vertec1/vertec_manual/AES_MarkE_DirRadiation.pdf


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## Diru

Abaddon said:


> So what exactly is the concept of these line array speakers?
> 
> No single origin point?





omarmipi said:


> Some essential reading:
> http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
> http://www.jblpro.com/vertec1/vertec_manual/AES_MarkE_DirRadiation.pdf



Good stuff, I'll add another.


http://www.meyersound.com/pdf/support/papers/meyer_line_array.pdf


Now mind you we are playing in the near feild, not hand in hand the same as pro audio arrays.


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## Abaddon

I just got a copy of Acoustics by Beranek.. and now you guys give me MORE to go through....

I read through the first few pages by Dr. Griffin though... interesting concept...


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## dBassHz

Diru said:


> Good stuff, I'll add another.
> http://www.meyersound.com/pdf/support/papers/meyer_line_array.pdf
> Now mind you we are playing in the near feild, not hand in hand the same as pro audio arrays.


Bookmarked. Ops, I forgot we're talk about near field. :blush:


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## Babs

I've always been fascinated by LA's... I wonder what proven kits or designs are out there that wouldn't kill a guy to build.. I know of one company here that I thought had a kit or two....
http://www.rawacoustics.com/item__RA8_Speakers_ARRAY,777.html
... They sell these as a kit.

And this company I think also had some serious kits, though I don't know if they had LA's specifically at present.. Used to have a huge LA speaker design:
http://www.creativesound.ca/


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## Babs

Yeah.. Here it is.. The AlphaLS.. apparently it's quite famous but discontinued.. might be able to at least get the specs though...

http://www.creativesound.ca/details.php?model=AlphaLS


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## Diru

hummm, maybe on the cheap

http://www.partsexpress.com/pe/showdetl.cfm?&Partnumber=289-086

$13 a plate [A: 12", B: 5-7/16", C: 2-1/4".] 24 plates / 12 in each cab 

$312 for the plates [maybe discount for qty?]
$100 for x-over parts, wire, connectors
$200 or less for a bare MDF cabinets

$600 for a pair of dirty slapped together arrays, now I wonder what those plates sound like.

And before some of you blow a gasket, no this is not a perfect array and the c-t-c is way out there. This is what it is array on the cheap and dirty.

Woofer specifications: All specifications with drivers wired in parallel *Power handling: 60 watts RMS/100 watts max *VCdia: 1" *Le: 0.22 mH *Impedance: 4 ohms *Re: 3.9 ohms *Frequency range: 75-6,000 Hz *Fs: 75 Hz *SPL: 89 dB 1W/1m *Vas: 0.05 cu. ft. *Qms: 6.96 *Qes: .59 *Qts: .55 *Xmax: 2 mm/driver. 

Tweeter specifications: *Power handling: 25 watts RMS/45 watts max *VCdia: 1" *Impedance: 4 ohms *Re: 3.7 ohms *Frequency range: 3,500-20,000 Hz *Fs: 2,000 Hz *SPL: 89 dB 1W/1m 

I asked PE if that is a perfect rectangular baffle or not. If it is would make it even easier, use as is.


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## dBassHz

Nice find! I would scrap the plate and use the drivers. Those tweeters are perfect because they are rear mountable. And the 4" drivers will be easy to cross.


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## Diru

huh huh huh??? look like that or something like it


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## dBassHz

I definitely dig your idea but I think there will be some problems with the tweeters and possibly the MTM woofer arrangement.


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## Diru

Im not a fan of it either , but it has been done. 

For the money, that is if the speakers in the plate don't suck too bad, would make some great diy line souce for someone to get that hugh wide stage thing going on.

The 2.83 sens at 1meter should be up to about 97db. Most likely need a bit of eq, and should play from 60~80hz all the way up. Just add sub.

You know what though *Chad* could use this maybe? maybe not?






NUTZ: got the one answer from PE

Talked to PE and they are slightly angled out, but you would only have to make a rectangular cutout since the face plate doesn't usually go flush with the wall. Hope this helps. If you want exact dimensions you can send them an e-mail or give them a call.


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## dBassHz

Hmmm... think you could request a picture of the back?


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## chad

Diru said:


> You know what though *Chad* could use this maybe? maybe not?


97dB ain't enough sensitivity


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## Diru

chad said:


> 97dB ain't enough sensitivity


ohhh bit me


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## Diru

omarmipi said:


> Hmmm... think you could request a picture of the back?


I give it a shot


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## dBassHz

Diru said:


> I give it a shot


Thanks. These would go well with an array of $5 eD EHQS8 8" woofers.


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## Diru

omarmipi said:


> Thanks. These would go well with an array of $5 eD EHQS8 8" woofers.



Wow , now thats a great price. 

Here is some Ebay raw KLH drivers on the cheap and looks like large qty could be had....

http://search.ebay.com/_W0QQsassZshadyskys


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## dBassHz

Diru said:


> Wow , now thats a great price.
> 
> Here is some Ebay raw KLH drivers on the cheap and looks like large qty could be had....
> 
> http://search.ebay.com/_W0QQsassZshadyskys


Yeah, I've been eying those. I just got 4 of the eD drivers for a dipole bass bin project! Now I just need an amplifier that can do ~2 x 100 Watts @ 2 ohms. Got any recommendations? Sorry for getting off topic.


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## bassfromspace

Diru said:


> huh huh huh??? look like that or something like it


Look at all that vinyl.


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## Diru

Behringer EP1500 or EP2500 seemed to a favorite in the budget class.

If you want to take it up a notch Parasound or Aragon [had Parasound still run Aragon {8008}]. 

Ebayed, I'm sure you could find either of them for a good price.

http://cgi.ebay.com/PARASOUND-HCA-1...ryZ39783QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

http://cgi.ebay.com/PARASOUND-Model...ryZ39783QQssPageNameZWDVWQQrdZ1QQcmdZViewItem


mutil ch

http://cgi.ebay.com/Aragon-2007-7-C...ryZ14973QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

This is a nice one, I still own a Van Alstine modded 400

http://cgi.ebay.com/dynaco-ST-400-s...ryZ39783QQssPageNameZWDVWQQrdZ1QQcmdZViewItem

The home of Van Alstine
http://www.avahifi.com/


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## dBassHz

I don't think these eD 8" woofers will need all of that power. You think I could use a dynaco. I'm kinda of a noob at the tube thing though so I know nothing about models or power ratings.


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## Diru

What dynaco you thinking ? Some of them have output taps down to 4 ohms.

The one thing you *CAN NOT*(should not) fudge is impedance matching your speaker load to the output impedance of the amp. You can if you don't mind taken the chance of cooking your output transformers.


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## dBassHz

Diru said:


> What dynaco you thinking ? Some of them have output taps down to 4 ohms.
> 
> The one thing you *CAN NOT*(should not) fudge is impedance matching your speaker load to the output impedance of the amp. You can if you don't mind taken the change of cooking your output transformers.


Yeah, that's what I was thinking because of the variable impedance nature of speakers. I guess I'll look else where.


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## Diru

omarmipi said:


> I don't think these eD 8" woofers will need all of that power. You think I could use a dynaco. I'm kinda of a noob at the tube thing though so I know nothing about models or power ratings.





Diru said:


> What dynaco you thinking ? Some of them have output taps down to 4 ohms.
> 
> The one thing you *CAN NOT*(should not) fudge is impedance matching your speaker load to the output impedance of the amp. You can if you don't mind taken the chance of cooking your output transformers.





omarmipi said:


> Yeah, that's what I was thinking because of the variable impedance nature of speakers. I guess I'll look else where.



That shouldn't stop you from your goal, just need to match up is all.

What are thinking about doing, full passive x-over? 

I know you are getting what 4 ed`s , a pair each channel? Two 2 ohms in serise will get you to 4 ohms, and/or two 4 ohms will get you to 8 ohms. 

I got to look back , was this a di-pole sub to be used with some arrays?

If this is the case that ~85db sens isn't going to make them 8's stand up to an array that could have a sens up to and possibly over 95db.


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## Diru

bassfromspace said:


> Look at all that vinyl.


Kind of sexy huh


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## Diru

I was bored and I can


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## Abmolech

You should be bored more often


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## Diru

Abmolech said:


> You should be bored more often


Ok then I will be........Here is someone else` work on the cheap. Look nice too.

http://www.marulla.com/audio/line-source-speakers/


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## Diru

Not on the cheap and WOW!










Chub










Ok back to doing on the cheap


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## nadaclue

So what exactly constitutes "near field"? Is there a usable distance that these line arrays can be used in?

Typically when I think near field, I think studio monitor / computer speakers. Something typically within 2-3' of the listener. But obviously sitting 2-3' from a line array is pretty pointless.


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## Abaddon

nadaclue said:


> So what exactly constitutes "near field"? Is there a usable distance that these line arrays can be used in?
> 
> Typically when I think near field, I think studio monitor / computer speakers. Something typically within 2-3' of the listener. But obviously sitting 2-3' from a line array is pretty pointless.


Some PDF files were linked to at the beginning of this topic.

One of theme specifically outlines what is considered near-field. Really good read.

But basically, the near field is based on the height of the towers. Taller = larger near field zone



http://www.audiodiycentral.com/resource/pdf/nflawp.pdf
http://www.meyersound.com/pdf/support/papers/meyer_line_array.pdf


Specifically, near field is frequency and height dependent.

The distance from the speaker considered near field is defined as

Distance = 1.5 * Frequency * height^2

Keep in mind that the units for Frequency are Kilo-hertz.

*Example:*
*
1m tall Line array, 300hz tone (300hz = 0.3Khz)*

*Distance = 1.5 * 0.3 * 1^2 = 0.45 meters * _(this is why all the line arrays pictured are taller then 1m)_


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## Diru

Having thoughts again


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## Weightless

Is that for a vertical curved array?


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## Diru

Weightless said:


> Is that for a vertical curved array?


Yes

Idea; 

if you got a room in mind for a listening room,

place you favorite chair at the apex or center of your speakers,

while sitting[going to need a bit of help here 2nd person] take length of string to where you would have the center of the array to be. Have a piece of cardboard or cheap thin panel to make templates for the front panel arc.

string to ear , place pencil in loop on the other end, sweep up and down. done deal,template


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## Weightless

Wouldn't you get some nasty nulls due to the CTC being so far apart for the tweeters even if the distance of each driver is +/- the same distance from the listener?


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## Diru

Weightless said:


> Wouldn't you get some nasty nulls due to the CTC being so far apart for the tweeters even if the distance of each driver is +/- the same distance from the listener?


I would think being on the 0* axis of all drivers would negate the c-t-c issues, or I might be nutz.........


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## Diru

thinking again watchout

LMAO< you must wait 30 seconds between post, try again in 4 seconds


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## Tommythecat

Diru said:


> I would think being on the 0* axis of all drivers would negate the c-t-c issues, or I might be nutz.........


Provided you put your head in a vise to listen to the system.


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## Diru

Tommythecat said:


> Provided you put your head in a vise to listen to the system.



Why in a vice, would two blocks of wood suffice? I think I made comment about listening positon.

I need coffee


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## Xander

Tommythecat said:


> Provided you put your head in a vise to listen to the system.


Hey, sometimes you gotta make sacrifices to get the most out of your system. Deal with it.


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