4 driver line array using fullranges

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I started a new thread as I did not want to hi jack the one below.

http://www.diyaudio.com/forums/showthread.php?s=&threadid=78772

Do 4 driver line arrays only work acceptably with some drivers (like the Jordans) or can one substitute cheaper drivers like the Fostex FE87, FF85K or Vervox 3?

Or is this excercise not worth the effort as for the cost on 4 FF85K or Veravox 3 one can get 1 Jordan JX92 which can easily produce as much bass as 4 3" fullrange drivers?

The JX92 however has a rising hf response while the 4 driver array would have a falling one. Both would require equallization or toe-in or some other form of "help".

As fas as using smaller fullranges goes, I understand that to compensate for polar interference the drivers used in line arrays must have a rising hf response or the line array must be equallised accordingly.

I have also seen loudspeakers (in particular a Snell Type C/III) that used a rear tweeter to add air to the HF.

Can one do the same with line arrays i.e. use a rear tweeter to compensate for the polar interference?
 
I have posted one or more threads similar to this one regarding "mini" arrays.

There are the Jordan 4-arrays with 50mm drivers, also the Seventh Veil array using four Bandor 50mm drivers. AFAIK people who have heard these systems do not typically talk about "combing", or high freq dropoff, etc.

After doing some back-of-napkin calcs based on nflawp, etc, my conjecture is that these mini-arrays operate in far-field mode for majority of situations, but still get a lot of the advantages of nearfield line arrays wrt power handling, etc. Theoretically you should get some high freq dropoff when your ears are below or above the extent of the array, but I haven't heard of that happening.

The Tangband 2x3 inch drivers look very interesting to me, in terms of putting together a 4-array, CTC distance same as Jordans or Bandors. They don't have the upper or lower frequency extension of the more expensive drivers, but might sound surprisingly good.
 
4 cheap (less-good) drivers are just going to sound like louder cheap drivers, rather than one good quality driver.

I've heard the linear array using JX53s and it works. I was less convinced by the 7th Veil but that was at a show, with the usual hotel room acoustics. Although similar in appreance, the drivers are quite different.

Navin - the JX92's rising response is deliberately to mimic the linear array's ability to hold a central image as you move left or right. And it works. See question 2 on the Jordan FAQ page.
 
sure 4 cheap drivers will sound as bad (if not worse) than 1 cheap driver but I was considering Fostex FF85K or Veravox 3 which are suppsoed to be good (but just a different kind of fish when compared to the JXR6).

Coiln: the JX92 is my reference. It is the driver I will fall back on if I cant find an alternate. It is also the only small fullrange driver I have heard. All I know for certain is the cabinets will have to flank a LCD sceen and have an internal volume of about 10 liters.
 
amt said:
Have you seen this? I had looked at it awhile back and thought it might be interesting.

http://www.madisound.com/pdf/fostexcabs/137_85k_tallboy.pdf


amt

Oh yes and that is what gave me the idea of usig the FF85K in a 4-in-line (geez it look like we are taking car engines here) configuration. Then I got to know of the Veravox 3.

I live in India. We dont get to hear these drivers much less order them and send them back. I have heard the JX92 and it sounded good (that is what got me interested in fullranges in the first place) on 2 channel audio unfortunately we did not have 5 JX92s to use in a HT system! :-(

So given my budget (about $150-200 per chanel) and size (8-10 liters each) constraints I was hoping to garner opinions on using ONE JX92 vs 4 x FF85K/Veravox3 or an alternate driver (tangband?) or even 2xFostex 108Sigma (if I can get them cheap).

The reason I did not mention the 2 x 108 sigma combo earlier is that I expect that given the larger dia of the 108 vs the 85K the HF roll off and other distortions associated with 2 drivers reproducing the higher frequencies would be worse with 2 x 108 vs 4 x FF85K/Veravox 3.

Same for the Tangband drivers like the W4-1320. Similarly I dont think the W3-1364 would compare well against Fostex or Vervox. I could be wrong though. I only wish we had reviews of these available.
 
I've used a pair of JX92s in the 48 MLTL flanking a screen and they worked really well for The Incredibles. Everything locked onto the image on screen, good stereo spread and the bass came across well. A couple more for background use (or the JX6s, suitably bandwidth-limited) would work well in small to medium rooms. It's a set up I intend to explore further once the projector and screen have permanent homes.

Note that the Jordans are good in humid environments - not sure what weather you're having out there right now.
 
navin said:
sure 4 cheap drivers will sound as bad (if not worse) than 1 cheap driver .....
/B]

Maybe, but not necessarily, .. in fact, one of the appeals of building line arrays with inexpensive drivers is that the interactions between them can even out the faults of the individual drivers


navin said:
Coiln: the JX92 is my reference. It is the driver I will fall back on if I cant find an alternate. It is also the only small fullrange driver I have heard. All I know for certain is the cabinets will have to flank a LCD sceen and have an internal volume of about 10 liters.

kinda expensive building an array of JX92s (as good as they are for single driver applications). Many will disagree with me, but it might make better sense to build a two way line array, additionally offseting the potential for high frequency nasties. Read Jim Griffins paper at http://www.audiodiycentral.com/resource/pdf/nflawp.pdf if you already haven't.

Good luck
 
Not concerned about this really as the speakers lock centre images well anyway. I doubt I'll use a 'proper' AV processor for this. In any case, any system I put together will have music as the main concern and my primary source is high quality FM.

However for centre channel, I think a JXR6 might work better than the JX92 as it has a flatter HF and is more relaxing to listen to when on-axis.

There are a couple of systems out there which do a Jordan theatre arrangement. Try searching for JX92 and HOme Theatre on Google. Meanwhile, if I find the addresses in my unmanagable Bookmarks folder, I'll post here.
 
zobsky said:
kinda expensive building an array of JX92s (as good as they are for single driver applications). Many will disagree with me, but it might make better sense to build a two way line array,

No I was comparing a 4 driver array of smaller drivers from Fostex (FF85K) or Veravox (3) vs a SINGLE JX92. No way I would consider a line array of JX92. If the budget allowed that I would much rather consider a Jx6R array.
 
Colin said:
Not concerned about this really as the speakers lock centre images well anyway. I doubt I'll use a 'proper' AV processor for this. In any case, any system I put together will have music as the main concern and my primary source is high quality FM.


I also use phantom center channel with good results. I use either a pair of FE167E MLTL's or DX2 MLTL's as my mains and a pair of FE167E up-firing BR's as rears. Dialog locks onto the TV screen pretty well over at least a 45 degree angle. Once I inadvertently turned on the center channel (not installed, of course) and there was virtually no sound from the mains. GM is right about the current mixes that ignore the mains entirely.

Bob
 
Bob Brines said:

I also use phantom center channel with good results. I use either a pair of FE167E MLTL's or DX2 MLTL's as my mains and a pair of FE167E up-firing BR's as rears. Dialog locks onto the TV screen pretty well over at least a 45 degree angle. Once I inadvertently turned on the center channel (not installed, of course) and there was virtually no sound from the mains. GM is right about the current mixes that ignore the mains entirely.

Using the 167 upfiring for the rear is a great idea. Can a JX92 be used that way?

gotta check this center channel out. I wonder why they ignore the mains. this is paying for 5 channels and getting 3!
 
Please don't get me started. I'm a bit of a quadraphonic-fan (trust me, if you haven't heard it, the good recordings were very good indeed. The Alan Parsons mix of DSOTM for instance embarasses the recent JG 5.1 mix on every level), and as such, I've been apalled at the obsession over the centre channel in recent recordings / film mixes. A good Tate II or Sansui Variomatrix still gives astounding channel separation far in excess of anything PLII can do, and frequently beeter than the poor discrete mixes that seem to be so common.

As far as I'm concerned, the centre channel is there simply to improve vocal location for off-axis viewers in films, it should not take over at the expense of stereo imaging. Or anything else come to that. If I wanted mono, I'd have a single ESL57 powered by a Quad II and have done with it. Not that there's anything per se wrong with mono, just that it's not quite the thing for all-out rock or The Lord of the Rings. Phantom centre actually seems to improve stereo imaging a bit; I get the feeling that someone in the studio has all too often been summing things and sending the lot to the centre. Pushing it back to the sides appears to clear it up, as if the signal were back where it [they] belong.
 
Sad to hear that they are mixing everything into the center channel but I dont know if there is a lot we can do about it.

Given this information it seems that the center would have to reporduce more than the left and right mains! In this case would it make sense for the center to actaully "better" than the mains?

For example lets consdier a LCD/Plasma based HT/AV/2 ch. audio system.

For the mains one could have a single JX92 (or a 4 in line array using 4 $30 8cm fullranges like the FF85K/Veravox3 etc.) which it turns out offers better sound.

For the center one might want to have something even more....consider a center that is below (or above) the LCD/Plasma TV. For a 42" TV the center could be 38-40" wide (to match the TV width).

What if one used 1 JX92 at either end of this center speaker? The jx92 would have a center to center distance of about 33-35" Would one expect a lot of interference from 2 drivers 3 feet apart?
 
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