NEO3 as tweeter in a Line Source/Array?

[Mediafreak]

Thanks for a great LS forum. :T
I am going to build LS speakers with closed cabinets – I am not a fan of ported cabinets. I have a DENON A11-XVA amplifier and a Velodyne sub (closed cabinet) Crossover 60-80Hz. I might need to buy an extra sub because of the high crossover.
As far as I know the bas speakers are not so important as the trebles in a LS. I bought 2x9 Vifa / Tymphany PL14W J09-04 (4ohm. – 5½”) and want the crossover around 1-1,2 KHz. with a 4/4 order filter. The LS bas will be in a 3L closed cabinet. The bas units are 1,5 meter tall, so because of the low crossover the treble need to be around the same length. The bas sensitivity is theoretically 95db so I need a Treble sensitivity between 95 and 100 db.

I am looking at the NEO3 (not the PDR version) in a sealed cabinet with a distance of 1” to the rear closure. 2x16 units so the speaker will be at 3,5-4 ohm. The Neo has 10W RMS and 20W program (160/320W) I have 3 questions for the forum:
1: Could the 16 NEO3´s be used with a crossover between 1-1,2KHz?
2: How is the sound of the non-PDR by less than +/- 30deg. horizontal off-axis compared to the PDR version? (Normally the PDR version is used).
3: the official price for the NEO’s is around 40$ each, does anyone know the price for roughly 40 units?
Mediafreak

[ThomasW]

1: Could the 16 NEO3´s be used with a crossover between 1-1,2KHz?

Nope....

[fjhuerta]

I've used the Neos crossed over at 2 KHz, and I really didn't like them. IMHO, and in my experience, they are a difficult driver to work with - I know some designs are crossing them over at 2.4 KHz or so (the Cryolites, for example), but I'd rather use them higher.

If you are going for 1.2 KHz, you could use the Neo8's, though. I use them at 800 Hz, and I love them.

[littlesaint]

Have you considered the Neo8?

[Rick Craig]

Thanks for a great LS forum. :T
I am going to build LS speakers with closed cabinets – I am not a fan of ported cabinets. I have a DENON A11-XVA amplifier and a Velodyne sub (closed cabinet) Crossover 60-80Hz. I might need to buy an extra sub because of the high crossover.
As far as I know the bas speakers are not so important as the trebles in a LS. I bought 2x9 Vifa / Tymphany PL14W J09-04 (4ohm. – 5½”) and want the crossover around 1-1,2 KHz. with a 4/4 order filter. The LS bas will be in a 3L closed cabinet. The bas units are 1,5 meter tall, so because of the low crossover the treble need to be around the same length. The bas sensitivity is theoretically 95db so I need a Treble sensitivity between 95 and 100 db.

I am looking at the NEO3 (not the PDR version) in a sealed cabinet with a distance of 1” to the rear closure. 2x16 units so the speaker will be at 3,5-4 ohm. The Neo has 10W RMS and 20W program (160/320W) I have 3 questions for the forum:
1: Could the 16 NEO3´s be used with a crossover between 1-1,2KHz?
2: How is the sound of the non-PDR by less than +/- 30deg. horizontal off-axis compared to the PDR version? (Normally the PDR version is used).
3: the official price for the NEO’s is around 40$ each, does anyone know the price for roughly 40 units?
Mediafreak

I measured a Neo3. It beams in the top octave quite a bit due to the wide radiating element. The Neo8PDR will cross lower but I can't say for sure how much lower until I measure the drivers I have on order for an array design.

[Dennis H]

You could probably get it to work but you'd need to remove the back cups and build a fairly large stuffed chamber (preferably the full depth of the enclosure) to absorb the backwave. The pic shows how removing the cup extends the LF response of the Neo3 PDR at the expense of overall sensitivity. The 800 Hz peak is probably from the narrow dipole baffle and shouldn't be there in a sealed enclosure.

[Rick Craig]

You could probably get it to work but you'd need to remove the back cups and build a fairly large stuffed chamber (preferably the full depth of the enclosure) to absorb the backwave. The pic shows how removing the cup extends the LF response of the Neo3 PDR at the expense of overall sensitivity. The 800 Hz peak is probably from the narrow dipole baffle and shouldn't be there in a sealed enclosure.

The problem is the sensitivity is too low running it dipole plus you have other issues as well. I think Zaph did some response tests running it dipole that showed lower crossover points to be unacceptable.

[Mediafreak]

You could probably get it to work but you'd need to remove the back cups and build a fairly large stuffed chamber (preferably the full depth of the enclosure) to absorb the backwave. The pic shows how removing the cup extends the LF response of the Neo3 PDR at the expense of overall sensitivity. The 800 Hz peak is probably from the narrow dipole baffle and shouldn't be there in a sealed enclosure.

Thanks Denns H. I guess you are right concerning the back of the chamber. I will make it moveable (1-7").

You have shown me some nice diagrams of the PDR version - etc. Please look at the non-PDR version with 4 in a line from BG - Fig. 3 :T

http://diymobileaudio.com/pics/NEO3.pdf

THIS is the situation I am thinking about - but with 16 in an array - not 4.

[Mediafreak]

Have you considered the Neo8?

YES really, but I do not like 4 things about them.
1: I whant to be able to play LOUD
2: My woofers have a teoretically sinsitivity of 97 db, in real life it is closer to 95db, but the trible must be at least as sensive as the woofer.
3: The Neo8 has a strange top that I do not like (on the paper ).
4: IMPORTANT - There must be a reason WHY BG always are using the NEO3 in top of their NEO8 or NEO10! :B

Mediafreak

[ThomasW]

4: IMPORTANT - There must be a reason WHY BG always are using the NEO3 in top of their NEO8 or NEO10!

Because they're using a much higher crossover point than the one you propose

[Rick Craig]

Because they're using a much higher crossover point than the one you propose

... and they work better as midrange drivers.

[chrismercurio]

Listen to Rick. He JUST tested a couple of the drivers mentioned in this thread.

Best,

C

[fjhuerta]

YES really, but I do not like 4 things about them.
1: I whant to be able to play LOUD
2: My woofers have a teoretically sinsitivity of 97 db, in real life it is closer to 95db, but the trible must be at least as sensive as the woofer.
3: The Neo8 has a strange top that I do not like (on the paper ).
4: IMPORTANT - There must be a reason WHY BG always are using the NEO3 in top of their NEO8 or NEO10! :B

Mediafreak

1) I have a single Neo8 crossed at 800 Hz and it plays as loud as I want it to. A single 8" woofer can't even dream of keeping up with it.

2) I'd assume that you'd use at least 4 Neo8's per side. That would give you as much sensitivity as you need.

3) You can use a notch filter on the upper end peak, or,

4) You can always use a 7 KHz or so crossover and add a Neo3 on top, like I did.

[Mediafreak]

The NEO 3 or 8 as the midrange/treble in a two-way line array / source:

... and they work better as midrange drivers.

The NEO 3 or 8 as the midrange/treble in a two-way line array / source:
The NEO3 is clearly the best as treble - BG is normally using it.
The NEO8 is a typically midrange – as mentioned by Rick C.
So the question is: Is one NEO8 better than two NEO3’s as midrange (1-4KHz.)? (The NEO8 is 200mm. long and the NEO 3 is only 89mm.)
I need to build a 4’th order filter by 1KHz (comb lines + driver interactions + Fs.)
(See fig. 3 in the link. With 4 NEO3’s in an array).

http://diymobileaudio.com/pics/NEO3.pdf

The power handling (20W) is the same, but the two NEO3’s has a few DB better sensitivity, and a flatter curve than one NEO8.
On paper the choice seems to be clear, but I have never been able to listen to the NEO8.
So I guess the REAL question is: Is one NEO8 a better sounding midrange (1-4KHz) than two NEO3’s when using a 4’th order 1KHz. filter.?

Mediafreak

[ThomasW]

The 'best' practice for loudspeaker design is to run each driver in it's sweet spot, and not to try and force any drivers to work overly high or low in their passbands. This means you should consider using the Neo3 as your tweeters and the Neo8 as your mids, since neither used alone is a good option...

[fjhuerta]

So the question is: Is one NEO8 better than two NEO3’s as midrange (1-4KHz.)? (The NEO8 is 200mm. long and the NEO 3 is only 89mm.)

Yes. Without any doubts whatosever.

[Mediafreak]

NEO8 or NEO3

The 'best' practice for loudspeaker design is to run each driver in it's sweet spot, and not to try and force any drivers to work overly high or low in their passbands. This means you should consider using the Neo3 as your tweeters and the Neo8 as your mids, since neither used alone is a good option...

Sooo.. because Line sources/arrays normally is 2 ways, I need to choose a "trade off" in the midrange or in the treble? I have seen speakers made with both units, but never with both of them (3 ways) in a LS.

Question ?? Would it be possible to make it 3 ways? - (I have never seen it) :roll:
mediafreak.

[Rick Craig]

Sooo.. because Line sources/arrays normally is 2 ways, I need to choose a "trade off" in the midrange or in the treble? I have seen speakers made with both units, but never with both of them (3 ways) in a LS.

Question ?? Would it be possible to make it 3 ways? - (I have never seen it) :roll:
mediafreak.

A 3-way can be done. It's just a matter of tolerating a wide baffle and having a large budget for drivers.

[Mediafreak]

3-way Line Array - filter issue?

A 3-way can be done. It's just a matter of tolerating a wide baffle and having a large budget for drivers.

one Subwoofer each side 20-80Hz.
Line source / array
bas 80 - 900Hz
Mid NEO8 900-5KHz.
Treble NEO3 5-20KHz.

As far as I understand the bas/mid must be minimum 3'th order, what about the filter between mid/treble? can it be a first order, or is there also problematic comb.issues etc. that require minimum 3'th order like the bas/mid?.
A 3 way passive pure 3'th or 4'th order filter will just kill all the fun. , and will be making the "wide baffle" a secondary problem

A 3/3 - 1/1 order filter would be wonderfull - if possible :B
A 4/4 - 2/2 order filter would be acceptable - if possible
Anything else I guess it would be best to go aktive! :E
Mediafreak

[fjhuerta]

Sooo.. because Line sources/arrays normally is 2 ways, I need to choose a "trade off" in the midrange or in the treble? I have seen speakers made with both units, but never with both of them (3 ways) in a LS.

Question ?? Would it be possible to make it 3 ways? - (I have never seen it) :roll:
mediafreak.

You'll have some acoustic cancellation between the 3's and 8's. I tried running them side by side early on my project, and I had major issues with off-axis response. So big, in fact, I had to scrap my original box and start with a new design.

[Rick Craig]

You'll have some acoustic cancellation between the 3's and 8's. I tried running them side by side early on my project, and I had major issues with off-axis response. So big, in fact, I had to scrap my original box and start with a new design.

It seems like they would work if the driver spacing and crossover points were optimal. Can you share some more thoughts on what you observed?

[Mediafreak]

The loudspeakers "sweet spot"?

The 'best' practice for loudspeaker design is to run each driver in it's sweet spot, and not to try and force any drivers to work overly high or low in their passbands. This means you should consider using the Neo3 as your tweeters and the Neo8 as your mids, since neither used alone is a good option...

Off cause you are right; but…
As far as I can understand it is worse for pure Aluminium tweeters to play below their sweet spot; than for a laminated aluminium tweeter like the NEO8/NEO3.
The X-over need to be aggresive because we are close to the Fs, but that is another story.

ThomasW: "neither used alone is a good option"
Mediafreak: Again - you are right- this is why BG never are using them alone. LS are always 2-ways! . I have been looking at the net and there are close to nothing concerning 3 ways arrays; only for PA use. :E
Mediafreak

[fjhuerta]

It seems like they would work if the driver spacing and crossover points were optimal. Can you share some more thoughts on what you observed?

Sure... actually, it's all documented here...

http://www.htguide.com/forum/showthread.php4?t=26798

[fjhuerta]

Off cause you are right; but…
As far as I can understand it is worse for pure Aluminium tweeters to play below their sweet spot; than for a laminated aluminium tweeter like the NEO8/NEO3.

The Neos aren't laminated aluminum tweeters. They are made of Kaladex, if I remember correctly.

[Mediafreak]

BG's Kaladex ?

The Neos aren't laminated aluminum tweeters. They are made of Kaladex, if I remember correctly.

Well I do really not konw if you are right or not. I am from Denmark, and my english might suffer a bit.

BG are writing "Transducers that use an innovative hightech diagrapm meterial called Kaladex from Dupont. This material combined with a new proprietary technology for etching aluminium/kaladex laminate, makes it possible to..."

Can anyone translate this to english for beginners? ops:

Mediafreak

[Mediafreak]

NEO8 + NEO3 in a 3 way.

Sure... actually, it's all documented here...

http://www.htguide.com/forum/showthread.php4?t=26798

Great tread. A lot to read and learn..thanks.
Look at the BG top model from the Radia series "R-800" It has an array of 6 NEO10 and 16 NEO3 and a gentle X-over 1,5KHz...

1: It seems possible to make an array of NEO8 and NOE3
2: The NEO3 seems to be usefull down to 1,5KHz; even with a gentle X-over like in the "R-800". :T

So the real question for a 3-way array would be: "will a line of woofers and a low X-over of 800-900Hz. disturb the interactions between the NEO8 and the NEO3's"?

[Piotr]

Could I please have a rational explanation why the Neo3 couldn't be used as proposed by the thread starter?

Don't forget he will use 16 pieces of them each side.

I also doubt you will need 95-100dB from the tweeter. You are going to use 9 midwoofers each side right? If you stay at nominal impedance (series paralell in groups of three) you will gain a max of 9dB. Also you need to subtract some for the baffle step. 90dB system sensitivty or slightly above seems reasonable.


/Peter

[fjhuerta]

Well I do really not konw if you are right or not. I am from Denmark, and my english might suffer a bit.

BG are writing "Transducers that use an innovative hightech diagrapm meterial called Kaladex from Dupont. This material combined with a new proprietary technology for etching aluminium/kaladex laminate, makes it possible to..."

Can anyone translate this to english for beginners? ops:

Mediafreak

The aluminum conductors are etched into the Kaladex (an insulator). These conductors carry the music signal. There are neodymium magnets in the front and back of the Neos.

[fjhuerta]

Great tread. A lot to read and learn..thanks.
Look at the BG top model from the Radia series "R-800" It has an array of 6 NEO10 and 16 NEO3 and a gentle X-over 1,5KHz...

1: It seems possible to make an array of NEO8 and NOE3
2: The NEO3 seems to be usefull down to 1,5KHz; even with a gentle X-over like in the "R-800". :T

So the real question for a 3-way array would be: "will a line of woofers and a low X-over of 800-900Hz. disturb the interactions between the NEO8 and the NEO3's"?

Well... you have to consider that I used mounting plates that are quite wide. The R-800 drivers' are very close together. I can't imagine a shallow crossover curve helping there, though - what I found is that steeper crossover slopes did help, but dropped the impedance to unacceptable levels.

As for the interactions - I believe I crossed over the Neo8 at 800 Hz and the Neo3 at 7 KHz, so there was none of that. As you may have guessed, I really don't like the Neo3. It's not that I think it's a bad driver - many great designs use it - but it's a pain to work with, IMHO.

If you are thinking about crossing the Neo3 as low as possible, I'd definitely recommend removing the back enclosure and building a bigger one for it. If I remember correctly, in my case I got an extra 500 Hz of so or extension.

[Mediafreak]

System sensitivity

Could I please have a rational explanation why the Neo3 couldn't be used as proposed by the thread starter?

Don't forget he will use 16 pieces of them each side.

I also doubt you will need 95-100dB from the tweeter. You are going to use 9 midwoofers each side right? If you stay at nominal impedance (series paralell in groups of three) you will gain a max of 9dB. Also you need to subtract some for the baffle step. 90dB system sensitivty or slightly above seems reasonable.


/Peter

The Vifa PL14W 4Ohm is 88dB - on paper - but in reality maby "only" 87dB.
I do not expect 87 + 9 = 96dB!, but clearly more than 90dB, and the tweeters must be at least as sensive at the woofers.
Mediafreak

[Mediafreak]

narrowing the array

Well... you have to consider that I used mounting plates that are quite wide. The R-800 drivers' are very close together. I can't imagine a shallow crossover curve helping there, though - what I found is that steeper crossover slopes did help, but dropped the impedance to unacceptable levels.

As for the interactions - I believe I crossed over the Neo8 at 800 Hz and the Neo3 at 7 KHz, so there was none of that. As you may have guessed, I really don't like the Neo3. It's not that I think it's a bad driver - many great designs use it - but it's a pain to work with, IMHO.

If you are thinking about crossing the Neo3 as low as possible, I'd definitely recommend removing the back enclosure and building a bigger one for it. If I remember correctly, in my case I got an extra 500 Hz of so or extension.

A narrow array is exactly what I am trying to do. I will mount the tweeters behind the front plate so they can be closer to the woofers. In an array there is no space for mounting plates, it all has to be woodwork in the front plate.

IF I am going to build a 3-way array – or later on a 3 way like your project I guess the NEO8 will be mounted 5mm. behind the NEO3 so the units can share the same space between them and therefore be 10mm. closer together. :T

Back enclosure of the NOE3: I guess you (again) are right. My back chamber will be movable for later adjustments. I have heard from others that 20 to 50mm. might be nice + a lot of dampening material.

Mediafreak