[bladesmith]

I believe the thread is called "Something new that sounds incredible"

http://www.audiocircle.com/index.php?topic=126112.msg1380855#new

I am reading it now. Seems Danny is getting good results with the Neo 3.
 The wing might work with a Neo 3 & 10, just no need for the second smaller wing, keep the larger wing.

[Davey]

For reference, here's a measurement of a Neo3 tweeter with and without the back cup installed.
This is a totally un-smoothed measurement with my microphone 1" from the driver face and the drivers mounted on a piece of plywood that's large enough to be an infinite baffle for this frequency range.

The relative differences should be pretty easy to see. 
(It might be a little hard to see, but the large amplitude divisions are in 10db increments.)

I appreciate that some users will be planning on crossing over this driver above the lower portion of this range, but you still have to be careful using lower-order filters.

I hope that helps to visualize the performance of this tweeter for those interested.  It's a good tweeter, but you simply can't treat it the same with or without the back cup installed.

Cheers,

Dave.

[HAL]

Davey,
For reference is this a BG NEO3 or NEO3PDRW driver being measured at 1"?

[Ric Schultz]

Calm down Davey!  I am not dense....and you are not dense....we are infinite love and bliss!  I am saying that you can use the "undamped" Neo 3 with a 12 db per octave xover without any other compensation and it sounds fantastic....that is all I am saying.  I understand and see your measurements......they are not what I get with my baffle and my x-over (I don't measure a few inches away from a driver...I mean, who listens there?).  We need to try things and measure at listening position and most importantly...listen!!!!....that is always what I am saying.  Your initial comments that these tweets were not as good as domes and that they need attention and eq for use (not my experience) can stop people from actually trying the driver and hearing how incredible it is and how easy it is to design a x-over for....that is why I keep replying.

Your point is "be careful, I measured something I don't like".  My point is "its incredible...I am using it and it sounds great. Try it". 

Have you tried each direction on a coil and listened?  How do you know it does not make a difference if you do not listen....of course, it measures the same each way.  But it sounds different.  The only way to know is to have an open mind and ear and experiment.  All of my truest knowledge about audio comes from using the best test instrument in the world.....the ears...along with an open inquisitive mind.

We are all intelligent enough to make up our own mind about something.  If we just read something on a forum and assume it means everything there is to know about something because someone measured something or says something then we are just sheep.  Don't believe anyone, including me!!!!!.....experiment and experience and listen for yourself.  That is the only way to true knowledge and happiness...in everything we do.  It's Sunday....so sermon is now over....please place excess stereo equipment in the coffer on your way out....he he.  Happiness to everyone, every second!

[Davey]

That's a Neo3 driver....and it's actually the same driver.  Initially tested with the back on and then with the back off.  The measurement setup is identical in every aspect except for the missing rear chamber.
It might look like a jagged mess upon first glance, but look closely.....there's much to be gleaned/learned from those response curves.
The relative amplitude response difference can easily be addressed when incorporating into the final design, but take notice of some of the other factors as well.
Close up measurements like these reveal much information about a driver.  (Information that wouldn't be seen with a 1-meter or listening position measurement.)
Keep in mind there's increased distortion associated with the un-chambered configuration.......even if both were equalized to identical amplitude responses.

Ric, I don't know what you're talking about.    Who's not calm?  I certainly am.
Start posting some well thought out objective information instead of silly nonsense and guys like me might start taking you seriously.

Cheers,

Dave.

[HAL]

Thanks.

Will be interesting to compare this set of measurements with the NEO3PDRW version at 1" from the face. 

[bladesmith]

The way I understand Danny at GR, IF I am correct.
He mounts the tweeter on the back and puts a 45°+  bevel on the front.

FWIW...

[Davey]

Thanks.

Will be interesting to compare this set of measurements with the NEO3PDRW version at 1" from the face.

If somebody has a spare one, send it to me and I'll test with the identical configuration.
I would expect to not see much relative difference (other than an amplitude offset) with an on-axis measurement since the PDR version is optimized for wider/better off-axis response.

Dave.

[SteveFord]

The "Are you dense?" post has been sent to the Intergalactic Wastebin.
No personal attacks also means no insults, please.
You're only discussing speakers, not planning the storming of Normandy Beach.
Thank you.

[Davey]

I hope you're not equating my comments aimed at Ric to the storming of Normandy Beach.
That's just ridiculous Steve.  Now you're insulting me.

C'mon.

Dave.

[SteveFord]

All I meant by that is it's only stereo stuff and it's just a hobby for the majority of us.
I'm not even sure what this thread is all about, to be perfectly honest.  Just keep it civil, that's all.

My main hobby is currently trying to master this Martin acoustic so carry on.

[bladesmith]

All I meant by that is it's only stereo stuff and it's just a hobby for the majority of us.
I'm not even sure what this thread is all about, to be perfectly honest.  Just keep it civil, that's all.

My main hobby is currently trying to master this Martin acoustic so carry on.

Playing the guitar, is like dating a difficult woman, sometimes.

[SteveFord]

The body width is what's throwing me off - after decades of electric guitars getting used to a big dreadnaught acoustic is quite the change of pace.
I remember reading how Johnny Winter bought this dobro and said he spent a solid month playing it because he wanted to master it.  That's pretty much what I'm trying to do with this Martin as I didn't buy it to have it sit in the case.
Shame work keeps getting in the way...
Sorry to derail the thread, back to the Neo PDRw vs the Neo 3w discussion.

P.S.
This guitar is kicking my ass!  Enough for one day.

[bladesmith]

Steve,

No problems. I am just researching information on a project.

Keep after the acoustic, it will pay off big in the end..

Smith

[JohnR]

I'm using a pair of backless PDRs crossed over at ~3k with second order electrical. They don't get a lot of volume (surrounds). Personally, planning to try other things in new projects.

I thought I had some measurements of the PDR with back on and off but can't find them. You will need to measure them yourself in your own baffle anyway.

[bladesmith]

JohnR,

Some people are using those minidsp moduals. Have you ever tried implementing any of those in your
projects ?

Understand about doing my own FR measurements, appreciate the input.

Smith

[nickd]

BG Radia uses the Neo3PDR in an open baffle (aluminum extrusion) between a pair of neo 10's in MTM. They have integrated a small wave guide into the design and lowered the crossover to just above 1500 Hz. I have heard a lot of dome tweeters good and bad, they do not sound like the Neo3. It has a transparency and air that are very special. It makes a really nice mate with the neo 10. Both fast and able to be mounted on the same plane for mechanical time alignment. The trick to a good sounding design seems to be in baffle width or a rear wing to get proper lower midrange weight and a wave guide to increase efficiency down low on the Neo3. BG Radia uses a pair of 7" paper mid woofers in a well built sealed box to cover the upper bass / low mids (>300 Hz) on the FS420.

[satie]

It is very simple baffle loading for the Neo3 family. The back cup damps the motion of the diaphragm and prevents dipole cancellation. The wide baffle, wings and waveguides prevent the dipole cancellation on one or both sides and alters the FR..

Measuring the dipole in the open is informative, in a box (cup) is useful to indicate how far down it could go given enough baffle/wings/horn or waveguide.

listening tells you immediately that the dipole setup is far more transparent and conveys more detail. Magical nearly like a true ribbon, just much tougher and rugged. Then stick it in the kind of baffle (with waveguide, wing or horn, or without) you would use in reality and measure it then. That would be the actual useful measurement. It comes out much flatter than the open air measurement and extends nearly as far down as the measurement with the cup given enough baffle. The baffle retains the magic of the dipole driver while the back cup makes it sound like a good dome tweeter, precise dry boring without the delicate rendition. The cup just adds a new family of resonances while reducing the diaphragm resonance frequency peak by internal cancellation.

Both Ric Schultz and Davey know this. The argumentative posturing is not useful.

 

[Davey]

Oren,

I'll tell you what.........I'll speak to what I know and Ric can speak to what he knows........and you speak to what you know.  How does that work for you??

Dave.

[lowtech]

Measuring the dipole in the open is informative, in a box (cup) is useful to indicate how far down it could go given enough baffle/wings/horn or waveguide...

The cup just adds a new family of resonances while reducing the diaphragm resonance frequency peak by internal cancellation.

This is a totally un-smoothed measurement with my microphone 1" from the driver face and the drivers mounted on a piece of plywood that's large enough to be an infinite baffle for this frequency range.

Funny how two people can read the same words and interpret the results completely differently.

Considering this tweeter was never designed to operate w/o a cup on the back, it does pretty okay if it's used within a range where it's not being over driven (> 4kHz), the crossover is steep enough (3rd order or better) and the crossover network properly compensates for the rising response before its rapid roll-off (especially if it's horn loaded).  IME.