Which Bohlender Graebener Neo3?

[otto88]

I'm doing an open baffle and after reading posts here (was it twest820 or cuibono?) switched the choice of tweeter to BG’s Neo3.
When I quickly piggy backed (to combine & save shipping) as a friend ordered from PE, I think I goofed with the model, not realising there was a PDR model.
I thought when I bought Bohlender Graebener Neo3-PDRW Planar Tweeter w/Back Cup, the sensitivity of 90.5 dB indicated to me it was the open backed version. Now it’s arrived, I see I was wrong.
Without me possibly messing up a driver, can the rear chamber be removed?
Or, can someone confirm my new order . .
Personally, I’d sacrifice a little directivity up high for a little more sensitivity.
If i now have it right, the “normal” non PDR Neo3 is more sensitive, and produces consistent directivity up to about 8.5 kHz, which is good enough for me (my hearing starts to drop off at about 6 kHz).
To get the open back version from Parts Express (who have lower shipping costs to here – Australia) - which isn’t a separate item number, I assume you specify that somewhere in the order . .
Thanks

[dlr]

From the first paragraph at the link:

Comes with an attached damped rear chamber, which may be removed for dipole use.

Dave

[otto88]

Thanks Dave

(I, er thought those words all would be spin)

[dlr]

Originally Posted by otto88

Thanks Dave

(I, er thought those words all would be spin)

Looking at the difference between the PDRW and the standard W versions, the difference is in the dispersion/sensitivity. They both have the removable rear cup. The descriptions indicate that the higher sensitivity of the standard non-PDR version is at the tradeoff of it being more directional with increasing frequency.

However, since the radiating area is much wider, horizontal off-axis response is not as good as with the PDR version. This produces a very narrow "listening window" that has rapidly decreasing high-frequency output outside of this window. When highest efficiency or tightly controlled directivity are the goals, the standard version is still the unit of choice.

I'm pretty sure that John K uses the PDR version in the NOTE. This would be a benefit for a more extended dipole configuration, helping to maintain the figure-of-eight pattern slightly higher. This at the expense of lower sensitivity and possibly a requirement of a higher crossover Fc, if they are issues for the design.

Dave

[twest820]

I believe I suggested contacting Madisound about getting the backless Neo3s used in the Note driver kit some months back. I bought a pair of non-PDR Neo3Ws before the Note came out so that's what I use. I'm unsure of Cuibono and Saurav's current status on Neo3s---think it's mainly Saurav on the Neo3 PDRW.

And, yes, there's a reason my avatar is a picture of a Neo3 on a milling machine table surrounded by plastic shavings.

[bigdh31]

You can use a knife blade to carefully pry off the back. I started with a corner. There is just a silicone like glue holding it on.

[DQ828]

Originally Posted by otto88

I'm doing an open baffle and after reading posts here (was it twest820 or cuibono?) switched the choice of tweeter to BG’s Neo3.
When I quickly piggy backed (to combine & save shipping) as a friend ordered from PE, I think I goofed with the model, not realising there was a PDR model.
I thought when I bought Bohlender Graebener Neo3-PDRW Planar Tweeter w/Back Cup, the sensitivity of 90.5 dB indicated to me it was the open backed version. Now it’s arrived, I see I was wrong.
Without me possibly messing up a driver, can the rear chamber be removed?
Or, can someone confirm my new order . .
Personally, I’d sacrifice a little directivity up high for a little more sensitivity.
If i now have it right, the “normal” non PDR Neo3 is more sensitive, and produces consistent directivity up to about 8.5 kHz, which is good enough for me (my hearing starts to drop off at about 6 kHz).
To get the open back version from Parts Express (who have lower shipping costs to here – Australia) - which isn’t a separate item number, I assume you specify that somewhere in the order . .
Thanks

You can buy the Neo 3 without the back cup from Danny at GR Research, I did, Drivers. Just tell him what you want.

[otto88]

Originally Posted by bigdh31

You can use a knife blade to carefully pry off the back. I started with a corner. There is just a silicone like glue holding it on.

Thanks bigdh,

Once I switched to a nice sharp 8 inch 200 mm bladed chef's knife, the backs were levered off in less than 30 secs

(The mids were to be the 95 dB B&C 6MD38, but will now be the Neo10)

[DQ828]

Originally Posted by otto88

Thanks bigdh,

Once I switched to a nice sharp 8 inch 200 mm bladed chef's knife, the backs were levered off in less than 30 secs

(The mids were to be the 95 dB B&C 6MD38, but will now be the Neo10)

Now they are starting to sound like my speakers, what bass are you using? what about some pictures.

[otto88]

Hi DQ

First time I tried to posted a pic online: its too large - any suggestion on how to trim it?

I'm thinking over the mid tweeter baffle shapes & colours etc

Have you got a pic or 'elevation' drawing?