New house...new 3 way OB built around BG Neo8S

zmyrna

Member
2009-11-24 8:19 pm
London
after living in tiny rental flats for 20 years, I bought a house in my hometown...
the selling point for the house was a decent sized basement with concrete walls which will be my music&movies lounge.

not interested in home theater for now... stereo only

there is a storage room downstairs in which I plan to house a slot loaded infinite baffle subwoofer. so lets assume below 60hz will be handled by the sub.

I have 2 options for the 3 way OB main speakers

1- 15" GPA 416-8B 60-600hz
Planar BG Neo8S 600-3500hz
Planar BG Neo3 3500hz +

2- GPA 416-8B 60-250hz
8" Vintage Seas 21TV-G 250-800hz
BG Neo8S 800hz +

I know that Neo8S will beam along its long axis especially if used as tweeter...but I will tweak it with felt so it will be less of a problem... so lets ignore Neo8S' beaming for the sake of this decision:

which option should I build? and why? thanks

PS: I have all the drivers mentioned + DSP crossover
 

tommus

Member
2009-07-12 12:38 am
I've used the BG Neo8S + Neo3 combo on a narrow baffle crossed lower at 2-2.5K for better vertical pattern matching. It sounds uniquely wonderful and has great dipole pattern control due to its narrow width. Yes the system will be dynamically limited at the low end of the 8S.

Have you considered using ALL the drivers? You could put a passive 2nd order on the planars and save a DSP channel.
 
Some random observations:

1) IMHO, the NEO8 sounds much better than NEO3. The NEO3 is limited by it's lack of xmax. I guess it might be OK if you set a high xover, but I literally blew up one of my NEO3s while testing it.

2) I think the peak in the NEO8 is caused by geometry. I'm not convinced it's a resonance. See my thread here : Phase Plug for Planars

You will *definitely* need some measurement equipment to test these hypotheses though.
 

zmyrna

Member
2009-11-24 8:19 pm
London
Option 2. Cones offer better headroom at low frequencies. You'll need it with OB. Especially if going narrow or nude.

Crossovers might have to move up a bit depending on output requirements.



Congrats on the new house! :cheers:

Just some Info I found on the web re Neo8S: Forum member Juhazi measured Neo8S nude and it is flat down to 800hz (that is where he crosses it). And the company recommended hifi crossover point is 600Hz.

"Congrats on the new house! "
Thanks :)
 

zmyrna

Member
2009-11-24 8:19 pm
London
Those Seas are great! Tried about ten different pairs of mids for OB, but they are my favorites by far! Only speakers that sounded better was in fact a fullrange from a Radionette cabinet system but one of them have a nasty coil rub. Crossed them a lot higher 1st order than 800 hz.

Indeed... Troels have a page for them called "blackcones"

BLACKCONES

lightweight and shallow cone with extra-smooth break-up....
 

zmyrna

Member
2009-11-24 8:19 pm
London
I've used the BG Neo8S + Neo3 combo on a narrow baffle crossed lower at 2-2.5K for better vertical pattern matching. It sounds uniquely wonderful and has great dipole pattern control due to its narrow width. Yes the system will be dynamically limited at the low end of the 8S.

Have you considered using ALL the drivers? You could put a passive 2nd order on the planars and save a DSP channel.

Yes; a 4 way and a 2 way (416-8B + Neo8S) can also be considered.

Have you compared combo vs. Neo8S alone?
 

zmyrna

Member
2009-11-24 8:19 pm
London
Some random observations:

1) IMHO, the NEO8 sounds much better than NEO3. The NEO3 is limited by it's lack of xmax. I guess it might be OK if you set a high xover, but I literally blew up one of my NEO3s while testing it.

2) I think the peak in the NEO8 is caused by geometry. I'm not convinced it's a resonance. See my thread here : Phase Plug for Planars

You will *definitely* need some measurement equipment to test these hypotheses though.

I agree: Neo8s sounds better. Although it has the same peak as Neo3, the HF sounds less pronounced and harsh.

I have read and contributed to your thread re the planar phase plug.
I will tweak the BG drivers in two ways:

BG NEO 3 FR optimization

Opzetje dipool Neo8 & 2x Seas L21RNX/P + cornerwoofers - Pagina 2 - forum.zelfbouwaudio.nl

and once again, I am a fan of your posts but cannot view your pictures :worship::headbash:
 
Tweeter designed to work in OB is a good idea. I do not say to buy the kit but to take note of the tweeter and the box design, novel for me.

New GR Neo 3 tweeters are here.

Speaker kits, loudspeaker design services, sub-woofers and amplifiers. - Drivers

-> GR Neo 3

You are right, without measurements, graphs :mad:


New GR Neo 3 frequency measurements - Google Search

-> BG NEO 3 FR optimization

It's far more effective than I though, nearly perfect response (green curve after modification, red before modification)
image.php
 
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^That speaker project presents typical AC stuff - strange combination of drivers and radiation patterns and bold claims without proper documentation. Better to forget that - this thread is about real dipoles, not extravagant effect boxes!

Juha;
Have you ever tried Neo8 as the tweeter without the Neo3?
I know that it would measure worse but I was wondering what you would think subjectively...
 
I tried, and it was quite good actually - at spot (eq'd rather flat). Vertical directivity is too high to be practical. It also made room decay too fast at high freq, because there was less reflections in the room. I didn't save measurements and now I have loaned my gear to a friend, so I can't test it right away again.

And my Neo8 and Neo3 are PDR models, open back. Still I get enough spl, but Neo8 is highpassed around 800Hz LR2.
 
I agree: Neo8s sounds better. Although it has the same peak as Neo3, the HF sounds less pronounced and harsh.

I have read and contributed to your thread re the planar phase plug.
I will tweak the BG drivers in two ways:

BG NEO 3 FR optimization

Opzetje dipool Neo8 & 2x Seas L21RNX/P + cornerwoofers - Pagina 2 - forum.zelfbouwaudio.nl

and once again, I am a fan of your posts but cannot view your pictures :worship::headbash:

You can't see my pics?

I use imgur for hosting, I wonder if it's geofencing?
 
I tried, and it was quite good actually - at spot (eq'd rather flat). Vertical directivity is too high to be practical. It also made room decay too fast at high freq, because there was less reflections in the room. I didn't save measurements and now I have loaned my gear to a friend, so I can't test it right away again.

And my Neo8 and Neo3 are PDR models, open back. Still I get enough spl, but Neo8 is highpassed around 800Hz LR2.

thanks for your kind and diligent response, as always...

i have the neo8s and it somehow sounds better than neo3.

i think neo8s has a surround similar to cone drivers allowing for higher excursion...

is it possible then that neo3 sounds as it does because of overdamping? to me overdamped drivers sound a bit too dry and sterile. overdamped sound may well be more accurate but it somehow seems boring to me.

anyway; i will try to tweak out the vertical beaming of neo8s first and see if i can live with it as the sole tweeter.