B&G Neo8 in waveguide?

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Fjendbo

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B&G Neo8 in waveguide?
« on: 9 Nov 2018, 11:49 am »
Hi,

Just a quick question.

Have anyone tried a B&G Neo8 in a waveguide similar to the waveguide used in the Hawthorne Rainier?

Thank you.

Danny Richie

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Re: B&G Neo8 in waveguide?
« Reply #1 on: 9 Nov 2018, 04:35 pm »
Hi,

Just a quick question.

Have anyone tried a B&G Neo8 in a waveguide similar to the waveguide used in the Hawthorne Rainier?

Thank you.

We've developed and used the Neo 3 from BG and our Neo 3 in various wave guides. We even have a Neo 3 in an application that crosses it as low as 1,200Hz in a wave guide. But the Neo 8 is really too tall to use as a single tweeter as the vertical dispersion will be very limited due to the longer length of the driver.

Fjendbo

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Re: B&G Neo8 in waveguide?
« Reply #2 on: 12 Nov 2018, 08:09 am »
I know the vertical dispersion will be very limited at higher frequencies, but how/how much different will a Neo8 setup be compared to an ESS Heil, Beyma TPL150H, Hawthorne or any other rather large planar/ribbon in a waveguide?

Thank you.

Danny Richie

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Re: B&G Neo8 in waveguide?
« Reply #3 on: 12 Nov 2018, 08:46 pm »
I know the vertical dispersion will be very limited at higher frequencies, but how/how much different will a Neo8 setup be compared to an ESS Heil, Beyma TPL150H, Hawthorne or any other rather large planar/ribbon in a waveguide?

Thank you.

The advantage of the BG planar drivers is their ability to play down really low. And they still play to 20kHz. And they have a very smooth response.

The Beyma model will not play as low, but has really high sensitivity.

I have yet to find a ESS Heil design that I was happy with. I'm still looking.

Fjendbo

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Re: B&G Neo8 in waveguide?
« Reply #4 on: 15 Nov 2018, 11:53 am »
Alright, thank you.

About the narrow vertical dispersion. Besides that you have to sit in the narrow horizontal "sweet spot", how is it bad?

Danny Richie

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Re: B&G Neo8 in waveguide?
« Reply #5 on: 15 Nov 2018, 02:49 pm »
Alright, thank you.

About the narrow vertical dispersion. Besides that you have to sit in the narrow horizontal "sweet spot", how is it bad?

The narrow vertical dispersion can be solved by using the Neo 3. It is a great tweeter choice and can cross as low as 1,200 to 1,300Hz real easily in a wave guide. That will give you a more even in room response and not truncate the spacial cues. So they image better.

The Horizontal response with the Neo 8 is not too bad. The playing surface openings are only about 1 and 3/8" wide. If using the Neo 3 pdr version the playing surface area is reduced to 5/8" and it has really good off axis response. And it a wave guide it is very controlled.

Fjendbo

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Re: B&G Neo8 in waveguide?
« Reply #6 on: 26 Nov 2018, 12:29 pm »
The narrow vertical dispersion can be solved by using the Neo 3. It is a great tweeter choice and can cross as low as 1,200 to 1,300Hz real easily in a wave guide. That will give you a more even in room response and not truncate the spacial cues. So they image better.

The Horizontal response with the Neo 8 is not too bad. The playing surface openings are only about 1 and 3/8" wide. If using the Neo 3 pdr version the playing surface area is reduced to 5/8" and it has really good off axis response. And it a wave guide it is very controlled.

I do have a pair of Neo 3's intended for the upcoming (next year) project. Together with a 5,5" midrange and 2x15" woofers. I was just wondering if it would be possible to cross directly from 15" to a Neo 8 in waveguide.

But I will stick with the Neo 3 and midrange. The Neo 8 just crossed my mind :)

I know you made a post a while ago, where you did a rather thorough review of length of side wings, but I can't seem to find it. What do I search for?
Also, is there a golden ratio between long and short wing? Or do you simply keep the short wing short and vary the long wing to match the desired system response?

Thank you.

Danny Richie

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Re: B&G Neo8 in waveguide?
« Reply #7 on: 26 Nov 2018, 03:53 pm »
I do have a pair of Neo 3's intended for the upcoming (next year) project. Together with a 5,5" midrange and 2x15" woofers. I was just wondering if it would be possible to cross directly from 15" to a Neo 8 in waveguide.

That would be pretty high to be playing a driver as large as a 15" woofer. But it is possible to make with reach each other depending on the 15" driver.

Quote
But I will stick with the Neo 3 and midrange. The Neo 8 just crossed my mind :)

You could get it down to around 800Hz if you are willing to give up some sensitivity.

Quote
I know you made a post a while ago, where you did a rather thorough review of length of side wings, but I can't seem to find it. What do I search for?

https://www.audiocircle.com/index.php?topic=160242.0

Quote
Also, is there a golden ratio between long and short wing? Or do you simply keep the short wing short and vary the long wing to match the desired system response?

The side wing length of the short wing depends on how high the driver is playing. If you box in a wavelength that is short enough to propagate within boxed in space then it will try to set up a cavity resonance. Rule of thumb is that if it is playing above 200Hz then you need to stick with an L shape using a long and very short side wing design. If playing below 200Hz only then it can be a full U shape.

Side wing lengths vary with application. I recommend measuring the response and seeing exactly what it is doing to dial it in.

Thank you.

Fjendbo

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Re: B&G Neo8 in waveguide?
« Reply #8 on: 30 Nov 2018, 10:37 am »
That would be pretty high to be playing a driver as large as a 15" woofer. But it is possible to make with reach each other depending on the 15" driver.
Well, it's a rather heavy cone, strong'ish magnet, so probably not ideal. That combined with the U-frame speaks for a low crossover point. The U-frame will only be the depth of the driver, so not very deep.

You could get it down to around 800Hz if you are willing to give up some sensitivity.
I do not play very loud so it could be an option. Experiments will tell.

https://www.audiocircle.com/index.php?topic=160242.0
Thank you. I know there's quite a lot information about this design out there. It's just to find the right thread and post :)

The side wing length of the short wing depends on how high the driver is playing. If you box in a wavelength that is short enough to propagate within boxed in space then it will try to set up a cavity resonance. Rule of thumb is that if it is playing above 200Hz then you need to stick with an L shape using a long and very short side wing design. If playing below 200Hz only then it can be a full U shape.

Side wing lengths vary with application. I recommend measuring the response and seeing exactly what it is doing to dial it in.
Alright. Since it's for the mid/tweeter section, then I'll try L-shaped. I see you have added a small wing for the mid's in some of your designs and none for the tweeter. Why a small wing for the mid section?
Last question, long wing on the inside or outside? If a side wall is closer than optimal, my mind would say long wing on the inside, so you would benefit from the off axis cancellation towards the side wall. Correct?

Thanks

Danny Richie

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    • http://www.gr-research.com
Re: B&G Neo8 in waveguide?
« Reply #9 on: 30 Nov 2018, 06:14 pm »
Quote
Alright. Since it's for the mid/tweeter section, then I'll try L-shaped. I see you have added a small wing for the mid's in some of your designs and none for the tweeter. Why a small wing for the mid section?

The small wing is essential for controlling the low end roll off.

See this link and notice what happens tot he response as the short wing length changes.

https://www.audiocircle.com/index.php?topic=154485.msg1651847#msg1651847

Last question, long wing on the inside or outside? If a side wall is closer than optimal, my mind would say long wing on the inside, so you would benefit from the off axis cancellation towards the side wall. Correct?

With the long wing to the inside it minimizes the reflection from the front wall between the speakers.

With the short wing to the outside it opens up the sound stage more.