Aino gradient - a collaborative speaker project

[burgunder]

Originally Posted by Juhazi

lolo, since you are a Shigeru Ban fan, I think we shoud visit also this church in Jyväskylä - Kuokkalan kirkko

Lovely church I would love to go there on a sunday for a service.

[Juhazi]

Edge is a wonderful neat little program by a marvellous programmer and researcher PhD Svante Granqvist

I simulated the response of my mid driver Beyma 12MwNd

Seems like it is wise to make an ellipsoid little baffle for it.

I have placed an order for miniDSP 4x10, U-MIK and a software plugin

[Juhazi]

edit was closed...

Seems like that with an ellipsoid baffle the
- 6dB is at 200Hz
- baffle diffractions start at 3500Hz

The simulation should be analyzed with the spl curve of Beyma in mind (this was measured in an infinite baffle)

Suits You, Sir!

[Rudolf]

Originally Posted by Juhazi

Edge is a wonderful neat little program by a marvellous programmer and researcher PhD Svante Granqvist

I simulated the response of my mid driver Beyma 12MwNd

Edge is fine when you know what is important.
"3" for the Speaker source density is way too few. Make it "20". The cone (or dome) should be filled with small squares. With "3" you only show what the surround contributes to SPL.

And DON'T put any baffle around the driver!!! Leo Kärkkäinen of Nokia Research Center can tell you why. Nothing but a magnet mount. It's already too large for the Xover frequency.

Rudolf

[Juhazi]

Rudolf, please - don't be so mysterious!

We Finns are a naion of only 6 million people, but I don't happen to know Mr. Kärkkäinen... Tell us a bit more about this, a link maybe? Do you mean a 12" is too big for M/T xo? But I want to use the high directivity area!

M/T xo is determined mainly by directivity of drivers in mind. The second factor is distortion, but I don't have that info about Fountek. The response is even enough to not be an issue here.

I made new plot swith 21 speaker sources. The response looks similar but cleaner. The -3dB at low end is around 230Hz with the baffle and 250Hz without - not a big difference.

[Juhazi]

The graphs are missing - a new try.

I found a distortion plot of Neo3.5 too Fountek NeoCd3.5H Horn Tweeter

Seems like I need a sharp M/T xo LR4@2500Hz

[Juhazi]

Dr. Granqvist has also a smaal polarity simulator, XDir

XO@2500Hz means trouble with vertical polar response and comb filtering near xo frequency

Coaxial arrangement has no lobing issues around xo. The Neo3.5 is too big to be positioned coaxial with Beyma 12" (acts as a diffusor)

miniDSP gives a possibility to do a 48dB/oct xo (LR8) - is this the least bad solution here?

[Rudolf]

Originally Posted by Juhazi

... but I don't happen to know Mr. Kärkkäinen... Tell us a bit more about this, a link maybe?

Download http://www.mellowacoustics.com/artic...lar_baffle.pdf
Look at Fig. 5-7. The relation between "b" and "a" is explained in Fig.1
Try to understand that there is a relationship between radiation pattern and baffle size.
If you want to learn more about that, go to the download section of my website dipolplus.de and download the second file "How open baffles work ..."

Rudolf

[Juhazi]

Okei, Rudolf, Offene Schallwand (OB)

The Beyma 12" works as a dipole up to 1000Hz and then dips at 1500Hz on-axis, when it loses it's directiviy and dipole function?

The Gradient 1.x has M/T xo at 1500Hz - a little too high?

I guess this means that I need a 4-way system for transitioning from the 12" to tweeter's monopole area. Sounds like NaO Note and LX521...

Those guys use a 10cm (4") upper mid drivers. But because my lower mid is a bigger one, perhaps a 5" for me -the directivity would suit better.

SEAS CA15RLY

Peerless HDS135 a special offer this week!

SB 15MFC

[Juhazi]

Here are "no baffle" Edge simulations of SB12 and SB15. They could do the job up to 3000Hz in dipole function

And of course there is the SEAS SL mid.