Aino gradient - a collaborative speaker project

[Juhazi]

I have 4 of these chairs by Alvar Aalto, the seats are bad but I think that I can use the back legs as tweeter stands. A pair of legs and tweeters between them? Or the back rests? Hmm...

[Juhazi]

Can someone show here, what kind of low end response can be expected from a 12'" driver without a baffle?

The bass sound is not localized <200Hz in normal size rooms. I am aiming to set W/M xo at 200-250Hz with something like LR2 acoustic slopes. It would be nice if the natural roll-off would help.

The M/T xo must be set so that directivity match is optimal. With 12" and Neo3,5 that means something between 1500 and 2500Hz. The other tweeter shoots upwars, making a source for roof reflections and thus "spaciousness" to the sound.

Here are directivity graphs of a 12" (SLS12) and Neo3,5

[Elias]

Originally Posted by Juhazi

Can someone show here, what kind of low end response can be expected from a 12'" driver without a baffle?

Do you have earlier experience with dipoles ?

Check Linkwitz pages, there are quite a bit of theory. Very usefull.

Originally Posted by Juhazi

The bass sound is not localized <200Hz in normal size rooms.

This can be argued, but I don't want to distract you from your plans

I have no problem locating phantom images while using my dipoles below 200 Hz in my 25m2 room.


- Elias

[Juhazi]

Suggested reading about speaker radiation and matching, especially dipoles: (yes I am familiar to these)

J Kreskowsky Power matching

S Linkwitz Frontiers

minidsp is a nice tool to test different slopes of xo. If the mid's HP is 200Hz, depending on the slope there is quite lot of output even at 150Hz.

I support John K about using monopole low bass. The transition from 2Pi to 4Pi space (150 - 600Hz) is the difficult and critical issue. Gradient style of using a tilted large dipole mid is the "clou" I am copying here. We are mixing the output from two drivers with different radiation - and like "cuisine" this is art.

This is the first speaker project that I design. I have been interested in audio and doing diy-kits for more than 40 years. I've been reading web pages about audio for 6 years now and I've been collecting info and ideas for this. My progress with this project might look fast, but all this has been bubbling under for yars.

[lolo]

Originally Posted by Juhazi

but all this has been bubbling under for yars.

let it go my friend!

[Juhazi]

^Thank you Iolo!

Just between us two, one source fo inspiration to Aino is this immortal classic! And I love KISS principle!


Iolo, if you ever come to Jyväskylä, I'll first take you to Aalto Museo and then to my sauna!

[lolo]

Originally Posted by Juhazi;3400038

Iolo, if you ever come to Jyväskylä, I'll first take you to [URL="http://www.alvaraalto.fi/aaltomuseum.htm"

Aalto Museo[/URL] and then to my sauna!

don't forget to stock some Koskenkorva! I like the green apple one!

[Juhazi]

John K says like this
"In view of the somewhat bizarre nature of these solutions to the power
response problem it is reasonable to look for a more appealing solution
where the axis of the woofer system is aligned with the axis of the
speaker. For this to be the case we must develop a woofer system with
an on axis, free space DF = 1.5. This can be accomplished by combining a
dipole woofer with a monopole. If we start with a dipole woofer and being to
sum its response to that of a monopole we find a gradual deformation of
the dipole radiation pattern into a cardioid at the point where the isolated
dipole and monopole on axis sound pressures are equal. "

I agree - and this is what I am doing here.

John himself uses dipole woofers too in many designs, but with help of dsp. Then the lowest octave is dealt with two woofers to get enough spl with decent distortion.

[Juhazi]

The amplifier could be made of B&O ICEpower modules ICEpower ? Class D audio amplifiers ? Solutions

Here are views of the room where Aino gradients will be placed (not all of the 1st floor shown). The shape is basically rectangular but has many openings. The roof is tilted, higher towards the midline of the house. The dimensions of the rectangular area are w 5,8m d 3,6m (21m2) the height is 2,6 to 3,8m. The floor is concrete with wood laminate. Walls are plasterboard with insulation. Outer walls are 40cm and inside walls 12cm thick. The ceiling is wood.

RT and EDT are in the graph.

[Juhazi]

Some of you might wonder what the *ell have cars to do with speakers.

Answer - rotate the CV2 van 90¤ to the left!


Did you ever think that VW Polo is musical - see this (we have a Polo)
Bohemian Rhapsody by Porkka Playboys - YouTube