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In the Forum: Horn-Loaded Speakers
In the Thread: Vertical Axis Midbass Horn

Post Subject: Industrial DesignPosted by skushino on: 8/9/2012

Midbass from horn in small room can be hugely benefited if it bounces but to make the assembly of horns visually pleasant, time aligned and functional at the same time is a big question. I do like the notion of Midbass fires to the floor but did you see any attempt to do it esthetically pleasing?

"Visually pleasant" - Yes, this is a challenge... My original idea was orienting the horns back to back, or driver to driver, with one pointed up and the other down. Sort of an hour glass shape. But the ceiling is only 8 ft high, and the max path length in hour glass configuration is around 3 ft per horn, less than 80 hz fc, hardly worth the effort. In order to make a longer horn, the throats will need to overlap, running parallel to each other but in opposite directions. This is a mess of an industrial design and I don't have an answer yet.

"Time aligned" - see below. If the vertical bass horns are located ahead of the mains by a distance equal to the path length, I think the problem is solved. Am I understanding correctly?

"Functional" - This idea is the result of answering the question of how to fit a 4' - 5' horn in my room. The only way I know to do it is vertically. There are other benefits like coupling with boundaries, and the opportunity to have both floor and ceiling coupling. The idea of having bass extending the entire height of my room is very cool.

Yes, the time alignment will include the horn path length, the distance from the boundaries sand so on.

If I understand correctly, the bass horns need to be in front of the satellite mains by a distance equal to the length of the horn. This seems logical to me. So looking at Tuneaudio Anima, the design could be improved by separating the bass horn from the MF and HF drivers, and moving the bass horn forward around 5 ft, correct? I want to make sure I understand this point correctly.

In case of boundary use you will be at much less critical time alignment demands and you will have a lot of diffusion of sound and your midbass will not shape an impulse too well. So, I would take the time alignment in consideration but would not go too anal retentive to it as I insist to do in case of direct radiator horns. At 55-200Hz and with indirect radiation you will have a LOT of room gain going on. You might pay a toll and have some kind of funny imaging but you might gain in many other aspects.

Well this is the part that's most interesting. I expect it will take a lot of experiments to find the balance between boundary gain, imaging, and flat bass response. My lower mid horns play down to ~ 160 hz. So I could move the x-over lower than 200, in theory. Would need to validate by listening first.

It is very hard to estimate what will happen with imaging. If you wish you can flip you current midbass horns vertically and to see what happen. Be advised that you would need a good month to work on your playback and to modify the associated channels in order to make your playback to sound properly with flipped midbass. Will you go for that investment of time and efforts?

This is a great idea! But rather than flipping my midbass horns up, I will point them down, with an appropriate gap separating the mouth and floor. This would simulate down firing and floor coupling together. I would expect more gain resulting from coupling to the floor boundary, and who knows what effect on imaging. Thanks for the idea.

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