Vertical mount of Econowave horn

[Spatz]

Hello everyone,

I'm interested in using the Econowave horn (Pyle PH-612 and Selenium D220Ti) in a slim column speaker in a D'Appolito-Configuration with two Peerless SDS 6.5 woofers. Should give a decent efficiency of about 90-93 dB (depends on baffle step compensation). Crossover should be somewhere between 1k5 and 2k.

I want to mount the horn vertically and mount the woofers directly on the baffle (no flush mounting) and they shall cover the ends of the horn a little bit.



But: Is the vertical mounting of the PH-612 reasonable. I would expect an smaller sweet spot due to the significantly narrower dispersion of the tweeter, but this could be an advantage in acoustically bad rooms. I'm also expecting the problems with the not-perfect D'Appo to be less as the directivity of the horn will reduce the side lobes. This should result in a better controlled vertical dispersion.

Has anyone made experiences with vertically mounting horns or the effects of tweeter directivity on not-perfect D'Appos?

Bye,

Spatz

[pos]

Yep the distance between the woofers will likely be a problem. You would certainly be better with someting more like a sam1HF/2LF:
sam1hf / sam2lf

regarding putting the horn vertically, it is not a bad idea but you will not get a constant directivity:
the horn will loose pattern control under 2khz, so you will be in a so called "pattern flip" situation under that (very large dispersion).

So lets say you cut it around 800Hz (and even that would be too high if you want a d'appolito), the dispersion will be very high, and will gently narrow to the nominal 50° at around 2khz, be almost constant, and then gently narrow again starting around 10khz (due to the size of the driver).

The horizontal dispersion will be more like one of a direct radiator 2way, but the power response will be similar to a constant directivity speaker (because it is almost constant directivity in the 1000-10000 range in the vertical plan). Interesting mix!

that is similar to the JBL array 1400 (but the have a tweeter to enlarge the dispersion up high), and these speakers are made to be used with a center speaker in a HC situation. But then again, many like them in a stereo setup, even with the narrow horizontal dispersion.

[Spatz]

I know that the vertical dispersion with this position of the woofers won't be perfect at all. But: There is almost no real D'Appolito and yet this concept is very famous. Plus I want to use the additional vertical directivity to reduce reflections with ceiling and floor.

The vertical (when mounted as usual) loss in pattern control is IMHO no problem, as a crossover point where the woofers are not yet beaming horizontally is possible. The additional control in the vertical plane should be suitable to the woofers' positions.

What do you think?

[pos]

if you want to reduce ceiling and floor reflexion then this design is counter productive: it will give you an almost constant 90° directivity in the 1k-10k range.

[Spatz]

Reducing reflections wouldn't be the main aim, just a bonus. A conventional tweeter with usual dispersion would be even worse than 90°...

[Robh3606]

that is similar to the JBL array 1400 (but the have a tweeter to enlarge the dispersion up high), and these speakers are made to be used with a center speaker in a HC situation. But then again, many like them in a stereo setup, even with the narrow horizontal dispersion.

They are not as narrow as you think. The large horns are 80x80 and the UHF is 30x60. The UHF horn is what defines the placement for this system. The UHF horn does help maintaing dispersion in the upper octave at the expense of a narrow verticle axis.

Rob

[pos]

Rob, as you know the 1400 array horn is directly derived from the H4338, which is a 90x50 horn. I have seen measurement of the 1400 directivity on a french forum (will try to find them...), and it was what was get... above 1500Hz. Under that the horn was loosing pattern control in its smaller dimension, which is normal. I guess the 80° figure is an average over the entier range of the horn.
I have measured my H9800 clones (quite similar to the H4338) and the same phenomenon can be observed.
In my view the 1400 array in an interesting speaker in that you get the directivity characteristic of a cone speaker, but the power response of a constant directivity horn system.

[pos]

here it is:
L'enceinte JBL Array 1400

[ScottG]

JBL Synthesis 1400 Array BG loudspeaker Measurements | Stereophile.com

[Patrick Bateman]

Originally Posted by Spatz

Hello everyone,

I'm interested in using the Econowave horn (Pyle PH-612 and Selenium D220Ti) in a slim column speaker in a D'Appolito-Configuration with two Peerless SDS 6.5 woofers. Should give a decent efficiency of about 90-93 dB (depends on baffle step compensation). Crossover should be somewhere between 1k5 and 2k.

I want to mount the horn vertically and mount the woofers directly on the baffle (no flush mounting) and they shall cover the ends of the horn a little bit.



But: Is the vertical mounting of the PH-612 reasonable. I would expect an smaller sweet spot due to the significantly narrower dispersion of the tweeter, but this could be an advantage in acoustically bad rooms. I'm also expecting the problems with the not-perfect D'Appo to be less as the directivity of the horn will reduce the side lobes. This should result in a better controlled vertical dispersion.

Has anyone made experiences with vertically mounting horns or the effects of tweeter directivity on not-perfect D'Appos?

Bye,

Spatz

A lot of speakers with waveguides use a crossover point designed to match the directivity of the low frequency driver and waveguide. For instance, the Gedlee Summas have a crossover around 900hz, because that's where the directivity of the waveguide collapses. With a 6.5" waveguide, you'd be looking at a crossover point of 2076hz.

This is "do-able" with your woofer choice, because the Peerless should be able to reach up to 2khz, and the waveguide can certainly play that low.

The tricky part is that the dual woofers creates a very strong forward lobe, due to their spacing.

But that doesn't mean your design won't work.

The easiest solution is to do this as a 2.5 way design. Basically stagger the crossover points, so that only one woofer is playing from 1khz to 2khz. That will reduce the forward lobe that's created by the array of dual woofers.


Another option is to flip the speaker ninety degrees. JBL did this with their "Control Now" array.

I've measured it, and the results were amazing. It basically works like a very efficient coaxial, and it's a helluva design.

HTH.