I've also considered building a bi-radial horn myself from wood after reading an article found here http://www.woodhorn.com/horn.htm that describes how. When making the horn, how do I construct it fr say 90 x 40 degree dispersion? Is it that the angles have to be 90 and 40 degrees, or is there more to it than that?

Are radial and bi-radial horns the same thing?

Thanks in advance for any type of feedback.... even if you dont know what your talking about anything would be cool :)

Bi-Radial® is a registered trademark of JBL and it is similar, but has a more complex flare shape. The popular 2370 acts very much like a radial horn, having greater horizontal dispersion and narrowing directivity in the vertical plane. Below 1.6kHz, its vertical directivity begins to widen rapidly because of mouth diffraction, and JBL recommends vertical arrays to lower the frequency where vertical dispersion control is maintained. This is true, of course, for all mixed-dispersion horn shapes.

For more information, see JBL's 2370 product literature.

As for the crossover, both JBL's Bi-Radial® and their older radial horns work very well with top octave compensation such as is used in the π® Crossover, as do most other CD horns. This crossover has the additional benefit of damping resonance to prevent peaking near the crossover frequency.

I think it was you before in another post mentioned something that 2" compression drivers should be used to do up to 20KHz. Is this true? I would like to go for a 2", but if 1" is better....

Oh yea, would you reccomend ANY radial horn? (assuming its the right size) or is JBL for example a lot better than others? (I'm thinking of some P Audio horns, but they dont state weather they are radial, conical etc. How can you tell if a horn is a radial one?).

Have you used or heard wood horns before? If so, what do ya think of them? Do they sound "nicer", or in particular, have less of a ringing, horn sound to them?

If I do decide to build a horn myself, where can I buy the flange that the horn mounts to? (one that takes bolts, not screw on driver). Cant find them anywhere!

Thanks again for any help! Alex :)

Don't rotate the horns because that would give tall vertical coverage and narrow horizontal coverage above through most of the passband, above about 2kHz. Below that, the pattern changes because of mouth diffraction. Essentially what is happening is that the horn's mouth forms a diffraction slot, so pattern widens at low frequencies. Since the vertical dimension is short, directivity control is lost along this axis first. Below about 1kHz, vertical dispersion of a single horn is actually wider than the horizontal pattern.

On radial horns where the horizontal and vertical dispersion pattern is the same (like 60 x 60 degrees etc) are these suitable for the compensation circuit of yours? As radial horns dont add any garbage to the response (or something!) so your circuit will work good with them, I am wondering if a horn like this will suit it as well (its still radial). That way I wouldn't need to stack them, or spend money on extra horns and a dual throat adapter. But I've also seen that 90 x 40 degree are the best dispersion pattern.

Just another note on the 2" compression driver, the response curve shows the high end response to be similar to comparable 1" compression drivers I've seen, with the compensation circuit making even better (like duh!). This is all on paper though, I dont have any experience with sorts of drivers, I actually want them to cover 500Hz to 20KHz (the JBL 2370 is 630Hz lowest I think which is close enough :) I've found graphs of 1" compression drivers that shows it going flat down to 500Hz, but the manufacture still states a resopnse from like 1.5K to 20KHz! Why's this? I'm thinking it might be best to go with a 2" driver, but I'd like to hear what you have to say on this! For the graph example this page here http://www.paudio-europe.com/products/db_product.htm?v_tipo=2&v_tipo_desc=DRIVERS&v_num_series=6&v_des_series=BM-SERIES&v_id_art=42 As you can see the specs say 1.5KHz-18KHz but the graph shows it going to 500Hz!

Thanks! Adrian

Also, don't run the driver too low because even though it may be capable of producing sound, diaphragm excursion goes up as frequency goes down, even if properly horn loaded. Modern compression drivers aren't designed to be used down deep in the midrange band.

I'm thinking that the 1" compression driver may indeed be the way to go so I dont loose out on HF performance. But the reason I wanted the horn to go to ~500Hz and up is that the vocals are supposed to sound a lot better when coming from the one speaker. I know there are vocals below 500Hz but this is meant to be the best way to do reproduce them. Also, I didn't want half the vocals coming from a direct radiator (like a 12" or 15" to cover down to 70Hz or so with the horn) and the other coming from a wide dispersion horn, might make it sound a bit funny off-axis? Have you got any comments on this matter?

Cheers! Adrian