Again another age old question, but the answer seems to be illuding me. Partly because manufactures seem to tell very little about the actual characteritics of the horn other than dispersion.
This brings me to my question, how do you go about choosing the correct horn with such limited information?
I am trying to find a nice horn flare for a 2" driver that will play down to about 900hz, have a good 60x40 dispersion, but the factor that is most confusing me, is that I would like something that give me a medium throw.
There are so many shapes and sizes that apear to have the same charactersitics.
Thanks for the help!
This brings me to my question, how do you go about choosing the correct horn with such limited information?
I am trying to find a nice horn flare for a 2" driver that will play down to about 900hz, have a good 60x40 dispersion, but the factor that is most confusing me, is that I would like something that give me a medium throw.
There are so many shapes and sizes that apear to have the same charactersitics.
Thanks for the help!
Jer said:
Not an expert here, but I'll try to point you in the right direction _grin_
Throw is determined by the length (depth) of the horn compared to the width of the horn. Throw and dispersion are relative to each other if all other things are equal - Long throw will be narrow dispersion and short throw will be wide dispersion -
You select a horn by dispersion, shape, spl and frequency range, type and material
Rectangular does sound different than round - but round is generally harder to incorporate into a design - so as usual, always the trade- offs - dispersion you want to match to other drivers and crossover point - spl match to other drivers and your requirements, frequency range -
last but not least here, you should pick a horn that you can incorporate well into an overall coherent design - Paying particular attention to crossover points, time alignment, etc. and this is related to your intended purpose -
Generally, we have a tendency to think that everyone intends to use them the same way - not so - a wide variety of uses, and purposes - so there is no _right way_
What is your usage here? Pro? Residential??
probably the best source to check out for 2" compression driven horns is
http://www.ddshorns.com/products.htm
They seem to be well thought of and make an excellent product.
Give them a call, they are nice to talk to and informative - and I bet will be up front if they're product isn't suitable for what you're doing.
Regards
Ken L
have a read at audioasylum
and the Pi forum
Hf horns are fiddly and require alot of knowledge to match comp driver to horn flare.
even a DIY midrange can be constructed not so difficultily...
Wayne at pi speakers will inform you .
http://www.audioasylum.com/forums/pi/bbs.html
and the Pi forum
Hf horns are fiddly and require alot of knowledge to match comp driver to horn flare.
even a DIY midrange can be constructed not so difficultily...
Wayne at pi speakers will inform you .
http://www.audioasylum.com/forums/pi/bbs.html
mikee12345 said:
I'm not sure I agree. I've read a lot of his posts on AA over the years and there have been excellent and often very contradictory points made by other people of experience and understanding, Bruce Edgar and Tom Danley to name two. Personally I would never use a 2370 domestically and every Emininence compression driver I've ever heard sounded pretty dire.
Ken L said:
Hi Ken,
It depends...
Eminence are designing for two things: high power handling and low cost. A third order high pass protects the tweeter, that's also why they put the fuse in there. A second order low pass keeps parts count down and therefore costs down as well.
If sound quality is more important, though, you can do better--particularly for a horn tweeter/non-horn woofer combo. One of the difficulties of mating a horn tweeter to a woofer is that if you mount both on the same baffle, the acoustic center of the woofer will be in front of the tweeter. You also have to consider the phase shift that the crossover adds to the system. With a 3rd order high pass/2nd order low pass, the woofer is shifted foward of the tweeter, which exacerbates the physical offset problem and you can get some serious comb filter issues.
A much more appropriate crossover for a horn system would be 2nd order high pass and a 3rd order low pass. In this case the phase shift of the crossover offsets the phase shift of the physical offset and if everything is done properly, you can actually get a better phase response than if the acoustical centers were aligned--one of the most widely held misconceptions in this business is that "time alignment" means aligning the acoustical centers of the drivers physically. Time alignment actually involves purposefully offsetting your drivers so that the physical offset cancels the crossover phase shift.
Another problem with odd order high pass filters in general is that the look-back impedance of an odd order filter is very high out of band, which means you get basically no electrical damping below crossover. As a result, the SPL from the woofer is going to be swinging that poor little tweeter all over the place. It would be hard to understate the importance of low look-back impedance on your high-pass filters--doesn't hurt on your low-pass filters either. This is one of the niceties of active filters, you get maximum electrical damping in band as well as out of band.
John
hancock said:
Thanks for the input, John.
I had a project going that I had a recent thread about in which I was seriously considering a DDS Eng 90-1 waveguide with the Azurahorns, but abandoned it due to the acoustic center/alignment issues and over point/source being spread so far apart due to the large round Azuras. I have the waveguides and played around it, but just didn't see how to integrate everything in a top-notch way.
Plus, the amp I have most of the parts for is boat anchor big and makes active impractiical.
But, I still like knowing more about it.
Regards
Ken L
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