I was wondering how hard it would be to build a horn that covered the range from 500hz all the way up to 20khz with a reasonably smooth response. I don't have any definite plans but I was wondering if it was possible with standard compression drivers and larger than average horns. It would be nice to achieve such a thing because most of the critical range would be covered by a single high efficiency low distortion source. The distortion might be on the order of ESLs with the advantage of higher efficiency and an easier load for amplifers. It would also invite experimentation with lower powered amps.
Hi bigwill,
Lots of horns have no trouble with 500, it's the driver that's tough to find. I don't know of any that will give you 500 - 20K. You may have to think about a super tweeter. Besides you're talking about something they used to do in the 50's and 60's. The old Altec stuff was XO'd at 500 but the top end was limited to around 15K, which IMHO is enough anyway. I don't know anyone that can hear 20K.
There were no high powered amps back then so they had to use horns. Once the bigger amps came out, horns kind of went by the wayside in favour of smaller cabinets.
Lots of horns have no trouble with 500, it's the driver that's tough to find. I don't know of any that will give you 500 - 20K. You may have to think about a super tweeter. Besides you're talking about something they used to do in the 50's and 60's. The old Altec stuff was XO'd at 500 but the top end was limited to around 15K, which IMHO is enough anyway. I don't know anyone that can hear 20K.
There were no high powered amps back then so they had to use horns. Once the bigger amps came out, horns kind of went by the wayside in favour of smaller cabinets.
).
I'm not an expert, but you might have to look at 'unconventional' approaches to hit the goals. Specifically either a Unity arrangement, or else something like the BMS coax drivers (4592).
I have a pair of Unities (U15's), and they do 300 to "20k" (probably only 18.5k) from the horn. The mids handle the first ~2 octaves of that. This pretty much requires buying a commercial speaker, though - none of the DIY attempts (including mine) seem to have ever made it to production quality.
The BMS should be OK down to 500 if it's for home use, although I'm not sure what horn would support that. 18Sound has one that looks good, but I haven't seen any concrete feedback from someone that has tried the combo.
I have a pair of Unities (U15's), and they do 300 to "20k" (probably only 18.5k) from the horn. The mids handle the first ~2 octaves of that. This pretty much requires buying a commercial speaker, though - none of the DIY attempts (including mine) seem to have ever made it to production quality.
The BMS should be OK down to 500 if it's for home use, although I'm not sure what horn would support that. 18Sound has one that looks good, but I haven't seen any concrete feedback from someone that has tried the combo.
A great 2 inch driver with a large flare can cover the 500 - 7k region smoothly and with a very flat response. This is the basis of most cinema systems and then the response then drops. JBL designed a crossover that reduces this band so that the higher frequencies are boosted, extended the top end results. To me it sounds very good.
The ideal way in my opinion is to use a super tweeter for the higher frequencies above 7k .
I have used many 2 inch compression horns over the years JBL 2446, EV Dh1, P.Audio D99 and BM750, Altec 288 (1.4 inch). I find that the results are equally impressive.
A quality 1" driver such as P. Audio PA D45 would be smooth up to 10 k and could be crossed over at 500 although I would probably start at 800hz.
I personally like the sound of quality cinema speakers and find the drop of of the extreme top end does not worry me. eq could extend the response to 16k. Perhaps try and add a super tweeter if neccesary.
For a great sounding response from 500hz the biggest and deepest flare you can get will give the most impressive results.
There are good reasons not to xo in the middle of our hearings most sensitive region, 500hz crossovers do have an advantage in this aspect.
The ideal way in my opinion is to use a super tweeter for the higher frequencies above 7k .
I have used many 2 inch compression horns over the years JBL 2446, EV Dh1, P.Audio D99 and BM750, Altec 288 (1.4 inch). I find that the results are equally impressive.
A quality 1" driver such as P. Audio PA D45 would be smooth up to 10 k and could be crossed over at 500 although I would probably start at 800hz.
I personally like the sound of quality cinema speakers and find the drop of of the extreme top end does not worry me. eq could extend the response to 16k. Perhaps try and add a super tweeter if neccesary.
For a great sounding response from 500hz the biggest and deepest flare you can get will give the most impressive results.
There are good reasons not to xo in the middle of our hearings most sensitive region, 500hz crossovers do have an advantage in this aspect.
Attachments
I agree with Cameron and Cal. It can be done, has been done- and done well. The driver is the trickey part.
I also don't care much that these horns tend to roll off at 15-16K. That's enough for me. Even in my youth I didn't like super tweeters. Even if they sound nice, they don't sound natural. Always too "Hi-Fi" for my tastes.
Let us know what you find. You could always start out with the classic Altec 511 horn and a nice dirver. Once you have those, see if you can build a better horn.
I also don't care much that these horns tend to roll off at 15-16K. That's enough for me. Even in my youth I didn't like super tweeters. Even if they sound nice, they don't sound natural. Always too "Hi-Fi" for my tastes.
Let us know what you find. You could always start out with the classic Altec 511 horn and a nice dirver. Once you have those, see if you can build a better horn.
I have seen similar limitations quoted elsewhere.planet10 said:
Are they true?
If a treble horn is short and has a wide taper and a mid horn has a long and narrow taper, then can a single horn work for all frequencies and still load the driver as if it were a horn for that whole range of frequencies?
I think a horn only works well and loads properly over a narrow octave range, whether this is 2 or 2.5 or 3octaves I cannot judge, but 5.5octaves seems like impossible.
Bert Doppenberg is crossing the BMS4592nd at 220hz in his Orphean horns, covering more than 6 octaves. 220hz-22khz 114db/W..... To good to be true?
http://www.bd-design.nl/
http://www.bd-design.nl/
AndrewT said:
Well, I used the term "High Quality" rather subjectively. I've used JBL's and TAD's. I wold consider both high quality with the TAD's coming out on top. In general, you'll get what you pay for regarding horn drivers so construction quality is usually a good gauge of sound quality when it comes to horn drivers.
...and yes there are other factors that need to be addressed, general driver quality being one and type of horn doing the loading another.
With high BW you will also have to pay attention to the power handling capability of the horn. When you drive the berylium diaphragm for a TAD too hard it breaks at the surround. You won't want to do this too many time (like I did). Also the horn used is a big factor. Horns big enough for proper loading at the bottom of the range will tend toward "beaming" at the top.
There are certainly more technical details to consider but not being a speaker designer, I wouldn't be able to address them with any accuracy here.
Hi
Some years ago I installed some horn speaker systems commercially in venues around London and also tried some at home.
The best arrangement I came up with was with a treble horn, a mid horn and a 12/15" reflex loaded paper cone base driver. The treble horn covered the frequencies from 5kh upwards ( from memory - if its important I can check as I still have details on file ) and was a short wide taper cone. The mid range was a flat and long taper horn. The treble unit was approx 2" diameter. The mid unit approx 6" x 2" rectangle. I tried various materials to make the horns but settled upon polypropylene as the best sounding.
I liked them in the venues they were installed in and tried them at home. I was not as impressed at home and changed to kef 107's.
At home I could not get the sound that I was looking for. It was never a relaxing sound. I am not sure but I think that may be a consequence of the horn loading or possibly the materials I used.
I hope this helps. I still think horns can work but from experience I think that the frequency range of each horn may have to be limited to a few octaves to retain the sound quality. This can lead you into complex crossover arrangements which themselves can degrade the sound.
Don
Some years ago I installed some horn speaker systems commercially in venues around London and also tried some at home.
The best arrangement I came up with was with a treble horn, a mid horn and a 12/15" reflex loaded paper cone base driver. The treble horn covered the frequencies from 5kh upwards ( from memory - if its important I can check as I still have details on file ) and was a short wide taper cone. The mid range was a flat and long taper horn. The treble unit was approx 2" diameter. The mid unit approx 6" x 2" rectangle. I tried various materials to make the horns but settled upon polypropylene as the best sounding.
I liked them in the venues they were installed in and tried them at home. I was not as impressed at home and changed to kef 107's.
At home I could not get the sound that I was looking for. It was never a relaxing sound. I am not sure but I think that may be a consequence of the horn loading or possibly the materials I used.
I hope this helps. I still think horns can work but from experience I think that the frequency range of each horn may have to be limited to a few octaves to retain the sound quality. This can lead you into complex crossover arrangements which themselves can degrade the sound.
Don
roddyama said:
I need to qualify what I said above.
I'm currently running a bit over 3 octaves (1200Hz-12,0000Hz)with my TAD's 4001's and McCaully horns. This is more because of the limitation imposed on my setup by the drivers above and below the TAD's than on the TAD's themselves.
The IM distortion can come from other design difficiencies and physical limitations. BW is only one factor. One of the trade-off to lower the IM with a given BW is diaphragm (or cone) excursion. Lower the excursion and you can (maybe) increase the BW over which the driver has to work with a given level of IM. Problem is, the lower excursion means lower output unless you increase the radiating area of the cone driver or the efficiency of the horn design (back to the loading issue again).
In '80 there was an Audio Magazine article that delt with this issue of radiating area vs BW. They wanted to make a full range (20-20k) speaker with less the 1% IM distortion. They did it by covering a 6ft tall 3ft diameter cylindrical box with multitudes of the same 6" speaker. They also gave a formula for relating power output (~SPL integrated over space), radiating area, cone excursion, and BW.
Hi Roddy,
sorry I misunderstood what you were referring to when you said
But just in case you have the information, can I ask again?
What makes a high quality horn? i.e. the curvy bit in front of the driver.
sorry I misunderstood what you were referring to when you said
I now see from your reply you were mostly referring to the driver and it's limitations rather than the horn.
But just in case you have the information, can I ask again?
What makes a high quality horn? i.e. the curvy bit in front of the driver.
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