I've seen some conflicting advice in this.
It seems the close to ideal solution to a crossover-less design. One small driver (2 - 3 inch) to take care of getting good spread of the higher frequencies and also more cone stiffness for those. And a larger driver for more pistonic area for the lower octaves. Each driver filling in where the other lacks.
I really can't see the big difference between having a fullranger with a caped tweeter or indeed the difference between having two drivers of the same kind, which I've seen several people doing.
Electrically I can't see how the above mentioned solutions would differ much from two different FRs.
Sonically the matter is pretty trivial. One solution would be to just point the drivers in different directions to avoid too much interference.
So why exactly is this a bad idea?
It seems the close to ideal solution to a crossover-less design. One small driver (2 - 3 inch) to take care of getting good spread of the higher frequencies and also more cone stiffness for those. And a larger driver for more pistonic area for the lower octaves. Each driver filling in where the other lacks.
I really can't see the big difference between having a fullranger with a caped tweeter or indeed the difference between having two drivers of the same kind, which I've seen several people doing.
Electrically I can't see how the above mentioned solutions would differ much from two different FRs.
Sonically the matter is pretty trivial. One solution would be to just point the drivers in different directions to avoid too much interference.
So why exactly is this a bad idea?
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If you are going to use two drivers, you might as well use a tweeter with a capacitor and make it a true two way.
Whatever combination of drivers you choose to use, if you overlap frequencies, you overlap impedance too. Better to use a crossover capacitor.
I really have no idea how overlapping drivers, overlapping frequencies would turn out, but I think it would really make a mess of the frequency response.
In an MTM or a line array, you use identical drivers not dissimilar drivers.
Whatever combination of drivers you choose to use, if you overlap frequencies, you overlap impedance too. Better to use a crossover capacitor.
I really have no idea how overlapping drivers, overlapping frequencies would turn out, but I think it would really make a mess of the frequency response.
In an MTM or a line array, you use identical drivers not dissimilar drivers.
Why? That kind of goes against the whole idea of fullrange, even though you can get good results. Theoretically it would be nicer to just combine the advantages of a large and small driver.
But isn't that exactly what happens in a configuration with a fullranger and a tweeter? The fullranger will cover a lot or all of the range of the tweeter, only more directionally.
Not any more so than other speakers with similar drivers in them, which there are more the norm than the exception, fullrange or not.
But they are still covering the same range.
Remember I mentioned pointing the drivers in slightly different direction to avoid some of the HF interference.
Thanks Scottmoose, interesting article. But the guy didn't build anything. What I'm looking for is someone who has done a serious attempt at this, who can say "bad idea!", "has potential, but...", or "excellent idea, why aren't everyone doing this?".
Edit: Sorry. It seems he actually did build a speaker (as pictured in the article - the Magnificat): http://fullrangedriver.com/singledriver/DIYBX1.html
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I've seen you site some time ago, but I didn't really pay attention to the fact that you are using different drivers. Guess I was too taken with the general creativity at play.
Very inspiring! AFAICS you are actually doing the opposite of what I'm proposing. IE, doing the HF with a secondary smaller FR driver to avoid beaming. But still, you prove that it's possible to build dualdriver setups with different FR drivers.
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Hello,
look the real measurements and single simulations of the Kornett to understand watt happend, best documented : kornettmess
for better understanding at about what? in english in the middle:
about what
look the real measurements and single simulations of the Kornett to understand watt happend, best documented : kornettmess
for better understanding at about what? in english in the middle:
about what
Have you seen the Boenicke Audio SLS? They use two identical full range drivers on the front baffle. Makes more sense to use two identical drivers than to use two dissimilar drivers.
6moons audio reviews: Boenicke Audio SLS
6moons audio reviews: Boenicke Audio SLS
The use of a small driver as a full range speaker is a problem. A 2"-3" driver will have limited power handling capacity and will be easy to push to its excursion limit at relatively low SPLs.
It might be possible to control excursion by using a very small sealed sub-enclosure. However an enclosure small enough to limit excursion would almost certainly cause an audible peak in the frequency response unless the driver had very low Qts to begin with.
If you must do away with the crossover entirely consider using multiple small drivers. A pair would be able to handle double the power, 3 for triple the power, and so forth. These can be arranged in a vertical line (line source array) or perhaps facing in 2 or more directions if you are concerned about dispersion at the highest frequencies.
It might be possible to control excursion by using a very small sealed sub-enclosure. However an enclosure small enough to limit excursion would almost certainly cause an audible peak in the frequency response unless the driver had very low Qts to begin with.
If you must do away with the crossover entirely consider using multiple small drivers. A pair would be able to handle double the power, 3 for triple the power, and so forth. These can be arranged in a vertical line (line source array) or perhaps facing in 2 or more directions if you are concerned about dispersion at the highest frequencies.
Yeah I gathered as much with the few experiments I conducted with a cheap 3 radio driver. The almost unavoidable large difference in SPL between large and small FRs makes it almost impossible to match them without putting components on the line.
Also the overlap in the mids will would probably give too much weight to that part of the spectrum.
I resolved that although it would be a good idea in principle, it's probably a better idea to just have two mid-size FR drivers (4 or 5) mounted horizontally, pointing left and right slightly, so the HF lopes don't overlap too much and you get a good horizontal dispersion.
My original idea could probably be better implemented with in a coaxial driver, with two independent but matched drivers, using the same magnet.
Anyone know of such a beast without crossover?
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Think of an MTM (D'Appolito) or an array. Those use multiple identical drivers not dissimilar drivers. But you can do whatever you want.
I've got a boat load of small TangBand full range drivers that I plan on using in some small line arrays that I'm building.
So what? (incidentally MTMs by definition aren't using identical drivers.
) I wasn't planning on doing anything. Facetious humour aside, assuming you meant that in a general sense, yes, AFAIK, people can do what they want, within certain legal & social limits, obviously. While as I think I've made clear I am far from being an advocate of this approach, some people have tried it & found the results satisfactory to their own criteria so YMMV as ever. I don't presume to tell people what they should or should not like.
Glory be.
FWIW, I'd be careful not to make it too short, or you'll be out of the fresnel zone, which isn't so good for arrays in hifi apps.
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I had originally planned on twelve drivers per side, a stereo pair. Then I got the idea to make a five piece system/setup using all the same identical full range drivers so that the timbre would be the same. Now my two mains will only have eight drivers each.
Not sure what you mean by Fresnel, even though I am familiar with Fresnel lenses. But I've never heard the term Fresnel being applied to line arrays. See Dr. James Griffins white paper on line arrays. Maybe you know more about it than he does.
"Design Guidelines for Practical Near Field Line Arrays." (nflawp.pdf)
I wish I had the link, but I cannot find it, it has moved a few times.
You obviously rejected my reasoning. Hopefully we will have no further communications on this subject, but while you are at it make yourself feel good and have the last word.
Not sure what you mean by Fresnel, even though I am familiar with Fresnel lenses. But I've never heard the term Fresnel being applied to line arrays. See Dr. James Griffins white paper on line arrays. Maybe you know more about it than he does.
"Design Guidelines for Practical Near Field Line Arrays." (nflawp.pdf)
I wish I had the link, but I cannot find it, it has moved a few times.
You obviously rejected my reasoning. Hopefully we will have no further communications on this subject, but while you are at it make yourself feel good and have the last word.
So what? (incidentally MTMs by definition aren't using identical drivers.
I wasn't planning on doing anything. Facetious humour aside, assuming you meant that in a general sense, yes, AFAIK, people can do what they want, within certain legal & social limits, obviously. While as I think I've made clear I am far from being an advocate of this approach, some people have tried it & found the results satisfactory to their own criteria so YMMV as ever. I don't presume to tell people what they should or should not like.
Glory be.
FWIW, I'd be careful not to make it too short, or you'll be out of the fresnel zone, which isn't so good for arrays in hifi apps.
If anyone is interested, here is the link to to the website where you can download the line array guidelines paper by James Griffin (.pdf)
nflawp.pdf
nflawp.pdf
Some inputs on line arrays and your question:
From my near field line array white paper: "The near and far fields are also known as, respectively, the Fresnel and Fraunhofer fields."
Another reference wherein Fresnel optical techniques are related to line array acoustics is from the L'acoustics researchers in their 2003 paper:
http://www.l-acoustics.com/aes/WST_2003.zip
Jim Griffin
From my near field line array white paper: "The near and far fields are also known as, respectively, the Fresnel and Fraunhofer fields."
Another reference wherein Fresnel optical techniques are related to line array acoustics is from the L'acoustics researchers in their 2003 paper:
http://www.l-acoustics.com/aes/WST_2003.zip
Jim Griffin
My Dad's old Magnavox console system...
...from the 50's had a 15 inch and an 8 inch running full range and a 5" tweeter in EACH speaker, open backed, powered by a 6v6 PP amp, and it kicked serious a$$. I wish I had that system now, it was a blast to crank.
From the era when speakers were big and TV's were small...
The thread on the 12LTA's has got me thinking about something big n brash with dissimilar drivers running free....
...from the 50's had a 15 inch and an 8 inch running full range and a 5" tweeter in EACH speaker, open backed, powered by a 6v6 PP amp, and it kicked serious a$$. I wish I had that system now, it was a blast to crank.
From the era when speakers were big and TV's were small...
The thread on the 12LTA's has got me thinking about something big n brash with dissimilar drivers running free....
Yeah, but I bet they were something like 16 ohms each.
5" tweeter is no good, at least not in this century.
If you don't use a crossover then your impedance really drops. Make sure your amp can handle low impedance loads.
5" tweeter is no good, at least not in this century.
If you don't use a crossover then your impedance really drops. Make sure your amp can handle low impedance loads.
Question??
Hi Scottmoose.
At what frequency would you cross- I was thinking about making a woofer(SDX7 per side in BR - 28 liter - 28 Hz) under my Fonken like box. My FR is the Alpair10.2.
I wa s thinking about using a filter on the SDX7 at about 170 Hz(+ a 5 ohm/10watt resistor on the Alp10.2 - so it will support the Alpairs very good midbass somewhere down to 50 Hz be supported from the SDX7. And eventually use a cap on the Alpair if that will free the midband on the system as a whole. The system is so revealing that even my HK 980 and ported speaker gives a sound-scape that is nearly as good as my friends electrostatic panel.
Will be grateful for answer for the best crossover-freq?
Best to all.
Olav
Hi Scottmoose.
At what frequency would you cross- I was thinking about making a woofer(SDX7 per side in BR - 28 liter - 28 Hz) under my Fonken like box. My FR is the Alpair10.2.
I wa s thinking about using a filter on the SDX7 at about 170 Hz(+ a 5 ohm/10watt resistor on the Alp10.2 - so it will support the Alpairs very good midbass somewhere down to 50 Hz be supported from the SDX7. And eventually use a cap on the Alpair if that will free the midband on the system as a whole. The system is so revealing that even my HK 980 and ported speaker gives a sound-scape that is nearly as good as my friends electrostatic panel.
Will be grateful for answer for the best crossover-freq?
Best to all.
Olav
Hello,
if you look at a simulation of impedance and membran movement you might
get a solution to couple two different drivers to get a lower movement for both and a
much better impedance by deleting each other.
look my measurements of the KORNETT and the simulations:
kornettmess
if you look at a simulation of impedance and membran movement you might
get a solution to couple two different drivers to get a lower movement for both and a
much better impedance by deleting each other.
look my measurements of the KORNETT and the simulations:
kornettmess
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