Two different fullrangers in the same cab without x-over

[Squeak]

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?

[Scottmoose]

http://www.fortunecity.com/rivendell...d/dddllqd.html

[AEIOU]

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.

Originally Posted by Squeak

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?

[Squeak]

Originally Posted by AEIOU

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.

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.

Whatever combination of drivers you choose to use, if you overlap frequencies, you overlap impedance too. Better to use a crossover capacitor.

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.

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.

Not any more so than other speakers with similar drivers in them, which there are more the norm than the exception, fullrange or not.

In an MTM or a line array, you use identical drivers not dissimilar drivers.

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

[hm]

Hello,
don´t you know my double horns,
i made a few solution look my:
Kornett, Trombone, Posaune, Saxophon, RDH20
with measurements and plan and feedback
saxophon
trombone
posaune
kornett
RDH

[Squeak]

Originally Posted by hm

Hello,
don´t you know my double horns,
i made a few solution look my:
Kornett, Trombone, Posaune, Saxophon, RDH20
with measurements and plan and feedback
saxophon
trombone
posaune
kornett
RDH

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.

[hm]

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

[AEIOU]

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

[Scottmoose]

Not necessarily. It depends on what your particular goals are. That said, if it's a question of a large & small FR unit, I'd personally prefer to use a woofer in place of the former & cross at the latter's mass corner, or slightly higher depending.

[stevebogus]

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.