The horn is designed to do two things:
1 Provide proper loading for the CD
2 Provide the desired directivity or sound coverage
Without proper loading the CD will not achieve the designed efficiency.
1 Provide proper loading for the CD
2 Provide the desired directivity or sound coverage
Without proper loading the CD will not achieve the designed efficiency.
drewmc said:
So if a CD was to be used without a horn, the the sensitivity would just be lower, and dispersion would be more or less like a dome tweeter, just with higher sensitivity?
So theres nothing stopping a CD to be crossed to say.... a small 3 khz waveguide to get good sensitivity and controlled dispersion? Seems like a much better alternative to the regular dome tweeter...
Only that a crossover around 3khz is said to be a bad idea, sound quality wise, since the human hearing is very accurate in this area. A waveguide for a 1khz crossover is also quite small and compression drivers are designed to go this low.
Defo said:
A compression driver IS a dome tweeter. Except it's buried inside of a compression chamber, with a sophisticated phase plug on the other side of the diaphragm.
Without a waveguide, the frequency resonse of a compression driver will be terrible... You definitely need to use one.
Defo said:
Could be, but you need a small sensitive pro mid, which mostly only does it down to about 400hz
Alternative to dome tweeter?
You will need a lot of attenuation best done actively
Or low gain power buffer amp 😀
btw, Bastanis doesnt have any horn/waveguide, but is crossed very high
But why cross high when it easily go lower with rather small waveguide
I see that as the main advantage of a CD
tinitus said:
The Bastanis has a short horn on the front, and no compression chamber. So it's a dipole tweeter with a horn on one side, but not the other. The horn side has a phase plug. Kind of an odd design, but sounds very good.
Nice picture
I knew it would be commented when I said no horn
Im sure the rounded edge have some effect
But I guess its mostly phase related
But from picture tweeter frontplate could seem to have become thicker
I suppose its only the most expencive version with this dipole option
It the backside of CD diaphragm we see on picture?
I always thought the dipole action was achieved by additional driver
ehh, does that mean that the voice coil is mounted in front of the diaphragm😕 says rear facing free voice coil, but its hard to see really
I knew it would be commented when I said no horn
Im sure the rounded edge have some effect
But I guess its mostly phase related
But from picture tweeter frontplate could seem to have become thicker
I suppose its only the most expencive version with this dipole option
It the backside of CD diaphragm we see on picture?
I always thought the dipole action was achieved by additional driver
ehh, does that mean that the voice coil is mounted in front of the diaphragm😕 says rear facing free voice coil, but its hard to see really
I've heard this backless CD as pictured. It sounds good and works well. There is a short horn on the front.
Also have run some other CD backless, the extra splash off the back can sound nice.
Also have run some other CD backless, the extra splash off the back can sound nice.
Have looked closer
And you are right
There seem to be more horn on CD than I have noticed previously
And other things changed since I looked last
Well, he does seem to break some rules of design
And you are right
There seem to be more horn on CD than I have noticed previously
And other things changed since I looked last
Well, he does seem to break some rules of design
Defo said:
That's what the small B&C DE10 + ME10 (a horn, not a waveguide) combo does for a handful of euros. I'm very happy with it, in a three way active system. 🙂
An externally hosted image should be here but it was not working when we last tested it.
"A compression driver IS a dome tweeter"
Nope. Just as there are cone tweeters there are CD without a dome. RCF N380 for one uses sort of a ring like diaphragm.
It's true most CD are inverted dome but it's not accurate to generalize.
Nope. Just as there are cone tweeters there are CD without a dome. RCF N380 for one uses sort of a ring like diaphragm.
It's true most CD are inverted dome but it's not accurate to generalize.
the majority of compression drivers are dome tweeters.
Is that sufficiently accurate?
or is it that the majority are not domes?
Is that sufficiently accurate?
or is it that the majority are not domes?
What exacly happens if a compression driver is used below horn cutoff? For example a shallow crossover just around horn cutoff.
Since most wideband compression driver diaphragms rest a fraction of a millimeter from the phasing plug, the likely scenario is that the diaphragm will make dramatic contact with the phasing plug at any real SPL. If it's a composite or polymer diaphragm, it will just sound bad. If it's a beryllium diaphragm, it will sound bad very briefly and become expensive confetti. 🙁
Also, keep in mind that, depending on the horn, "horn cutoff" may be well below the Fs of the bare driver.
Here's an interesting loudspeaker from Deep Audio, which seems to have gone under. This loudspeaker was thoroughly roasted on this forum in this thread. Quite uncharitable, I thought.
Just to present a minority view, though, I'd say that a hornless compression driver isn't necessarily always a non-starter. Like any driver, you simply have to look at its capabilities in the intended alignment and judge whether it fits your goals. Sans horn, you have to take its reduced power handling into account and its likely non-flat FR.
Common wisdom isn't always wisdom. A bare compression driver certainly won't always work as you might hope, but there is a small sub-set of cases in which it might work very well.
Common wisdom isn't always wisdom. A bare compression driver certainly won't always work as you might hope, but there is a small sub-set of cases in which it might work very well.
As far as I understand, a compression driver will be damaged if operated without its horn at anything above a small fraction of its 'normal' power. The horn is an impedance matching device, and without it, the diaphragm is poorly coupled to the mass of air it is intended to move. You get excessive diaphragm excursion, which will do it no good.
That's a really good point which is why I never run my JBL cds without their horns. In addition I do not run them below their recommended cut off either in order to prevent over excursion of the diaphragms. The diaphragms are really expensive to replace which is why I am careful. I've blown up enough drivers over the years - I'm so over that.. 😀
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