Megaton Horns - Experiences?

MethMan

Member
2004-06-18 11:12 am
Praha
I don't know of anyone using this kind of combo. A9090 is made for 1" compression driver and you cannot mate it with 1" coil tweeter, because of surround. For better orientation - letters are for throat diameter A(1"), B(1.5"), C(2")
I own A9090, but I didn't use them already, just measured with DE250 years ago. Then I found Geddes work ...
For surrounds I'm using Monacor WG300 with seas 27TBFCG. I can show a polar measurements lately.

If you are requesting something more concrete than "opinions" I can ask at prodance forum for you.
 
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Hi Methman,

for the XT25 I want to use the C9090, the A9090 would interest me for the use with smaller tweeters with 19mm-voicecoil...

Do you think the A9090 would be okay according to Geddes' ideas?

How is the build quality of the horns? In the pictrures at Prodance it looks rather crappy...

Bye,

Spatz
 

MethMan

Member
2004-06-18 11:12 am
Praha
Hi Methman,

Do you think the A9090 would be okay according to Geddes' ideas?
Spatz

NO WAY. It is heavily diffractive device. It has not diffraction slot per-se but it change profile very rapidly at the throat and angle at throat itself is, say, 40deg.

How is the build quality of the horns? In the pictrures at Prodance it looks rather crappy...

Bye,

Spatz
It is raw sandstone cast aluminium with machined backplate. Solid, reliable, predictable, low cost - exactly as PA guys needs. No shines, sharp edges and submilimeter tolerances.
 

MethMan

Member
2004-06-18 11:12 am
Praha
A9090+ B&C DE250
 

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MethMan

Member
2004-06-18 11:12 am
Praha
Hey Tomas,

thanks for you opinion. Let me rephrase: Do you think the C9090 is more according to Geddes' ideas than the Dayton H12RW. The C9090 at least has a smooth mouth and is not that deep...

The measurement looks pretty good off axis...

Bye,

Spatz

Well I don't know which one is "more", but no one is. I have never took a look at C9090 nor Dayton. The advantage of OSWG is constant directivity with the least diffraction, not the smoothness per-se. All translates into very fine sound. If you look at horns made by Fane, B&C, Megaton, Dayton etc. you will find also CD and relatively smooth, but little bit gritty sounding. IMO controled directivity is more valuable than axially smooth hifi tweeter or little brightness.

GM: probably all Megaton horns are copies of good old whoever-made-it-before.
 
C9090

I've received the C9090 a couple of days ago and mounted it today on my JBL 2445J (equipped with new diaphragms some weeks ago). Listening tests only, in my system, which comprises in the bass pseudo-Onken W (with 2x15" Ciare), JBL2490/2392, passive xover.

I use the 2445J as a "tweeter", with Xover around 2kHz and a UHF boost using an autoformer in reverse mode (i.e. for signal increasing and not signal decreasing as is usually the case). Boost is set at +7.5 dB as from 10kHz or so. Usual horn (for comparison) is the JBL 2382A.

Impressions:
++ extremely clean sound, very smooth, not much distorsion on certain frequencies, and good image (as regards smoothness and image I prefer it to the 2392A which spreads too wide in my listening room). For a round horn/waveguide, the big surprise is that I can move everywhere in the room, the tonal balance doesn't change much. Fusion with the large midrange horn (90x50°) is good too, no feeling of a hole or of something wrong in between.
- - HF extension is is not as good as the 2382A, which is something I expected given the wide and fast opening of the C9090.


Note: the horn comes without mounting holes (not even to attach the compression driver), but all places are pre-marked for drilling. Since the horn seems to be made of some kind of aluminium sand agglomerated or cooked together in a mold, it is not too difficult to drill the holes (alu is not a hard metal anyway).
 

uk75

Member
2014-05-20 3:44 pm
I have Megaton C9090 waveguides in my LA215 style PA mid/hi boxes. I use them with B&C DE85 drivers. Good thing about this combination is that the driver has a wide 34,5°exit angle, which is approximately the angle at the throat of the waveguide.
I think C9090 are great, on axis high frequency response with DE85 is excellent, the throw isn't bad either, they reach 15-20m without problem. And most important, there are no traces of honky sound anymore, that was audible at vocal peaks with my previous plastic CD horn.
 

SoundRight

Member
2010-07-28 10:47 am
I'm a bit baffled and annoyed in equal measure! The Megaton horns are still listed and priced on the Prodance-cz site....except neither Prodance nor their distributors seem to know anything about them. Odd because I thought this type of ignorance was just a UK thing.

If anybody knows how or where I can purchase, please let me know!