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Thread: ld systems icoa 15 vs yamaha dbr 15

  1. #21
    Quote Originally Posted by knuf View Post
    LD Systems says this is horn-loaded woofer
    It isn't. What looks like a horn in front of the woofer is too short to work as a horn in the frequencies where the woofer operates. It may work well for what it is, but it won't produce the bass that a real subwoofer does.
    Bill Fitzmaurice
    Bill Fitzmaurice Loudspeaker Design
    www.billfitzmaurice.info/forum

  2. #22
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    LD systems means back-loaded horn apparently. The horn on top the woofer is HF horn which can be turned by 90 degrees.

    I think HornResp could model/calculate such enclosure.

    LD Systems : "The horn-loaded woofer's outstanding bass reproduction makes the ICOA 15 the ideal choice for dance schools, musicians, bands and entertainers. It also allows DJs to play sets without the need for a subwoofer. The speaker also makes a good impression in fixed installations due to its freedom of flexibility."
    Last edited by knuf; 07-26-2022 at 07:01 AM. Reason: information added

  3. #23
    It's not a back loaded horn. It's a very short front loaded horn that only serves to allow recessed mounting of the driver so that the HF horn doesn't extend beyond the front of the cabinet. Being perhaps 6 inches long it does nothing below 600Hz, give or take. That will have zero effect on bass reproduction. Advertising claims without measured SPL charts to back them up are just that, claims. In this case I'm afraid that they're phony. Caveat Emptor.
    Bill Fitzmaurice
    Bill Fitzmaurice Loudspeaker Design
    www.billfitzmaurice.info/forum

  4. #24
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    Don`t understand why are you still discussing the HF horn. I am talking about the air volume inside the cabinet behind the woofer.

    As i said before it is not regular back-loaded horn, tapered, inversely tapered or whatever, but i would say that numerical computational methods can provide working while more complicated design than simple models.

    So if not horn-loaded woofer, what is it then? Just multi-ported vented enclosure? SPL measurement without knowing efficiency of speaker itself would tell you nothing about the efficiency of the enclosure.

  5. #25
    I'm not discussing the HF horn. Haven't said a word about it. You do realize that I design loudspeakers for a living, right? With over 100 horn loaded designs to my credit?

    What is it? A front loaded horn (albeit too short to do anything) bass reflex. In concept it's not all that different from an Altec A-7 or JBL 4560, other than using a coaxial driver. SPL charts by definition show the sensitivity of the speaker, referenced to a specific power or voltage input, so I have to assume that you don't know what an SPL chart is. Efficiency is something else entirely that's very seldom used when talking about loudspeaker specs.

    For the benefit of those who don't have one of these to look at this is a picture without the grille:
    Bill Fitzmaurice
    Bill Fitzmaurice Loudspeaker Design
    www.billfitzmaurice.info/forum

  6. #26
    The coaxial aspect is nice, the "horn" on the woofer will have an effect only in the upper end of the range of that woofer, it's more of a mid horn than a bass horn.


    I own four old Community RS series boxes that are three-way all horn loaded and they too have this kind of short horn, as did my EAW KF650's which I no longer have.. they make more of a difference when you have multiple boxes coupled.

  7. #27
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    It is funny how people here still stick to the "horn on the woofer, which have effect only on upper side of the woofer"

    Again - the horn placed in the center of the woofer is HF horn. LD Systems says, the woofer is also horn loaded ( apparently back-loaded horn ).

    "Front loaded horn bass reflex" is total misunderstanding of this enclosure design. Air mass loading the woofer inside cabinet has so much freedom to move (because of 4 ports) in oppossition to traditional vented boxes with single bass reflex that LD Systems1 description this being horn loaded woofer is really not far from reality.

  8. #28
    No. The cabinet is an ordinary bass reflex with a coaxial hf. Adding more ports doesn't change that. It's far too small to have any horn effect at bass frequencies.

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