|
Posted by js on
11-04-2009
|
|
fiogf49gjkf0d Hello!
Could anyone please advise me as to the recommended rear chamber volume for a Le C'leach horn with a throat of 240cm2, mouth of 7089cm2, length of 47cm, cutoff of 160Hz, T of 0.8? I'm thinking of using a Beyma 122Nd which has a sd of 530, Bl of 24.2, sensitivity of 103dB, fs of 56Hz, Re of 5.2ohms, Qes of 0.14, Qts of 0.14, Vas of 72l, Vd of 106cm3, Le of 1.5mH. Front chamber volume is 433cm3, (not including the cone volume).
|
|
|
|
Posted by Romy the Cat on
11-04-2009
|
|
fiogf49gjkf0d  js wrote: | | Could anyone please advise me as to the recommended rear chamber volume for a Le C'leach horn with a throat of 240cm2, mouth of 7089cm2, length of 47cm, cutoff of 160Hz, T of 0.8? I'm thinking of using a Beyma 122Nd which has a sd of 530, Bl of 24.2, sensitivity of 103dB, fs of 56Hz, Re of 5.2ohms, Qes of 0.14, Qts of 0.14, Vas of 72l, Vd of 106cm3, Le of 1.5mH. Front chamber volume is 433cm3, (not including the cone volume). |
|
Js, sorry to disappoint you but there is no answer to this question. Thos type of the questions are for the “HornResp academics” – at my site they, thanks God, have no reason to show up. Why do you care about the rear chamber volume with such a precession if you never will be able to calculate the back chamber volume precisely? Will you be able to measure the exact volume of your Beyma’ back basket? I do not think so. Also, each single driver reacts to a given loading differently in term of sound. It is absolutely impossible to predict to which resonance frequency you need to target your loaded driver. I mean you can slide the Fs with back chamber up and down - it all will be right and it all will create different sound from the driver. If you use midbass horn he SOME perdition might be made as you might want to get max amount of bass from it. In your case of your 160Hz La-horn I do not think that you would shoot for more bass but rather for better MF sound of your driver. Only god would know how YOUR driver will react to back channel dumping.
The Cat
|
|
|
|
Posted by js on
11-04-2009
|
|
fiogf49gjkf0d Thanks for the reply. I'm using a Jabo KH-55 horn for hf/upper mid, so I think I'll have to experiment with different size chambers. Beyma quote the volume displaced by the driver as 5.5 litres, so I'll start by trying a 9 litre (gross volume) back chamber.
|
|
|
|
Posted by Romy the Cat on
11-04-2009
|
|
fiogf49gjkf0d | js wrote: | | Thanks for the reply. I'm using a Jabo KH-55 horn for hf/upper mid, so I think I'll have to experiment with different size chambers. Beyma quote the volume displaced by the driver as 5.5 litres, so I'll start by trying a 9 litre (gross volume) back chamber. |
|
Js, you can’t imaging imagine how might irrelevant all this information. This T/S data is so much not applicable for horn loading, or at least need to be interpreted in absolutely different way then it was done in case of box speakers. The Beyma quote the volume displacement of 5.5 liters is no meaning at all. Are you planning to use it for acoustic suspension? Of course not! What the size of the volume displacement has to do with back chamber ion horn? The exertion, displacement and anything else imaginable for f a horn-loaded driver will be absolutely different then in open air and ALL T/S data shall be trashed as soon you load the driver. Do not waste your time to ask me question or even to think about it. What you do need to spend your time is to learn how YOUR driver SOUND will be changed with change of the of the back chamber volume.
The Cat
|
|