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Marc HENRY wrote:

hi all, thanks for your interest ! yes the frame is curved, HF and MF are // yes there is a phase plug in the bass horn. This cover 80-300Hz. there is a separate infra-bass section, covering 20-80Hz. images of the bass phase plug and the infra-bass section are not available yet... crossover is full passive, firt order. all driver are time aligned for a listening position at a distance of 3 meters and over. much more details comming soon on our website... Best regards, Marco --- http://musique-concrete.com/MC/Galerie.html#17

Well, Marc, what you said addressed all my concerns. The HF and MF are parallel, the upperbass is not. I think it might be OK in this case as your upperbass is dipole that would greatly mask out any phase anomalies. The upperbass is very narrow banded with 80-300Hz. That is a good range foe this topology of horn. I presume it it has a resonance somewhere around 80Hz and with a proper selection of driver it might work very well. The presence of the separate sub 80Hz section imidetaly brings this system from the state of stupid wishful thinking into a realm of very lucid design, my congratulations.

Looking at what you have done I think that the only “slippery” moment in this speaker is the high knee of the upperbass and lover knee of MF. If your MF driver goes down to 300Hz then it is very “pushy” I would say. That would require a good 120Hz -140Hz horn but your MF horn strike me as 170Hz-200Hz horn. I do not know you but let presume that since you did not make other mistakes then you know what you do and what you hear. Then you would not load into a 200Hz Le Cléac’h horn 300Hz compression driver with first order. Well, you might go for it if you need it and it you upperbass cannot go up enough but in your case, having the shallow upperbass horn and a phase plug in the upperbass, you have no necessity to kill the upperbass at 300Hz.  So, if to presuming that you know what you hear and that your speaker sounds good then most likely here is what happen in them. You most likely do not let the MF god all the way down to 300Hz. You might highpass the upperbass at 300Hz electrically with your “crossover is full passive, first order” but in reality a single coil would not stop those drivers. At 300Hz the inductance of those midbass woofers become co-measurable with the inductance of the filter coil, so you crossover point slips all the way up. I might presume that the actual -3dB from upperbass you have at 700-1000Hz that would mask out your lower knee of your MF channel.  So, the octave where your MF and upperbass work together you use as a virtual Macondo’s “Fundamental Channel”. This is might take how your speaker work if it sounds balanced.

Ok, to conclude the things. It looks like from what it presented now the speaker is done with no mistakes and even I can’t find a rational to bitch about them. I nominate this “La Grande Castine” as the second “The most promising ‘best’ commercial horn speaker” right after the Cessaro Gamma. So, how the La Grande Castine sounds? Since there are no strategic mistakes in the design then the speaker will sound as good as the drivers are able to.  I have no idea what drivers La Grande Castine use and it looks as then went into extend to hide the drivers identity. If the drivers are very good then the Castine might sound very promising.

When the information about the bass section become available then, please, post a note.

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