Hybrid OB / Horn project

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iansr
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#1 Hybrid OB / Horn project

Post by iansr »

Quite a while back I posted about this speaker project. For reasons I won’t trouble you with, I’ve not been able to progress things, but in a few months I’ll be in a position to set things up so I’m now looking to finalise the design. The speaker is centred around Joseph Crowe’s ES290 biradial horns that Steve made for me. If needed, I have some Fostex T925A bullet tweeters to handle the upper end, but I’ll try the speakers with and without these.

To cover the FR up to the horn at c.500hz, I have 4 (sic 😀) x AE Dipole 12 woofers per side. My current focus is on how I configure these 4 woofers.
Steve recently brought Bert Doppenberg’s Sigma to my attention and I’m thinking about the possibility of cloning the woofer section albeit with 4 woofers rather than 6. I’ll post some pics of the Sigma once I’ve remembered how to do it!
"Its good enough for Government work."
iansr
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#2 Re: Hybrid OB / Horn project

Post by iansr »

Image
Attachments
632F14B6-FA42-4804-8332-C92EB5D17AE2.jpeg
632F14B6-FA42-4804-8332-C92EB5D17AE2.jpeg (28.71 KiB) Viewed 1449 times
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"Its good enough for Government work."
iansr
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Posts: 401
Joined: Thu Nov 08, 2007 10:44 pm
Location: West Riding

#3 Re: Hybrid OB / Horn project

Post by iansr »

I’d welcome comments about the Sigma woofer system, or indeed any other suggestions re the 4 woofers.

(My original plan was a vertical stack - WW/HORN/WW - but that would be 2m tall and that is too tall for my liking.)
"Its good enough for Government work."
vinylnvalves
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#4 Re: Hybrid OB / Horn project

Post by vinylnvalves »

That 3D cad image confirms it’s a slot loaded open baffle, Bert has just used the wings as wave guides. As long as the chamber is very small the 1/3 and 1/5 wave length modes will hopefully be above 500 Hz, may need a higher order xover to mitigate them, also allow you to cross the horn a little lower. Scott probably could suggest the best way of modelling it in Hornresp.

The bathroom board off cuts I have got could make the guides. A nice marble effect. :D
Seriously to others - it’s phenolic decorative finish 10mm birch ply, but is fully water proof. The cost of a full sheet is 2/3’s that of bulk standard birch ply.
iansr
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Posts: 401
Joined: Thu Nov 08, 2007 10:44 pm
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#5 Re: Hybrid OB / Horn project

Post by iansr »

Steve
How would you bend those boards - kerf?
"Its good enough for Government work."
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