Bass enclosure for 3 way

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Thanks! Top sections have been on hold way too long really haven't they! Still running ugly prototypes.

I've found that, although the M8a can probably play to 800Hz comfortably, I can hear resonances from the cabinet up this high. Even with what I thought was quite heavy construction. Because of this I am considering revising the top section before building it properly.

It will use something which can cross over lower to meet the woofer. Numerous options here when you're tri-amplifying! What are the implications of having the ribbon tweeter side by side with a small midrange cone driver?
 
Thanks! The pine isn't rebated in and I'd have to say it probably isn't all that helpful by itself. It allowed me to add those thin braces at the bottom of the cab though.

I think the culprit might be the side panels at the top, right by the side of the driver. They arn't too heavily braced and if you knock on the cab in certain places you can distinguish tones. They decay quickly, but are there. They sound fairly high up and if I could cross these at 250Hz, instead of 800Hz, I think the problem would be gone. But that means a different midrange.

If I change the mid, the top would likely be changed to a more typical box shape with the ribbon by the side of the midrange. So many options for such a midrange. I'd love to try the new Scan-speak 4624 but it's quite big and I'd feel like I would be choking by trying to put it in what is quite a restricted volume. More likely, a 3-4" full-range type driver could be employed. I could then build a very well braced (probably sand damped) enclosure and use plenty of stuffing, leave lots of clearance to the side walls. The Scan-Speak is beautiful but deserves more room!
 
Funny you should mention that new driver, I was looking at it too ( 92dB).
Philip at Bamberg Audio recommended to me the smaller 4424(a good looking little unit too).

How about using Corian/Himacs panels to cut out the resonance? They come 4/6/9/12/19 mm thick.. if bonding to MDF just use epoxy. Pretty easy to cut to size.
Tip, Corian fabricators always have offcuts that they would be willing to sell cheap or give away. they come in useful!
 
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