FP4 vent kit radius

[noodle_snacks]

I am currently re-building my Adire Tempest into an EBS alignment and am considering either using the FP4 vent kit ($110AU plus a bit of shipping to tassie) or buying a 1.25in round over bit ($70-$130AU depending on brand) and routing my own MDF flares.

What sort of radius would the vent kit give (measure from where flare starts to surface) and if significantly larger, would the effect on port noise be significant?

Which would be the better value buy considering the router bit could be used time and time again on future ports, and also be used for rounding baffles to help with diffraction.

[Collo]

The Adire site doesn't seem to give out any sizes for the FP4.
Somone who owns a set might measure them for you.

In the meanwhile, looking at other brands you'll find:

Precision Ports
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Have a flare radius of about 1-1\8 inch
Available in 2, 3, and 4 inch diameters
http://www.psp-inc.com/psp-inc.com/public_html/why.htm

Lightning Audio PNP Aeroports
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Have a flare radius of about 1-1\8 inch
Available in 2, 3, and 4 inch diameters
http://www.crutchfield.com/S-1GBRhrW...&i=495PNR3#Tab


Geniune European Aeroports
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Info is a bit hard to find but apparently their 6 incher is 9.5 inches at the end, giving a flare of 1.75 less any flat flange. Taking off half inch for that brings you back to 1-1/4 inches
http://2loud4you.ca/shop/index.php?m...&products_id=3


From this sample, you can see that making your own with a 1-1/2 inch rollover will give you a flare that is every bit as good as a commercial unit!

It's not likely that the FP4 would have radius that is significantly larger than this because 1-1/8 inch will eliminate turbulence for airspeeds that are typically used. Trying to move more air results in port compression, so you move up to the next sized port. Airspeed drops and you are back to the 1-1/8 flare being sufficient!

I've done flares with a 10mm rollover and a cheap Bunnings router and it's so easy it's not funny. For the larger bit you are considering, you'll need a full sized router.

Collo