Considering Enclosures for pair 421-8H

**everydaylight** · August 16th, 2022, 02:05 PM

Originally Posted by Old Guy

They should work. I recommend putting the interior dimensions into a modeling program to come up with port size.

Thank you, sir! That is all the encouragement I think I needed to try them out. Just need find terminal cups and handles. Any inexpensive sources lurking out there?

The existing port(s) along the bottom are flared to a 7 3/4" tall x 13" wide (each). Is the "port" size the smallest opening at the back of these? It would be easiest to fill in to make the port smaller, but as a flared horn shape, I don't know how that affects the port's calculated size /area and length.

GM · August 17th, 2022, 10:01 PM

Originally Posted by everydaylight

Is the "port" size the smallest opening at the back of these? It would be easiest to fill in to make the port smaller, but as a flared horn shape, I don't know how that affects the port's calculated size /area and length.

No and don't; truly flared has to be calculated based on its flare frequency and factor whereas a parabolic flare's [one side pair parallel] mean can be calculated using the end areas: mean area = [A1*A2]^0.5 for simming purposes. That said, Hornresp can do accurate enough sims just inputting the two areas and length as well as the horn flare.

**everydaylight** · August 18th, 2022, 12:39 AM

Thank you for the suggestion and link to Hornresp. I know horn design is in my future, but didn't know the time was now. I have not used this slick software before. I'll pull up the help file, and see if I can find the fields you suggested I simply input to see how these ports add up...

**Old Guy** · August 18th, 2022, 04:39 PM

Any pictures?

**everydaylight** · August 18th, 2022, 10:21 PM

Carvin_IMG_20220818.jpg

**Old Guy** · August 21st, 2022, 07:27 PM

Blast from the past. Carvin actually offered the 421 in that enclosure.

**Alien_Shore** · August 22nd, 2022, 06:38 PM

Originally Posted by Old Guy

Blast from the past. Carvin actually offered the 421 in that enclosure.

Incredible the stuff you remember right off the cuff, OG.

GM · August 23rd, 2022, 12:17 AM

Originally Posted by Old Guy

Blast from the past. Carvin actually offered the 421 in that enclosure.

Interesting! Vents way larger than the driver's piston area without proper horn loading is normally a recipe for disaster unless there's a near infinite slope limiter.