Making a 416 out of a 421

[les winter]

Hi Earl. The Fs was 19. I should check the WT3 instructions again.

[les winter]

OK, so after much fooling around, I've determined that the qts is 0.45, the vas is 40 ft^3 and the fs is 18.5 . This is driving me towards a very large sealed box to get the system Q down below 1. Any suggestions on altering the vas? I'm figuring if I really stuff a 5 cubic foot box, the stuffing will drop the system Q. I would really like to get this into a 3 ft^3 box but I don't see how. Maybe applying some kind of goop to the spider?

[GM]

I would really like to get this into a 3 ft^3 box........

Go open back and adjust stuffing to get response down to ~80 Hz to XO to the sub system. Use tightly stretched double knit for a rear cover.

What makes vintage drivers such as the 416 special is its high Vas which allows better tracking of the signal at low input than modern day low Vas drivers [all else equal], so don't recommend altering the driver except through acoustic mass loading [stuffing]. Anyway, seems there's other ways: Modyfying the parameters of a 15" woofer - diyAudio

BTW, what are the rest of its specs?

edit: How come the embedded link isn't highlighted in some way?

GM

[les winter]

This started out as an inquiry about Model 15's over at the Audio Asylum. GM suggested that I consider building something like a small Model 19. So I got a pair of trashed 421's (one from Old Guy's Brother; thanks Old Guy) and a pair of 416 recone kits and off I went.

The lower cabinets are around 7 cubic feet and the upper ones around 3. Still to go: Mrs. Darst's foam (I hope) laminate the lower cabinets and cut the holes to connect the upper volume with the lower one. The crossover is a Model 19 clone. The horn is a 811B and the driver is a GPA 902.

Sounds pretty fair, even with an old Sony HT receiver.

Thanks for all the help I received.
Les

[gearfreak]

Sweet, looking good!