604 vent size

[David Deratany]

I'm reinstalling my 604B/E's into cabs that at varying times have had 416's in them, and I've lost track of what vent size went with what. Can someone suggest where I might start out with 7.25 net cu. ft. boxes? Will a few square inches either way matter a great deal?

[donaldpatten]

The 1962 Altec Loudspeaker Enclosure booklet has a chart ( figure 4 ) on page 3 that should help. They list the 604 Res. Freq. as 40. The chart suggests with a 40Hz speaker use 20 sq inches for a 7 cu ft box. The text recommends the aspect ratio not higher than 5:1 ; or 10" x 2". You can tweek the size buy measuring the impedance curve. Start with a small hole.
Don

[LICORNE]

Here is a site that could be of help.

http://www.lansingheritage.org/image...ure/page04.jpg

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