Does anyone know what I can use these Foster 8F3 for. My friend gave me two pairs of these along with the crossovers for them. Crossover is a 1st order with a 2mh choke to woofer and a 30uf cap to the tweeters which wired in parallel. He does not have woofers for them and can't remember where/how he got these neat looking things. I borrowed these picts from ebay but mine look exactly the same.
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Neat. I've always wanted to find a pair of 10F3 locally, no luck yet. I understand the 8F3 is the 3" model.
One thing to check for is Stiff Surround Syndrome. You can sometimes tell by how supple the surround feels, but measuring Fs is a better way to tell. In any case, I'd expect the Fs for good surrounds to be quite high anyway, so you're likely better off crossing these around 300Hz in a small sealed box or aperiodic stuffed-line, or even OB if you fancy that. I recommend a PLLXO to save money and avoid interaction with the impedance peak that is likely around 150Hz-250Hz.
IG
One thing to check for is Stiff Surround Syndrome. You can sometimes tell by how supple the surround feels, but measuring Fs is a better way to tell. In any case, I'd expect the Fs for good surrounds to be quite high anyway, so you're likely better off crossing these around 300Hz in a small sealed box or aperiodic stuffed-line, or even OB if you fancy that. I recommend a PLLXO to save money and avoid interaction with the impedance peak that is likely around 150Hz-250Hz.
IG
I have 3 of these, althou the cones are dark. A lovely driver... think 40-50 yr old precursor to FE83, or FF85. Mine came out of a Noresco FAST ... XOed to (IIRC) an 8 Isophon alnico woofer.
Cal, i've not found a use for these yt, so maybe we can do a deal. I think mine are at least part-way to phase plugs installed.
dave
Cal, i've not found a use for these yt, so maybe we can do a deal. I think mine are at least part-way to phase plugs installed.
dave
Sure. I will sell you one pair though you may want to check with Dave first as he is in the same area as you and shipping cost maybe a lot less than coming from Texas.
They are "fullrange" drivers AFAIK. A more sensible term might be mid-tweeter though.
Dave, what's the Fs on your 8F3's?
IG
Wassa matter - out of fuel for your jetpack
yeah, a round trip can chew up a whole day and the best part of $200 (not including the beer, so double(?) that )
That's OK, it was out of general curiosity. I'd expect something around 150Hz even for supple surrounds on these.
IG
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