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Question about FAST
Question about FAST
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Old 2nd December 2015, 02:35 PM   #1
soundchaser001 is offline soundchaser001  Canada
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Question Question about FAST

Hi All;

I have a question about FAST implementations. My understanding that FAST is typically a full range with a helper woofer.

Has anyone ever seen/heard/implemented a FAST design with a full range and woofer of the same diameters (say and 8" full range and 8" woofer) so that they have similar directivities at the crossover frequency and a narrowing radiation pattern with increasing frequency? This is in an attempt to emulate the behaviour of some of the waveguide type systems with directivity control but with the benefit of keeping the crossover frequency down near 300(ish) Hz.

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Old 2nd December 2015, 08:09 PM   #2
xrk971 is offline xrk971  United States
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Question about FAST
With a 300Hz XO there won't be any issue integrating a small (say 3in driver) with a larger 8in woofer at the polar response will match well at that low frequency. Using a 8in full range top will have beaming issues at higher frequencies where the 3in will be able to go much higher before beaming is an issue. So what you suggest can be done and would work. However, there is no advantage over using a smaller full range on top - other than maybe more visceral punch in the 300Hz range.
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Old 3rd December 2015, 03:07 PM   #3
Cal Weldon is offline Cal Weldon  Canada
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Question about FAST
Agreed. The whole point of a FAST is to accommodate for the lack of low end. The 8" FR doesn't suffer from that and has the beaming issues of which X alludes.
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