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Straight side walls [message #19123 is a reply to message #19121] |
Fri, 23 February 2007 11:12 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
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Wayne Parham
Messages: 18756 Registered: January 2001
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Illuminati (33rd Degree) |
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The 1970's ten π was a great midbass horn, but it was large. It used a single fold, much like a scoop. Just like my seven π, it was a very simple design. The only downside was it was huge, as big as the 12π basshorn sub.A conical horn has no more problem with standing waves than any other horn. If the horn is flared in both axis, then standing wave nodes don't set up side to side, like they would in a basshorn having fixed width the whole length of the horn. That's where the problem lies. Basshorns with straight side walls and straight passages inside can develop standing waves along those dimensions if they're used up to high enough frequency. So it's not the expansion rate that causes notches in response, it's the constant width of the pathways, in a cabinet so constructed. If the horn isn't used to high frequency where the first standing wave node causes a notch, it's not a problem. Most basshorns are used only at low frequency, so straight side walls don't matter. But if used high enough, they'll cause notches in response.
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Re: I was considering a B&C 8PE21 [message #19139 is a reply to message #19138] |
Thu, 01 March 2007 20:14 ![Go to previous message Go to previous message](/forum/theme/AudioRoundTable/images/up.png) |
Cuppa Joe
Messages: 103 Registered: May 2009
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Viscount |
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Yup, it's a 70 degree conical with a throat that's just a wee bit smaller than 4.75" square. The lower cutoff is a little higher than I like (350Hz), but that's easily fixed. The 1" driver is a B&C as well.
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