pi one question [message #42060] |
Wed, 30 July 2003 12:58 ![Go to next message Go to next message](/forum/theme/AudioRoundTable/images/down.png) |
Demetrius
Messages: 4 Registered: May 2009
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Esquire |
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First and foremost I'd like to thank Wayne. You are consistently kind and generous. This is a fascinating and, well, cool place. I appreciate the commonsense and elegant engineering and conversation. I've been reading in here for a bit and recently collected some drivers. I had some JBL 077's and just added a pair of 2115H's. I have these in a recycled box, crosoverless,with a .47 microfarad cap. for the 077. Is the 077 sufficiently similar to the 2405 to pair with the 2115H and fashion a pi 1? Is the 2115H sufficiently similar to the 2115? I read ina thread about matching the sensitivities since the slot tweeter is more efficient than the full-range, 92db and 105 db respectively I think. Couldn't find specs for the 077. So, can I make a pi one with these and if so could I get some guidance. Thanks.
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Re: pi one question [message #42062 is a reply to message #42060] |
Wed, 30 July 2003 16:23 ![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) |
ToFo
Messages: 219 Registered: May 2009
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Master |
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I looked at some info from jbl obsolete specs page and I think that with the right tweeter attenuation and a crossover above 5 khz, you would have a NICE speaker. That tweet doesn't handle as much juice as the 8", so you want to pad it down anyway. Attenuation about 12 dB would be a good starting point. That 8" has a rising response from 1.5 to 5 Khz and would be good with pseudo butterworth. I guess about .3 mH coil ought to do it. I am no expert, but I bet these would really cook! Have fun and let us know what happens, Thomas
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Series coil for JBL 2115's [message #42063 is a reply to message #42062] |
Wed, 30 July 2003 20:52 ![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: 18748 Registered: January 2001
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Illuminati (33rd Degree) |
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Hi Thomas! You're exactly right about the Pseudo-Butterworth series coil for the 2115. I ran 'em with 0.5mH on 2115H's or 1.0mH for 2115J's. Without a Zobel, the circuit develops a shelved response that reduces the rising response without having an electrical crossover slope. Wayne
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