15" Jensens [message #8394] |
Mon, 12 March 2007 01:01 |
C4ster
Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
|
Senior Member |
|
|
Hi guys, I am replacing 4 Jensen C15L speakers in my red siren Ross cabinets. The cones look like they have limited "in" travel because of the at rest position. I would think these speakers are due for a recone. Your thoughts.
Conrad
|
|
|
|
Re: 15" Jensens [message #8401 is a reply to message #8399] |
Mon, 12 March 2007 08:22 |
C4ster
Messages: 686 Registered: June 2001 Location: Mukwonago, WI (Milwaukee...
|
Senior Member |
|
|
I have to respectfully disagree. Your output from the amp at idle should be 0 volts. It is absolutely imperative that the amp be biased to achieve that goal. The output applied to the speaker will not cause any movement at 0 volts. That being said, the output goes from positive to negative with every alternation and the speaker cone MUST move both in and out and the excursion MUST be equal in both directions. I agree, too much movement in can cause the VC to bottom but the speaker must be able to move in both directions smoothly and equally. I have never heard that a speaker only moves out. When a battery positive is applied to the positive terminal, the speaker should move out, and if the battery is reversed th cone moves in. JBL's are opposite but it's all north-south magenetic physics. The polarity is only important when phasing multiple speakers of the same frequency range, ie subs, lows, mids, highs, with lows being most important. Speakers in the same cabinet must be phased or the movements will cancel.
Conrad
|
|
|
|
Re: 15" Jensens [message #8426 is a reply to message #8394] |
Tue, 13 March 2007 06:58 |
stevem
Messages: 4772 Registered: June 2004 Location: NY
|
Senior Member |
|
|
Another important thing to check in reguards to phase is when using 2 different amps, 2 weeks ago was the second time in 6 months that I saw a band whos guitarist used two amps with a stereo modeling pedal, one of which was out of phase with the other.It was not too teribly bad with his amps on oposite sides of the stage, but during a break we put both amps side by side and the problem was right in your face.
|
|
|