MrMcGoo Posted February 4, 2005 Share Posted February 4, 2005 What is the significance of the phase ange on the RF-7s being at -68.48 degres at 74 Hz? How or why does a phase angle of a speaker affect the difficulty in driving the speaker? What charateristics in an amplifier, if any, would be affected by a speaker's phase angle? Please keep the answer as simple as you can. Bill Quote Link to comment Share on other sites More sharing options...
3dzapper Posted February 5, 2005 Share Posted February 5, 2005 Bill, It is insignificant. It's one of those things you can't escape from in a multidriver speaker. All inductors and capacitors alter the phase relationship between the voltage and current passing through. There is a complex quadratic equation used to figure this "J" angle. I used to be able to do it on a slide rule, don't ask me how. Some speaker lines, like Meadowlark, use the fact of simple one capacitor crossovers and phase coherence as selling points. Although Meadowlarks sound "airy" they lack the lifelike realism of Klipsch speakers. Rick Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted February 5, 2005 Author Share Posted February 5, 2005 Rick, Thanks for the reply. I was aware that the phase is changed by the crossover, but have yet to understand why this angle allegedly makes the speaker more difficult to drive. Impedance chages seem far more relevant to me. Bill Quote Link to comment Share on other sites More sharing options...
3dzapper Posted February 5, 2005 Share Posted February 5, 2005 Your right Bill. The amplifier "looks" at the impedance. If the RF_7 were such a hard load (impedance) to drive, those that use a 2A3 SET would never be happy with them. I kow of at least one member here who is very happy with his and SET. Good night. Rick Quote Link to comment Share on other sites More sharing options...
mike stehr Posted February 5, 2005 Share Posted February 5, 2005 "I was aware that the phase is changed by the crossover, but have yet to understand why this angle allegedly makes the speaker more difficult to drive. Impedance changes seem far more relevant to me." You got wondering now, google search homework for tonite I suppose. I do know in amplifier such as tube PP that has the stages capacitor coupled, that you have to keep the phasing different with the Fc of the coupling caps, or you could end up with a oscillator. That's about totally irrelevent to the topic..... I've been listening to my little version of the Sonic Impact amplifier with my homebrew speakers. I have a audio control phase coupled activator with a two-way crossover. It's a bass restoration device basically. It gives my little 10" woofers a nice little needed boost in the LF. But the phase seems weird, I reversed polarity at the amp and that helped. Not relevent to the topic again..... The Digi-amp and the bass restoration seemed to give my little Criterion 10"/JBL 075 setup quite the boost on the bottom end, subwoofer like....not bad for junk, not bad at all... The last thing I did was swap the JBL 075 tweeters out for a pair Usher dome tweeters I have. I know they are domes, wah. But they are nice and smooth, and the Sonic Impact tri-path chipamp seems to push them real nice. All my tube amp hate pushing the Ushers, the 300B almost can. Too much fun.... You still work at EWU, Bill? Quote Link to comment Share on other sites More sharing options...
MrMcGoo Posted February 5, 2005 Author Share Posted February 5, 2005 Mike, I am still at EWU. The phase issue is important at the crossover from the woofers to the tweeter, since cancellations at the crossover would leave a sonic hole. What I cannot see is how some magazine writers can infer that phase angles can make amplifier operation more difficult. Bill Quote Link to comment Share on other sites More sharing options...
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