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Sound Reinforcement - Forums for Live Sound Professionals - Your Displayed Name Must Be Your Real Full Name To Post In The Live Sound Forums => Audio Measurement and Testing => Topic started by: sam jashan on February 17, 2012, 09:41:18 am

Title: How use phase adjustment on dr260
Post by: sam jashan on February 17, 2012, 09:41:18 am
Hello everyone; I have 2 jbl srx725's that sit on top of some double 18" subs. It seems like the sound is not working together (the system is not performing to it's potential). It seems like I may have some comb filtering problems????
Every time I play with the phase adjustment on the subs, things change, but it's hard to get the result I want. Does anyone have any tips on how to get use the phase adjustment on the drive rack 260??
Title: Re: How use phase adjustment on dr260
Post by: Doug Fowler on February 17, 2012, 03:47:47 pm
Hello everyone; I have 2 jbl srx725's that sit on top of some double 18" subs. It seems like the sound is not working together (the system is not performing to it's potential). It seems like I may have some comb filtering problems????
Every time I play with the phase adjustment on the subs, things change, but it's hard to get the result I want. Does anyone have any tips on how to get use the phase adjustment on the drive rack 260??

What are your crossover settings for sub and LF?
Title: Re: How use phase adjustment on dr260
Post by: Charlie Zureki on February 18, 2012, 10:01:43 am
Hello everyone; I have 2 jbl srx725's that sit on top of some double 18" subs. It seems like the sound is not working together (the system is not performing to it's potential). It seems like I may have some comb filtering problems????
Every time I play with the phase adjustment on the subs, things change, but it's hard to get the result I want. Does anyone have any tips on how to get use the phase adjustment on the drive rack 260??

   Hello,

   It might be helpful to list the make/model of the subs and amplifiers you're using/ intending to use.  What are the current settings on the processor now?   What is it that you're hearing, exactly?   What is the result that you're "trying" to get ?

  Are you certain that: 
     #1  you've  not gotten  the settings on the processor wrong ... Crossover, delays, etc...
     #2  That the speaker cables to the sub from the amp(s) are not terminated properly ?  mis-wired...and that the "polarity" is wrong on either the sub end, or the amplifier end ?

     #3 That the signal cables (XLR) going from the output of the mixer to the input of the processor have continuity and that the polarity is correct from end to end ?

     #4 That the subs (you did not mention make/model) are inferior and cannot possibly keep up with the JBL tops...and/or are using too small of an amp ?

     #5 That you're expecting waaayyyyy too much from these un-named subs, and, that you really need to ADD subs and amplifiers for the bottom end that you're seeking ? 

     #6 That the problems you're having are either all, or a combination of many of the above reasons that this "system" is not meeting your expectations ?


     What do you think is the definition of "Comb filtering" ?  Did you operate one sub at a time...and then switch the cabling to the other sub doing a comparison ?

  The many times I've been called to trouble-shoot someone's system based on similar complaints....it was that one sub was wired in opposite polarity... or, that they were expecting their subs to bring the walls down...and, what they really needed was more amps and subs.

   Hammer