Adjusting Sub, Three knobs!!! What's the best way to adjust!!??

Discussion in 'Archived Threads 2001-2004' started by Bill Johnston, Dec 19, 2001.

  1. Bill Johnston

    Bill Johnston Stunt Coordinator

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    I just am getting use to my new satalites (Jamo 310 Apollo bundle)... Now, the speakers sound great.... Maybe a tad trebby... But I notice that with allot of satalites are... Anyhow... The powered sub is 9" and definatly BOOMS!!!

    I have a 9" sub... And there are three adjustments on the sub... Level , Cut off Frequency (40Hz to 150Hz), and Phase (0 to -180 degree's)...

    How to I tackle seeting the Cut off and Phase... The manual is a little stupid seeing they only use pictures NO WORDS...

    Can anyone please give me insite... I am 90% sure that all powered subs have these same settings....

    Thanks!!!

    Bill
     
  2. Mike LS

    Mike LS Supporting Actor

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    First you need to know what frequencies your sat speakers handle. If they handle say 80htz (or whatever) then set the sub cutoff to the lowest frequency that your sat speakers will handle. That way you've got no gap in the sound.

    As for the phase....I think that'll depend on your room. I'd leave it at 0 myself. But that's something you can play with in different settings and see what works best in your setup.
     
  3. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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    Mike's advice is correct presuming you are feeding the sub full range speaker outputs. However, if your sub is connected with a single RCA line from a "sub out" or "LFE out" jack, then the signal is already filtered by the receiver and you want the sub's crossover to leave it alone. That means defeat the sub crossover if possible, or set it to the max if not.

    Phase adjustment is trial and error. The best method is to play a low frequency noise signal that is coming with rouhly equal stregnth from the mains and the sub, and use an SPL meter to find the phase setting that is loudest. If you have no meter and cannot perceive any effect on loudness by ear, then don't worry about it.
     
  4. Bill Johnston

    Bill Johnston Stunt Coordinator

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    So, seeing I have an Onkyo 595 and hooked up the sub via Sub Pre Out... Then... I just turn the cutoff, ALL THE WAY UP? if that's correct... I will do that tonight...

    Thanks again!

    Bill
     
  5. Bob Christensen

    Bob Christensen Stunt Coordinator

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    I like to set the sub XO at a point that it slightly higher than the sat's advertised low freq. range. The sat manufacturers typically are a bit "optimistic" in these figures and, at any rate, unburdening the sat from the lowest freq duties will undoubtedly clean up their sound, at least a little bit. But don't be afraid to experiment a bit!
     
  6. Brian Fellmeth

    Brian Fellmeth Supporting Actor

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  7. Bob Christensen

    Bob Christensen Stunt Coordinator

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    Brian: You are absolutely correct. I was thinking cross-over for the entire system, not just the sub. Actually, I run my sub with the XO bypassed, preferring not to re-process the signal. For the LFE signal in HT, running with no internal (to the sub) XO is much better. You are right, the receiver will process the signal properly. If you have the ability to change the XO in the receiver, this can unburden the sats of the LF signals, which is a great thing to do. Often this is done by setting your sats to "small", or setting the LF feed to "sub" instead of "main" or "both".
     
  8. Nick G

    Nick G Stunt Coordinator

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    Bill, if you have the crossover on the sub turned all the way up (which is as you should) don't foreget to set your speakers to "small" on the Onkyo.

    Nick
     

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