From: someone@anywheret.net   
      
   "JimD"  wrote in message news:2018041820024566423-email@nowherecom...   
      
      
   > I typed a lot the other day, was on a rant.   Yes, there are people who   
   > can do " thinking required " jobs, and people who can't. I explained   
   > density altitude to someone the other day. He had no idea, had never ever   
   > considered that could affect taking off and landing. Not a pilot,   
   > obviously, neither am I, but the point is ... he'd never heard of the   
   > thing.  There are limitations to real world gear that aren't obvious the   
   > unaided human senses.   
      
   Or there are experiences that most don't typically experiences, which is   
   why, at least to my estimation, there schools, and education generally.   
      
   > Spent yesterday working with some RTA apps.  Learned, that my JBL1500's   
   > have pretty much exactly the freq specs their spec sheet says. Duh.  And   
   > they ARE NOT bass bins.  They can be eq'ed to extend the low end to all   
   > we'd need, but, do that and you have to be aware that all the excessive   
   > wattage on the low end will blow that driver way before you expect.  They   
   > simply aren't bass cabs.   
      
   It's okay to boost the bass just so long as you consider the power handling   
   limits and not exceed them. A very good way to go about that is to Listen to   
   the bass, or look at the  waveform if you can, because so long as it's   
   Linear, you're okay, because that means that the voice coil and  flux field   
   are still coupling efficiently...but if too much power is applied, the   
   coil's excursions, due to the amplitude, will begin to pull it beyond it's   
   coupling with the flux field and its acoustic efficiency will plummet. And   
   because it will be spending more time in excursion in a decoupled state, it   
   will not transduce in those decoupled areas acoustically at that point but   
   instead transduce thermally i.e. it'll heat up until it burns up if there's   
   too much power...but long before that (assuming the cranking up is more   
   gradually instead of all of a sudden), you'll hear the  speaker's output   
   become distorted due to clipping, and can then respond by turning the amp   
   back down before the frying begins.   
      
   > If we want that level of low end, we either have to keep the volume down   
   > ( my choice ) or, add some more cabs.   
      
   Good choice. Any large area speaker can be used for bass - you just have to   
   carefully watch the power.   
      
   > I used a flat response omni mic into the XR18, then over to my laptop and   
   > into a software RTA in Logic. Pink noise and / or single freq sine waves   
   > from logic into the XR18 and out into my pa cabs. Adjusted the  XR18's   
   > built in 31 band eq's, while watching the spectrum display on the mac.   
   > This setup worked well. The XR18 has nice built in eq's ... on each   
   > channel and on the mains and aux sends.  Again, quite a lot for such a   
   > small package.   
      
   Those  1/3rd octave band eq (parametric is available too) built in on each   
   channel on the  XR18 sure are cool!   
      
   > So, yeah, we could sound a little better with some bass bins.  I have   
   > some, but they are very heavy, more than we'll bother with now. So, search   
   > is sorta one for some newer lighter units.   
      
   Now there's a real challenge, light weight bass cabs...so use the Eighth   
   Space if at all possible, that's a corner, floor or ceiling, and two   
   walls...it'll sure help with the  bass.   
      
   > My friend's raock band used a single BOSE L1 as their vocal pa recently.   
   > Absolutely useless ......   
      
      
   Jim   
      
   We've got two of those Bose-O L1s at my church - they sound 'great', that   
   means that it takes hardly any output to be heard well there, and those L1s   
   have hardly any output ;) Another Gimmicky Rip-Off from Bose-O, the clowns   
   of the audio industry.   
      
   Ouisie   
      
   --- SoupGate-Win32 v1.05   
    * Origin: you cannot sedate... all the things you hate (1:229/2)