adam.misst Posted November 14, 2010 Share Posted November 14, 2010 Hi guys and girls... First post and it's a bit of a desperate one! Were opening our shop in Nottingham tomorrow and I've installed 4 x Mackie MR5's, one in each corner... I've ran balanced XLR cables to a tidy little splitter which allows me to put in 4x jack leads and get out 1. We had no problems for the first few minutes, however now the sound starts to fluctuate and for example we can't hear vocals in the tunes were playing? The female XLR at the splitter end is connected via a XLR to jack converter... Hope someone can help me out as we open tomorrow!! Kind Regards. Link to comment Share on other sites More sharing options...
paulears Posted November 14, 2010 Share Posted November 14, 2010 Hopefully an easy one. Somewhere you have messed up the conversion of an unbalanced stereo output to mono balanced ones. It's not clear from your post how the splitter system is wired. If I read it right, you have a stereo source and then 4 speakers? Are you trying to do stereo? If the source is unbalanced on jacks or phonos - then you'll need to unbalance the XLRs used to feed the Mackies. So the hot for left output from the source goes to XLR pin 2, while the screen from the left output goes to XLR pins 1 AND 3. What I suspect you're splitter has done is take the hot from the left to pin 2, the hot from the right to pin 3, with the ground to pin 1. All you will hear is the difference between left and right. Anything equal in volume on the left and right channels will be effectively removed, sort of leaving an echoey ghost image. You just need to split left and right, and then unbalance as above. This will mean some re-soldering. XLR to jack adaptors are fine - BUT they are no good for converting a headphone style output to a powered mono loudspeaker. Link to comment Share on other sites More sharing options...
kerry davies Posted November 14, 2010 Share Posted November 14, 2010 Technically I have no idea but from experience try sending a mono signal, check the phasing and if the room is square try pointing the speakers so that they are not directly opposed. Paul is probably right but with the time limitations you have there may be no time to rewire/resolder. I used to DJ in a pub where stereo sound was absolutely appalling and the cure was to play in mono, out of phase speakers in a square can produce all sorts of problems and when I did (a famous band) with a 7m square configuration the bass could be heard 3 miles away because of wavelength problems. The dancers didn't mind but the sound did exactly what you state and fluctuate with heavy resonance muffling the mid-highs. Come back with more specifics and someone will have a long-term fix but, for now, try the easy checks first. Link to comment Share on other sites More sharing options...
Dan Gruner Posted November 14, 2010 Share Posted November 14, 2010 Yes, it sounds like the "classic" mistake of wiring a stereo phono cable to a XLR connector and not doing it correctly! Visited a church the other week to sort out their system A single XLR output (aux) from the mixing desk had been connected to a CD recorder using a lead wired with the hot/cold connected to the left/right phono inputs respectively. No surprise their recordings were very poor! What was very concerning was that apparently the system including this rogue lead, was installed and commissioned by another sound company relatively recently :) Dan Link to comment Share on other sites More sharing options...
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